Essential tremor (ET) is the most common type of movement disorder, affecting approximately four out of 1000 people, and is significantly more common, though less recognized, than Parkinson’s disease. ET affects men and women equally and is inherited as an autosomal-dominant condition in about 60 percent of cases.
Although often referred to as benign essential tremor, it is hardly benign in patients who may not be able to write legibly, hold a glass of water or use a knife and fork. ET is primarily an action tremor of the upper extremities but may involve resting tremor of the head and neck and/or lower jaw, and also tremor of the voice. The latter may be so severe that speech becomes unintelligible.
Medication and surgical treatment options
Primidone and beta blockers are useful in reducing tremor in the early stages of ET, but as the tremor progresses, medical management often becomes less effective or side effects can prevent the use of adequate doses of medication. ET patients then are candidates for surgical or radiosurgical treatment.
The mainstay of the surgical treatment of ET is deep brain stimulation (DBS), in which an electrode is implanted in the ventral intermediate nucleus (VIM) of the thalamus. Neurosurgeons Peter Nora, M.D., and Ryder Gwinn, M.D., have been implanting DBS electrodes at Swedish Medical Center for several years. The treatment is effective, but it requires implantation of permanent hardware (wires and batteries) into the brain and chest wall. Patients who take anticoagulants or have severe cardiovascular disease are not suitable candidates for DBS. These patients, however, may be candidates for radiosurgical treatment.
A new option for difficult-to-treat patients