1 and 2 Sep - Stroke potpourri

Two cases this week have been of unusual nerologic deficits in young patients.  One patient presented with an episode of syncope and awakened with a headache and residual hemipareisis.  There was significant sinus bradycardia present and CNS imaging with MRI revealed multifocal lesions consistent with "emboli or vasculitis or small vessell ischemic disease."  The second case was a 27 year old male with R sided weakness and expressive aphasia who was found to have a L MCA distribution stroke.  TTE suggested PFO with shunt, TEE did not reveal any PFO, shunt, or thrombi.  In both patients classic stroke risk factors were not present.

The impact of an atrial septal defect on the risk of recurrent stroke is debated, but the current practice guidelines review from the Neurology journal suggest that an isolated ASD has no impact on recurrent stroke risk.  An ASD associated with an atrial septal aneurysm does appear to increase recurrent stroke risk.  The choice between antiplatelet and anticoagulant therapy is currently weighted towards antiplatelet therapy.  Anticoagulation with warfarin does not clearly improve outcomes and does increase the incidence of minor bleeding.

The evaluation of stroke in young patients (15 - 45 years) encompasses a search for risk factors that are not typical of stroke in older adults.  In a recent review of the topic, atherosclerosis accounted for 21%, cardioembolism in 17%, non-atherosclerotic vascular (migraine, dissection, etc) in 17%, but 36% had undetermined cause. 

Some zebras to consider:

Sneddon syndrome - livedo reticularis associated with ischemic cerebrovascular disease and hypertension.  Antiphospholipid and anticardiolipin antibodies are commonly found.  Usually seen in adult women and the rash follows the stroke.

Moyamoya syndrome (reviewed in May 2009 NEJM) - progressive stenosis of internal carotids in young patients.  Leads to development of distal small vessell collateral ciculation that gives a "puff of smoke" (moyamoya in Japanese) appearance on angiography.  Can lead to ischemic or hemorrhagic stroke.  Cranial XRT, down syndrome, and NF1 predispose to this condition.  Rule of thumb - if a disease is reviewed in NEJM it is fair game for an ABIM examniation question.