Essential tremor (ET) is a chronic condition characterized by involuntary, rhythmic trembling of a body part, most typically the hands and arms but may also affect the head, voice, and legs.

ET is considered the most common movement disorder and may affect as many as 10 million people in the United States. ET can occur at any age, but the usual age of onset is 45 or after. It may occur randomly or be inherited.

Symptoms of ET

ET is usually associated with purposeful movement. It can be socially embarrassing and may cause difficulty in performing fine motor tasks such as writing, eating, and drinking. The tremor is usually absent or minimal with rest and disappears during sleep.

Diagnosis

Although ET is a common movement disorder, it may be difficult to diagnose at times. ET is a clinical diagnosis; there is no definitive test. Evaluation of ET includes a thorough history and physical examination.

Treatment Available

Medical treatments include:

• Beta blockers: Propranolol (Inderol)
• Anticonvulsants: Such as primidone (Mysoline), gabapentin (Gabarone), or topiramate (Topamax)
• Benzodiazepines: Such as clonazepam (Klonopin) or diazepam (Vicadin)
• Local injections of botulinum toxin type A (Botox)

Surgical Treatment

Surgery may be suggested to treat some patients with ET, particularly those who have not responded to conventional drug therapies. Surgical treatment involves thalamic deep brain stimulation and is usually reserved for patients with severe, disabling tremor and functional disability that interferes with the activities of daily living.