Isolated Monoparesis Is Usually Caused by Superficial Infarction

In a well-defined prospective series of 252 patients with a first-ever supratentorial brain infarct, 7 patients (3%; 95% confidence interval 1–5%) had acute isolated monoparesis. Prognosis was favourable with complete recovery within 2–4 weeks. In 6 patients, computed tomography (CT) showed a small infarct involving the cortex and adjacent subcortex in the territory of the middle cerebral artery. In 1 patient, no lesion was visualized. None of the patients had small, deep (lacunar) infarction compatible with occlusion of a single, deep perforating artery on CT. Our findings show that isolated monoparesis is usually caused by small infarcts involving the superficial middle cerebral artery territory.