Sunday, December 07, 2008

Stroke prevention in sickle cell anemia


STOP I demonstrated transfusions reduced stroke risk by 92 % in high risk children and TCD is used to select patients for transfusion. STOP II showed rising TCD velocities, especially above 200 cm/s cutoff, led to more strokes upon transfusion discontinuation.

Eleven percent stroke by age 20.
25 percent by age 45

Recommend at least annual TCD between ages 2-16

mortality with hemorrhage is 24-65 percent
Associations with hemorrhage: Hypertension, recent transfusion last 14 days, steroids, possibly NSIAA

nonatherosclerotic
point mutation valine for glu in Beta polypeptide chain

younger patients tend to get ischemic strokes, older patients hemorrhagic strokes, two thirds recur


Treatment of AF based on risk stratification

ACC

ASA 325 or no therapy- lone AF, age <60
ASA 325-- Age <> 60, no risk factors;

Anticoagulation
1. Age> 60, coexistant DM or CAD (optional addition of ASA)
2. Age >75-- especially women
3. Heart failure
4. LVEF<.35
5. thyrotoxicosis
6. HTN
7. RHD
8. Prosthetic heart valves
9. Prior thromboembolism
10 Persistent atrial thrombus on TEE

Intensity for anticoagulation:
Numbers 1-6 keep INR 2-3
Numbers 7-10 keep INR 2.5-3.5


ICH due to anticoagulants

Pearls
1. In SPAF virtually all ICH was due to INR > 3
2. Oral anticoagulants increase risk of parenchymal hemorrhage 7-10 times
3. In patients >60, actual risk of ICH was 0.3 - 1.0 per year.

Stroke therapy in pregnancy

Pearls
1. Evaluation is similar to nonpregant patients
2. Low dose ASA (80-150 mg) in second and third trimesters in high risk women is safe for mother and fetus
3. VKA's are dangerous especially 6-12 weeks due to embyopathy, fetal wastage and are dangerous in second and third trimesters due to neurodevelopmental problems. Postpartum is believed safe.
4. UFH and LMWH does not cross the placenta or enter breast milk and is believed safe for fetus, although it can cause bleeding at uteroplacental junction.
5. ASA and heparin can be used combined during pregnancy.

Antiphospholipid antibodies

Spectrum in order of increasing risk is
asymptomatic individuals with positive antibody tests
women with pregnancy loss alone (1 fetal loss after 10 wks or 3 before 10 wks)
patients with thrombosis
rapidly progressive multisystem vascular occlusion
lab - need 2 titers 6-12 weeks apart, of present LA, ACL AB's, or anti beta 2 glycoprotein 1 . LA is more sensitive than APL testing. You CAN run aPTT or DRVVT on warfarinized sample if diluted 2:1 prior to testing.

Factors increasing the risk are
high titers especially lupus anticoagulant
smoking
use of oral contraceptives
surgery
immobilization
pregnancy
inherited coagulable states

APASS showed relation of ACL's with first ischemic stroke. Study within WARRS trial showed no increased risk of thromboocclusive events in patients with antibodies on coumadin.

Other pearls : venous strokes are more common than arterial strokes, and cardiac emboli also occur. Large and small vessel disease can occur. Chorea is more common in primary APL than secondary APL syndrome ( ie lupus) and is usually bilateral

Associations of secondary APL:  CTD esp SLE

Aortic arch atheroma

1. Independent risk factor for stroke especially plaques greater than 4-5 mm, ulcerated plaques and MOBILE COMPONENTS BY TEE. Annual risk in these risk factor settings are 11.9--33 %. Role of warfarin in under study.

2.Bob Brown believes its indicated

Cardiomyopathy, reduced EF, CHF and stroke


Pearls
1. Cardiomyopathy is second most common cause of cardioembolic stroke with a 3/ relative risk.

2. Ventricular thrombus occurs is 3-4 % of dilated cardiomyopathy with an annual risk of systemic embolism of 3-4 %. Further risk factors for emboli are stasis, low ventricular flow velocity, and hemostatic abnormalities and low EF.

3. CHF has an annual stroke risk of 1-4 % and anticoagulation is recommended for EF of < 35 % regardless of cause. WARCEF will study warfarin v. aspirin for this indication.

4. RHD with valve disorder has 1.5 to 4.7 % annual risk of emboli, with 12 % presenting with emboli as first sign of. 30-65 % of cases have recurrent emboli, usually within 6-12 months. Anticoagulation reduces annual stroke risk in old observational studies from 10 to 0.8-3 %.

5. MVP has stroke risk in young adults of about 1:6000.

6. Mitral annular calcification has 2.1 increase stroke risk and associates with AF.

7. Mechanical valves embolize at a rate of 2-4 % /year WITH anticoagulation. Further risk factors of thrombus formation are LAE, atrial stasis, AF, valve type and position (tilting disc), and in one study ventricular pacers.

8. Patients with bioprosthetic valves without anticoagulation have a risk of emboli of 6% in first 3 months.

9. Combined therapy of antiplatelet plus anticoagulation therapy risk is 1.3 to 24.7 % for major hemorrhage.

10. Anticoagulation may be continued in setting of infective endocarditis although opinion is divided on efficacy in this setting.

Anticoagulation pearls

1. Effects of heparin include interaction with Antithrombin 3, charge dependent interaction, and modulation of factor Xa generation. The low affinity for AT3 leads to greater effect when it binds PF4, which may lead to heparin antibodies (IgG) which activate platelets and lead to HIT. Heparin also binds to plasma proteins, macrophages, and endothelial cells, causes increased vessel wall permeability, and supression of smooth muscle proliferation, and activation of osteoclasts. It can be reversed with protamine, 1 mg per 100 units of UFH received over several hours.

Pearls on HIT
arterial OR venous clots occur
AB's against Factor 4 platelets complexes PF$ and heparin
10X more common with heparin than with LMWH

Mechanisms of heparin:  binds tissue factor and F VIIa at site of injury. Inhibits propagation of clot when F IXa binds to coafactor, and F VIIIa (intrinsic pathway)

2. LMWH's preferentially inactivate Xa with less HIT, and has a more predictable dose response relationship due to decreased binding to endothelial cells, proteins and macrophages. Protamine neutralizes only 60 % of anti Xa activity of LMWH's.

3. Prothrombin time (PT) to monitor VKA's is performed by adding calcium and thromboplastin to citrated plasma. INR is international normalized ratio where = (patient P/mean normal PT)*ISI (international sensitivity index).

4. Ximelegatran can use fixed dose, has no food or drug interactions,

Heparin, LMWH are indirect thrombin inhibitors
hirudin, argabotan, inactivate bound thrombin and are direct inhibitors


Statins and stroke

Heart protection study showed benefit in patients with statins. LDL triggers macrophage transition to foam cells, promotes metalloproteinase production, inflammatory adhesion molecule expression, platelet adhesion, NO synthase.

Landau analysis/critique (Neurology, letter 73;817 2009)

risk reduction of atorvastatin for 72.5 year old was 0.4 % (NNT>200) from 3.3 to 2.9 %. this is annual second stroke risk. The risk of having a stroke for those not taking drug is 96.7%. Vital statistics show death rate from any cause is 3.2 % at age 72, 4.2 % at age 75, 6.7 at age 80, and 10.2 at age 85. Treatment group with atorvastatin had twice as many hemorrhagic strokes, larger death rate from all causes, and some occurrence of hepatotoxicity and rhabdomyolosis.

Michael Strupp (Munich) opined that the primary endpoint, risk of fatal aor nonfatal stroke, was reduced in treatment group by ten percent which was not significant. Bianchi et al. differentiated effects in younger and older patients. They compared in SPARCL the 25 % reduction in younger patients, the 10 % reduction in older patients, and lack of significant interaction between age and treatment group. They argued effect diminishes with age.

Therapy of hypertension and stroke


Lowering sbp 10-12 points and DBP 5-6 points leads to 38 % fewer strokes . PROGRESS trial of ACEi v indapamide v. plac showed 9/4 bp reduction led to 28 % fewer strokes. HOPE randomized 9297 patients to ramipril or placebo, leading to 3/2 bp reduction and 32 % less strokes. LIFE (losartan ) trial showed 25 % reduction in stroke without change in blood pressure with ang II blocker. ALLHAT showed more strokes in patients getting lisinopril v. thiazide . Rec is for ACEi + diuretic to get bp < 140/90, or less than 130/80 in diabetics.

Or each 20/10 increase in BP over 115 to 185 doubles risk of stroke

Sunday, November 30, 2008

Cardiac disease and stroke pearls

from Continuum based on vascular boards review

1. One percent of acute strokes are complicated by coexisting acute MI
2. Treatment issues: STEMI (ST Elevation MI) and Unstable Angina/non STEMI(UA/NSTEMI) are treated differently. The former group contains Q wave MI patients or candidates for; the latter group contains non MI patients and non Q wave MI patients. Differentiate with troponins. Only the first group gets alteplase or acute cath, latter group may get later? cath. ASA 81-162 is always indicated, clopidogrel in suggested in UA/NSTEMI for 12 months based on CURE study (Clopidogrel in Unstable angina to prevent Recurrent iscemic Events). In STEMI clopidogrel is suggested only for those unable to tolerate aspirin or those who receive a stent.
3. Warfarin indications include alternative to aspirin for secondary prevention in aspirin intolerant; addition to asa in post MI or ACS, mural thrombus, or af; as short tern addition to ASA and clopidogrel in a post MI patient with a stent who also has an indication for anticoagulation. In this case, clopidogrel therapy is limited to 1 month for bare metal stents, 3-6 months after coated stents.
4. The use of dipyridamole in patients with stable angina, is problematic due to vasodilatation. ACC/AHA cautions against, although the ESPS II trial did not indicate such.
Summary-- patients may need dual/triple therapy; patients with combined treatment may have been left on dual therapy too long and may need reduction to monotherapy; warfarin after an ACS is added to, does not replace ASA.


