Imagine not being able to hold a glass, tie your shoelaces or write a check. For people with the common movement disorder known as essential tremor, simple tasks requiring fine motor coordination become increasingly difficult, sometimes even impossible.
Three times more prevalent than Parkinson's disease, essential tremor involves uncontrollable shaking of the hands, arms, head or voice. The largely hereditary neurological condition can begin in early adulthood and worsen with age.
In an effort to help physicians and patients best cope with essential tremor, the American Academy of Neurology has released the first guidelines for its treatment. The report, posted online, will be published in the June 28 issue of the journal Neurology.
Specific drugs commonly used to treat high blood pressure and seizures can be beneficial in the treatment of essential tremor, according to the guidelines. For limb tremors, surgery can be an option if drug therapy is ineffective.
"Essential tremor can be quite debilitating and cause embarrassment in social situations. For instance, in a restaurant the person may have difficulty eating when they try to pick up a fork or spoon and bring food to their mouths," said lead guideline author Theresa Zesiewicz, MD, an associate professor of neurology at the University of South Florida (USF)College of Medicine. "Though the tremors do not completely disappear with treatment, they can be managed, making a huge difference in the daily lives of people with essential tremor."
The guideline panel reviewed 211 articles to make evidence-based recommendations on the treatment of essential tremor.
Propranolol, long-acting (LA) propranolol, and primidone were each found to significantly reduce limb tremors and were strongly recommended in the guidelines. Propranolol is also used to treat high blood pressure. Primidone is an anti-seizure medication. Propranolol and primidone may be used in combination for limb tremor when either drug is insufficient alone. Propranolol was also recommended for head tremors, although not as strongly as it was recommended for limb tremors.
The panel also found supporting evidence for other medications to be considered for limb tremors. Sotalol or atenolol – drugs used to regulate blood pressure – can be used as alternatives to propranolol and primidone. The anti-seizure drugs gabapentin (as monotherapy) and topiramate were also recommended.
The panel found modest evidence to recommend injections of botulinum toxin A for limb, head, or voice tremors.
Surgery can be recommended if drug therapy is ineffective for limb tremors. Deep brain stimulation was found to have fewer severe complications than thalamotomy, according to the guideline. In deep brain stimulation, an electric probe is placed inside the thalamus which helps block the impulses that cause tremors. A thalamotomy places a lesion on a small part of the thalamus, which helps stop the signals that cause tremors.
"Both surgeries were more effective than medications at improving the tremors, reducing their magnitude by as much as 60 to 90 percent, compared to 50 percent or less for medications," Dr. Zesiewicz said. "However, patients who underwent surgery experienced more adverse side effects, so the procedures are only recommended for those who do not respond to medications."
The panel found insufficient evidence to recommend deep brain stimulation to treat head or voice tremor.