In people with multiple sclerosis, the bifrontal transcranial direct current stimulation was well-tolerated and remarkably improved daytime sleepiness. However, it did not yield any profound effect on the objective sleep measures.

A pilot study was carried out to investigate the effects of transcranial direct current stimulation on objective (like actigraphy) and subjective (like Epworth Sleepiness Scale) sleep measures.

In total, 7 people finished the study. The recruited subjects were randomized to get 2 blocks of five daily sessions each in a crossover design (sham and active, with a washout interval of 3 weeks). The cathode and anode were placed over the right and left dorsolateral prefrontal cortices, respectively. Sleep evaluation included Epworth Sleepiness Scale, total sleep duration, sleep onset latency, number of awakenings, time in bed, waking after sleep onset, and sleep efficiency.

In comparison with the baseline scores (11.14 ± 4.06), a profound drop was noted in Epworth Sleepiness Scale following active intervention (7.86 ± 4.18), but not following sham intervention (9.57 ± 5.62). Regarding actigraphy measures, no profound alterations were noted. The sessions showed good tolerability, and no severe adverse effects were noted at any time.

Hence, the use of transcranial direct current stimulation in multiple sclerosis patients led to significant improvement in daytime sleepiness. However, additional robust studies are warranted.