Improvement Seen in First Clinical Trial of Magnetic Stimulation for PARKINSON’S DISEASE
A double blind, randomized trial tested two targets of magnetic stimulation as well as a sham stimulation on 60 subjects that had moderate PARKINSON’S DISEASE. They received their usual Parkinson’s medications in addition to the stimulation. Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive treatment that researchers hope will augment pharmaceutical treatments for PARKINSON’S DISEASE. This trial has safety and efficacy as its primary outcome measures as well as improving clinical results when the subjects were off their drugs. While other studies have reported mixed results from transcranial magnetic stimulation, this trial used a larger, unique coil with the ability to generate a larger field of stimulation that penetrated deeper into the brain.
Principal investigator of this trial was Mario FIchera, M.D. from the Institute of Experimental Neurology at the Scientific Institute Hospital San Raffaele in Milan, Italy who presented his findings at the 24th Meeting of the European Neurological Society on June 1, 2014. He stated that compared to the group receiving sham stimulation, both groups that received targeted stimulation improved significantly, with no serious adverse events. In addition to reported improvements as measured by the Unified Parkinson’s Disease Rating Scale (UPDRS) part III, subjects reported they experienced a better quality of life, but he cautioned that a further trial should be done to “validate the efficacy seen in this trial and to gauge the duration of the effects.”
Transcranial Magnetic Stimulation is a relatively new technique that changes neuronal function by using an electromagnetic field generated by a coil. Electricity passes in opposite directions through the shape of the coil and where the current crosses it generates an electrical field, whose intensity can be modified by regulating the amount of electrical current. Pulses can be applied singly or repetitively and at varying intensities. The strength and frequency of the pulses can determine excitability or inhibition of the target neurons. The coil is placed against the scalp and the magnetic field passes through the skull to change the electrical field of the underlying neurons. In this study TMS was applied in repetitive pulses, timed milliseconds apart. TMS treatment is usually done several times a week for several weeks.
In this study, all groups of subjects received treatment three times a week for four weeks. One group received treatment on the motor cortex region, contralateral to their affected side, and also to the prefrontal cortex. Group two received treatment to the motor cortex region, but sham treatment on the prefrontal cortex. Group three received sham treatments on both treatment sites. Both groups that received actual treatment showed reductions in the motor symptoms and tremors compared to the sham group.
Dr. Josep Valis-Solis, a neurologist and neurophysiologist at the Hospital Clinic in Barcelona, Spain said “I think that we have to promote a bit this kind of treatment that is noninvasive and nonpharmacological, so some hope that we are escaping from toxicity from drugs.” It is still early and there needs to be more investigation into the types and differences of effects from different coils. Cost and availability of the equipment and training and availability of personnel to administer treatment is another issue that needs to be studied together with the rate of retreatment necessary to maintain a positive effect over an as yet unknown, period of time.
Magnetic Stimulation Improves Parkinson’s Symptoms, Medscape Jun 17, 2014
Review by Marcia McCall.