In Parkinson's, a brain structure that acts as a brake on movement is overactive, producing stiffness and immobility. Dr. Fred Lenz says pallidotomy often returns a measure of muscle control. When they take their medication they have pretty good motor function, but after the medication wears off they become very Parkinsonian and unable to move. These are jerky or twisting movements and these can be fairly mild and just a source of embarrassment of they can be very severe to the point that the patient is even unable to sit in a chair.
Studies show pallidotomy is safe and effective.