It is the first new treatment approach in 30 years for disabling tremor. The device, called Activa Tremor Control Therapy, includes an insulated wire lead that is surgically implanted in the thalamus. The lead is connected by an extension wire passed under the skin to an implanted pulse generator, similar to an advanced cardiac pacemaker, which is implanted near the clavicle. It delivers mild electrical stimulation to block or override the brain signals that cause tremor. The device can be turned on or off by the patient by passing a hand-held magnet over the implanted pulse generator.
Physicians program the generator to deliver the precise stimulation needed for each patient.
In multicenter clinical trials, the brain stimulator was implanted in 113 persons with Parkinson's disease and 83 persons with essential tremor. More than 80 percent of the subjects in the trials experienced a reduction in tremors. According to the manufacturer of the device, the most common potential side effects include temporary paresthesia, slight paresis, dysarthria and disequilibrium. These side effects can be reduced or disappear when stimulation is decreased or stopped. Risk typically associated with the surgery includes loss of effect and intracranial hemorrhage.