Objective: To determine the efficacy of continuous electrical thalamic stimulation in the treatment of pharmacotherapy-resistant tremor in patients with Parkinson's disease and essential tremor.
Design: Descriptive study.
Setting: Academic Medical Centre, Academic Hospital of the University of Amsterdam.
Method: Five patients with Parkinson's disease and one with familial essential tremor suffering from pharmacotherapy-resistant tremor were treated by implantation of a four-polar stimulation electrode in the contralateral ventrolateral thalamic nucleus connected subcutaneously to a stimulator. Continuous electrical stimulation was applied in the daytime and switched off during the night. Three of the Parkinson patients were subjected to contralateral thalamotomy as well.
Results: Three patients (including the one with essential tremor) had complete tremor suppression during stimulation, and the other three had intermittent minimal tremor. There were no early complications (follow-up: 1 month-1 year). One patient had mild hemi-inattention and pyramidal signs due to the thalamotomy.
Conclusion: Continuous thalamic stimulation appears to be a good alternative to thalamotomy. It renders possible bilateral surgical treatment for severe bilateral tremor.