Nimodipine is a third-line treatment for essential tremor. Research suggests that the medication, a calcium-channel blocker, can provide improvement, but it is difficult to get insurance companies to approve it, said Dr. Hedera. Botulinum toxin A may reduce hand tremor, but the treatment is associated with dose-dependent hand weakness. Treating voice tremor with botulinum toxin A may be effective, but also may cause breathiness, hoarseness, and swallowing difficulties.
The concept of rational polypharmacy is more scientifically developed in the treatment of Parkinson’s disease, but neurologists also can apply it to essential tremor. Rational polypharmacy entails using several medications with distinct mechanisms of action to enable greater functional improvement. “I like to use monotherapy first, but I don’t shy from a combination,” said Dr. Hedera. “But there’s no data at all about any [combination’s] effectiveness, so you really have to use your clinical judgment.”
Surgical Interventions
Surgical interventions can treat essential tremor effectively, but neurologists do not have clear-cut guidelines about when to consider surgery. “It’s not a last resort,” said Dr. Hedera. If neither first-line medication successfully controls a patient’s tremor, the neurologist should strongly consider DBS treatment, he added. DBS may work best during the early part of the disease course, as it does in Parkinson’s disease.
Ventral intermediate nucleus thalamotomy and DBS produce marked or complete suppression of limb tremor in 70% to 90% of patients, according to a review published in 2009. DBS is associated with fewer adverse events than thalamotomy is, and the technique may provide long-term benefits and safety.
Although treatment can promote functional improvement and reduce anxiety, neurologists should follow their patients attentively. “It’s not like you really control tremor,” said Dr. Hedera. “You have to be on guard because it will come back at some point. We need better medications.”
—Erik Greb