Other pearls
1. Andersen et al. suggested that fewer strokes occur with atrial rather than ventricular based pacing; a question exists abotu identifying AF in paced patients due to pacer artefact. In not completely accepted. Temporary pacer reprogramming to low ventricular response rate can sort out underlying rhythm.
2. MOST trial (MOde Selection Trial in sinus node dysfunction) showed atrial high rate events esp. bpm>220 for >10 consecutive beat signal risk of stroke and death. Atrial high rate events showed twice the risk of death and six times risk of AF.
3. Pacer insertion is associated with a one year risk of AF of 10 % and 2 year risk of 11 % in patients not with history. No difference based on reason for pacer insertion (AV node dysfunction v. SSS). Stroke risk is higher though in patients paced for SSS or AV Neurologist role is " insure underlying rhythm evaluation is performed"
4. 25-40 % of stroke patients have known IHD, another 25 % have silent disease
5. Early cardiac death (first 30days) occurs in 1 percent of ischemic stroke patients; in next two years, risk of another stroke is 3-4 times risk of MI; risk of MI reaches parity at abot 5 years.

Tuesday, November 11, 2008

HAT score to predict hemorrhage after alteplase

The Hat Score A simple grading sclae for predicting hemorrhage after thrombolysis


Lou M et al. Risk stratification measure to predict hemorrhage after alteplase given for stroke. Collective rate of symptomatic ICH is two percent (0 points); 5 % (1 point), 10 % (2 points), 15 % (3 points), 44 % (>3 points).

diabetes-- 1 point for history of DM or entry glc > 200
pretreatment NIHSS score-- 1 point if 15-20, 2 points if > 20
presence of easily visible hypodensity on initial head CT-- 1 point if yes but <> 1/3 of MCA territory

Sunday, November 09, 2008

Continuum CVA risk factors: Behavioral: cigarrette

Cigarette smoking is an independent risk factors that is DOSE DEPENDENT (Gorelick, 1989). A meta-analysis found a rr of cigarettes was 1.5 (Shinton,Beevers 1989) . Passive exposure to smoke increased the progression of atherosclerosis (Howard et al 1998). By stroke subtype, rr is, ICH .74; ischemic stroke 1.92; SAH 2.93. Dose dependent: rr of <10 20 ="1.82." 74=" 1.75;">60 grams/da leads ot rr of 1.64. , hem stroke is 2.18. Less than 12 grams/day shows rr of .8.

Physical activity -1994 Behavioral risk factor surveillance shows increased physical activity lowers stroke risk. Northern Manhattan Study showed physical activity led to 63 % reduction of risk of recurrent stroke. Both exercise intensity and duration is key. Suggest 30 minutes per day of moderate activity.

Diet results conflicting . However moderately increased homocysteine in a risk factor for stroke. However, Vitamin in stroke trial showed no benefit of treatment with b6 b12 and folate. FRUIT and vegetable increased intake lowers stroke risk. Cruciferous and green leafy vegetable and citrus protects against ischemic stroke more. May be due to antioxidants. Milk, calcium, cereal fiber, and fish consumption and carotenoids may be helpful. Limited saturated fat consumption may be important.

Abdominal obesity is an independent risk factor. Men with waist-hip ratios of more than 0.93 and women above .86 have more stroke especially in younger patients. FFA (free fatty acids) and TNF alpha lead to insulin resistance.

Other nontraditional risk factors for stroke are mitral annular calcification, mitral valve prolapse, aortic arch atherosclerosis, PFO, exogenous estrogens, chronic infections, migraine and hypercoagulable state.

Continuum CVA risk factors:TIA DM lipids


TIA-- annual stroke risk is 1-15 %. In hospital referred, annual risk of stroke, MI or death was 75. % (Hankey 1991). Amaurosis not as bad. 10 % of those with TIA got stroke and 25 % an AE within 90 days. HALF THE PATIENTS WITH STROKE DEVELOPED STROKE WITHIN 2 DAYS OF TIA. Risk factors for stroke after tia included age, duration > 10 minutes, dm, weakness, speech impairment.

Diabestes has an independent effect on stroke demonstrated in the Honolulu heart program (2x risk) and a large population based study of 14,000 found fbs>140 was associated with rr of stroke of 2.26 after adjusting for other risk factors Folsom et al. 1999). One study found a greater effect among women with stroke. Attributable risk of stroke to diabetes was higher in N Manhattan Stroke study due to 22 % prevalence of dm. Insulin resistance was associated with 1.19 rr of cva (Folsom 1999). ADA now classifies fbs>110 as diabetic, aqnd 100-109 as prediabetic.

LIPIDS- increased TG, total cholesterol and LDL are risk factors. For LDL relation to stroke is "less clear" than for IHD with mixed study results. One large meta-analysis of 450,000 found no relation to stroke. By subtype, large artery disease may be more related to cholesterol. HDL may be protective per N Manhattan Stroke Study with higher HDL helping elderly. Statins help.

Continuum CVA risk factors: carotid as. + CAD

CAD confers 2 x risk of stroke, with LVH is 3x risk, chf is 4x risk. The attributable risk of CAD is 12 % and ranges from 2.3-6 % for CHF. Post MI stroke risk over five years is 8.1 percent, higher in older patients, in pts with ef< 28 % (rr 1.86).

Symptomatic carotid stenosis confers 26 % risk of recurrent stroke with medical treatment after tia/minor stroke over ? time, and asymptomatic stenosis risk is 1.3 % annually if stenosis is <75> 3.3 %. (Norris 1991). The combined tia/stroke risk is 10.5 % per year with >75 % stenosis(????). ACAS randomized 1662 patients. Angio risk was 1.2 % and perioperative risk was 2.3 %. After median followup of 2.7 years, study was stopped due to benefit ( 11 % of those with medical treatment had stroke ipsilateral, whereas surgical + medical had 5 % ipsilateral stroke, perioperative stroke or death in five years, 55% risk reduction). More benefit among men, no effect of degree of stenosis. Halliday et al, 2004, showed in another trial that in patients <75 with severe carotid stenosis, the stroke risk in the surgery deferred group was similar to that seen in ACAS. Medical group risk was 11 %, in immediate surgery group was 3.8 % at five years, Perioperative risk of stroke/death was 3.1 % effect equal in gender groups.

Wednesday, October 29, 2008

Major lacunar syndromes


Pure motor hemiparesis-- could be capsular, corona radiata, or basis pontis lacune with mild dysarthria. History of prior transient gait abnormality or vertigo favors pontine. Ischemic cortical lesions may also cause this.

Pure sensory-- due to stroke VPL thalamus (pansensory), corona radiata (st sensory), parietal cortex or pontine stroke of medial lemniscus may cause. A pain and temperature deficit due to midbrain stroke of st tract is described. Tract specific deficit of sensory favors lesion away from thalamus.

Ataxic hemiparesis. due to lacune in posterior limb, or pons.LE weakness and hemiataxia is rule. Dysarthria is rare, but a Babinski sign is present. Other localizations are thalamocapsular, red nucleus, superficial aca infarcts.

Dysarthria-clumsy hand syndrome is due to lacune of pons or internal capsule, or small hemorrhages of putamen and genu with micrographia. There is supranuclear facial weakness, deviation of protruded tongue, dysarthria, dysphagia, loss of fine control of hand, and extensor plantar response.

Watershed syndromes


types
Between MCA and ACA-- crural paresis with noncortical sensory loss matching; mutism followed by TMA or if nondominant, mood disturbance (apathy or euphoria)

Between MCA and PCA-- Hemisanopsia with macular sparing always noncongruent was most common, in lower quadrant, followed by cortical hemihypesthesia (2 pt discrim and sterognosis) but rarely limb weakness; anoma, YSA, and rarely Wernicke's aphasia. Mutism never occurred and half of patients were severely depressed.

Between superfical and deep territories of the MCA (subcortical watersheds) had hemiparesis, hemisensory loss (usually noncortical), aphasia and neglect.

Capsular genu syndrome


Consists of contralateral facial and lingual paresis with dysarthria, possibly with unilateral mastication -palatal-pharyngeal weakness, vocal cord weakness, and hand weakness (latter due to anterior part of the posterior limb). A behavioral syndrome may ensue (due to anterior thalamic involvement??). Behavioral involvement is controversial. Sensory changes and eleventh nerve involvement are excluded.

Hemorrhagic encephalitis


Also called brain purpura , pericapillary encephalorrhagia) is incorrectly called hem encephalitis. Clinically one sees difuse encephalopathy, no cells in CSF, diagnosis is pathologic not imaging or clinical. Lesions are confined to callosum, centrum ovale and middle cerebellar peduncles. Origin is obscure. Occassionally, it may complicate viral pneumonia, uremia, arsenical intoxication or metabolic encephalopathy

Differentiate from acute hemorragic leukoencephalitis (Hurst type) which is an extreme form of ADEM.

SAH Board pearls

1. 90-95 percent of berry aneurysms are on the anterior part of the circle of Willis.
2. In order of frequency, they occur at proximal ACOMA, origin of PCOM artery from the stem of the ica, the first major bifurcation of the MCA, and the bifurcation of the ICA into ACA and MCA. Other sites: cavernous sinus, origin of the opthalmic artery, junction of the post com and PCA, bifurcation of the BA, origin of the 3 cerebellar arteries.
3. Other aneurysm "types" defined are mycotic, or named morphologically, fusiform, diffuse and globular.
4. Seizures occur in 10-25 %
5. Nimodipine 60 q 4 hours does not alter occurrence of vasospasm but does reduce the risk of stroke with vasospasm.
6. Rate of rupture of incidentally discovered aneurysm relates to size, is .1 % yearly for less than 7 mm, .5 % for 7-10 mmm and .6-3.5 percent annually for 13-24 mm.
8. Occurrence of UIA in family members (first degree) is 3-4 % in them if one family member has, screening is not mandatory but some want it. If 2 family members have, 9 % of first degree relatives over 30 also have and screening with CTA/MRA is indicated.
9. Smoking, hypertension, and female gender are predictors of ICA in relatives
10. Others who need to be screened are those with ADPKD if others in family have a history of aneurysm, and those with coarctation of aorta (10% have aneurysm).
11. Warfarin can be used in those with aneurysm (Bob Brown) if otherwise indicated. For small aneurysms (< 10 mm) there is not evidence that risk of rupture is elevated. For larger aneurysms, risk is unknown.
12. Risk factors for SAH include hypertension, smoking, cocaine use, positive family history and excessive alcohol use. HTN also is a risk factor for bad outcome if not controlled. Risk of rupture increases with increased aneurysm size, prior SAH, and posterior circulation location.

