Pontine infarction extending to the basal surface.

Abstract

Etiology and symptomatology in pontine infarction extending to the basal surface are supposed to be different from those in deep pontine infarction of the lacunar type. The aim of this study was to compare the infarct size and location, vascular lesions, risk factors, and neurological deficits in three different types of acute pontine infarction. We studied isolated pontine infarction extending to the basal surface on brain imaging (group 1, n = 30), deep pontine infarction without extension to the basal surface (group 2, n = 23), and pontine infarction with simultaneous extrapontine infarct in the posterior circulatory system (group 3, n = 20). Clinical features, angiographic findings, and risk factors such as emboligenic heart disease, hypertension, and hypercholesterolemia were compared among the groups. The infarct area was 2.5 times greater in group 1 than in group 2. On angiogram, atherosclerotic stenosis of the basilar trunk was observed in 50% of the patients studied in group 1, in 0% in group 2, and in 78% in group 3. Emboligenic heart diseases were observed in 23%, 0%, and 30% in groups 1, 2, and 3, respectively. However, hypertension (60% to 65%), diabetes mellitus (35% to 45%), and hypercholesterolemia (13% to 17%) were equally distributed among the three groups. Classic lacunar syndromes were seen in 14 patients (47%) in group 1, in 20 patients (87%) in group 2, but in none of the patients in group 3. Patients belonging to group 1 showed a higher incidence of hemiparesis involving the face (37%), sensorimotor stroke (20%), and hemiparesis with confusion (17%) than those in group 2 (22%, 0%, and 4%, respectively) or in group 3 (0%, 5%, and 0%, respectively). Pontine infarction in group 1 may have several different causes, such as cardioembolism, artery-to-artery embolism, or atherosclerosis of the basilar artery affecting pontine branches. Severe neurological symptoms often result that differ from those seen in the deep pontine lacunar infarction in group 2.