Intellectual Changes Associated With Levodopa Therapy

Abstract

To the Editor:— In addition to changes in motor behavior associated with levodopa (L-Dopa) therapy in Parkinson's disease, 1 we have been monitoring the intellectual functioning of these patients by means of the Wechsler adult intelligence scale (WAIS) 2 and the Porteus maze test. 3 Although previous preliminary investigations 4 did not reveal measurable changes in intellectual functioning after L-Dopa therapy (Boshes B., et al: Trans Amer Neurol Assoc 94 :229, 1969), it seemed appropriate to examine possible intellectual effects of the drug in a larger series of patients. The WAIS and Porteus procedures were administered while the patient was being treated with conventional medication and again after six weeks of L-Dopa therapy. The extension series of the Porteus was utilized in the second testing to reduce practice effects. The WAIS subtest scores were subdivided into factor scores or deviation quotients which were derived from earlier factor analyses of this