Deficits of grasping in cerebellar disorders

Given its stereotyped cytoarchitecture, the widespread connections with cortical and subcortical sensory-motor structures, and the neural activity of cerebellar Purkinje cells during sensory-motor tasks, the cerebellum is considered to play a major role in the control of grasping. The cerebellum is involved in the timing and coordination of hand transport, grasp formation, and isometric grip force when reaching for, grasping, and handling an object. In addition, there is evidence from human lesion and brain imaging studies that the cerebellum is essential for the establishment and maintenance of internal sensory-motor representations, so-called internal models, related to motor output and sensory input during grasping. These representations are necessary to predict the consequences of ones’ own movements. This chapter summarizes theoretical aspects, data from brain imaging, and behavioral data obtained from patients with cerebellar lesions characterizing the specific role of the cerebellum for grasping movements.