Saturday, June 06, 2009

North American moya moya is different


Hallemeier et al. Stroke 2006. Authors looked at 34 adults with the condition. 22 had bilateral and 12 unilateral moya moyal vessels. North Americans present more often with ischemic stroke whereas Asians present with hemorrhage more often. 0/12 unilateral patients subsequently developed contralateral symptoms. Symptomatic patients had high levels of recurrence both homolaterally and contralaterally, and asymptomatic patients had a low risk of ischemic events. Surgical treatment revascularization led to less recurrence, with a fairly high perioperative morbidity and mortality ( as high as 17 % for the latter). N American moya moya may be a different entity than the Japanese kind.

Statins prevent vasospasm after subarachnoid hemorrhage


McGirt Mj et al. J Neurosurg 2006; 105: 671-674. (Duke) 115 patients were retrospectively reviewed with multivariate regression analysis. Statin therapy started on admission with SAH resulted in a elevenfold decrease in vasospasm. ACA/ICA aneurysm also was associated with vasospasm. Tseng MY al (Stroke 2005; J Neurosurg 2007) also published 2 articles on the subject . The mechanism is thought to be cholesterol independent, perhaps related to nitrous oxide.

Number to harm with iv tpa


Saver JL Hemorrhage after thrombolytic therapy for stroke. The clinically relevant number needed to harm Stroke 2007; 38: 2279-2283

Author reviews original NINDS data on hemorrhages, n=20/312 patients treated, and noted that they tended to be older, have mass effect on CT, have higher serum glucose, and more severe strokes. The number needed to harm, ie an additional dead or disabled outcome (MRS>= 3) attributable to SICH is 707, based on the expected outcome of these 20 patients.

NNH for dead disabled outcome MRS (.=4) 126, for fatal outcome 36.5, and for worsening of any degree between 30 and 40.

Basic conclusion is that most patients with SICH are destined for bad outcomes from the get go.

IV alteplase plus mutlimerci is safe


Smith WS et al. Safety of mechanical thromobectomy and iv tpa in acute ischemic stroke. Results of the Multi Mechanical Embolus in Cerebral Ischemia (Merci) trial part I. AJNR 2006; 27: 1177- 1182.

Study enrolled patients who either did not receive iv tpa or received it and did not recanalize. It was an international prospective single arm trial up to 88 hours post stroke. 111 patients received the procedure with mean NIHSS of 19 +/= 6.3 30/111 received tpa prior. 60/111 recanalized with retriever alone, 77/111 with adjunctive therapy. 9 % has SICH. 5 % had procedural complications.

Clinical outcomes not given

Blogger note: Like many radiology studies, this one has important limitations. The study does show that Multi Merci is safe and efficacious using recanalization, but fails to look at clinical outcome of the patient. PROACT 2 is the single study showing clinical benefit of interventional therapy for stroke, namely intrarterial lysis.

Warfarin in elderly -- Birmingham study


Mant J et al. for BAFTA investigators. Warfarin v. aspirin in an elderly community population with atrial fibrillation (the Birmingham Atrial Fibrillation Treatment of the Aged Study, BAFTA): a randomized clinical trial

patients: 973 patients 75+ age, mean 81, SD 4 from primary care were randomized to aspirin 75 mg or warfarin with INR target of 2-3, and followed a mean 2.7 years. The endpoint was fatal or disabling stroke, ICH, an arterial embolism.

results: in warfarin group there were 24 events, with 2 ICH and remainder ischemic strokes, in aspirin group there were 48 events. Yearly risk reduction was 3.8 percent in aspirin group, 1.8 percent in warfarin group, risk reduction 2 %, p=0.003. Risk of hemorrhagic events increased 0.2 % in warfarin group, 1.4 to 1.6 percent.

Warfarin is treatment of choice.

Friday, June 05, 2009

Aspirin v. anticoagulation in carotid dissection


Georgiadis D, Arnold M, et al. Neurology 2009; 72:1810-1815

A study of 298 patients with spontaneous Carotid artery dissection

Main points

ischemia is relatively rare after dissection in 3 months ischemic stroke occurred in 0.3 %, TIA 3.4 %, retinal ischemia 1 % with no significant difference between groups. Ischemic events were commoner in those with ischemic events at onset. It is important to separate these two groups. Anticoagulation had a predictable 2 % complication rate. There was 97 % followup with exam or structured telephone interview. In literature review , 2 recent meta analyses showed no difference. (see Cochrane database Syst Rev 2003, and Lyrer et al, Stroke 2004). This was not a RCT, and warfarin was prescribed up to 1997 and aspirin thereafter. The number of patients was too small to evaluate treatment differences. The primary finding was the low rate of strokes after sicd.