Pharmacological management of essential tremor.

Essential tremor (ET) is a common movement disorder with clinical features that manifest with both motor (tremor and balance disorders) and non-motor (such as mild cognitive deficits and hearing loss) symptoms. The diagnosis of ET is based on the presence of an action tremor of greater severity than enhanced physiological tremor, without other identifiable causes. Patients with ET experience a decrease in the performance of their motor skills and social activities, and a decline in their quality of life. The pathophysiology of ET is still not clear. Pharmacotherapy for ET is indicated if the disease interferes with the patient's quality of life. Propranolol, a nonselective β-adrenergic receptor antagonist, and primidone, an antiepileptic, remain the standard treatments for ET. However, studies show that several other agents, including topiramate, gabapentin and zonisamide, might also be beneficial. Local injections of botulinum toxins and surgical interventions such as thalamic deep brain stimulation play a role as alternative options when pharmacological treatment is not satisfactory. Several new agents including 1-octanol, pregabalin and sodium oxybate are currently under investigation.