Pure motor stroke: a reappraisal.

ABSTRACT

We studied the correlations between the pattern of weakness, stroke type, topography, and etiology in 255 patients whose first stroke was manifested by isolated hemiparesis. They represented 14% of consecutively admitted stroke patients. The weakness distributions were as follows face, upper limb, and lower limb (FUL) (50%); face and upper limb (FU) (29%); upper limb (U) (10%); and upper and lower limb (UL) (9%). Twenty-nine percent of the patients had dysarthria, which was of no localizing value. Less than one half of the patients had a deep infarct, and one third had a potential embolic source from the heart or large arteries. Logistic regression analysis showed that history of hypertension and type of weakness distribution were the main factors accounting for lesion localization patients with FUL distribution and hypertension had a 90% probability of deep infarct; patients either with FUL distribution but no hypertension or with UL distribution and hypertension each had 70% probability of deep infarct. Pure motor monoparesis was almost never caused by a deep infarct. We suggest that the assumption of a lacunar etiology to a pure motor stroke should be applied only to patients with FUL involvement.