Randomized, controlled trial of anal electrical stimulation for fecal incontinence. Effects of unilateral repetitive transcranial magnetic stimulation of the motor cortex on chronic widespread pain in fibromyalgia.
Anal electric stimulation has been described as effective for fecal incontinence in several case series, but no study has addressed possible mechanism of benefit. We wished to examine whether anal electric stimulation, using an anal probe electrode, used on a daily basis at home for eight weeks, in the absence of any adjunctive exercises or advice, would improve symptoms of fecal incontinence and anal sphincter pressures when compared with "sham" electric stimulation.
                Ninety patients (9 males, 81 females), with median age of 55 (range, 30-77) years were randomized, 47 to active anal stimulation at 35 Hz and 43 to "sham" stimulation at 1 Hz. Outcome measures included a one-week bowel diary, symptom questionnaire, manometry, and patients' evaluation of outcome.
                Seventy patients completed the study. On an intention-to-treat analysis, there was no difference between the two groups on any of the outcome measures after eight weeks. Of those who completed stimulation, 44 (63 percent) felt the stimulation had improved their continence. Those with intact anal sphincters were not likely to rate their change more positively than those with sphincter disruption (P=0.71). Median patient rating of bowel control increased from 3 of 10 before stimulation to 5 of 10 after stimulation (P=0.001).
                Eight weeks of anal electric stimulation was rated by patients as having improved their bowel control to a modest extent. There was no statistically significant difference detected between the groups, suggesting that 1 Hz was as effective as 35 Hz. This raises the possibility that the main effect is not sphincter contraction but sensitization of the patient to the anal area, or simply the effect of intervening per se. Home electric stimulation is a relatively cheap and generally well-tolerated therapy in the conservative treatment of fecal incontinence. Non-invasive unilateral repetitive transcranial magnetic stimulation (rTMS) of the motor cortex induces analgesic effects in focal chronic pain syndromes, probably by modifying central pain modulatory systems. Neuroimaging studies have shown bilateral activation of a large number of structures, including some of those involved in pain processing, suggesting that such stimulation may induce generalized analgesic effects. The goal of this study was to assess the effects of unilateral rTMS of the motor cortex on chronic widespread pain in patients with fibromyalgia. Thirty patients with fibromyalgia syndrome (age: 52.6 +/- 7.9) were randomly assigned, in a double-blind fashion, to two groups, one receiving active rTMS (n = 15) and the other sham stimulation (n = 15), applied to the left primary motor cortex in 10 daily sessions. The primary outcome measure was self-reported average pain intensity over the last 24 h, measured at baseline, daily during the stimulation period and then 15, 30 and 60 days after the first stimulation. Other outcome measures included: sensory and affective pain scores for the McGill pain Questionnaire, quality of life (assessed with the pain interference items of the Brief Pain Inventory and the Fibromyalgia Impact Questionnaire), mood and anxiety (assessed with the Hamilton Depression Rating Scale, the Beck Depression Inventory and the Hospital Anxiety and Depression Scale). We also assessed the effects of rTMS on the pressure pain threshold at tender points ipsi- and contralateral to stimulation. Follow-up data were obtained for all the patients on days 15 and 30 and for 26 patients (13 in each treatment group) on day 60. Active rTMS significantly reduced pain and improved several aspects of quality of life (including fatigue, morning tiredness, general activity, walking and sleep) for up to 2 weeks after treatment had ended. The analgesic effects were observed from the fifth stimulation onwards and were not related to changes in mood or anxiety. The effects of rTMS were more long-lasting for affective than for sensory pain, suggesting differential effects on brain structures involved in pain perception. Only few minor and transient side effects were reported during the stimulation period. Our data indicate that unilateral rTMS of the motor cortex induces a long-lasting decrease in chronic widespread pain and may therefore constitute an effective alternative analgesic treatment for fibromyalgia.
There was some evidence that electrical stimulation enhanced the effect of PFMT in the short term but not after six months. There were, however, more adverse effects (pain or discomfort) with electrical stimulation.