Other Drug Therapies

Second-line drug therapies for the treatment of ET include benzodiazepines, a class of drugs that interferes with chemical activity in the nervous system and brain, serving to reduce communication between nerve cells and to a "slowing down" the central nervous system. Such medications promote sleep, relieve anxiety, reduce restlessness, and relax muscles. Examples of benzodiazepines that have been used to treat patients with ET include clonazepam (Klonopin®), lorazepam (Ativan®), alprazolam (Xanax®), and diazepam (Valium®).

Nadolol (Corgard®) is a nonselective, beta-adrenergic receptor antagonist that is similar to propranolol. It may be an effective treatment for individuals with ET who were previously responsive to propranolol.

Methazolamide (Neptazane®) has been studied and seems to have limited usefulness in the treatment of essential head and voice tremor. Side effects may include drowsiness, nausea, stomach discomfort, paresthesias, or loss of appetite. The drug gabapentin (Neurontin®) has also been studied in a double blind, controlled trail for its effectiveness in the treatment of ET. The results suggested that, as an adjuvant therapy, gabapentin has limited benefit in patients with ET.

Topiramate (Topamax®). According to the results of a randomized clinical, topiramate (Topamax from OrthoMcNeil) effectively reduces tremor. Twenty-four patients with ET received either placebo (no drug) or topiramate. The dose was gradually increased to 400 mg/day over at least 8 weeks. This was followed by a 2-week period without drug or placebo and then reassignment to the other arm of the study. Fifteen patients completed the trial; six patients withdrew while on topiramate (two for dizziness or disorientation) and three patients withdrew while on placebo (one for failure to take the placebo as directed one for memory problems and ataxia). In the 15 patients who completed the study, the mean final dose was 333 mg/day. Topiramate treatment improved tremor scores by approximately 25%; placebo improvement was approximately 1%. Improvements remained significant for all scores except functional disability (p=.06).

Selected patients with ET who do not respond to drug therapy may receive local injections of botulinum toxin (BTX) type A (Botox®). Some improvement in symptoms has been noted. Chemodenervation with BTX may significantly ameliorate essential hand tremor in patients who fail to improve with conventional pharmacologic therapy.

A small, randomized study compared the relative effectiveness of propranolol or gabapentin (Neurontin®) against a placebo. Treatment with propranolol or gabapentin yielded improvement in symptoms as measured by the Tremor Clinical Rating Scale (TCRS including clinical examination, motor task performance, ADLs, and subjective assessment), accelerometry, and a patient-reported disability scale. The results suggest that gabapentin may have a role in the treatment of ET; however, more studies are needed to determine the long-term safety and efficacy of gabapentin for the treatment of individuals with ET.

	Surgical Approaches to Treatment