Cerebral hemorrhage: eccentric pearls to know for boards


1. Fifty percent of hemorrages are putamenal. In order of frequency, then are lobar, thalamic, cerebellar and pontine hemorrhages.
2. Hematocrit effect refers to fluid fluid level due to red cells settling and is particularly prone to occur in anticoagulant associated hemorrhages.
3. Color wise, as oxyhemoglobin is liberated and becomes deoxygenated, methemoglonin is formed and is brown. With phagocytosis, color changes from dark red to pale red to golden brown of hemosiderin stain.
4. Hypertensive hemorrhage classically is due to segmental lipohyalinosis and false aneurysm (microaneurysm) of Charcot-Bouchard (CMF found absent CB aneurysms in some studied cases)
5. The presentation of putamenal hemorrhage is usually HA, vomiting, and hemiplegia that worsens.
6. The frequency of lobar hemorrhages in order is occipital, temporal, frontal and parietal.
7. Cerebellar hematomas are most dangerous if more than 4 mm ind located in vermis. 2mm or less is managed medically. 2-4 mm is a typical conundrum.
8.

Causes of peripartum stroke PEARLS


1 Highest risk in 6 weeks postpartum. During pregnancy arterial thrombosis prevailed, postpartum, venous occlusion prevailed in first month.
2. Consider carotid dissection
3. Paradoxical embolus occurs due to stasis, formation of DVT and clots in pregnancy
4..Amniotic fluid embolus is usually associated with multiparous women with uterine tears. Usually pulmonary disease coexists due to occlusion of lung vessels.
5. Peripartum cardiomyopathy occurs especially with certain predisposing infections (VZV?).
6.  Risk of ischemic stroke increases 8 x; of hemorrhagic stroke increases 28 x

Tuesday, October 28, 2008

Genetic stroke syndromes


Autosomal dominant-- CADASIL, VHL, cavernous malformations (CCM1), most types of amyloidosis, Hereditary hemorrhagic telangiectasia, and PCK disease.

Autosomal recessive-- virtually all clotting disorders (pro C res due to Leiden FV mutation, PT 20210, pro C, pro S, VWF def, AT 3, plasminogen def, Marfan, Fabry, SCD, heparin cof 2, F XII, hyper homocyst, hyper cysteinemia,


Maternal-- MELAS

ICA dissection


Erdheim's medionecrosis aortica cystica is mechanism. usually related to injury or stressful event ,a few to fmd, Marfan's or Ehlers Danlos syndrome, osteogenesis imperfecta and alpha one antitrypsin deficiency. Interestingly, many have warnings of unilateral facial or cranial pain followed within minutes to days by dissection. The pain is nonthrobbing and usually centered in or around the eye, occassionally frontotemporal or at the angle of the mandible. Horners syndrome is common, rarely facial numbness and syncope. Mokri described 2 syndromes: 1) unilateral HA with ipsilateral Horner's, and 2) unilateral HA and delayed focal cerebral ischemic symptoms. Involvement of X, XI and XII nn may occur due to small twigs from carotid.

Per Ropper ,early recanalization of occluded artery in stroke patients is beneficial. Pseudoaneurysms may form, do not require surgery or preclude anticoagulation. Steroids relieve pain.

Carotid syndromes

Recall the right ica arises at the sternoclavicular notch from the inominate artery and the left cca comes directly from the aortic arch. Division to eca and ica occurs at C4 level. CCA occlusion is less than one percent but can become atheromatous at origin especially on the left side. Midcommon carotid occlusion typically occurs postradiation.

ICA occlusion is clinically silent 30-40 percent of the time.

Won't go over every syndrome but a few unusual ones. If one carotid occludes and later the other one occludes, a bilateral cerebral infarction can occur with coma, quadriplegia, and continuous horizontal metronomic conjugate eye movements.

Headaches as a rule are above the eyebrow but is not invariable. MCA headaches may be more lateral eg. temple; pca headaches may be in or behind the eye.

Watershed strokes are 2 types. Cortical watershed and deep watershed (lenticulostriates) due to carotid stenosis tend to produce shoulder/hip weakness (man in barrel). If longstanding it may go toward mca affecting face or motor aphasia.

In case of circulatory collapse get multiple border zone infarcts.

TMB occurs prior to stroke in 10-25 percent of cases of symptomatic carotid occlusion.

Anterior choroidal artery exits just after posterior communicating artery, supplies the globus pallidum interna and posterior limb of capsule, and contiguous structures including optic tract. Occlusion causes contralateral hemiplegia, hemihypesthesia, and homonymous hemianopia without a behavioral component in most cases. However, Decroix studied 16 patients and noted that some suffered spatial neglect and costructional apraxia (right sided ones) or mild aphasia (left sided ones). Stroke occurs in posterior limb of capsule, encroaches on the tip of the globus pallidus laterally. Visual defect typically spares the horizontal meridian due to LGB involvement. Bilateral anterior choroidal strokes result in acute pseudobulbar mutism, facial diplegia, hemiparesis, hemisensory loss,lethargy, neglect and affective symptoms.

Bruits and stroke exam minutiae

1. If at angle of jaw the stenosis is usually proximal ICA. If lower, its usually CCA or subclavian artery (with diaphragm)
2. Bruits that extend into diastole and are high pitched are invariably associated with tight stenotic lesions, ess than 1.5 mm.
3. Bruit over the contralateral eye (ocular) with bell can reflect carotid occlusion, due to increased contralateral flow, or stenosis of intracranial ipsilateral carotid artery.
Bruit can also be heard with cavernous carotid fistula. Pulsatile exopathlamos is seen in NF-I due to absent sphenoid bone. Palpable reduction of pulsation in the cca in the neck, in the eca in front of the ear, and in the ica in the lateral wall of the pharynx are not dependable signs and risk dislodging plaque material.
5. Central retinal artery pressure is reduced ipsilateral to a tight stenosis or occlusion which can be appreciated by gentle globe pressure while viewing the vessels from the optic nerve head.

Vascular neurology board type minutiae

1. AF increases the risk of stroke 6 fold, 18 fold if cardiac valve disorder is also present.
2. Diabetes doubles risk fo stroke compared to age matched controls
3. Flow factors studies in macaques and gerbils show functional impairment with flow below 23 mL/100g/min (normal is 55) but this is reversible for a time. Flow below 10-12 is irreversible and causes infarction. The EEG is slowed at rates 12-23, and is isolelectric below 12.
4. Low K causes stroke although the mechanism is obscure.
5. In penumbra, K increases (efflux from injured depolarized cells), ATP and creatine phosphate are depleted. Disturbance of calcium homeostasis and accumulation of free fatty acids impairs recovery. FFA's appearing as phospholipases are activated and destroy phospholipids of neuronal membranes. leading to accumulation of prostaglandins, leukotrienes, and free radicals.
6. Autoregulation operates from BP of 50-150 mm Hg and affects small pial vessels.
7. Irreversible inury is caused by excitatory transmitters affecting NMDA receptors and causing an influx of Ca and Na. Damage is accentuated also by an inflammatory response that activates endothelial cells to express cell adhesion molecules that attract more inflammatory cells, upregulate inflammatory proteins (metalloproteinases) and cytokines (interleukins and chemokines) as reviewed by Lo et al.
8. Ames and nesbitt studying rabbit retina showed cells can withstand complete anoxia for 20 minutes but irreversibly infarct after 30 minutes. Tolerance is less with HYPOglycemia and is prolonged with magnesium that reduces energy requirements in the cells.
9.

Monday, October 27, 2008

Vascular anatomy of aortic branches to eye

First branch of the aorta is the inominate artery, which divides to form the right subclavian and right common carotid artery. Next off the aorta is the left common carotid artery. Finally is the left subclavian.

Each cca enters the neck through the carotid canal in the temporal bone (petrous carotid) across foramen lacerum to enter to cavernous sinus. Minor branches from the petrosal carotid are the corticotympanic branch to the tympanic cavity and the vidian branch to the pterygoid canal. Then, and after exiting the cavernous sinus, gives off the first major branch the opthalmic artery. In ten percent, the opthalmic artery originates from the cavernous carotid. The opthalmic artery supplies the optic nerve, retina, and other eye. Muscular branches supply the extraocular muscles. The central retinal artery enters the optic nerve and supplies the anterior optic nerve head and retina. Most of the optic nerve derives from two or more long posterior ciliary arteries. The optic nerve head is a potential watershed area between the posterior ciliaries.

After the opthalmic artery, the ICA gives off the posterior communicating then the anterior choroidal artery. Penetrators from the PCOM supply the ht, optic tract and chiasm, and anterior and ventral thalamic nuclei.

Wednesday, October 15, 2008

Thromboangiitis obliterans (Burger's disease)


TAO is a disease of the small and medium size arterioles affecting the distal arms and legs and rarely, cerebrum, viscera, or veins. In the acute phase, there is endothelial proliferation, lymphocytes in the intima, and fibrinoid necrosis of the intima. Chronically there is recanalization and perivascular fibrosis. In brain, it has a predilection foer small artery occlusion without atherosclerosis, and the cerebral surface in the watershed region between the MCA and PCA territories. Fisher doubted cerebral involvement. Males predominate by 3-8:1. Median age is 35-45. It is seen almost exclusively in smokers and remits with smoking cessation. It is a CMI to certain collagen components, possibly due to a tobacco antigen, related to HLA Dr4.

Clinically it involves claudication in both legs, and to a lesser extent, both arms. It progresses distally to proximally. Raynauds, upper ext involvemnt, and superficial phlebitis (all about 35 %). 2 limbs in 16 %, 3 or 4 in 84 %. Leg and finger amputations occur in up to 20 %. Diagnosis requires exclusion of an ambolic source, AI disease, DM and hyperlipidemia, with normal arteriography to the level of the brachium/popliteal fossae and absent atheromatous disease fo the large vessels. Cessation of smoking will halt the disease progression. utility of immune suppression is unknown. Antiplatelet drugs and anticoagulants are not effective.

TTP (Moschcowitz syndrome)

A severe multisystem disorder with an array of fever, thrombocytopenia,microangiopathic hemolytic anemia, neurologic and renal involvement. There is thrombosis of capillaries and arterioles without much inflammation. The thrombus is primarily platelets-fibrin. It is floridly disseminated into almost all organs including pancreas, adrenals, heart, brain and kidney. Its slightly more common in women and peaks in third to fourth decades. Mortality is much lower with plasma exchange, but about 40 % of survivors will relapse.

