The effects of anodal stimulation of primary motor cortex pain among older adults with fibromyalgia: A randomized, double-blind, placebo-controlled trial

Fibromyalgia includes a fatigue syndrome with chronic pain that declines the patients’ quality of life. Previous studies confirm these observations, but there is no study on aged-population regarding this issue. Thus we investigated the impacts of anodal stimulation on the life quality in aged-population suffering from fibromyalgia.

Fifty aged females with fibromyalgia were randomized to receive sham stimulation or real tDCS with the anode centered over the primary motor cortex (M1) and a cathode over the contralateral supraorbital area (2 mA for 20 minutes for 10 sessions). The overall effect of fibromyalgia on the quality of life was assessed using the Fibromyalgia Impact Questionnaire (FIQ) and SF-36 quality of life questionnaire. Also, the mood and anxiety levels were evaluated with Beck depression inventory and Hamilton Anxiety Rating Scale. All assessments were done before, after the last session, and 30 days after the last session of the stimulation.

The quality of life was evaluated for shame stimulation group as well as stimulation group, before the intervention, immediately after the last session, a month later on that were as follows: FIQ: 58.84, 58.4 (p=0.796), 56.17, 49.26 (p=0.020),57.86, 52.32 (p=0.050) and SF-36 score: 38.04, 41.31 (p=0.43), 45.49, 49.84 (p=0.376), 40.40, 45.38 (p=0.138) respectively. In addition, the levels of anxiety and depression for both control and intervention groups were 20.36, 18.84 (p=0.219), 16.68, 15.52 (p=0.106), 18.00, 16.12 (p=0.112), respectively.

Although the quality of life for the intervention group was increased, it was not significant. In this regard, the results were inconsistent with the result of previous literature, investigating this issue. Furthermore, the results of the level of anxiety and depression were not significantly different for both groups.