Comparing the effects of multi-session anodal trans-cranial direct current stimulation of primary motor and dorsolateral prefrontal cortices on fatigue and quality of life in patients with multiple sclerosis: a double-blind, randomized, sham-controlled trial.

OBJECTIVE

To compare the effects of anodal trans-cranial direct current stimulation (a-tDCS) over primary motor and dorsolateral prefrontal cortices on Fatigue Severity Scale and its lasting effect on fatigue reduction and improvement in quality of life in patients with multiple sclerosis.

DESIGN

A randomized, double-blinded, sham-controlled parallel clinical trial study.

SETTING

Neurological physiotherapy clinics.

SUBJECTS: Thirty-nine participants were randomly assigned to three groups: dorsolateral prefrontal cortex a-tDCS, primary motor a-tDCS (experimental groups) and sham a-tDCS. Finally, 36 participants completed the whole study (n = 12 in each group).

INTERVENTIONS: Participants in the experimental groups received six-session a-tDCS (1.5 mA, 20 minutes) during two weeks (three sessions per week). The sham group received six sessions of 20-minute sham stimulation.

MAIN MEASURES: The Fatigue Severity Scale and quality of life were assessed before, immediately and four weeks after the intervention.

RESULTS

Findings indicated a significant reduction in the Fatigue Severity Scale and a significant increase in the quality of life in both experimental groups, immediately after the intervention (P < 0.001), while Fatigue Severity Scale and quality of life changes were not significant in the sham a-tDCS group (P > 0.05). In addition, improvement of the variables remained four weeks after the intervention in dorsolateral prefrontal cortex a-tDCS (mean differences (95% confidence interval): 0.03 (-0.63 to 0.68) as compared to primary motor (-0.62 (-0.11 to -1.14) and sham a-tDCS groups (-0.47 (-1.37 to 0.43)).

CONCLUSION

Both primary motor and dorsolateral prefrontal cortex a-tDCS as compared to sham intervention can immediately improve fatigue and quality of life. However, the effects last up to four weeks only by the dorsolateral prefrontal cortex a-tDCS.