Magnetic stimulation provides relief for movement disorder, UNM study shows
A newly published study from a researcher at the University of New Mexico Health Sciences Center suggests that precisely targeting areas of the brain with a powerful magnetic field may provide relief from painful involuntary muscle contractions known as dystonias.
The treatment offers a ray of hope for people suffering from cervical dystonia, a rare condition in which the neck muscles contract involuntarily, twisting the head to one side.
Dystonias involve a loss of the inhibition in the brain that normally modulates the circuits that excite muscle movement, says Sarah Pirio Richardson, MD, a movement disorders specialist and assistant professor in UNM’s Department of Neurology.
Pirio Richardson and colleagues at the National Institute of Neurological Disorders and Stroke and the University of Toronto in Canada tried a technique called repetitive transcranial magnetic stimulation (TMS) on eight dystonia patients.
Each patient received five 15-minute treatments, in which a TMS device created a pulsing magnetic field in specific areas of the brain associated with movement and motor control.
In her paper, “Repetitive Transcranial Magnetic Stimulation in Cervical Dystonia: Effect of Site and Repetition in a Randomized Pilot Trial,” published April 29 on the PLoS One website, Pirio Richardson reported that stimulation of two areas – the dorsal premotor cortex and the primary motor cortex – was associated with a significant reduction in symptom severity.
“We saw some immediate change,” Pirio Richardson says of the pilot study. “We also saw some change over time. What was unexpected was that there was this prolonged benefit – some kind of plasticity enhancement or normalization of these abnormal interactions was occurring.”
She is applying for funding to study many more patients at four sites over a five-year period.
Pirio Richardson notes that in most movement disorders patients “have moments of normality” in which, given the right cues, their involuntary movements temporarily subside.
“This suggests that interventions can be effective,” she says. The repetitive use of TMS seems to increase the stimulation or inhibition of specific brain circuits.
TMS currently is approved by the Food and Drug Administration for the treatment of depression, which means Pirio Richardson can only use it as a research tool, for the time being.
“It clearly needs to be tested in a bigger population,” she says. A successful Phase 2 trial could help set the stage for TMS becoming an FDA-approved dystonia treatment.
Movement disorders have been Pirio Richardson’s focus since the Albuquerque native joined the UNM faculty in 2007 following a three-year National Institutes of Health fellowship in Maryland.
In addition to her research commitments, she heads UNM’s Parkinson’s Disease and Movement Disorders Program, where she and fellow neurologist Amanda Deligtisch, MD, see over 200 patients a month. She also provides clinical care and education at the Veterans Affairs Medical Center.
In her clinical practice, Pirio Richardson deploys the full suite of treatments for movement disorders, including oral medications, botulinum toxin injections that counter the muscle spasms characteristic of dystonia and implanting microelectrodes to provide deep brain stimulation for selected Parkinson’s, essential tremor and dystonia patients.
Pirio Richardson has also co-authored a forthcoming book, Fundamentals of Neurologic Disease (Springer, 2d Ed., 2015), with Larry E. Davis, MD, chief of the neurology service at the Albuquerque VA Medical System.
“I like what I do,” she says. “There’s always more questions. That’s fun.”