Abstract

For reasons that are still unknown a destructive lesion in one cerebral hemisphere, correctly placed and of appropriate size, can relieve the tremor and rigidity in the opposite limbs. The relief is known to last for at least five years in favourable cases. Symptoms in the arms are more successfully treated than in the legs and complete and permanent relief of rigidity is more easily achieved than of tremor. Rigidity of the face, tremor of the tongue, rigidity of the trunk, slowness and other disorders of gait, and weakness, slurring and monotony of speech are among the symptoms which respond least. Drug treatment is usually continued post-operatively but often in smaller doses, and post-operative physiotherapy may help considerably.