Unilateral radiofrequency lesion versus electrostimulation of posteroventral pallidum: A prospective randomized comparison

Microelectrode-guided posteroventral pallidotomy (PVP) has shown to be an e ffective method in the treatment of a group of patients with advanced Parki nson's disease. A non-lesioning approach by means of deep brain electrodes connected to a programmable neuropacemaker has also been used to inhibit th e internal segment of globus pallidus (posteroventral stimulation [PVS]) re porting comparable clinical efficacy to the one obtained with the ablative method. Nevertheless, no controlled studies have been performed to compare the efficacy of both procedures. A prospective series of 13 patients with a clinical indication for globus pallidus surgery was randomized either to a pallidotomy or stimulator implantation, and comparisons on motor and neuro psychologic measurements were made on a 3-month follow-up basis. Primary me asurements of efficacy showed a comparable effect on Unified Parkinson's Di sease Rating Scale and activities of daily living score after both procedur es. Secondary measurements of efficacy showed that although both techniques improve hand tapping score and dyskinesia score, the bilateral improvement in the former was greater after PVS whereas the latter improved more signi ficantly after PVP. No significant changes in neuropsychologic parameters w ere observed after either PVP or PVS. Side effects and surgery complication s occurred in six of 13 patients (three after PVP and three after PVS): the y were mild, transient, and unrelated to optic tract injury. In conclusion, the short-time effect and safety of both procedures is comparable.