Long-term effects of deep brain stimulation in Parkinson's disease.

The history of stereotactic neurosurgery for treatment of Parkinson's disease has a remarkable track record. The traditional lesion method, employed and refined over half a century, seemed to have reached its end with the advent of l-dopa medication. But, paradoxically, levodopa-induced motor fluctuations and dyskinesias led to a renaissance of surgical therapy and the introduction of deep brain stimulation by Alim-Louis Benabid et al . (1987) opened a new therapeutic window for treatment of the late levodopa syndrome. From the beginning it appeared that the effects of stimulation mimic those of stereotactic lesions. Whereas the advantage of the fine tuning of treatment and its reversibility spoke for the new method, its long term efficacy still awaited the test of time. Recently, the Grenoble group reported the results of a 5 year follow-up showing that subthalamic nucleus deep brain stimulation had persistent beneficial effects in 42 patients (Krack et al ., 2003). In this issue of Brain , Rodriguez-Oroz et al . (2005) report results of the first worldwide multicentre study on long term effects of deep brain stimulation. Eight groups enrolled 69 bilaterally implanted patients who were assessed preoperatively and 3–4 years postoperatively. What is particularly valuable is the comparative evaluation of the effects of stimulating …