Posteroventral medial pallidotomy in levodopa-unresponsive parkinsonism

Background: Parkinsonism in a 42-year-old patient, which was presumably related to peripheral trauma, did not respond to levodopa therapy. Observation: We treated the patient with microelectrode-guided unilateral posteroventral medial pallidotomy and followed up with magnetic resonance imaging and prospective clinical evaluation. Pallidotomy resulted in marked improvement of right-sided parkinsonian symptoms and functional disability at 4.5 months after surgery. Microelectrode recording during pallidotomy revealed discharge patterns that were similar to those seen in patients with Parkinson disease. Post-operative magnetic resonance imaging confirmed the location of the lesion in the posteroventral medial pallidum. Conclusions: Posteroventral pallidotomy usually has limited benefit in patients with degenerative atypical parkinsonism who do not respond to levodopa therapy. Nevertheless, pallidotomy can be an effective treatment for other levodopa- unresponsive parkinsonian disorders.