Abstract

Proprioceptive afferent signals provide the central nervous system with information about the biomechanical state of the body. These signals are vitally important for the reflexive control of muscle tone. They also form the basis for our sense of body awareness and are vital for volitional motor control. Altered or impoverished proprioception after brain injury is known to severely impair motor control. Other sensory modalities can only incompletely compensate such proprioceptive loss. In this talk I will present a series of studies that investigated proprioceptive function in patients with dysfunction of the cerebellum and the basal ganglia, which are both known to be important substructures for motor control and learning. I will highlight that basal ganglia related diseases like Parkinson's disease and dystonia show tactile, proprioceptive and haptic deficits, while kinaesthesia remains unimpaired in cerebellar patients. I will argue that many of the observable motor deficits have in fact a somatosensory origin.