Dr. Leigh E. Charvet and Dr. Yulin Ge use MRI to study the real-time effects of transcranial direct current stimulation.
Photo: Ƶ Staff
Recent pioneering studies from Ƶ’s Multiple Sclerosis Comprehensive Care Center are showing the benefits of remotely supervised transcranial direct current stimulation (RS-tDCS). The new research demonstrates how this protocol enhances quality of life by reducing symptoms such as cognitive impairment and fatigue, and improving outcomes of rehabilitation. Treatment is delivered at home, increasing access to care for patients with multiple sclerosis (MS), Parkinson’s disease, and other neurological disorders and psychiatric conditions.
The latest research joins a portfolio of groundbreaking Ƶ studies on RS-tDCS completed over the past year. The work has demonstrated the efficacy of this protocol for reducing MS-associated fatigue, as well as enhancing complex attention and response variability among patients with MS.
The telerehabilitation protocol, developed at Ƶ, harnesses the therapeutic potential of tDCS, which safely stimulates the brain by applying noninvasive, low-grade electric current. Following training during a baseline intake visit, patients perform the at-home treatment by placing electrodes on the scalp and connecting with center experts over a HIPAA-compliant live video conference for each day’s live session.
These first-of-their-kind studies build on Ƶ’s distinction as the only center offering a home-based protocol for MS. Researchers also recognize the significant potential of RS-tDCS to reduce troublesome symptoms across a spectrum of neurological disorders, but despite the extensive safety record and indications in the literature demonstrating benefits, tDCS is not yet available for clinical implementation. This is due to the challenges of scientific rigor—accruing a reliable sample size and repeat clinic visits in a population with limited mobility.
“Our remotely supervised tDCS protocol is designed to deliver that rigor and accumulate quantitative evidence for tDCS benefits within the structure of patients’ homes,” explains Leigh E. Charvet, PhD, associate professor in the , who leads the MS-related tDCS research. “Having now delivered over 4,000 RS-tDCS treatments for telerehabilitation, our protocol has been verified as a safe treatment modality feasible for use in the majority of patients with varying levels of impairment. And its use has facilitated rapid recruitment and high treatment adherence for extended protocols.”
Studies Support Improvement in Function and Movement
The new body of RS-tDCS research applies a sham-controlled approach to deliver a dose of active simulation or placebo to patients on a randomized basis. One large trial, funded by the National Multiple Sclerosis Society, aims to validate the benefits of RS-tDCS on MS fatigue as a primary outcome and cognitive functioning as a secondary outcome, using 30 sessions of at-home stimulation paired with cognitive training. Another active study, funded by the U.S. Department of Defense, combines RS-tDCS on the motor cortex with occupational therapy to investigate potential benefits of the technology for improved hand function.
Additional research, presented at the 35th Congress of the European Committee for Treatment and Research in Multiple Sclerosis, examined the synergistic effects of aerobic exercise and tDCS on gait function in 34 patients with MS. The study found a strong, cumulative effect with repeated in-clinic treatment sessions. Participants showed a reduction of self-perceived limitation, a 30 percent improvement in gait speed, and lengthened stride.
“We looked at whether tDCS facilitates plasticity of the neural pathways responsible for walking,” Dr. Charvet notes. “Our study suggests that the treatment can enhance the short- and long-term benefits of physical activity by enhancing gait function—supporting our goal of harnessing tDCS to improve function in patients living with MS.”
Mechanistic Research Elucidates Neural Reactivity and Functional Connectivity
To enhance the treatment’s clinical value, center investigators also engaged in a study examining the neural mechanisms of tDCS to identify optimal stimulation protocols and variation of individual response. This pilot study, funded by the National Institutes of Health, applies a combined tDCS/MRI protocol to test the real-time effects of tDCS in participants with MS ages 18 to 79 with varying levels of disability. Participants receive a baseline scan, and then repeated scans with tDCS are administered. Initial imaging studies suggest that MS fatigue correlates with decreased cerebral blood flow and neuronal reactivity.
Simultaneous tDCS and MRI are used to capture the brain’s response to tDCS in real time in order to identify predictors and markers of treatment response.
Image courtesy of Dr. Charvet
“Early findings suggest not only an increase in that activity across participants, but a return to normal levels in participants with MS,” Dr. Charvet says. “Further, we have observed an increase in functional connectivity within the cortico–striato–thalamo–cortical loop, thought to be key to unlocking MS-associated fatigue. We are learning a great deal about how the brain responds to tDCS, both at baseline and after treatment, to help us better utilize the treatment clinically.”
Pushing the Boundaries on Benefits
In addition to these RS-tDCS studies, research continues to push the boundaries of applicability of tDCS in patients with neurological disorders of any origin. Case reports from the MS Comprehensive Care Center have demonstrated benefits in patients with ataxia and depression. Also, the open-label protocol offered improvement in patients who have aphasia after a stroke, as presented in November 2019 at the American Speech-Language-Hearing Association (ASHA) Convention.
“Our entire research program continues to target symptoms in these patients that lack reliable treatment options but are troublesome to their day-to-day cognition, energy levels, and function,” Dr. Charvet says. “We are adding a verified therapy to their daily at-home regimens to reach these patients and enhance their outcomes.”
Separately, MS Comprehensive Care Center clinicians are integrating RS-tDCS visits into the full suite of digital tools offered within the Ƶ Health app. The goal is to expand the availability and benefits of tDCS to a larger clinical population through innovative care. This is in keeping with the institution’s goal of making high-quality care more accessible to more patients.
