Surgery for other movement disorders: dystonia, tics

Abstract

Various movement disorders are now treated with stereotactic procedures, particularly deep brain stimulation. We review the neurosurgical treatment of dystonias and tics, focusing mainly on the surgical aspects and outcome of deep brain stimulation. Pallidal stimulation is nowadays the mainstay surgical treatment for patients with dystonia, particularly generalized dystonia. Various well designed recent clinical trials support the efficacy of the procedure. Improvements of 40-80% have been reported in primary generalized, segmental and cervical dystonia. For secondary dystonia, a similar outcome has been described in patients with tardive dystonia and pantothenate kinase-associated neurodegeneration. In patients with Tourette's syndrome, the results of the first trials with thalamic and pallidal deep brain stimulation have been very promising. Improvements of 70-90% in the frequency of tics have been reported with surgery in both targets. Deep brain stimulation has become an established therapy for dystonia and is currently being used to treat Tourette's syndrome. With accumulation of experience, clinical features that are more responsive to surgery and the best surgical candidates will be revealed. This will likely improve even further the outcome of surgery for the treatment of these disorders.