PONTINE INFARCTION EXTENDING TO THE BASAL SURFACE

Background and Purpose Etiology and symptomatology in pontine infarcti on extending to the basal surface are supposed to be different from th ose in deep pontine infarction of the lacunar type. The aim of this st udy was to compare the infarct size and location, vascular lesions, ri sk factors, and neurological deficits in three different types of acut e pontine infarction. Methods We studied isolated pontine infarction e xtending to the basal surface on brain imaging (group 1, n=30), deep p ontine infarction without extension to the basal surface (group 2, n=2 3), and pontine infarction with simultaneous extrapontine infarct in t he posterior circulatory system (group 3, n=20). Clinical features, an giographic findings, and risk factors such as embolgenic heart disease , hypertension, and hypercholesterolemia were compared among the group s. Results The infarct area was 2.5 times greater in group 1 than in g roup 2. On angiogram, atherosclerotic stenosis of the basilar trunk wa s observed in 50% of the patients studied in group 1, in O% in group 2 , and in 78% in group 3. Emboligenic heart diseases were observed in 2 3%, 0%, and 30% in groups 1, 2, and 3, respectively. However, hyperten sion (60% to 65%), diabetes mellitus (35% to 45%), and hypercholestero lemia (13% to 17%) were equally distributed among the three groups. Cl assic 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%, respectiv ely) or in group 3 (0%, 5%, and 0%, respectively). Conclusions Pontine infarction in group 1 may have several different causes, such as card ioembolism, artery-to-artery embolism, or atherosclerosis of the basil ar artery affecting pontine branches. Severe neurological symptoms oft en result that differ from those seen in the deep pontine lacunar infa rction in group 2.