Introduction

Before the advent of computed tomography (CT) and magnetic resonance imaging (MRI), descriptions of cerebellar infarctions were mainly based upon necropsy findings and neurosurgical reports (Amarenco, 1995). CT and MRI techniques have led to a comprehensive description of the clinical features and distribution of cerebellar strokes, allowing clinicians to make precise clinico-anatomic correlations before the death of the patient.

The cerebellum is supplied by three main arteries arising from the vertebrobasilar system: the two vertebral arteries and the basilar artery. The complex formed by the cerebellum, brainstem, and brain occipital areas receives about one-third of the cardiac output (Mettler, 1948). Because the cerebellum and brainstem are supplied by the same arteries, they are frequently damaged together when artery occlusion occurs. Stroke in the territory of cerebellar arteries may be life threatening. However, edematous stroke in the cerebellum may have a relatively good functional outcome if emergency surgery is performed. Therefore, early recognition of the clinical pictures of cerebellar stroke is of the utmost importance.

Vascularization of cerebellum

Vertebrobasilar system

The vertebral artery is divided into four segments. The first segment (V1) courses directly from its origin (the subclavian artery) to the transverse foramen of C6. The second segment (V2) is within the transverse foramen from C6 to C2–C1. Usually, the third segment (V3) begins at the transverse foramen of C2 and emerges on the surface of the costo-transverse foramen of the atlas. It passes behind the posterior arch of C1 and is then located between the atlas and the occiput.