Outcome of unilateral and bilateral pallidotomy for Parkinson's disease: Patient assessment

OBJECTIVE: Pallidotomy has recently regained acceptance as a safe and effec tive treatment for Parkinson's disease symptoms. The goal of this study was to obtain the patients' perspective on their results after undergoing this procedure. Special attention was focused on the potential complications an d the respective advantages and risks of unilateral versus bilateral pallid otomy. METHODS: Fifty-six patients were studied during a 2-year period; 44 complet ed the evaluation, with a median follow-up of 7 months. Of these patients, 22 underwent unilateral pallidotomy, and 17 had bilateral simultaneous pall idotomy. Five patients who underwent staged bilateral pallidotomy were excl uded from the statistical analysis, because the number of patients was cons idered too small for analysis. The procedures were performed with magnetic resonance imaging determination of the target, combined with physiological confirmation, including microelectrode recording. RESULTS: According to Visual Analog Scale scores, unilateral pallidotomy si gnificantly improved dyskinesias (P < 0.05) but no other symptoms. Simultan eous bilateral pallidotomy improved slowness, rigidity, tremor, and dyskine sias (P < 0.05) but worsened speech function (P < 0.05). According to the p atients' most frequently chosen answers to multiple-choice questions, unila teral pallidotomy improved night sleep, muscle pain, freezing, overall "on, " overall "off," and the duration of "off periods," but it worsened the vol ume of the voice and articulation, increased drooling, and reduced concentr ation. Bilateral pallidotomy improved night sleep, muscle pain, freezing, o verall "on," overall "off," duration of "off periods," and the amount of me dication taken, but it increased drooling and worsened the volume of the vo ice, articulation, and writing. Subjective visual disturbance was noted in 36 and 41% of patients who underwent unilateral and simultaneous bilateral pallidotomy, respectively. Globally, the result of the procedure was rated "good" or "excellent" by 64% of the patients who underwent unilateral palli dotomy and by 76% of the patients who underwent bilateral pallidotomy. An a ge less than 70 years was a positive prognostic factor for the global outco me (P < 0.05), as were severe preoperative dyskinesias (P < 0.05). CONCLUSION: This study confirms that, from a patient standpoint, unilateral and simultaneous bilateral pallidotomy can reduce all the key symptoms of Parkinson's disease (i.e., akinesia, tremor, and rigidity) and the side eff ects of L-dopa treatment (i.e., dyskinesias). Preoperative severe dyskinesi as and younger age are positive prognostic factors for a successful outcome . Simultaneous bilateral pallidotomy was more effective than unilateral pal lidotomy regarding tremor, rigidity, and dyskinesias, but it conferred a hi gher risk of postoperative speech deterioration.