Triggers include no identifiable cause in 90 %, but the others include infection, CT disease, immune complex disease, drug reaction, neoplasia, pregnancy, penicillamine, penicillin, HIV and postpartum state.

Onset is usually subacute with headache, confusion, disorientation, and fluctuating neurological signs. Also, patients get hemorrhagic cutaneous lesions (purpura, petecchiae, ecchymosis) andominal pain, arthralgia and myalgia. Rarely it causes sudden death due to involvement of cardiac conduction system. Most common neurologic symptoms are confusion (80%), headache (30%), pareses (30%), transient aphasia (30%), seizures (20%), and coma (10%).

The hemolytic anemia is Coombs negative, with fragmented and misshapen blood cells, with severe thrombocytopenia around 20K or so. PT, PTT, fibrinogen, FDP are usually normal or nearly so. Biopsy of gingiva, bone marrow, spleen, and skin show characteristic microvascular hyaline thrombi about one third to half the time. CT may or may not be normal. MRI shows deep punctate lesions. After an average of nine exchanges, platelet count will be normal although improvement will be seen sooner. Other treatments are IVIG, vincristine, iv prostacyclin, splenectomy. In relapses, repeat exchange is used and splenectomy can induce long term stabilization. Don't transfuse platelets.  +/- steroids, antiplatelet agents

Associations:  thienopyridines esp ticlopidine

Behcet's and stroke


Behcet's is an inflammatory condition of unknown cause with the characteristic triad of recurrent oral apthous ulcers, genital ulcers, and relapsing uveitis. It is multiorgan and is most common in the Mediterranean, Middle East and Japan. NeuroBehcet's occurs in about a third , by far, most often with meningoencephalitis, beginning months or years after mucocutaneous symptoms and concomitantly with other systemic symptoms. Rarely, it can be inaugural. The meningoencephalitis begins in the brainstem with fluctuating headache, bilateral corticispinal spinal signs, cerebellar incoordination, CN palsies, dysarthria, pseudobulbar palsy, seizures,stupor, pleocytosis. CT/MR shows enhancing lesions in non vascular distributions. They mimic MS without usually being periventricular. Most commonly they affect the brainstem, hypothalamus, and basal ganglia. Angio is normal. Path shows small foci of softening with lymphocytic perivascular infiltration, diffuse microglial activity, and small areas of demyelination.

Cerebral venous thrombosis and other venous thrombosis, including vena cava and portal vein, occur in one third. CVT was long overlooked and is the main cause of the papilledema that occurs in twenty percent (misdiagnosed as pseudotumor cerebri). Differences from that condition may include abnormal CT or CSF. Also, greater than 50 % present with focal signs seizures, deficits. CVT occurs in any cerebral vein. CVT must be differentiated from neuroBehcet's , which more commonly occurs with extravascular nonneurologic symptoms, and has a worse prognosis. Immunosuppression is not indicated in CVT without neuroBehcet's; anticoagulation is.

Other rarer arterial vascular complications include aneurysms, single or multiple, that are "far" less frequent than systemic aneurysms, arteriovenous malformations, intracranial hemorrhages (may be related to htn), dissection, large artery occlusive disease (rare). Aneurysm rupture complicates the prognosis for patients with arterial disease, for whom the prognosis is worse than it is for venous disease. Actual arteritis is rare. Steroids and immunosuppressive medication is indicated.

Other neurologic manifestations includeaseptic meningitis, myelitis, ON, PN, myositis.

Pseudoxanthoma elasticum (Groenblad-Strandberg D.)

Pseudoxanthoma elasticum (PXE) with angioid streaks in the fundus comprise Groenblad-Strandberg disease. There are gray or red lines radiating peripherally from the fundus with striking skin changes including thickened soft easy to lift fold in the inguinal and lower abdominal area. Angioid streaks are not specific, but are present in 85% of cases. They are due to ruptured Bruch's membrane.

PXE is a rare AR CT disease. There is a slight preponderance of women. There is multisystem involvement with premature ocular, skin and cardiovascular complications leading to reduced life expectancy. HTN is common and GI hemorrhage occurs. PXE leads to stroke premature athero, hemorrhages, sacular aneurysms, large artery disease. Skin biopsy is diagnostic.


Genetic ABCC-6

laxity of the skin, redundant skin, and ocular fundus abnormalities. Associations include MVP, cardiac abnormalities. Complications include stroke, intracranial hemorrhage, seizures and dementia.

Eales disease

Idiopathic obliterative vasculitis of retina.  Opthalmologic condition with recurrent episodes of retinal and vitreous hemorrhages in young adults. Also called retinal periphlebitis, retinal perivasculitis, angiopathia reretinae juvenilis. There are white sheaths around retinal veins, perivascular infiltrates and occlusion of retinal vessels. It affects more men, especially aged 20-30. Patients present with obscuring spots, floaters, cobwebs, clouds to diminished acuity and blindness. It begins unilaterally and involves the other eye. Ocular inflammation is seen with thin white lines or heavy exudative sheathing. Flame shaped hemorrhages, iridocyclitis, posterior uveitis, and macular edema occur. Most have good recovery but a few lose vision. The diagnosis is one of exclusion, after other retinal vasculitis conditions are excluded, including CT disease, sarcoid, granulomatous disease, Behcet's s, DM, SCD and MS. Treatment is photocoagulation of vessels. Steroids are controversial.

CNS involvement is rare and controversial. Reports exist of CSF abnormality, seizure, myelopathy, SN hearing loss, brainstem and cerebellar dysfunction and stroke.

Tuesday, October 14, 2008

Branches of the PCA


Peduncular, ambient, and quadrigeminal segments are named after the cisterns through which they pass. The P1 segment (before the PCoA branches) is also called the mesencephalic artery, or the precommunal portion of the PCA. In 10 %, the PCA originates from the carotid in a persistent fetal pattern. The branches are the paramedian mesencephalic arteries, the thalamic-subthalamic arteries, and the medial posterior choroidals, NOT the polar arteries that come off the PCoA. The ambient portion of the PCA gives off the peduncular perforatings and the thalamogeniculates supplying the lateral thalamus. Then the lateral posterior choroidals, then the four cortical branches: anterior temporal (from the ambient segment), posterior temporal (between the tentorium and medial temporal lobe), parieto-occipital (which give off the posterior pericallosal arteries which circle the splenium of the corpus callosum) and calcarine arteries.

Thalamic strokes due to other arteries


1. Rostral BA disease with diencephalic-mesencephalic ischemia-- superior mesencephalic arteries can form a pedicle with thalamic-subthalamic arteries. Infarct of the perimesencepahlic Periaqueductal gray, third nerve nuclei and fascicles, and intralaminar and parafascicular nuclei , median and central nuclei, superior cerebellar peduncle and its decussation, and the medial third of the cerebral peduncle (Tatemichi et al, 1987) present like a thalamic-subthalamic artery with added third nerve palsy, contralateral HP or hemiataxia, vertical one and a half syndrome, bilateral complete ptosis, down gaze or up and downgaze palsy, retraction nystagmus, and sixth nerve pseudopalsy with hyperadduction of the eyes.

2. Proximal PCA infarct with infarct of the paramedian, peduncular perforating arteries plus occipital and temporal lobes. Ipsilateral III n palsy, contralateral HP with HS loss, hemianopia, and behavioral abnormalities mimic MCA infarct. More often, infarct spares the origin of the PCA and one gets a lateral thalamic infarct plus occipital-temporal lobes such as hemianopia, amnesia, dyslexia, anomic, TSA, or visual neglect.

Blood supply of the thalamus and strokes

Nice illustration p 277 of Stroke Syndromes, ed by Bogousslavsky and Caplan, first edition


Polar artery of the thalamus (also tuberothalamic, anterior internal optic or premamillary pedicle) usually arises from the PCoA (posterior communicating artery) and supplies NOT the anterior nucleus but anteromedial and anterolateral thalamus, reticular nucleus, mammillothalamic tract, part of the ventral lateral nucleus, the dorsomedial nucleus, and the lateral aspect of the anterior thalamic pole. In one third, the thalamic subthalamic artery supplies these areas and the polar artery is missing.

Thalamic subthalamic arteries (paramedian thalamic, deep interpeduncular profunda, posterior internal optic, or thalamoperforating pedicle) arise from the P1 portion of the PCA (the part before the PCoA branches off) and in one third, both arise from one side or a common pedicle. They supply the posterior medial thalamus, including the rostral interstitial nucleus of the MLF, the posterior inferior portion of the DM nucleus, the nucleus parafascicularis, intralaminar nuclei and sometimes the mammillothalamic tract.

The thalamogeniculate arteries arise as a pedicle of 6-10 aa from P2 ambient cistern segment of the PCA and supply the ventrolateral thalamus including VPL, VPM, lateral part of CM and rostrolateral pulvinar.

Posterior choroidal aarise from the P2 ambient cistern after above and supply the pulvinar, posterior thalamus, geniculate bodies, and anterior nucleus.

Supply by a fifth branch, the anterior choroidal, is variable and of little consequence.

Strokes of:
1) Lateral thalamic of thalamogeniculate arteries have 3 types a) pure sensory-- paresthesia followed by pure hemisensory often slight affecting part of such as face/hand, face only, trunk, or upper and lower limbs . It often is dissociated, sparing pain and temperature and can lead to a severe thalamic pain syndrome in the anesthesia douloureuse of Dejerine and Roussy (1906) b) Sensorimotor-- same as above with hemiparesis and long tract signs due to involvement of adjacent capsule (see Dejerine/Roussy or Mohr 1977) c) "thalamic syndrome" a+b+interruption of EPS/cerebellar trats synapsing in the lateral thalamus (caplan 1988) with ataxia, oscillations, hypermetria, dydiadochokinesia and abnormal gait called "thalamic astasia." Hemisdystonia and posture of the hand "la main thalamique" is seen (Foix/Hillemand 1925a, Caplan 1988). Cognition is normal.

