RESUMEN
Twenty-three patients with Parkinson's disease underwent stereotactic surgery. To study the long-term motor performance, the patients were evaluated at the pre-operative period and at the 1st, 3rd, 6th, and 12th post-operative months, with the following scales: Unified Parkinson's Disease Rating Scale (UPDRS) motor score and Larsen's Scale for Dyskinesias. The patients under levodopa therapy were assessed both in "on" and "off" periods. Fourteen unilateral ventrolateral thalamotomies (VLT), 4 unilateral posteroventral pallidotomies (PVP), 2 bilateral PVP, and 3 VLT with contralateral PVP were performed. The motor improvement was significant and long-lasting in the "off" period, except for 2 patients. The "on" period quality improved, mainly due to the control of dyskinesias. The improvement of dyskinesias was long-lasting for the majority of the patients. There was no significant decrease in the levodopa dose. Three patients showed permanent complications, but none was severe