Motor strokes sparing the leg - Different lesions and causes

Background: A considerable number of patients develop stroke without involv ement of the lower limb. However, there are few reports about the motor syn drome when the leg is spared. Objective: To study clinical findings, causative factors, and lesion topogr aphy in stroke patients with a motor deficit sparing the leg. Patients and Methods: We studied 895 patients with paresis sparing the leg from the 3901 patients enrolled in the Lausanne Stroke Registry. They were compared with 1644 stroke patients with paresis involving the leg, by means of univariate and multivariate analysis. Results: Eight hundred forty-four infarcts (94.3%) and 51 hemorrhages (5.7% ) led to weakness sparing the leg. Different sites of lesion were found, bu t the majority were caused by superficial infarcts. Almost half of the lesi ons were confined to superficial branches of the middle cerebral artery ter ritory, with 276 (30.8%) in the anterior (superior) and 138 (15.4%) in the posterior (inferior) middle cerebral artery. More than half of the infarcts had a presumed embolic source from large-artery disease or from the heart. In comparison with patients with paresis involving the leg, patients witho ut leg involvement had a lower prevalence of small-artery disease (P<.001), but a higher prevalence of migraine (P<.001), transient ischemic attack (P = .001), atherosclerosis without stenosis (P = .005), large-artery disease (P<.001), and left hemispheric strokes (P<.001). They also had a lower fre quency of hemorrhagic stroke. Conclusions: Patients without leg involvement had different stroke lesions and causes and were characterized by more superficial infarcts mainly cause d by emboli from large-artery disease and atherosclerosis without stenosis.