Essential Tremor (ET) is called "essential" because in the past it had no known cause. It's not caused by another neurological condition, by injury, or as a side effect of a medication. ET usually affects the hands, but it may also affect the head and neck, face, jaw, tongue, voice (causing a shaking or quivering sound), the trunk, and rarely the legs and feet. The tremor may be a rhythmic "back-and-forth" or "to-and-fro" movement produced by involuntary (unintentional) contractions of the muscle. Severity of the tremor can vary greatly from hour to hour and day to day.
Some people experience tremor only when the body or a part of the body is held in certain positions. This is postural tremor. Tremor that worsens during a particular action such as writing or eating is kinetic or action-specific tremor. Most people with ET have both postural and kinetic tremor.
As many as 1 in 20 people older than age 40, and 1 in 5 people over 65 may have ET. There are approximately ten million people with ET in the United States, and many more worldwide. Of all neurologic diseases, ET is the most common with the exception of stroke. It is estimated that ET is eight to ten times more common than Parkinson’s disease – a disorder characterized by resting tremor, stiffness and slowness of movement.
Treatment for essential tremor involves medications as well as surgery.
Medical treatment for essential tremor may include beta blockers (e.g. propanolol), benzodiazepines (e.g. Klonopin), Botulinum toxin (Botox) and anti- seizure medications.
Surgery for essential tremor can include deep brain stimulation, surgical (radiofrequency) thalamotony or gamma knife (radiosurgical) thalamotomy.
Deep brain stimulation involves a surgically implanted medical device, much like a pacemaker, that delivers electrical stimulation to very specific areas in the brain and is proven to significantly reduce tremor in patients.
Surgical thalamotomy involves using a small electrode to burn a small region of cells in the brain felt to be responsible for tremor. It results in significant improvements in patients with tremor.
Gamma knife thalamotomy uses a focused beam of radiation
to burn a small region of cells in the brain felt
to be responsible for tremor. It results in significant
improvement in patients with tremor.