Conference Coverage

Peripheral nerve stimulation can reduce tremor symptoms


Key clinical point: A wrist-worn stimulation device can reduce tremor symptoms in people with essential tremor.

Major finding: Subjects using the devices saw improvement in their upper-limb tremor scores, compared with those receiving sham treatment (P less than .01)

Study details: Two randomized studies (n = 77 and n = 61) comparing in-home or in-office treatment with stimulation or sham treatment.

Disclosures: The device manufacturer sponsored the study. One employee is a coauthor.

Source: Pahwa R et al. AAN 2018, Abstract P4.474.



– A noninvasive peripheral nerve stimulation device has been shown to reduce symptoms of hand tremor among people with essential tremor, offering a possible alternative to invasive treatments such as deep-brain stimulation.

The neuromodulation device is worn on the wrist and uses electrodes to stimulate the radial and median nerves at a frequency that interrupts tremor. It contains sensors that measure tremor and adjust stimulation accordingly.

In two small, randomized, controlled studies presented at the annual meeting of the at the American Academy of Neurology, investigator Rajesh Pahwa, MD, of the University of Kansas in Kansas City, said that treatment with the device significantly reduced tremor symptoms, compared with sham treatment.

On April 26, the device’s manufacturer, Cala Health, announced in a news release that the U.S. Food and Drug Administration had granted marketing clearance for the device, based on this evidence.

For the first study, conducted in-clinic, 77 patients were randomized to either treatment (n = 40) or sham stimulation (n = 37) of the tremor-dominant hand. Tremor was measured before and immediately after a single 40-minute session of stimulation, and patients were asked to perform tasks in accordance with the Essential Tremor Rating Assessment Scale or TETRAS, a severity measure.

Subjects in the intervention group had about a 65% improvement in their upper-limb TETRAS scores, compared with those receiving sham treatment (P less than .01) and in total TETRAS performance (P less than .05).

Subjects also were tested in-clinic with props simulating common daily tasks such as unlocking a door with a key, holding a cup of tea, picking up loose change, or dialing a phone. Patients in the treatment group self-reported greater ease with all of these tasks after treatment, compared with the sham-treated group. Differences for some tasks reached statistical significance.

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