2) Polar artery strokes-- abulia, apathy slovenly (pseudofrontal), aphasia (if left sided) acute amnesia (verbal is left sided, visual memory if right sided, severe and permanent if bilateral). Occassionally a transient HP or HS loss occurs.

3) Paramedian thalamic-subthalamic arteries--triad of alteration of consciousness, neuropscyhological disturbance, and vertical gaze abnormality. Somnolence or coma may be due to intralaminar nuclei. Gaze is upgaze or combined up/downgaze palsy or skew deviation. Pure downgaze palsy is only found in bilateral paramedian infarcts. Later, apathy and amnesia, confabulations, temporary neglect, abnormal movements (asterixis, tremor or dystonia after delay of several weeks), blepharospasm, compulsive assumption of a sleeping posture, and utlization behavior.

4) Posterior choroidal-- visual field deficits due to LGB involvement with upper or lower quadrantanopsia, or more often, horizontal wedge shaped or tubular sectoranopias. Involvement of the pulvinar, posterior and anterior nuclei can also produce impaired pursuit movements of the eyes, mild HP or HS loss, dystonic movements, and neuropsychological symptoms such as aphasia, amnesia, abulia, and visual hallucinosis.

Divry- Van Bogaert Syndrome


Synonyms: familial type orthochromatic leukodystrophy with diffuse leptomeningeal angiomatosis, sudanophilic leuokodystrophy with meningeal angiomatosis, infantile form of above.

In adults it affects men with deep and superficial strokes with corticomeningeal noncalcifying angiomatosis, dementia, livedo reticularis, seizures, and pseudobulbar palsy presenting between ages 18-40 with death within two decades. Some have called it "Binswanger's with LR." It can be familial or sporadic. Most patients have stiff or slow movements and gait, altered speech, rigidity, ataxia and hyperreflexia. Path, U fibers are spared. EM shows splitting of vascular basal membrane and electron dense lysosome like entities and hypertrophic pericytes.

The infantile form is usually familial, can affect girls also, and is not associated with LR.

Sneddon's syndrome


Arteriopathy affecting the brain and skin (livedo reticularis). The combination was previously described (before Sneddon's 1965 paper) in patients with endarteritis obliterans and syphilis. The diagnosis mandates EXCLUDING a recognized infectious, inflammatory, or connective tissue disease.

Livedo reticularis is arterial constriction due to a progressive obliterative process due to cutis marmorata, whereas livedo racemosa is a netlike skin pattern is a response to cold that persists on warming. LR has many associations besides Sneddon's syndrome. Stroke may occur decades after or even before LR with average age 42. Stroke can occur in MCA, TIA, seizures, cognitive impairment, TMB, and others. Association of Sneddon's syndrome include labile hypertension, ischemic heart disease, mitral valve thickening, aPL's and miscarriages. Primary antiphospholipid syndrome, has , in addition to the above, common thrombocytopenia, venous thrombosis, but unlike Sneddon's, not LR or cerebral ischemia.

On MRI in Sneddon's see single or multiple small or medium sized infarcts and angio shows occlusions of multiple distal branches. Angio of hands also shows multiple arterial occlusions. Path, Sneddon's is an arteriopathy of small and medium sized vessels although the skin biopsies may be negative. The role of APL's and genetics is probable but not clear. Coumadin is preferred if cardiac valvular disease exists or venous thrombosis.

Monday, October 13, 2008

BA Occlusive disease in the NEMC registry

407 patients in the New England Medical Center Posterior Circulation Stroke Registry were divided into 3 groups, including 109 with BA disease. 87 were moderate to severe.
(39) Group 1 had intrinsic and isolated disease usually atherosclerosis with superimposed thrombus.
(36) Group 2 had severe and extensive athero with additional/multiple sites in posterior circulation
(12) Group 3 had emboli to the BA from the heart or vertebral arteries.

Differences: Group 3 (embolic group) were significantly younger (49) v. 66, 60.
All groups had patients with many risk factors. Those without risk factors included 2 traumatic dissections, 1 BAM, 1 hypercoagulable state due to AIDS. Women were more likely to be in Group 2, men in group 1 (women had more widespread athero). Of the cardioembolic patients, 2 took BC pills, 75 % had 0 or 1 risk factors.

Presentation in group 1 was most often hemiparesis, in group 2, vertigo and dizziness, and in group 3, eye movement disorders, alteration of consciousness and tetraparesis.

TIA was much more common, with or without stroke in groups 1 and 2. TIA followed by stroke was more common than TIA only or stroke only (2/3 had TIA, 40 % followed by stroke, 27 % not). Stroke mechanism by far, was most commonly due to hemodynamic compromise with large artery occlusive disease (74%) becomes 87% if embolic are excluded. The rest were mixed (artery to artery embolus, BAM, coagulopathy, unknown). Cardiac mechanism was congenital heart lesions in 4, ASD in 2, PFO in one, AF due to thyrotoxicosis or chronic, mural thrombus.

Prognosis was worst in group C due to major deficit (58%), best in group 2 with 83 % having no or minor disability. Bad prognostic signs were impaired LOC, tetraparesis/tetraplegia. and pupillary abnormalities. BA occlusion was worse than stenosis. Involvement of the distal territory of the BA was highly predictive of disability whereas all patients with proximal stenosis alone had favorable prognosis. Overall mortality at 30 days was low and only one fifth had major disability.

Blogger note: Discussion indicates a benign outcome in many patients with such disease including BA occlusion, and the current registry analyzes factors that affect prognosis. Julien Bogouslavvsky wrote the editorial called "basilar occlusive disease: the descent of the feared foe?" and compares his experiences. He also mentions the embolic "proximal-distal syndrome" characterizes by ataxia and visual field deficits, usually due to occlusion of PICA with emboli northwards.

Sunday, October 12, 2008

Cerebellar infarcts, review


based on Amarenco,The Spectrum of cerebellar infarctions. Neurology 91:41:973-979. Review.

The PICA, which comes from the termination of the VA, has a medial branch that supplies the lateral medulla, and a lateral branch that almost never does.

The AICA, which emanates from the caudal third of the BA, supplies the lateral pons, including the nuclei of V, VII, and VIII (both cochlear and vestibular),the root of the VII and VIII nn, and the spinothalamic tract. The AICA can encompass the PICA territory when the latter is hypoplastic.

The SCA arises from the rostral BA, near the ostia of the PCA and thalamoperforating arteries. It supplies the rostral cerebellum vermis and dentate nucleus. The lateral tegmentum in pons is gotten affecting the superior cerebellar peduncle, the st tract, the lateral lemniscus, corticotegmental tract, decending sympathetics and the root of IV nerve.

Clinically Amarenco "concurs with Heros" that a patient able to walk normally is unlikely to have a substantial cerebellar infarct. In addition to the symptoms in other post, including dysarthria, lateropulsion, vertigo, nausea, vomiting, posterior headache, nystagmus and dysmetria, coma is common, as are signs of brainstem or PCA involvement.

AICA infarcts (figure 3, C through F; table). Considered uncommon, AICA infarcts are certainly underestimated. They involve the lateral portion of the pons, the middle cerebellar peduncle, the flocculus, and the anterior caudal part of the Cerebellum. The main clinical manifestation is a crossed syndrome, often misdiagnosed as lateral medullary infarction (Wallenberg’s
syndrome) because of dysmetria, vestibular signs, Homer’s syndrome, facial sensory impairment, contralateral pain and temperature sensory loss in the limbs, and sometimes dysphagia. Other signs, unusual in Wallenberg’s syndrome, are severe facial palsy, deafness
with or without tinnitus, lateral gaze palsy, and multimodal sensory impairment over the face. There may be an isolated vestibular manifestation, as recently shown in a case of probable occlusion of an accessory supplementary AICA.


PICA infarcts are as frequent as SCA infarcts . If restricted to the PICA territory, they are often small in size and benign. In a clinical series, only one-fourth of 36 patients had signs of brainstem compression (all of these had full PICA territory infarct), one-fifth had
obstructive hydrocephalus, and one-ninth died from cerebellar swelling.In this series, PICA infarcts presented mainly with vertigo, headache, gait ataxia, Wallenberg’s
syndrome or appendicular ataxia, and horizontal nystagmus. Infarcts of the medial branch
may be clinically silent or present with three mainpatterns: (1) isolated vertigo often misdiagnosed as labyrinthitis with ipsilateral axial lateropulsion of trunk and gaze,SOa nd dysmetria or
un~teadiness(h~e~n ce, cerebellar signs can be minimal,
and MRI may be required for diagnosis); (3) Wallenberg’s
syndrome when the medulla is also involved.
3*32.61C.6l2in ical manifestations of infarcts of the
lateral branch of the PICA are unknown since reported
cases have been chance autopsy findings with no available
clinical information

Superior cerebellar artery infarcts


Amarenco P and Hauw JJ. Neurology 1990; 40: 1383-1390. Reviewed 33 cases and found only one classic SCA infarct case. Many cases had other associated strokes including PICA, PCA, AICA, top of the basilar syndrome (73%) and even MCA (3 cases). Some cases had tonsillar herniation. 8 patients had coma at onset, 11 had tetraplegia, 9 had cerebellar/vestibular signs. Most cases were embolic either to the distal vertebral artery or the distal basilar artery.



The "classic" syndrome due to occlusion of the artery itself with infarct in the pontine tegmentum includes ipsilateral ataxia and Horner's s, contralateral thermoanalgesia involving face, arm , trunk and leg, fourth nerve palsy, with or without ipsilateral movement disorders. Some cases involved only the medial or lateral branch of the SCA. Delayed coma occurs in SCA only infarcts due to cerebellar swelling. The only "classic" case had associated additional infarcts rostrally.

Amarenco published a companion article on infarcts in the lateral branch of the SCA (Neurology 1991; 41L253-258). Most patients had ipsilateral ataxia, dysarthria, unsteadiness, and axial lateropulsion. One had clumsy hand dysarthria mimicking a lacune. This was usually benign with minimal.no brainstem compression although cardiac emboli were common.

