Bilateral pallidotomy in Parkinson's disease: a retrospective study

We evaluated the effects of bilateral pallidotomy in patients with advanced Parkinson's disease. Thirteen patients with Parkinson's disease had a staged bilateral pallidotomy if they had severe response fluctuations, dyskinesias, painful dystonia, or bradykinesia despite optimum pharmacological treatment. Assessment scales were the Unified Parkinson's Disease Rating scale (UPDRS), the Schwab and England scale, and a questionnaire on the effects of disability in activities of daily living and adverse effects. Postoperative magnetic resonance imaging was evaluated for lesion location and extension. The median off-phase UPDRS motor score was reduced from 43.5 to 29 after the first pallidotomy, and it was further reduced to 23.5 after the second pallidotomy (n = 8). The UPDRS activities of daily living off-phase score improved from 28.5 to 20.5 after the first pallidotomy and to 19 after the second pallidotomy (n = 6). The Schwab and England scale off-phase score showed an improvement after both procedures, first from 40 to 60, and thereafter to 90 (n = 8). On-phase dyskinesias were reduced substantially. Eight patients had adverse effects, of whom five had problems with speech. One patient became hemiplegic due to a delayed infarction. Ten patients experienced further benefit from the second procedure. Bilateral pallidotomy reduces dyskinesias. A second contralateral pallidotomy may reduce parkinsonism, although to a lesser degree compared with the first pallidotomy and with an increased risk for adverse effects.