High-frequency deep brain stimulation for the treatment of movement disorders

Stereotactic surgery for movement disorders has regained importance in recent years. Reasons for this development are a better understanding of the pathophysiology of movement disorders, safer surgical procedures and a clear definition of indications for surgery. Thalamotomy for the treatment of all types of drug resistant tremors and pallidotomy for treating akinesia, rigidity and L-Dopa induced dyskinesias in Parkinson's disease are established therapies. During these routine procedures a stereotactic lesion is placed in the target area. Deep brain stimulation via chronically implanted electrodes is a new interesting therapeutical alternative to the established destructive procedures. The high-frequency stimulation with low currents leads to a functional blockade of stimulated areas. For this purpose a commercially available stimulating electrode is stereotactically implanted into the target area and connected to a current generator placed into an infraclavicular skin pocket. The indication for deep brain stimulation of the thalamus corresponds to the indication for thalamotomy. The advantages of deep brain stimulation lie in the possibility of performing safe bilateral procedures, the lower risk of permanent neurological deficits, the individual adaptability of stimulation parameters throughout the course of the disease and the principal reversability. Chronic bilateral high frequency stimulation of the pallidum and subthalamic nucleus are promising therapies for the symptomatic relieve of all cardinal symptoms in advanced Parkinson's disease. The long-term results are being investigated currently.