Males and females, ages 18 and over.

Diverse racial groups.

Amputees and others with whom we will have no patient-care relationship may also be considered to be volunteers.

Patients will be recruited from those referred to the Human Motor Control Section, NINDS who have neurological syndromes that are of interest.

On rare occasions we may attempt to study children as young as 10 years with TES.

Individuals without indwelling cardiac lines and pacemakers.

Patients recruited for study would come from those referred to the EMG laboratory and to the Human Motor Control Clinic who would have distinct neurologic syndromes from well defined peripheral and central nervous system lesions including hemiplegia from stroke, trauma, tumor or focal demyelination (most commonly patients would have hemiplegia from stroke), peripheral nerve lesions, amputations, spinal cord injury.

Normal volunteers, including NIH employees, would be healthy adults without history of physical examination evidence of neurologic disease and individuals with different types of amputations involving upper and lower extremities.

Volunteers may also be participants in the electrophysiological protocol (84-N-0196).

No history of epilepsy.