Ischemic stroke of unusual cause: clinical features, etiology and outcome

The clinical features, etiology and neurological outcome of ischemic stroke of unusual cause (ISUC) have rarely been reported. We retrospective review ed all patients with this stroke subtype entered in the Sagrat Cor Hospital of Barcelona Stroke Registry, which includes data from 2000 consecutive fi rst-ever stroke patients admitted to the hospital between 1986 and 1995. Pa tients with previous ischemia and/or hemorrhagic stroke were excluded. Topo graphic, anamnestic, clinical and neuroimaging characteristics of ISUC were assessed. Predictors of this stroke subtype were determined by logistic re gression analysis. Ischemic stroke of unusual etiology was diagnosed in 70 patients (32 men and 38 women), with a mean +/- SD age of 52 +/- 22.4 years . This stroke subtype accounted for 4.3% of all first-ever strokes and 6% o f all first-ever brain infarcts. Etiologies included hematological disorder s in 17 cases, infection in 11, migraine stroke in 10, cerebral infarction secondary to venous thrombosis in nine, primary inflammatory vascular condi tions in six and miscellaneous causes in 17. In the multivariate analysis a fter excluding cerebral venous thrombosis (n = 9) and arterial dissection ( n = 4), because of typical clinical and radiological features, independent predictors of ISUC included 45 years of age or less (odds ratio [OR] 14.8), seizures (OR 6.8), headache (OR 5.2), hemianopia (OR 2.6) and occipital lo be involvement (OR 3.0). Patients with ISUC presented a lower in-hospital m ortality rate (7.1% vs. 14.4%; P < 0.05), were more frequently symptom free at discharge (35.7% vs. 25.8%; P < 0.05) and experienced a longer mean len gth of hospital stay (23.7 days vs. 18.2 days; P = 0.06) than non-ISUC pati ents. We conclude that ISUC is infrequent, etiologies are numerous and hema tologic disorders are the most frequent cause. We emphasize the better prog nosis and the need to distinguish it from other ischemic stroke subtypes wh ich have a different treatment approach and outcome.