Dr. Leslie D. Cahan MD is a top Neurosurgeon in Los Angeles. With a passion for the field and an unwavering commitment to their specialty, Dr. Leslie D. Cahan MD is an expert in changing the lives of their patients for the better. Through their designated cause and expertise in the field, Dr. Leslie D. Cahan MD is a prime... more
Essential tremor (also called familial tremor or benign essential tremor) is a common movement disorder. In fact, it is six times more common than Parkinson’s disease. It is frequently confused with Parkinson’s disease; while it is true that some patients have both, it is important to distinguish the two conditions. Essential tremor is an action tremor—this means the shaking increases when one tries to use the muscles; in Parkinson’s disease, the tremor is usually a resting tremor and the patient may also have rigidity and stiffness.
Essential tremor usually involves the hands. Typically it has a rhythm of 4-12 Hz. Using a ruler or a scissors can become difficult. As the tremor worsens, driving, feeding, dressing (buttoning clothes) can become nearly impossible. Stress may worsen the tremor. Tremor may also involve the voice; in early stages singing (vibrato only) may be a symptom, but as the condition worsens, it may also make speech (especially on the telephone) difficult to understand.
In some people, the tremor may also involve the head or jaw. These patients may also have a tremulous voice that makes talking on the telephone particularly difficult. For unknown reasons, women seem more at risk to develop head tremor than men. Some patients may also have trouble with walking and balance.
While the cause of essential tremor is unknown, half the patients have a family history implying a genetic mutation that is inherited in an autosomal dominant pattern.
Treatment of essential tremor begins with medications—beta blockers and the anti-seizure medicine primidone are effective. Other anti-epileptics may be tried but are often less successful.
When activities of daily living are significantly impaired, surgical treatments may be offered. Deep brain stimulation involves placement of electrodes in the brain—the electrodes are attached to generators that block the tremor center in the thalamus. Deep brain stimulation has the advantage of being a reversible operation (that is the generator can be turned off). However, many patients have other medical problems (anti-coagulation, diabetes, heart disease) that increase the risk of the procedure. In addition, patients with deep brain stimulators may require additional surgery to replace batteries, repair broken electrode wires or deal with infections.
Gamma knife radiosurgery (thalomotomy) is equally effective as deep brain stimulation. In this procedure, the gamma knife is used to make a small lesion in the tremor center. Treatments are done one side at a time with a year between treatments. The effect is usually seen within a few months after treatment.
How effective is Gamma Knife treatment for essential tremor?
- About 80% of patients receive substantial or complete relief of tremor—usually within a few months. Many patients are able to stop their use of medications.
- Another 10% receive some relief—but less dramatic.
- Complications of weakness, numbness or speech disturbance are usually brief, but 1-2% of patients do experience lasting complications that can be serious.
- Patients with voice/head or chin tremor may also benefit but often require treatment on both sides to get full benefit.
The picture included with this article shows a patient trying to draw a spiral before the gamma knife procedure and one year after the procedure.
You can learn more about this treatment at www.CaliforniaGammaKnife.com/essential-tremor