CINCINNATI—In a pilot study based at the University of Cincinnati Neuroscience Institute (UCNI), researchers concluded that patients with functional or psychogenic tremor could benefit from tremor "retrainment” involving performance of a voluntary rhythmical movement of the affected limb.
Results were published online ahead of print in Parkinsonism & Related Disorders, a peer-reviewed publication that is the official journal of the International Association of Parkinsonism and Related Disorders.
Alberto Espay, MD, an associate professor in the department of neurology and rehabilitation medicine at the UC College of Medicine and neurologist at UCNI’s Gardner Center for Parkinson’s Disease and Movement Disorders, was the study’s first author. All participating patients were recruited at the Gardner Center. UCNI is a partnership of the College of Medicine and UC Health.
According to the National Institute of Neurological Disorders and Stroke, an institute of the national Institutes of Health (NIH), functional tremor (also called psychogenic tremor) can appear as any form of tremor movement. Characteristics may vary but generally include sudden onset and remission, increased incidence with stress and greatly decreased or disappearing tremor activity when the individual is being distracted.
"These are tremors that occur presumably for psychological causes, although many of these causes are not obvious to the patients themselves,” Espay says. "They don’t follow any of the rules of other kinds of tremors, and they don’t result from organic lesions such as a tumor or stroke. But even though the brain is not structurally impaired, it is functionally impaired.”
Ten patients were recruited for the pilot "proof of concept” study, all from the Gardner Center. Researchers taught them tremor retrainment, hypothesizing that it would help in facilitating self-modulation of the frequency and severity of their tremors and open the possibility of eventual voluntary control over their movements.
In a typical retrainment session, patients responded to tactile and oral cues for the affected limb. In addition, they received real-time visual feedback on a computer screen. Through the cues, patients were coached to achieve and accept a tremor rate different than their own.
"It’s a biofeedback strategy – we’re asking patients to literally ‘hijack’ their own tremor by adopting a new frequency,” says Espay.
Of the 10 subjects, six remained markedly improved after six months, including one completely free of tremor. Four patients relapsed anywhere from two weeks to six months after retrainment.
"We believe that this can be an effective short-term treatment strategy,” says Espay, "but future studies will be needed to determine the long-term benefits, the effects of ‘booster’ sessions and the potential synergy of combining retrainment with cognitive behavioral or specialized physical therapy.”
The study was supported by a Gardner Family Center Research Grant. UC’s Center for Clinical and Translational Science and Training (CCTST) was a partner.