Staged lesions through implanted deep brain stimulating electrodes: a new surgical procedure for treating tremor or dyskinesias.

Thalamotomy and pallidotomy have been shown to have some efficacy for treating some movement disorders such as disabling tremor or parkinsonian levodopa-induced dyskinesias (LID). Compared to continuous deep brain stimulation (DBS), this surgical procedure has the disadvantage of irreversibility and a lack of adaptability. Making a lesion involves a risk of inducing permanent side effects, especially if the lesion is large, or of observing a resurgence of the symptoms if the lesion is too small. We performed unilateral pallidotomy in one patient suffering from LID and unilateral thalamotomy in two patients suffering from tremor through the lead classically used for DBS. The technique of lead implantation was similar to that used for DBS treatment but, instead of connecting the lead to a pulse generator, it was left in place and used to make a radiofrequency lesion. This technique allowed the lesion to be kept as small as possible, thereby minimizing the risk of permanent side effects and made possible to extend the lesion if the symptoms reappeared. One lesioning session was enough to relieve tremor in the two patients treated by thalamotomy; three lesioning sessions over a 7-month period were required to relieve drug-induced dyskinesias in the patient treated by pallidotomy. In all 3 patients, disabling symptoms were still relieved without any permanent side effects 6 months after the last lesion was performed. Copyright 2003 Movement Disorder Society