Rehabilitation following brain damage: some neurophysiological mechanisms. The effects of repetitive stimulation in recovery from damage to the central nervous system.

There is a growing body of evidence that the central nervous system (CNS), even in the adult animal, is capable of adaptation and reorganization not only as a result of partial damage to the CNS but also in response to stimulation. Environmental stimulation produces changes including expansion of visual cortex, increases in dendritic branching, glia and cholinesterase. Environmental stimulation also produces behavioural changes. Experimental electrical stimulation produces changes in synapse size, synaptic vesicle change, dendritic branching and changes in synaptic transmission. In man, repetitive electrical stimulation via epidural electrodes increases plasma levels of norepinephrine, epinephrine, and dopamine, and CSF levels of norepinephrine. Repetitive electrical stimulation in man dates back to 1967 and has been used for the control of pain, to improve spasticity, bladder control, motor deficit and the autonomic hyperreflexia of spinal cord injury. In addition, improvement has been reported in epilepsy, cerebral palsy, torticollis and peripheral vascular diseases. The best controlled studies are in multiple sclerosis and peripheral vascular disease, and these results will be presented in more detail.