Posted 06.17.2020 | by AMRA

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system affecting around one million Americans. Depending on the areas in the brain and spinal cord involved, MS can cause alterations in sensation, balance, muscle strength, coordination, autonomic nervous system activity, mood, and cognition.

Cognitive symptoms may include impairments in attention, processing speed, working memory, and executive function. Computerized cognitive training is often employed in MS rehabilitation programs, but the results for improved cognitive function have been variable.

Mindfulness-based interventions offer potential promise in MS rehabilitation because of their proven effects on brain areas involved in attention and executive function. Manglani et al. [Neuropsychology] tested the efficacy of mindfulness training compared to computerized cognitive training and a wait-list control on improving working memory and processing speed among persons with MS.

The researchers randomly assigned 61 persons with MS (77% female; 72% Caucasian; average age = 46 years) to mindfulness training, computerized cognitive training, or a wait-list control. The four-week mindfulness training was an abbreviated version of the Mindfulness-Based Stress Reduction (MBSR) program involving the body scan, breath awareness, awareness of sensations, thoughts and emotions, and choiceless awareness. Patients met weekly in groups for two hours, and were encouraged to engage in 40 minutes of daily home mindfulness practice.

The computerized cognitive training group also met in groups every week for two hours over the course of four weeks. The first hour of each group was devoted to didactic material on cognitive deficits and allowed for group sharing of experiences. The second hour consisted of computer game playing designed to maximize working memory and processing speed. The games required increasing degrees of attention, identification of stimuli, and memory.

Participants were assessed before and after intervention on a computerized neuropsychological battery that included symbol digit substitution and serial addition tasks. The symbol digit substitution task required participants to quickly use an answer key of matched symbols and numbers to look up the numerals correctly matching symbols flashed on a computer screen. The serial addition task required participants to listen to an audiotaped series of numbers, and mentally calculate the sum of the last two numbers they heard.

The researchers compared performance across groups on these tasks and tested the effects of several moderating variables including baseline neuropsychological performance, amount of mindfulness or computer practice, and improvements in mindfulness disposition.

The results demonstrated that only the mindfulness group showed significantly improved performance on the symbol digit substitution task which measured processing speed. Their average symbol digit score improved by 8.8 points, whereas the cognitive training group improved by 0.2 points and waitlist group improved by 1.2 points.

Serial addition scores, which measure working memory, improved for all three groups (η2p = 0.44) by an average of 8 points, without any significant group differences. The fact that the waitlist group also improved suggests this improvement is due to the practice effect of having taken the pretest. Neither baseline neuropsychological performance nor the amount of mindfulness or computer game practice affected processing speed or working memory improvement.

Within the mindfulness group, increases in mindfulness disposition scores were correlated with improvements in working memory (r =.52), but not processing speed (r = -.11). Within the cognitive training group, improvements in game performance were not significantly correlated with processing speed or working memory.

The results suggest that mindfulness training can increase cognitive processing speed in MS patients compared to cognitive training or a waitlist control. The study is limited by a small sample size, reliance on single measures to assess processing speed and working memory, and uncertainty about whether improvements on a processing speed task translate into day-to-day improvements in adaptive functioning for persons with MS.

Reference:

Manglani, H. R., Samimy, S., Schirda, B., Nicholas, J. A., & Prakash, R. S. (2020). Effects of 4-week mindfulness training versus adaptive cognitive training on processing speed and working memory in multiple sclerosis. Neuropsychology.

[Link to study]