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January 5, 2008
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Timothy C. Hain, MD Page last modified:
January 5, 2008
Essential tremor (ET) is a common movement disorder in which a high frequency (typically 7 hz) tremor occurs in the hands, variably accompanied by a head and/or vocal tremor. It affects 5% of those aged 65 or over. The tremor ordinarily is abolished by ingestion of alcohol, and is increased by nervousness and medications or situations (e.g. stress) that increase adrenalin levels. ET often runs in families, and is generally not associated with brain lesions. ET is common, affecting roughly one in 1000 persons.
Unsteadiness is not a prominent part of the essential tremor picture, but occasionally it can accompany the tremor.
Essential tremor is generally easily distinguished from the common tremor of Parkinsonism, which is slower and present at rest. The tremor generally affects the hands, sometimes also the head and voice. It is not present at rest -- when the hands are simply on the knees (for example), there should be no tremor. The tremor is typically seen with the arms extended.
The head tremor is usually a "yes-no" tremor -- that is, the head pitches forward and backward, about 2 times/second.
The voice tremor manifests itself as a "quavery" voice. Sometimes there are other types of voice problems too -- straining or hoarseness. It can be seen with video-stroboscopy.
The good news is that ET is very treatable.
Beta blockers (such as propranolol), benzodiazepines (such as klonapin), and a very low dose of mysoline (50 mg) are all commonly used in treatment. A small amount of propranolol (such as 20 mg) is sometimes used by public speakers with this tremor. It is taken about 30 minutes prior to the stressful event. Beta-blockers reduce the effects of adrenalin. Benzodiazepines (i.e. drugs resembling Valium) and mysoline increase the effects of GABA (an inhibitory neurotransmitter). Thus the two types of treatments are somewhat independent.
Topiramate, a seizure medication, has also been reported to improve ET (Ondo et al, 2006). Unfortunately, the effect was small and very close to the effect of placebo. We see no reasonable role for topiramate in the treatment of ET.
Of course, one should avoid ingesting substances that increase anxiety or cause agitation -- caffeine should be avoided as well as decongestants containing pseudoephedrine and related substances. Also drugs that increase or cause tremor such as depakene (a seizure medication).
Recently it has been reported that ET can be treated with bilateral thalamic stimulation. We have encountered patients who can turn their tremor on or off, using a small box that controls a stimulator. This treatment seems most appropriate for persons who have very severe and disabling tremor, refractory to medication.
At Northwestern, the Essential Tremor Support group meets monthly. Call 312-503-0787 to get more information.
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