SPARCL and hemorrhagic stroke


Article and editorial in Neurology 2008 70:24 June 10. In SPARCL 4734 patients were randomized to 80 mh atorvastatin or placebo. Patients had 16 percent reduction in stroke risk over five years (absolute risk reduction 1.9 percent). Posthoc analysis showed increased amount of hemorrhagic stroke. 55 patients in the treated group (2.3%) v. 33 of placebo group (1.4 percent) had hemorrhagic stroke. Those 88 patients were also associated with male sex, older age and hemorrhagic stroke at study entry, and uncontrolled hypertension. Study does not indicate that lower cholesterol is related to stroke. It may be due to antithrombotic mechanism of statins (reducing thromboxane A2, thrombin formation, or blood viscosity) or some other mechanism. It may affect arterioles or be related to amyloid angiopathy. It remains a "mystery." In most strokes statins still have benefits that outweigh the risks. In patients with past hemorrhagic stroke, the risk and benefit is less well defined.

Auditory symptoms in cerebrovascular disease

Based on clinical scientific notes in Neurology Lee et al., 2008 70: 2413-2415.

Hyperacusis usually occurs in peripheral labyrinthine dysfunction, but is reported in depression, migraine, and certain infectious diseases. Paracusia (altered sensation of timbre, pitch, or loudness) and palinacousis (perseveration of auditory image) after MGB hemorrhage. Auditory hallucination is reported with pontine hemorrhage. Bilateral hyperacusis is due to caudal tectal hemorrhage. This paper has unilateral hyperacusis due to contralateral pontine hemorrhage. Authors suggest hypersensitization and relationship to ipsilateral sensory discomfort, and an association with complex regional pain syndrome patients, who may have same symptom. See references.

Also see hearing loss and ischemia post http://strokenotes.blogspot.com/2007/02/sudden-hearing-loss-is-ischemic.html


Saturday, October 11, 2008

Primary CNS vasculitis of the spinal cord


Salvarani C et al. Neurology 2008; 70:2394-2400. Study is retrospective and culls 5 cases from the "Mayo experience" that involve "prominent" spinal symptoms at presentation (another 10 had "slight" spinal symptoms). All patients had weakness, leg paralysis, urinary and in 3, fecal incontinence. It took a mean 29 days to diagnose. 1 patient had constitutional symptoms of fatigue and fever. All had "cerebral" symptoms as well. In one patient, the spinal symptoms preceded the brain symptoms by 10 months, in the others they were concomitant or after cerebral symptoms. CSF findings included mean protein of 280 and WBC in CSF of 350. Sed rates were normal. Gado showed diffuse enhancement of the cauda/nerve roots. 4/5 responded to some form of immune suppression but all had at least one relapse. In lit there are twelve cases associated with malignancy especially Hodgkin's disease. Cases involved the T spine whereas other AI disease often involved the C Spine.

Anterior cerebral artery strokes

Stroke mechanism and clinical imaging in 100 patients. Kang SY, Kim JS. Neurology 2008;70: 2386-2393.

Findings
91 % had motor findings due to SMA/paracentral lobule involvement, 43 had apathy/abulia, due to callosal/cingulum/frontal involvement esp. bilateral. 68 patients had local athero, 10 had cardiac emboli, 6 had ICA disease. Patients with intrinsic ACA athero were more likely to have abulia and callosal involvement than those with cardiac or carotid emboli.

Anatomy: Branches of ACA: in order, orbitofrontal artery, anterior, middle and posterior internal frontal arteries, callosal marginal artery, paracentral artery, and superior parietal artery (7 branches).

30 patients were incontinent. 18 had aphasia (transcortical mixed, global, or motor). 25 had grasp reflex especially women with callosal involvement. Sensory loss was variably tested and invariably found in paretic limbs. Other findings were alien limb, lability,agitation, apraxia, amnesia, Parkinsonian, and anosognosia. Some mechanisms reported were different in studies of Western subjects. Many have impaired articulation and a soft whispering voice.
About 2/3 had callosal involvement at various levels especially the genu. Only 6 patients had subcortical involvement incl CN and PUT. Whole ACA involvement occurred only in four patients.

Motor weakness occurred including hemiparesis in 70 (in 38 leg more than arm), leg monoparesis in 18, and paraparesis in 3 patients. In 29 arm was same as leg, and in 4 arm was worse than the leg. The shoulder was more involved than the distal arm/hand. Usually the SMA was involved.

Different paper: ACA infarct caused contralateral eyelid opening apraxia (Korn et al., Arch Neurol 2004; 61-273-275. It was an occluded carotid on right with right ACA infarct and left finding. Initially brachiofacial paresis occurred, but that cleared. Alteplase was used. Authors speculated the lesion in the forceps of the callosum caused a disconnection syndrome and left lid apraxia.

Notes occlusion of the stem of the ACA prior to ACOM are well tolerated as long as the stem does not supply both sides and adequate anastomosis exists. Occlusion is usually embolic. Huebner's branch to CN head comes off and cause transcortical motor aphasia.

Differential of leg predominant weakness due to stroke-- is due to ACA only 25 %. Others include corona radiata, capsule, anterior choroidal artery stroke, perforators, brainstem, or with thalamic hemorrhage. Small strokes in premotor area can cause especially if lateral .

Superficial ACA stroke can cause syndrome of crural paresis and homolateral arm predominant ataxia. A similar syndrome can occur in the pons.

Monday, October 06, 2008

Call-Flemings syndrome

Reversible angiitis multifocal postpartum, multiple transient symptoms, treat with calcium channel blockers. Notes sertraline was overrepresented in group with vasoconstriction due to this. triptans, cocaine, phenylpropamine, cannabis, esp with alcohol can ppt this. esp in men. Men often had cannabis, women had ssri's. French called it peripartum angiopathy. Also occurs in young girls at menarche and menopause. Also after carotid surgery, hypercalcemia, pheo, eclampsia. History of migraine is common. Emphasized feature is sudden onset thunderclap headache, scattered MRI abnormalities and TCD's show flow abnormalities and can see focal SAH's. "1000x more common than isolated CNS angiitis" (Lou Caplan). Also suggest reperfusion during migraine presenting as thunderclap HA is more important than acknowledged. consider bartelson's with migraine flavor, 2-3 episodes per day for 2 mo and self limited with pleocytosis, get repeated events in same hemisphere, avoid brain bx or give verapamil. See http://neurologyminutiae.blogspot.com/ for a case series with more clinical descriptions.

Saturday, October 04, 2008

Fwd: More on risk of BA stenting

listened again to Marc Chimowitz' presentation at AAN which is free and listed here:  http://198.174.119.11/aan2008/viewer.php?pf=yhQrXc0MrAOPdFasxSXDMQ==&ud=I+ld1u1vbwERuUlz7ZfDxA==  see slide 30.

Using the NIH wingspan registry, the 24 hour stroke or death rate after intracranial stenting is 6.2 % which is the number quoted by Alex previously.  The 30 day risk is 9.6 % and the six month risk of ipsilateral stroke is 14 %.  This is for intracranial stenosis.   The risk of more than 50 % restenosis is not counted and that is 25 %.  The technical success of the procedure is 96.7 %.Chimowitz compares the risk to wasid untreated patients wherein risk is in the low 20s for more strokes, although the risk stratifies to those with severe stenosis (more than 70%) and less than 30 days from a qualifying event.  Therefore there is potential for benefit with intracranial stenting possibly around 8 % (NTT would be around 12.5).   However, the conservative risk to quote to a patient is 14 % of complications in good hands with no data on direct benefit (since the trial head to head is not complete).  That is because the late strokes are probably embolic, or due to restenosis and late failure.  Presumably, the other 11 % of restenosis cases are asymptomatic.  Based on my prior post, also, watch out that you don't stent the lenticulostriates (where is the stenosis, which part of the artery). 

Again, Ron, my advice is to get the second event from a nontechnician and take the quoted data about risk with a grain of salt. Make a clinical decision based on your own experience and consideration. 

What they're saying about late alteplase


Based on thoughts expressed in conversation with other neurologists. Sorry can't attribute but these are high powered people's thoughts
1. No position statement yet exists from ASA or elsewhere
2. Patient selection was no diabetics, NIHSS < 25
3. ATLANTIS a negative study had 30 minute time difference, and twice as many diabetics
4. Genentech has opportunity to go for a label change if they feel the data are compelling
5. DEFUSE and EPITHET suggest use of neuroimaging to guide patient selection
6. An updated metaanalysis may not meet FDA requirement of 2 Randomized clinical trials
7. Improved peristroke care and better systems have led to better outcomes, including glycemic control
8. Better rate of SICH was definitional-- if they defined it as NINDS did, their SICH would have been around 8 % leading to more "pushback"
9.The prior 3-6 hour studies had lots of patients outside the 4 and a half hour window which might account for their negative results
10. Better definition for treatment of tia's needed as well as pushing tpa window
11. Smaller strokes might be better treated up to the longer window
12. Need to review ATLANTIS again http://www.ncbi.nlm.nih.gov/pubmed/10591384?ordinalpos=2&itool=EntrezSys which was Genentech sponsored, highly powered negative study unlike the characterization in NEJM
13. Study should be compared to SAINT study
14. In Atlantis 32% of the placebo and 34% of the tPA treated had NIHSS 0,1at 90 days. Diabetes in 18% placebo, 25% tPA. AF 14%/19%. In ECASS3 43% of the placebo and 50% of the tPA treated had NIHSS 0,1 at90 days. Diabetes 17% placebo, 15% tPA. AF 14%/13%. Though age and NIHSS on entry was not different something different ledto improved outcome in the Europeans. More diabetes and AF in treated group in Atlantis. Would be interesting if Europeans release infarct volume data.

Saturday, September 27, 2008

Profess finally published


Sacco RL et al. NEJM 359:1238-1251 2008
Yusuf et al IBID 1225-1237 2008
editorial DM Kent and DE Thaler IBID 1287-88

Aggrenox v. clopidogrel (Sacco et al.) As a neurologist not a statistician I will cut to the chase. They studied over 20,000 patients in a double blind 2x2 factorial design, randomly assigned to aggrenox or plavix. There was not evidence of the trial meeting the predefined criteria for noninferiority and there was no evidence that either treatment was superior to the other in the prevention of recurrent stroke.

Telmisartan to prevent recurrent stroke and cardiovascular events (Yusuf paper). Same 20,332 patients were randominzed to telmisartan 80 mg/day v. placebo. Interval to randomize was 15 days. Therapy continued 2.5 years . There was no evidence that therapy with telmasartan lowered the rate of recurrent stroke, major cardiovascular events or diabetes.

