Classification of tremor and update on treatment.

Tremor is a symptom of many disorders, including Parkinson's disease, essential tremor, orthostatic tremor, cerebellar disease, peripheral neuropathy and alcohol withdrawal. Tremors may be classified as postural, rest or action tremors. Symptomatic treatment is tailored to the tremor type. Combination therapy with carbidopa and levodopa remains the first-line approach for parkinsonian tremor. Essential tremor may be amenable to propranolol or primidone. Propranolol may be useful in treating alcohol withdrawal tremor, and isoniazid may control the cerebellar tremor associated with multiple sclerosis. Clonazepam may relieve orthostatic tremor. Other agents are also available for the treatment of tremor. When medical therapy fails to control the tremor, surgical options such as thalamotomy, pallidotomy and thalamic stimulation should be considered in severe cases. Thalamic stimulation, the most recent of these surgical approaches, offers the advantage over ablative procedures of alleviating tremor without the creation of a permanent lesion.