Quantitative Criteria for the Neurosurgical Treatment of Parkinsonism

THOUGH the syndrome of parkinsonism first was described ahnost a hundred and forty years ago, it has been only within the last decade or so that neurosurgical approaches to the t reatment of this disease have been feasible. In the past several years, we have been interested in the development of measures of the disabilities that this disease produces, both in regard to the fundamental problems of neurophysiology and particularly with reference to the development of objective criteria by which the natural course of the disease and the effects of drugs, surgery, and physiotherapy may be studied. The present report is a preliminary study of some of the methods that have been developed for the preand postoperative study of parkinsonian patients who have undergone thalamotomy for their symptoms and describes a technique whereby the surgical procedure itself can be monitored. Neurosurgical approaches to the t reatment of parkinsonism in the past have included lesions placed in all levels of the central and peripheral nervous systems. 1-a,9,1~ In the last few years, most attention has been placed on the development of methods of producing lesions either in the globus pallidus or ventrolateral nucleus of the thalamus, with acceptable rates of mortal i ty and morbidity. 1~ If properly selected, good results have been reported in 80 per cent of subjects under 40 years of age with early symptoms, involvement restricted primarily to one side, and with rigidity and tremor (as opposed to bradykinesia) as main symptoms. 1~ As the symptoms become bilateral and the patient