WHITE-MATTER MEDULLARY INFARCTS - ACUTE SUBCORTICAL INFARCTION IN THECENTRUM OVALE

Acute infarction confined to the territory of the white matter medulla ry arteries is a poorly characterised acute stroke subtype. 22 patient s with infarction confined to this vascular territory on CT and/or MRI were identified from a series of 1,800 consecutive admissions to our stroke unit (1.2%) between August 1993 and March 1997. 19 patients had small infarcts (<1.5 cm maximum diameter) and 3 large infarcts (> 1.5 cm). Small infarcts were associated with a history of smoking (69%), hypertension (58%), and hyperlipidaemia (37%), and less frequently wit h atrial fibrillation (21%). Significant (>50%) ipsilateral carotid st enosis (16%) was a less frequent finding in this group. Patients most commonly presented with weakness and/or sensory disturbance affecting mainly the upper limbs, but dysarthria, dysphasia, and ataxia were als o seen. Large infarcts were infrequent in our series, but did not diff er significantly from small infarcts with respect to clinical presenta tion or risk factor profiles (p > 0.05 for all comparisons). The major ity of symptomatic patients with white matter medullary infarcts are a ssociated with small (<1.5 cm diameter) lesions and a risk factor prof ile consistent with small vessel disease. More data are required to el ucidate the mechanism of larger (>1.5 cm) infarcts. Because of the pot ential overlap between white matter medullary infarcts and internal wa tershed infarcts, suggested criteria for each are presented.