Introduction

Clinical symptoms and signs as well as management of patients with ischemia in t¥he posterior circulation are far less well defined than of patients with ischemia in the anterior circulation. Several studies have addressed the issue of extended, space-occupying infarcts in the cerebellum and their management, but there exist only few data on extended or multiple infarcts in the brainstem and their prognosis. Only few attempts have been made to correlate extended infarcts in the brainstem and the cerebellum with the underlying causes and mechanisms. The following sections will review the clinically important factors on the frequency and causes of extended and multiple infarcts in the brainstem and cerebellum with special attention to particular topographic patterns and etiological mechanisms as well as existing data on management and prognosis of these types of infarcts.

Extended or multiple infarcts in the brainstem

Clinical features

Patients with extended brainstem ischemia of sudden onset have often very severe to life-threatening neurological symptoms and signs depending on the localization of the lesion. The neurological symptoms of isolated mesencephalic, pontine or medullary ischemia have been presented in the last chapters. Infarctions involving several brainstem levels are likely to be caused by either basilar artery thrombosis or occlusion of both intracranial vertebral arteries.

Basilar artery occlusion can give rise to a variety of clinical pictures. Many years ago it was thought that basilar artery thrombosis was a life-threatening disease in all patients but now it is known that, if it occurs slowly over time, basilar artery thrombosis can be survived without major disability in some patients (Caplan, 1979; Bogousslavsky et al., 1986; Berlit et al., 1994).