Multiple sclerosis (MS) is the most common progressive neurological disorder in working
age adults, nearly 70% of whom will experience cognitive
impairment with symptoms including slower information processing and
difficulties with memory and problem solving. Other common symptoms of
the disease include fatigue and mood, sensory and motor problems.
Patients with multiple sclerosis had better problem solving ability
and response time after training with a technology called transcranial
direct current stimulation (tDCS), according to a new study published
in Neuromodulation: Technology at the Neural Interface
‘Transcranial direct current stimulation (tDCS), while done remotely under a supervised treatment protocol, may provide an exciting new treatment option for patients with multiple sclerosis who cannot get relief for some of their cognitive symptoms.’
During tDCS a low amplitude direct current is applied through
electrodes placed on the scalp using a headset. The stimulation can
change cortical excitability in the brain by making it easier for
neurons to fire, which can help improve connections and speed up the
learning that takes place during rehabilitation.
Led by researchers at NYU Langone's Multiple Sclerosis Comprehensive
Care Center, the new study reports that participants with MS who used
tDCS while playing the cognitive training computer games designed to
improve information processing abilities showed significantly greater
gains in cognitive measures than those who played the computer games
alone. Importantly, the participants completed the cognitive training
and tDCS while at home.
By enabling patients to be treated without repeat visits to the
clinic, which can be a major challenge for people with MS as their
disease progresses, the approach may improve quality of life for this
patient population, according to the study's authors.
"Our research adds evidence that tDCS, while done remotely under a
supervised treatment protocol, may provide an exciting new treatment
option for patients with multiple sclerosis who cannot get relief for
some of their cognitive symptoms," says lead researcher Leigh E.
Charvet, associate professor of neurology and director of research
at NYU Langone's Multiple Sclerosis Comprehensive Care Center. "Many MS
medications are aimed at preventing disease flares but those drugs do
not help with daily symptom management, especially cognitive problems.
We hope tDCS will fill this crucial gap and help improve quality of life
for people with MS."
In this study, the brain's dorsolateral pre-frontal cortex, an area
linked to fatigue, depression and cognitive function, was targeted for
25 participants were provided with a tDCS system with a
headset they learned to apply with guided help from the research team.
In each session, a study technician would contact each participant
through online video conferencing, giving him or her a code to enter
into a keypad that commenced the tDCS session in order to control for
dosing. Then, during the stimulation, the participant played a research
version of computerized cognitive training games that challenged areas
of information processing and attention and working memory systems.
Members of the tDCS group participated in 10 sessions, and the
researchers compared their results to 20 participants with MS who only
played cognitive training games in their 10 sessions.
Researchers found participants in the group treated with tDCS showed
significantly greater improvements on sensitive, computer-based
measures of complex attention and increases in their response times
across trials compared to the group that did cognitive training games
alone. Improvements were shown to increase over time with the number of
sessions, which suggests the tDCS may have a cumulative benefit. But,
more research is needed to determine how long these effects may last
following culmination of sessions.
The group that participated in tDCS plus cognitive training however
did not show a statistically significant difference from the group that
only played cognitive training games as measured by less sensitive
standard neuropsychological measures like the Brief International
Cognitive Assessment in MS (BICAMS) tests or on computer-based measures
of basic attention. Those findings suggest the cognitive changes brought
on by tDCS may require more treatment sessions to have noticeable
improvements in daily functioning, according to Dr. Charvet.
The researchers are recruiting for additional clinical trials
involving 20 tDCS sessions and a randomized sham-controlled protocol, to
look for additional evidence of benefits of tDCS. New research has also
begun at NYU Langone to test tDCS for other neurological conditions,
including Parkinson's disease.
However, Dr. Charvet warns that some tDCS products on the market
are sold straight to consumer without any clinical research behind them
or information or guidance on dosing frequency, so it's important for
anyone considering these technologies outside of a controlled research
environment to consult with their physician.
The device was designed in conjunction with inventor Marom Bikson, a professor of biomedical engineering at The City College of New
York, and Abhishek Datta, PhD, the chief technology officer of Soterix
Medical which holds a patent on the tDCS device. Dr. Charvet provided
Bikson's team with feedback from participants enrolled in the trial to
help better design the device. The study was funded by the National
Multiple Sclerosis Society and The Lourie Foundation, Inc.