Essential tremor (ET) is a slowly progressive condition causing tremor, usually in bilateral hands, head or voice, which can be associated with significant disability, limiting writing, dressing, eating, and drinking.
At Pacific Movement Disorders Center, we provide optimized medical and surgical care for patients with tremor, beginning with an accurate diagnosis. Essential tremor and Parkinson’s disease can often be misdiagnosed, and Providence Saint John’s has the latest diagnostic tools to distinguish between the two: the DaTscan.
The term “essential” refers to the idea that the “essence” of the condition is tremor. It’s another way of saying primary tremor, or tremor for its own sake, rather than tremor secondary to something else such as Parkinson’s disease or stroke.
Tremor which is present with posture (making it hard to hold things like the newspaper, your smart phone, or a cup on a saucer) and with action (making it hard to write, type, drink from a cup or eat using a spoon or fork).
Primarily diagnosed based on the clinical exam. Most cases of essential tremor are very easily distinguished from Parkinson’s disease with certainty. However, in cases of uncertainty, DaTscan can be very helpful. This is a SPECT scan of the brain using a novel tracer, looking for areas of low dopamine (which is seen in Parkinson’s disease). Blood tests are useful to exclude other causes of tremor such as thyroid overactivity.
Most patients can enhance their coping skills through the benefit of adaptive devices. Ranging from magnetic “buttons” to tremor-stabilizing silverware, patients have a variety of options to improve quality of life and maintain independence despite a tremor. Other coping tips can be found on the International Essential Tremor Foundation website.
First-line medications include propranolol (a blood pressure medication), which lowers the stress response, but can cause fatigue, light-headedness because of effects on heart rate and blood pressure; and primidone (an anti-seizure medication), which can cause fatigue, dizziness, somnolence and imbalance. Second-line treatments include benzodiazepines (e.g., clonazepam), gabapentin, and topiramate.
For disabling tremor not responsive to medication, deep brain stimulation (DBS) is a very effective treatment option. DBS is the non-permanent suppression of overactivity in a deep part of the brain, called the ventral internal medial nucleus of the thalamus (VIM). Like a pacemaker for the brain, the battery (pulse generator) is implanted under the skin of the chest, and leads (wires) are tunneled under the skin into the deep part of the brain into a quarter-sized opening into the skull. All parts are internalized. The procedure is done in two stages: The placement of the leads (the brain surgery), which is done with the patient awake (the patient feels no pain because there are no pain receptors in the brain tissue) and the placement of the pulse generator, which is done under general anesthesia. The pulse generator needs to be replaced about every 3-4 years.
Focused ultrasound (FUS) was approved by the FDA in May 2016 for treatment of ET, a procedure called Exablate. This is a minimally invasive technique which causes a small lesion (about 2mm, a third of a pencil eraser) in the thalamus (the tremor generator of the brain). No incisions are necessary and tremor improves on average 40-50% compared to baseline. The procedure takes about 4 hours. Effects are immediate and irreversible.
Gamma knife radiosurgery uses radiation to create a small lesion in the thalamus. The procedure takes about an hour but effects may take several weeks or months for optimal control and the effects are not adjustable or reversible.