Editorial note.(Kent and Thaler). titled "Insights from Incoherence" authors properly note the tendency of some to make indirect comparisons based on different clinical trials (showing a better effect of aggrenox in this case) were mistaken. They also properly note that the "compelling logic of the transitive property, so reliable in mathematics, has little authority in the often illogical world of clinical trials" (I love it, but credit goes in a cite to Baker and Kramer). However Kent and Thaler liken the result to the Zen koan, a result incomprehensible to rational understanding, the contemplation of which may lead to a deeper realization. They summarize realization with the original haiku "For stroke prevention/use an antiplatelet drug/Treat hypertension."

Robert Frost, look out!

Late alteplase 3- 4.5 hours


Two articles and one editorial
Hacke W. et al. NEJM 359:1317-1329 2008. Also called ECASS III
Trial replicated in many ways the seminal NINDS trials except studied the 3-4.5 hour period. 821 patients were enrolled and randomized 1:1 with primary endpoint being favorable outcome at 90 days (modified Rankin score of 0 or 1). Safety endpoints were death, symptomatic ICH and other SAE's. Median time of enrollment was 3 hours 59 minutes. Treated group had more favorable outcomes (52.4 v. 45.2 %) or stated otherwise number to treat to have one more good outcome is about 14. sICH occurred in 2.4 v. 0.2 % (NTT for one more symptomatic hemorrhage is 45). Overall hemorrhage was 27 v. 17.6 % (NTT for one more hemorrhage is about 11).

Criticism-- did not study severe strokes with high NIHSS scores. Editorial by Lyden P NEJM op cit. 1393-5 also noted study tended not to enroll as many diabetics. Editorial also pointed out data showing earlier treatment is more beneficial earlier and less beneficial later; treatment in 3-4.5 hour bloc is successively less successful than treatment in each earlier time bloc. Authors allowed use of small doses of SQ heparin after alteplase to prevent DVT's.

The article itself explains that prior trials of 3-4.5 hour window ECASS II and Atlantis, were not powered to detect a positive finding in 7-10 % range.

Alteplase in first 90 minutes after stroke is nearly twice as effective as in second ninety minute bloc. Odds ratio for global outcome in first 90 minites is 2.81, in second ninety minutes is 1.55, in the third 90 minutes is 1.40 (based on pooled analysis of prior studies) and in current study is 1.34 in third 90 minutes. Time to needle is still paramount.

The previous article from Lancet cited (Wahlgren et al. Lancet 2008, dubbed the SITS-ISTR trial Safe Implementation of Thrombolysis in Stroke) compared 664 patients receiving alteplase in 3-4.5 hour time period to 11,685 who received it in 3 hour window. The outcome was symptomatic intracranial hemorrhage in first 24 hours with NIHSS deterioration of 4 points or more, and 90 day outcome based on modified Rankin score of 0-2. The result was no difference in any outcome measure and the conclusion is that alteplase is safe when given 3-4.5 hours.

Friday, August 08, 2008

lovenox and alteplase

Regarding Lovenox and tPA, Lovenox (enoxaparin) at full dose (1 mg/kg q
12 hours) is equivalent anticoagulation to full dose unfractionated
heparin or warfarin, and would definitely be a
contraindication to tPA. Monitoring its effect requires a
Factor Xa level, not rapidly available in most hospitals. Lovenox at DVT
prevention dose, e.g. 40 mg sc daily, is much less clearly a
contraindication. It is thought equivalent to sc heparin at 5000 units q
8-12 hours. There is no published information of which I am aware and it would be up to practioner whether to go ahead with alteplase

Friday, July 11, 2008

Presentation and treatment of air embolism after cardiac ablation procedure

Hinkle DA, Raizen DM, McGarvey ML, Liu GT.  Cerebral air embolism complicating cardiac ablation procedures.  Neurology 2001; 56:792-794.

Authors present 2 cases of air embolus following cardiac ablation procedure.  In both cases air was suspected of entering the sheath travelling to the left ventricle.  In the first case the patient became confused and apneic and awoke with a gaze preference and hemiplegia, normalized and 2 hours later again became confused and agitated.  Hyperbaric chamber and iv fluids were utilized and the patient improved.

In the second case the patient became agitated and globally aphasic and confused and within 20 minutes awoke with a fluent aphasia.  30 minutes later he became confused again and remained aphasic.  CT and MRI with DWI was normal in both cases.  The first patient had a normal angiogram. 

This presentation of an unusual cause of stroke with an unusual treatment is notable and important to recognize.  Hyperbaric chamber minimizes endothelial thromboinflammatory injury and improves outcome.  A third case was reported separately (Akhtar N, Jafri W, Mozaffar T Neurology 2001l56:136-137).   

Tuesday, June 17, 2008

hormones in young postmenopause


For Menopausal Hormone Therapy and Stroke Risk, Timing Makes a Difference
New NHS results corroborate previous findings about HT and stroke risk while providing reassurance for young menopausal women using HT for fewer than 5 years.
Previous results from the Nurses’ Health Study (NHS; Ann Intern Med 2000; 133:933) and the Women’s Health Initiative (WHI; JAMA 2003; 289:2673 and Circulation 2006; 113:2425) have shown that menopausal hormone therapy is associated with a 30% to 40% higher risk for stroke. In a new NHS analysis of data from questionnaires completed in 2004, investigators evaluated timing of HT initiation, duration of use, and estrogen dose as factors in determining risk for various types of stroke. Because vasomotor symptoms are most likely to be bothersome in young menopausal women and to diminish over time, for the analysis of HT duration, the authors focused on women who were within 4 years of menopause or were younger than 55.
Current use of estrogen-alone HT or combined HT was associated with age-adjusted relative risks for total stroke of 1.33 (95% confidence interval, 1.13–1.55) and 1.17 (95% CI, 0.96–1.42), respectively. RRs were generally similar for ischemic, hemorrhagic, nonfatal, and fatal strokes. Timing of HT with respect to onset of menopause did not change these risks appreciably. Despite a limited sample size for the analysis of HT duration, use of HT for fewer than 5 years was not associated with significant elevations in risk for stroke, particularly among women who were younger than 55. Estrogen dose correlated with stroke risk: For a 0.3-mg dose of conjugated equine estrogen, no excess risk was observed. In contrast, doses of 0.625 mg and 1.25 mg were associated with adjusted RRs of 1.54 and 1.62, respectively.
Comment: These results agree with prior NHS and WHI findings, which showed that HT use is associated with a small elevation in stroke risk regardless of age or time after onset of menopause. However, NHS and WHI researchers alike have found that HT use by young menopausal women is associated with a lower risk for heart disease. Among young menopausal women, excess risk for stroke (if any) seems particularly modest, especially when duration of HT use is limited and low estrogen doses are employed.
Andrew M. Kaunitz, MD
Published in Journal Watch Women's Health June 5, 2008
Citation(s):
Grodstein F et al. Postmenopausal hormone therapy and stroke: Role of time since menopause and age at initiation of hormone therapy. Arch Intern Med 2008 Apr 28; 168:861.
Original article (Subscription may be required)
Medline abstract (Free)

Monday, May 12, 2008

Polyarterial clustered recurrence of cervical artery dissection appears to be the rule


Dittrich R, Nassenstein I, Bachmann R et al. Neurology 2007; 69: 180-186. Summary: Spontaneous cervical artery dissection is (wrongly ) thought to a monophasic disorder. The listed rate of recurrence 0-8 % over 8.6 years is low, WAYYY low. Serial MRI of 36 patients over six month showed the following: 6 % had polyarterial involvement on the first MRI. 25 % had recurrence in one or more (same or different ) arteries over the course of followup. Of the 25 %, most recurrences occurred within 4 weeks (19%), but 6 % were noted at six months. All but one of the recurrences were asymptomatic or mildly symptomatic. All patients (ie the ones with benign results) were treated with anticoagulation followed by ASA.

Tuesday, March 25, 2008

Fasting causes stroke


Saadatnia M et al. showed an fourfold increase in cerebral venous sinus thrombosis during Ramadan, a month during which Muslims fast. P02.007 AAN book 2008.

Misdiagnosis of Fabry disease

Po1.145 AAN book 2008 first author L Marchesoni. Argentina.

Fabry's disease is an x linked recessive lysosomal storage disease due to deficient alpha galactosidase A. Untreated males usually die by the end of the sixth decade. The initial presentation is usually acroparesthesias, not relieved by rubbing, but prevented with acetophenacetin and ingestion of large amounts of liquids. Subsequently, abdominal pain, angiokeratomas and anhidrosis occur. Most are diagnosed after 15 years or more. Misdiagnoses included cryptogenic/psychogenic pain, RF, flatfoot, gout, food intoxication, cholecystitis, "glandular block", petechiae, vascular fragility, and others. Angiokeratomas are seen first around the umbilicus, and on the extensor surfaces of the elbows and knees, and in body creases including the hips and the genital areas. Opthalmic signs include whirl like feathery opacities, dust like haziness on cornea, dilated and tortuous corneal vessels, and corneal dystrophy on slit lamp that does not affect vision(cornea vittilicata). The opthalmic abnormality is present in nearly 90 % including female carriers who can thus be diagnosed by slit lamp exam.

Features can include tinnitus and deafness, although that is not in many textbooks (Lou Caplan); also vertigo. Other features are heat intolerance, inability to sweat, with the skin turning beet red on heat exposure. Other factors are postprandial abdominal cramping, and diverticula that can rupture. Left ventricular hypertrophy is seen as is small fiber neuropathy with decreased TEMPERATURE sensation. A recent case was reported of a patient presenting with a mimic of TGA (The Neurologist 2012; 18:413-4).

Strokes occur in posterior circulation  , large and small arteries.

Pathologically, thickened walls in smaller arterioles is noted and in the brain, a double refractile material is seen. Cardiac and renal disease predominate, and many strokes are subclinical. Treatment must begin very early. Misdiagnosis of MS is common especially with brainstem strokes. CRAO, optic atrophy, loss of nasal field, third nerve palsy, lateral medullary syndrome, TMB are all reported, as are various lacunar syndromes. Cardiac evaluation shows hypertrophic cardiomyopathy and MVP in more than half. Renal failure is due to the deposition of lipid in glomeruli and tubules.  Proteinuria is a feature.  Lymphedema is seen . Basilar artery is described as pathologically enlarged and at times dolichoectatic.

