Effect of multi-session trans-cranial direct current stimulation of dorsolateral prefrontal area on depression and sleepiness in patients with multiple sclerosis (PP-32)

Introduction: Multiple sclerosis (MS) is one of the most common diseases of the central nervous system with high prevalence in the world and Iran. The common complications of disease are depression and sleepiness. Due to structural and functional brain changes following depression and sleepiness in patients with MS, brain electrical stimulation may be considered as an effective intervention in therapy.
 
Materials and Methods: In this double blind clinical trial, 30 patients with MS were randomly divided into experimental and sham a-tDCS groups according to the inclusion and exclusion criteria. Correspondingly, the anode electrode was placed on the left dorsolateral prefrontal cortex (DLPFC) and cathode on the opposite supra orbital. In the experimental group, 20-minute DLPFC a-tDCS with intensity of 1.5 mA was performed during 10 sessions for 20n days with a one-day rest interval between sessions. However, in the sham a-tDCS group, although the electrodes were nplaced in the same positions as it used for the experimental group, the stimulation was slowly turned off after 30 seconds.
Results: The results in the experimental group showed that the depression after intervention was significantly decreased as compared to before intervention (P<0.05), but there was no significant differences in the rate of sleepiness before and after the intervention (P>0.05), although the trend of sleepiness was toward reduction. Also, sleepiness and depression level were significantly improved after the intervention in experimental as compared to control group. Conclusion: Multi-session a-tDCS over the left DLPFC have a significant effects on the improvement of depression and rate of sleepiness in patients with MS.