Four year follow-up study after unilateral pallidotomy in advanced Parkinson's disease

Background: Pallidotomy is widely accepted as a treatment for patients with Parkinson's disease (PD) who have disabling symptoms that are inadequately controlled with pharmacotherapy. There are, however, only a few studies, with a small number of patients, showing evidence after prolonged periods of time about the clinical outcome after pallidotomy. Methods: We have conducted a four-year follow-up study of 23 patients with PD who had undergone unilateral pallidotomy. Six patients were lost to follow-up. The remaining 17 were evaluated before surgery and at three months, one year, and four years after surgery, following standard protocols. Results: At four years, patients still showed significant amelioration in contralateral and axial dyskinesias and off-period contralateral parkinsonian signs. Total motor UPDRS and Activities of Daily Living scores also remained improved four years after surgery. Ipsilateral and axial parkinsonian symptoms and Hoehn & Yahr and Schwab & England scales were not significantly changed from baseline values. The initial beneficial effects on motor fluctuations were not maintained at last visit. All patients considered themselves to be improved with respect to their clinical condition before surgery in a clinical global impression estimation done at the four-year follow-up. Conclusion: Unilateral pallidotomy can provide sustained improvement of contralateral parkinsonism and dyskinesias during at least four years. Early benefits observed in axial symptoms and motor fluctuations wane with time. On period akinesia worsened significantly in the limbs contralateral to pallidotomy after four years.