Cognitive dysfunction caused by infratentorial lesion

Abstract

The cerebellum has traditionally been viewed as a structure that contributes primarily to motor coordination and control. The brainstem plays an important role in balance, coordinated movement, hearing, speech, ocular movement and swallowing. However, beginning in the mid ─ 1980s, anatomical, behavioral, and neuropsychological evidence began to suggest that the role of the infratentorial region extends beyond a purely motor domain. Especially, electrophysiological and neuroimaging studies indicate that the cerebellum and brainstem contributes to cognitive functions such as attention, memory, visuospatial cognition, planning and language. Clinically, several cognitive or psychiatric disorders, for example autism and attention─ deficit hyperactivity disorder, have been reported to show neuropathological changes in the cerebellum or brainstem, mainly volume reduction. In addition, there have been some reports about cognitive dysfunction caused by infratentorial lesions after stroke. The converging evidence has prompted generation of new theories to explain the contributions of the infratentorial region to such functions. The emerging hypotheses include monitoring and feedback on inner thought, coordination and control of information processing, and internal control of timing. However, the results of studies and hypotheses about relationship between infratentorial region and cognitive function remain controversial, because, in previous studies, there ware some problems to establish the critical evidence. Further productive approach to understanding the contribution of infratentorial region to cognitive functions will be to work toward the accumulation of well ─ specified studies that address the problem from diverse points of view.