Deep Brain Stimulation for Involuntary Movements

stimulation (DBS) has been developed during the last two decades by several investigators. In 1987, Benabid and his colleagues suggested the usefulness of high-frequency stimulation of the ventral intermediate nucleus of the thalamus for treating drug-resistant tremors and avoiding the adverse effects of thalamotomy. Since then, DBS has been used as an alternative to functional neurosurgery for movement disorders, and more recently, it has been applied to the treatment of epilepsy, obsessive-compulsive disorders and cluster headache, in addition to other applications in experimental models. In regard to the treatment of movement disorders, recent clinical studies have demonstrated that DBS affords great benefits in terms of improvement of the activities of daily living in patients with Parkinson’s disease (PD), essential tremor, dystonia and poststroke hyperkinetic movement disorders. We have treated patients with movement disorders by DBS of the thalamic nuclei ventralis oralis (Voa/Vop) et intermedius (Vim), globus pallidus internus (GPi), and subthalamic nucleus (STN). The site of permanent electrode placement was identified using magnetic resonance imaging and multiunit extracellular recording. The implantable pulse generator was internalized after postoperative test stimulation for one week. The stimulation parameters were modified by physicians at each followup visit on the basis of the findings on neurological examination, as well as the patient’s report concerning the activities of daily living. The advantages of DBS include reversibility and controllability of stimulation. In addition, DBS carries a smaller risk of side effects, particularly when employed bilaterally. Thalamic DBS is useful for controlling tremor that is unresponsive to medication. DBS of the STN and GPi improves the motor functions in PD patients, mainly during the offperiod. Moreover, STN-DBS attenuates levodopa-induced dyskinesia through reducing the requirement of DOPA, whereas GPi-DBS directly attenuates DOPA-induced dyskinesia. In addition, GPi-DBS is very useful for controlling the symptoms of idiopatic generalized dystonia. According to reports, DBS is associated with few serious adverse effects associated with DBS. In general, the operative mortality is less than 1%. The incidences of hemorrhage are in the range of about 1―6%, and the incidences of device-related complications, シンポジウム2「神経疾患の電磁気刺激による診断と治療」