Parkinson's disease and multiple sclerosis (hereafter referred to as P.D. and M.S. respectively) represent progressive chronic diseases of the central nervous system. A large proportion of the afflicted persons fall within the geriatric population. In each instance, the disease may result in alterations of the motor and sensory systems of the brain and spinal cord, and thus produce various abnormalities of movement and sensation. The specific et,iology in both diseases is largely unknown (although continuing investigations reveal much new information concerning the pathology) and this lack of knowledge has thus far prevented the development of any specific therapy. Recently chemosurgery has been found useful in the symptomatic relief of both P.D. and M.S., specifically in alleviating certain of the associated abnormal movements (1-3). Because of the manifold neurologic symptoms, the relative obscurity of the etiologic factors, the lack of specific treatment, and the many and diverse behavioral effects of these diseases, recent years have witnessed an increase of investigations concerning their psychologic and psychiatric aspects. It is the purpose of the present review to summarize a portion of these investigations, most specifically those which may provide information concerning the relationship between psychologic factors, neurophysiologic substrata, and the resulting disease processes and symptoms. Thus, this review is not intended to be all-inclusive, but limited rather to those studies concerned directly or indirectly with psychosomatic and somatopsychologic relationships.
THE PROBLEM O F "OEGANICITY"In psychologic studies of diseases of the cent>ral nervous system, the question frequently arises as to whether the pathologic process which culminates in the neurologic symptoms may also affect certain aspects of higher integrative functioning. Thus, several investigators have addressed themselves to the problem of "organic" mental factors in neurologic diseases. Several such studies in P.D. have revealed both intellectual and cognitive impairments in at, least a portion of the patients so evaluated (4-6). In each instance, the changes were attributed