COGNITIVE IMPAIRMENT IN YOUNG-ADULTS WITH INFRATENTORIAL INFARCTS

Objective: To describe cognitive functions and functional outcome in y oung patients with isolated infratentorial infarcts. Background: Conte mporary knowledge implies a cerebellar contribution to cognitive behav ior. Neuropsychological examination of patients with selective cerebel lar lesions provides an opportunity to document the existence and natu re of clinically relevant cognitive manifestations from lesions of the cerebellum. Methods: Prospective case series. The patients were asses sed acutely and at 4 and 12 months after onset. Twenty-four patients f rom a consecutive series of 105 patients aged 18 to 44 years with cere bral infarction had a brain stem or cerebellar infarction. Fourteen ag e-matched controls were used for neuropsychological comparisons. Evalu ation included MRI, angiography, and transesophageal echocardiography. Disability and neurologic dysfunction were assessed by the modified R ankin scale, NIH stroke scale, and maximal working capacity. A compreh ensive neuropsychological battery was performed at baseline in 20 of t he 24 patients. Results: Eighteen patients had a cerebellar infarct. T wo patients had lateral medullary infarcts, and two isolated pontine i nfarcts. Twenty-two patients had a favorable outcome according to the modified Rankin scale (grade 0-2) and the NIH scale. In contrast, 12 p atients were granted full or partial sick leave at the 4 months follow -up, and 10 patients at 12 months. Patients generally performed worse than controls in various aspects of cognitive function, especially in tasks concerning working memory, the temporary storage of complex info rmation, and cognitive flexibility. Measures of verbal IQ (r = -0.74) and performance IQ (r = -0.78) were related to the size of the infarct . The block design task performance in the early poststroke period pre dicted maximal working capacity at 12 months. Conclusions: Cerebellar damage impairs central aspects of attention and visuospatial skills. I n contrast, intelligence and episodic memory remain unchanged. When th e lesion involves large portions of the cerebellar hemispheres, change s concerning broad areas of intelligence may occur. The prognosis is f avorable for neurologic dysfunction, but cognitive deficits may preven t return to work.