Basilar artery embolism. Clinical syndrome and neuroradiologic patterns in patients without permanent occlusion of the basilar artery.

Abstract

The objective of this study was to clarify the clinical and radiologic features, risk factors, and prognosis of basilar embolism without permanent basilar artery occlusion. Forty-five patients (mean age, 59 years) with basilar artery embolism participated in the study. Patients with basilar artery occlusion were excluded. The Glasgow Coma Scale (GCS) score on admission was < 7 in five patients, 7 to 12 in 11 patients, and > 12 in 29 patients. Etiologic factors were cardiac arrhythmia (17 patients), vertebral artery occlusion (12 patients), cervical spine trauma (4 patients), embolism following angiography (2 patients), and surgery (1 patient). MRI was performed in 17 patients and CT in 39 patients. Radiologic examinations were initially normal in 14 patients and remained normal in three patients. Final infarct localization was the thalamus (36 patients), cerebellum (20 patients), posterior cerebral artery territory (21 patients), midbrain (12 patients), and pons (8 patients). Eight to 12 weeks after stroke 12 patients were without clinical signs (Glasgow Outcome Scale [GOS] 1), 15 patients had minor neurologic deficits (GOS 2), 10 were severely disabled (GOS 3), and eight patients had died (GOS 5). Outcome correlated with GCS on admission (p < 0.0001) and with the number of ischemic lesions (p = 0.0001). The typical syndrome is an acute loss of consciousness followed by multiple brainstem symptoms. Usually, clinical symptoms improve rapidly and, in some patients, completely. Compared with basilar occlusion, basilar embolism has a relatively low mortality and outcome is frequently excellent.