Tremor is a
hyperkinetic movement disorder characterized by rhythmic oscillations of one or more body parts. It can be disabling and may impair quality of life. Various etiological subtypes of
tremor are recognized, with
essential tremor (ET) and Parkinsonian
tremor being the most common. Here we review the current literature on
tremor treatment regarding ET and head and voice
tremor, as well as dystonic
tremor, orthostatic
tremor,
tremor due to
multiple sclerosis (MS) or lesions in the brainstem or thalamus, neuropathic
tremor, and functional (psychogenic)
tremor, and summarize main findings. Most studies are available for ET and only few studies specifically focused on other
tremor forms. Controlled trials outside ET are rare and hence most of the recommendations are based on a low level of evidence. For ET,
propranolol and
primidone are considered drugs of first choice with a mean effect size of approximately 50 %
tremor reduction. The efficacy of
topiramate is also supported by a large double-blind placebo-controlled trial, while other drugs have less supporting evidence. With a mean effect size of about 90 %
deep brain stimulation in the nucleus ventralis intermedius or the subthalamic nucleus may be the most potent treatment; however, there are no controlled trials and it is reserved for severely affected patients. Dystonic
limb tremor may respond to
anticholinergics.
Botulinum toxin improves head and voice
tremor.
Gabapentin and
clonazepam are often recommended for orthostatic
tremor. MS
tremor responds only poorly to
drug treatment. For patients with severe MS
tremor, thalamic
deep brain stimulation has been recommended. Patients with functional
tremor may benefit from
antidepressants and are best be treated in a multidisciplinary setting. Several
tremor syndromes can already be treated with success. But new drugs specifically designed for
tremor treatment are needed. ET is most likely covering different entities and their delineation may also improve treatment. Modern study designs and long-term studies are needed.