Transcranial direct current stimulation for fatigue in patients with Sjogren’s syndrome: A randomized, double-blind pilot study

Abstract

Background: Transcranial direct-current stimulation (tDCS) has shown promise to decrease fatigue. However, it has never been examined in primary Sjogren Syndrome (pSS). Objective: To assess the effect of a tDCS protocol on fatigue in patients with pSS. Methods: This is a parallel, double-blind pilot study (NCT04119128). Women aged 18–65 years, with pSS, on stable pharmacological therapy, with complaints of fatigue for at least three months, and with scores >5 on Fatigue Severity Scale (FSS) were included. We randomized 36 participants to receive five consecutive or sham tDCS sessions, with an intensity of 2 mA, for 20 min/day. Results: After five tDCS sessions, fatigue severity assessed by the FSS (primary outcome) demonstrated a mean group difference of −0.85 [95% confidence interval (CI) −1.57, −0.13; effect size 0.80] favouring the active group. The active group presented significantly greater reductions in fatigue as measured by the EULAR Sjögren’s Syndrome Patient Reported Index after five tDCS sessions [mean group difference: 1.40; 95%CI -2.33, −0.48; effect size 1.04]. Although there were no between-group differences in the secondary outcomes of sleep, mood and anxiety, within-group comparisons evidenced a small but significant difference in the active group for pain and sleep. There were no significant cortisol changes. All reported adverse events were mild and transitory. Conclusion: tDCS seems to be safe and reduce fatigue in pSS. A differential effect on pain and sleep may underlie its effects. Further studies are needed to optimise tDCS treatment strategies in pSS.

Keywords

• Sjogren’s syndrome
• Fatigue
• Transcranial direct current stimulation