#ACTRIMS2022 – Cognitive Training Paired With tDCS Aids Patients

Electrically stimulating the brain while doing at-home cognitive training games can help to prevent a decline in cognition for people with multiple sclerosis (MS), particularly those with more advanced disability, a study indicates.

“This could lead to a therapy that can remediate cognitive impairment, we just need to optimize” the intervention protocol, said Leigh Charvet, PhD, a professor in the neurology department of New York University.

Charvet presented study findings at the Americas Committee for Treatment and Research in Multiple Sclerosis (ACTRIMS) Forum 2022, in the talk “Cognitive Functioning in MS Improves with At-Home Online Training Paired with Transcranial Direct Current Stimulation (tDCS): Results from a Sham-Controlled Randomized Clinical Trial.”

Over three-quarters of MS patients experience cognitive difficulties as a symptom of the disease. These difficulties usually start off mild — like slight delays in processing speed — but worsen with progression, often leading to problems with learning, memory, and other cognitive domains.

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Adaptive cognitive training is an intervention broadly aiming to boost skills by having a person play computer games specially “designed to target processing speed that then has a transfer effect to other aspects of cognitive functioning,” Charvet said.

Charvet noted that the “adaptive” part of this kind of training is key: Based on how well a person is doing on the various exercises, the computer will adjust the difficulty of exercises to match.

“For instance, [the training] slows down when the user slows down or speeds up to drive the learning to maintain a level of engagement to get the most out of the training session,” she said.

Charvet and colleagues previously ran a clinical trial that enrolled 135 MS patients with mild-to-moderate cognitive impairment, who were given 12 weeks of at-home adaptive cognitive training (from Brain HQ) or video games with no active component. Results showed a significant benefit in intervention group patients on measures of neuropsychiatric function after the 12 weeks.

In their new study, the researchers wanted to test whether applying transcranial direct current stimulation, or tDCS, might increase the benefits derived from adaptive cognitive training.

tDCS is a non-invasive, painless procedure that involves using electrodes on the scalp to stimulate specific parts of the brain. In this case, it is used to stimulate the left dorsolateral prefrontal cortex, a brain region that is important for cognition. The overall goal is to help facilitate changes in the brain’s architecture that lead to cognitive benefits.

tDCS is “a very safe and well-tolerated technique,” Charvet noted.

Researchers enrolled 120 people with MS, mostly female and white, who had clinically significant fatigue but not depression or severe cognitive impairment. All underwent 20-minute sessions of adaptive cognitive training daily for 30 days, and they were randomly divided to receive active tDCS or a sham procedure during the training sessions.

Charvet noted that the trial included less training than has been shown to be effective in previous studies, since the goal was to assess whether tDCS might improve the intervention’s effectiveness.

The entire trial was conducted remotely: Monitoring was done via videoconferencing, and the tDCS devices were pre-programmed to provide tDCS or the sham. All these steps were taken to make a “minimal technical burden for the participant,” Charvet said.

Of note, the trial finished enrolling rather quickly — within 22 months — and nearly all participants (92%) completed more than 25 sessions, which Charvet said highlights how hungry MS patients are for interventions that can be done at home.

“This intervention of at-home and remotely supervised tDCS paired with cognitive training is very feasible to do in a home-based study,” she said.

Cognition was measured via the Brief International Cognitive Assessment for MS (BICAMS), a standardized metric that includes three assessments related to cognition: processing speed, verbal learning, and visual learning. Cognitive data at the study’s start and end were available for 106 patients.

Among patients given tDCS, all BICAMS scores were found to be largely stable throughout the trial. By contrast, participants given the sham intervention had a marked decline in BICAMS scores from its start to end.

Charvet stressed that the decline seen in sham-treated patients was too small to be considered clinically significant, but it was significantly different from the overall changes seen in those given tDCS. Similarly, changes in each BICAMS assessment were also significantly different between the two groups.

The effects of tDCS on BICAMS were particularly pronounced among patients with greater physical disability, evidenced by higher scores on the Expanded Disability Status Scale.

Active tDCS paired with adaptive cognitive training “boosts cognitive training outcomes, and that finding was most pronounced among the people with higher levels of disability,” Charvet concluded.

She added that data for patient-reported outcomes are still being analyzed, but said that “anecdotally, participants definitely noticed a difference in the benefit” of the training paired with active tDCS.

This work was funded by the National MS Society.

Editor’s note: The Multiple Sclerosis News Today team is providing in-depth coverage of the ACTRIMS Forum 2022 Feb. 24–26. Go here to see the latest stories from the conference.