Essential Tremor: Updated Guideline for Treatment
Although estimates of its prevalence vary widely, essential tremor is one of the most common neurologic disorders in adults.1,2 It may be up to 20 times more prevalent than Parkinson disease.3
Because essential tremor can interfere with eating, writing, and other activities of daily living, this disorder can be disabling for those who are affected. It typically develops in persons who are older than 40 years; however, symptoms can appear at any age.
Recently, the American Academy of Neurology (AAN) updated its 2005 guideline for the treatment
of essential tremor.4 Highlights are presented here.
RECOMMENDED TREATMENTS
The only medication that has been approved by the FDA to treat essential tremor is propranolol. Primidone is another medication that is often used to treat essential tremor. However, up to 50% of
patients do not respond to either of these medications.5
According to the guideline, the anticonvulsants gabapentin and topiramate, along with the antihypertensives atenolol and sotalol and the anxiolytic alprazolam, can be beneficial (Table). In addition, there is weak evidence to show that nadolol and nimodipine, as well as clonazepam and botulinum toxin A, may be helpful. For those patients who do not benefit from drug treatment, deep brain stimulation and thalamotomy may be effective.
WHAT’S NEW IN THE GUIDELINE
The updated guideline differs from the AAN’s 2005 guideline in that it does not recommend levetiracetam and flunarizine or 3,4-diaminopyridine (used in rare muscle diseases) to treat tremors of the arms and legs. In addition, the updated guideline found insufficient evidence to support the use of clozapine in persons with essential tremor.
FUTURE DIRECTIONS
The key obstacle to the development of effective treatments for essential tremor is the limited understanding of its underlying pathophysiology. Evidence from recent postmortem studies shows a heterogeneous set of degenerative changes in the brains of persons with essential tremor; these findings suggest that essential tremor is a syndrome or a family of diseases, rather than a single disease.3
1. Louis ED, Marder K, Cole L, et al. Differences in prevalence of essential tremor among elderly African-Americans, Caucasians, and Hispanics in northern Manhattan. Arch Neurol. 1995;52:1201-1205.
2. Louis ED, Ottman R, Hauser WA. How common is the most common adult movement disorder?
Estimates of the prevalence of essential tremor throughout the world. Mov Disord. 1998;13:5-10.
3. Rautakorpi I, Takala J, Marhila J, et al. Essential tremor in a Finnish population. Acta Neurol Scand. 1982;66:58-67.
4. Zesiewicz TA, Elble RJ, Louis ED, et al. Evidence-based guideline update: treatment of essential tremor: report of the Quality Standards subcommittee of the American Academy of Neurology.Neurology. 2011;77(19):1752-1755.
5. Koller WC, Vetere-Overfield B. Acute and chronic effects of propranolol and primidone in essential tremor. Neurology. 1989;39:1587-1588.