Pallidotomy versus pallidal stimulation.

Both posteroventral pallidotomy and pallidal deep brain stimulation (DBS) have a documented effect on Parkinsonian symptoms. DBS is more costly and more laborious than pallidotomy. The aim of this study was to analyse the respective long-term effect of each surgical procedure on contralateral symptoms in the same patients. Five consecutive patients, two women and three men, who at first surgery had a mean age of 64 years and a mean duration of disease of 18 years, received a pallidotomy contralateral to the more symptomatic side of the body. At a mean of 14 months later, the same patients received a pallidal DBS on the side contralateral to the pallidotomy. All patients had on-off phenomena and dyskinesias. There were three left-sided and two right-sided pallidotomies, and, subsequently, two left-sided and three right-sided pallidal DBS. The latest evaluation was performed 37 months (range 22-60) after the pallidotomy and 22 months (range 12-33) after the pallidal DBS. Mean UPDRS motor score pre-operatively was 49 and at last follow-up 33 (32.7% improvement, p<0.05). Appendicular items 20-26 contralateral to pallidotomy remained improved more significantly than contralateral to DBS. Dyskinesia scores were also improved more markedly contralateral to the pallidotomy. Two patients exhibited moderate dysarthria and one patient severe dysphonia following DBS. Symptoms contralateral to the chronologically older pallidotomy, especially dyskinesias, rigidity and tremor, were still more improved than symptoms contralateral to the more recent pallidal DBS, despite numerous post-operative patient visits to optimise stimulation parameters.