The gene for alpha galactosidase a is Xq22.1, and different mutations are known. Female heterozygotes still have early stroke and can have heart and kidney disease and elevated ceramide trihexoside in urine. Treatment is biochemical Fabrazyme made by Genzyme (see pubmed how to do). CBZ, PTN, ASA ticlid, Vit E can be used for various symptoms/problems.

Additional material:
Testai FD, Gorelick PB.  Inherited metabolic disorders and stroke part I:  Fabry disease and mitochondrial myopathy, encephalopathy, lactic acidosis and stroke like episodes.  Arch Neurol; 2010: 67: 19-24.

More than 400 mutations of the alpha gal gene are identified, most being missense or nonsense substitutions.  Absent family history does not rule out the diagnosis.  The incidence is 1: 117,000 births and 1: 40,000 men.  However, in cryptogenic stroke in the young, FD is responsible for 1.2 % (of age less than 55).  Inn the database, women have more strokes than men, 2:1 with mean age 43 for women, and 28 for men.  Basilar artery diameter is said to be a sensitive measure of FD (Neurology 2009). 

Due to skewed organ specific X chromosome inactivation (nonrandom lionization), women may have atypical organ specific presentation, leading to challenges in diagnosis.  These may include cardiac, renal and cerebrovascular manifestations.  Diagnosis is made by alpha gal activity in leukocytes or plasma, but in women, gene sequencing and linkage studies may be needed, due to heterozygosity.

Acroparesthesias are associated with accumulation glycosphingolipids  in DRG and Nerve conductions and EMG's are negative.

Measurement of leukocyte GAL activity is 100 percent sensitive in males but only five percent in women

MRI shows T2 hyperintense signal in frontal and parietal white matter and T1 hyperintensity in pulvinar as well as dolichoectasia.  Treatment decreased LV mass and pain but unknown if it helps stroke.

The varicella zoster virus vasculopathies: clinical, CSF, imaging and virologic features


Nagel MA, Cohrs RJ, Mahalingam R et al. Neurology 2008; 70:853-860.

Review article of 30 patients, the first large review in about 30 years, busts some myths about VZV stroke. Among them:

1. Rash occurred in only 63 %, often many months prior to the stroke (mean 4 months)
2. CSF pleocytosis occurred in only 67 %
3. Angiography was abnormal in only 70 %
4. Large arteries were involved with small arteries (50%) or small arteries were involved alone (37% ) whereas large arteries alone occurred in only 13 %.
5. VZV DNA was found in only 30 %
6. The best lab test, by far, was CSF anti VZV IgG antibody with reduced IgG index (serum : CSF) confirmed intrathecal synthesis. The only 2 negative cases out of 30 were children who developed vasculopathy after chickenpox.
7. Case series was not large enough to determine optimal treatment (acyclovir v. acyclovir + steroids); however, some cases relapsed and then improved when either acyclovir course was extended or steroids were addded to acyclovir. Overall in the small series, 2/3 improved with acyclovir alone, and 3/4 with acyclovir + steroids.
8. 11 patients out of 30 were immunocompromised (2 AIDS, 3 HIV +, 2 leukemia, 1 CREST s, 1 lymphoma, 1 low CD4 count, and 1 treatment for RA/SLE).
9

PRoFESS Trial


Diener HC , Sacco R, Yusud S et al. Rationale, design and baseline data of a randomized, double blind controlled trial comparing two antithromobotic regiments (a fixed dose combinations of ER dipyridamole and plus ASA with clopidogrel) and telmisartan versus placebo in patients with strokes: the prevention regiment for effectively avoiding second strokes trial. Cereebrovasc Dis 2007; 23:368-380.

Blogger comment: The authors were obviously science and not English majors, and the lower case "O" is annoying. In sum this study compares aggrenox against plavix, and makes a side study of telmisartan.

There are 695 sites from 35 countries, involving patients over 50 with stroke within 120 days, with recurrent stroke as the primary outcome in a time to event analysis. The secondary outcome measure is the composite of stroke, MI or vascular death. The main study is non-inferiority, then superiority and the side study assesses suuperiority over placebo. Over 20,000 patients are randomized. The mean age was 66, 2:1 male, large and small vessel strokes are included. The deisgn is 2 x 2 factorial design.

The expected event rate in the clopidogrel group was 5.25 % per year, necessitating 15,500 subjects but the number was increased when the event rate turned out to be lower.

COL4A1 mutations and stroke


Vahedi et al. Neurology 2007; 69: 1564-8
and editorial
Meschia JF and Rosand J. Fragile vessels handle with care Neurology 2007; 69: 1560-1561

COL4A1 gives the brain resistance to minor head trauma. It encodes the gene for collagen alpha 1. Human conditions linked to a mutation include autosomal dominant porencephaly, retinal arteriolar tortuosities, and traumatic or antithrombotic associated symptomatic cerebral hemorrhages and otherwise undetected microhemorrhages on MRI. MRI can also show diffuse leukoencephalopathy and enlarged perivascular spaces. The report by Vahedi includes a patient who died of subarachnoid hemorrhage and another who died at age 40 of anticoagulation associated hemorrhage.

The editorial authors compare the condition to CADASIL insofar as many different mutations can cause the condition. The theme of trauma or injuries to vessels as triggers to hemorrhage recurs. Treatment of affected patients may including withholding antithrombotics or anticoagulants, avoiding contact sports, genetic screening in pregnancy, and of family members (including asking specifically about congenital hemiplegia rather than "porencephaly"), periodic screening with MRI's, further evaluating tortuous vessels seen on funduscopy and others.

Monday, March 24, 2008

Imaging Pearl for cerebral venous sinus thrombosis


Courtesy of David Lee Gordon, Chairman Oklahoma (the neurology department not the musical)

Look at the parenchymal MRI (not MRV) images, particularly the T1noncontrast sagittal images. If the noncontrast T1 sagittal images shownormal (hypointense = black) flow void in the left transverse sinus andlack of flow void (hyperintense = white) in the right transverse sinus,you have your answer without a venogram.The left transverse sinus is commonly hypoplastic, not the right (sinceuually the right transverse sinus drains the larger superior sagittalsinus and the left transverse sinus drains the smaller straight sinusand the confluence is usually not a confluence at all). Also a temporalhemorrhage is precisely what I would expect from an ipsilateraltransverse sinus thrombosis. If the patient does indeed have CVT,anticoagulation often leads to improve despite the presence ofhemorrhage.

Monday, February 11, 2008

SCA infarction and emotional facial paresis

SCA infarct classically produces ipsilateral limb and gait ataxia, static or intention tremor, Horner's syndrome, contralateral loss of pain and temperature and decreased masseter response. Other symptoms may include deafness, impaired sweating (with Horner's) and emotional facial paresis . This derives from dorsolateral pontine pathologyThis area is distinct from the corticobulbar tract mediating voluntary facial innervation (Neuroimages, Hopf HC, Fitzek C, Marx J et al., Emotional facial paresis of pontine origin, Neurology 2000; 54: 1217).

Blogger comment-- review brainstem anatomy including lateral st tract (crossed sensory), mes tract of V (masseter r), central sympathetic tract (Horners s), lateral lemniscus (responsible for deafness), MLF

Subclavian artery dissection and triple infarction of the nervous system

Garewal M, Selhorst JB. Arch Neurol 2005; 62:1917-1919.

Background-- subclavian dissection is rare, and is usually associated with anomalies of the aortic arch, trauma or catheterization. The main clinical manifestations are chest and back pain preceding stroke, often with pain and weakness in the arm. This contrasts with vertebral artery dissection that is associated with headache and neck pain and arm pain/weakness.

In the case described, a 54 year old hypertensive developed crushing intrascapular pain and vertigo and vomiting and could not lift his arm over his head. His father had had an abdominal aortic aneurysm. He had decreased pinprick perception on his left lower jaw. He had weak deltoid, triceps, supraspinatus, and triceps. He had decreased left biceps and triceps jerks. He had dysmetria bilaterally and an ataxic gait. His radial arteries WERE SYMMETRIC!. DWI showed a left cerebellar stroke. On angio he had a subintimal thrombus in the subclavian artery. He improved over a month or two. The authors describe 3 strokes: cerebellar, spinal between C4 and C5, and multiple rootlet infarction with weak arms and denervation on EMG study.

The lit review describes a patient who developed subacute thoracic pain and bilateral arm pain.

Saturday, February 09, 2008

Natural history of vertebrobasilar dolichoectasia

Passero SG, Rossi S. Neurology 2008; 70:66-72.

There is a high degree of variability in outcome ranging from benign to malignant. Clinical expression includes compression of cranial nerves or brainstem, obstructive hydrocephalus, ischemic and hemorrhagic stroke. This study of 156 patients followed an average of 11.7 years showed that 93 patients (60 % ) had at least one event; 59 ischemic strokes, 21 hemorrhagic strokes, 31 compressive symptoms, and 2 hydorcephalus. Risk stratification was based on the severity of , diameter, height of bifurcation, nad lateral displacement of the vertebral artery. Progression of VBD was associated with a worse outcome. 43 % of patients did progress.

Detail: the maximum diameter of the BA ranged from 4.6 to 13.4 mm (mean 6.8). 86 % invlved the VA's and 45 % the anterior circulation. Strokes were more likely among patients who were hypertensive and smokes. Of the strokes, 41 % were brainstem, 29 % superficial arterial territory of PCA, 24 % thalamus, 2 % cerebellum, 66 % lacunes, 34 % large artery.

Of 56 patients who presented with ischemic stroke, 50 received antiplatelet drugs and 6 anticoagulation. 54 % had recurent ischemic strokes, and 13 % recurrent hemorrhagic strokes. 73 % of recurrent strokes happened in first five years of followup.

Treatment initially was NOT related to risk of stroke. 42 % of treated patients (n=33) and 34 % of untreated patients (n=26) had one or more ischemic strokes during followup. Death from stroke (40 % of deaths) occurred among patients who first presented with stroke.

The ten year risk of recurrent stroke among patients presenting with stroke was 56 % which compares to the Rochester experience of 29 % (Meissner and Whisnant, Stroke, 1988).