Deformities of the hands and feet in Parkinsonism and their reversibility by operation

Abstract

Stereotactic lesions in the ventrolateral nucleus of the thalamus improved deformities of hands and feet in 150 cases of Parkinsonism. Early hand deformities include extension of fingers at the interphalangeal joints with flexion at the metacarpo-phalangeal joints, extension of thumb at both joints accompanied by adduction and opposition, and slight ulnar deviation. The next more advanced stage is characterized by hyperextension of the fingers at the interphalangeal joints. In the late stages of deformity, the hyperextension is so severe and chronic that subluxation occurs at the distal interphalangeal joints. Since both the joints and ligaments remain healthy, the deformities are caused by muscular rigidity. Foot deformities include flexion of the toes and a crowding together which produces a painful cramp. The foot is held in inversion, gait is impeded and many patients have difficulty in maintaining balance. Since surgical lesions in the ventrolateral nucleus of the thalamus can alleviate the tremor and rigidity of Parkinsonism, improvement of hand and feet deformities accompany improvement of rigidity.