Tremor, Essential

Key Features

• Tremor may begin at any age

• Cause is uncertain

• Sometimes inherited in an autosomal dominant manner

• Tremor is enhanced by emotional stress

Clinical Findings

• Postural tremor usually involves one or both hands, the head, or the hands and head, whereas the legs tend to be spared

• Speech may also be affected if the laryngeal muscles are involved

• Physical examination reveals no other abnormalities

• Ingestion of a small quantity of alcohol commonly provides remarkable but short-lived relief by an unknown mechanism

• Typically becomes more conspicuous with time

• Occasionally, it interferes with manual skills and leads to impairment of handwriting

Treatment

• Propranolol long-acting, either intermittently or indefinitely, 60–240 mg once daily orally

• Primidone may be helpful, but patients are often very sensitive to it

  • Starting dose is 50 mg once daily orally

  • Daily dose is increased by 50 mg every 2 weeks depending on the response

  • Maintenance dose of 125 mg three times daily orally is commonly effective

• Occasional patients do not respond to these measures but are helped by

  • Alprazolam (up to 3 mg daily orally in divided doses)

  • Topiramate (up to 400 mg daily orally, titrated up over 6–8 weeks)

  • Gabapentin (1800 mg daily orally in divided doses)

• Botulinum toxin A

  • May reduce tremor

  • Adverse effects include dose-dependent weakness of the injected muscles

• Disabling tremor unresponsive to medical treatment may be helped by high-frequency thalamic stimulation ("deep brain stimulation") on one or both sides, according to laterality of symptoms

• Focused transcranial ultrasound thalamotomy using MRI guidance is also effective as is stereotactic radiosurgery for unilateral upper extremity tremor