normal thrombin time and dabagitan

(reprinted not practice in our facility)

A normal thrombin time essentially rules out any anticoagulant effect due to Dabigatran. Thrombin time is a widely available and inexpensive test. For patients known or suspected to be on Dabigatran, our stroke team policy is to consider treatment with IV-t-PA only when thrombin time is normal.

CADASIL typical temporal lobe imaging involving temporal pole

SAMMPRIS trial stopped

CLINICAL ALERT

The National Institute of Neurological Disorders and Stroke (NINDS) has stopped enrollment in a clinical trial that is evaluating whether intracranial angioplasty combined with stenting adds benefit to aggressive medical therapy alone for preventing stroke in patients with symptomatic intracranial arterial stenosis. The Stenting and Aggressive Medical Management for Preventing Recurrent stroke in Intracranial Stenosis (SAMMPRIS) study is the first prospective randomized multicenter trial to compare aggressive medical management alone versus aggressive medical management plus angioplasty combined with stenting in patients with symptomatic high grade (70-99%) stenosis of a major intracranial artery (intracranial carotid, middle cerebral artery, intracranial vertebral artery, and basilar artery).

Full NINDS Alert (PDF)

billing code for administering alteplase by MS

You can use the CPT code 37195 if you are personally at the bedside while
> the tPA is given by a physician. 

Lambl's excrescences and fibrous strands

The serpentine mitral valve and cerebral embolism

James Ker

Cardiovascular Ultrasound 2011, 9:7 

 

Vilem Dusan Lambl, a Bohemian physician (1824-1895) were the first to describe the occurrence of small, filiform processes he observed on the aortic valve in 1856[5] . Today, these Lambl's excrescences are also referred to as valvular strands and have been observed on all native and prosthetic valves[5] . These strands may occur as single strands, in rows or even in clusters[5] . They can vary in length from 1 mm to 10 mm and are usually less than 1 mm in thickness[5] .

Valvular strands are composed of a fibroelastic, avascular core, covered by a layer of endothelial cells[5,6] .

The exact pathogenesis of formation of these structures are still unclear, however current opinion is that the initiating factor is that of an endocardial lesion in areas of trauma and/or high shear stress[5,6] . These denuded areas are then covered by fibrin with subsequent covering by an endothelial layer[5,6] . The prevalence of valvular strands has been estimated as 5.5% in a general population referred for transesophageal echocardiography and 40% in patients with stroke of unknown cause[1,2] .

The differential diagnosis for valvular strands includes the following[5] : a myxoma, thrombi, valvular vegetations, nonbacterial thrombotic (marantic) endocarditis, cardiac metastases, a fibroelastoma and other primary cardiac neoplasms.

Of all of the above, the most difficult distinction is that between a valvular strand and a fibroelastoma[5,7] . Histologically, these two entities are very similar with both containing a central core of elastic connective tissue, covered by endothelium. However, valvular strands are covered by a single layer of endothelial cells, but fibroelastomas contain regions of multiple layers of endothelial cells[5,7] .

Echocardiographically, fibroelastomas are more bulky, with stalks or pedestals sometimes present and multiple, fingerlike projections on their surface[5] . As fibroelastomas are usually found on the mechanically less strained parts of valves and endocardium they tend to be larger than valvular strands[5] . Valvular strands (Lambl's excrescences) are always found on the affected valve's line of closure and this limits their growth[5] .

Several published case reports have shown that valvular strands are associated with emboli to the coronary, pulmonary, spinal, retinal and cerebral circulation[1] .

Specifically regarding stroke, numerous reports have demonstrated an association with valvular strands, particularly in young patients[3,4,8,9] . The mechanism for embolic events is either that of thrombi forming on the strands which then embolize or it is possible that the valvular strand itself can embolize[2] . Direct visualization of thrombus on a valvular strand have indeed been described before[10] .

In conclusion, a case of a valvular strand, attached to the coapting edge of the mitral valve is presented, giving a serpentine appearance to the mitral valve. This valvular strand was the cause for a cerebral embolism which presented with a transient right sided hemiparesis. This is the only current case in the literature, where the combination of aspirin and clopidogrel is used for the prevention of further episodes of cerebral embolism. In the only randomized treatment study to date, no difference in relation to efficacy of warfarin compared to aspirin was found in patients with valvular strands and previous embolic episodes[2] . For this reason a combination of antiplatelet therapy was initiated as a therapeutic trial.

It is proposed that a randomized controlled study involving the combination of aspirin and clopidogrel is warranted in patients with valvular strands presenting with a first episode of cerebral embolism.

1. Wolf RC, Spiess J, Vasic N, Huber R: Valvular strands and ischemic stroke.

   Eur Neurol 2007, 57:227-231.

   Homma S, Di Tullio MR, Sciacca RR, Sacco RL, Mohr JP: Effect of aspirin and warfarin therapy in stroke patients with valvular strands.

2. Stroke 2004, 35:1436-1442.

   Freedberg RS, Goodkin GM, Perez JL, Tunick PA, Kronzon I: Valve strands are strongly associated with systemic embolization: A transesophageal echocardiographic study.

3. J Am Coll Cardiol 1995, 26:1709-1712.

   Roberts JK, Omarali I, Di Tullio MR, Sciacca RR, Sacco RL, Homma S: Valvular strands and cerebral ischemia. Effect of demographics and strand characteristics.

4. Stroke 1997, 28:2185-2188.

   Jaffe W, Figueredo VM: An example of Lambl's excrescences by transesophageal echocardiogram: A commonly misinterpreted lesion.

5. Echocardiography 2007, 24:1086-1089.

   Roldan CA, Shively BK, Crawford MH: Valve excrescences: Prevalence, evolution and risk for cardioembolism.

6. J Am Coll Cardiol 1997, 30:1308-1314.

   Gowda RM, Khan IA, Nair CK: Cardiac papillary fibroelastoma: A comprehensive analysis of 725 cases.

7. Am Heart J 2003, 146:404-410.

   Lee RJ, Bartzokis T, Yeoh TK, Grogin HR, Choi D, Schnittger I: Enhanced detection of intracardiac sources of cerebral emboli by transesophageal echocardiography.

8. Stroke 1991, 22:734-739.

   Tice FD, Slivka AP, Walz ET, Orsinelli DA, Pearson AC: Mitral valve strands in patients with focal cerebral ischemia.

9. Stroke 1996, 27:1183-1186.

   Nighoghossian N, Derex L, Loire R, Perinetti M, Honnorat J, Riche G, Barthelet M, Ninet J, Chazot G, Chassignolle J, Trouillas P: Giant Lambl excrescences.

10. Arch Neurol 1997, 54:41-44.