Disorders of the Neurological System Practice Test

Cerebellar stroke arises from disruption in the posterior circulation that supplies the cerebellum. The cerebellum gets its blood from arteries that branch off the vertebral and basilar arteries—the vertebral arteries form the basilar artery and give rise to the posterior inferior cerebellar artery, as well as branches like the anterior inferior cerebellar artery and the superior cerebellar artery. When this vertebral-basilar system is occluded, the cerebellum loses blood flow, leading to ataxia, dysmetria, dysdiadochokinesia, vertigo, nystagmus, and gait instability. In contrast, the posterior cerebral, middle cerebral, and anterior cerebral arteries come from the carotid system and primarily feed the cerebral cortex; occlusions there produce cortical deficits such as visual field losses, aphasia, neglect, or contralateral motor/sensory abnormalities rather than the characteristic cerebellar signs. Thus, cerebellar strokes are most closely associated with occlusion of the vertebral-basilar system.