Repetitive peripheral magnetic stimulation (rPMS) is a form of therapy that creates painless stimulation of deep muscle structures to improve motor function in people with physical impairment from brain or nerve disorders. Use of rPMS for people after stroke has been identified as a feasible approach to improve activities of daily living and functional ability. However, no systematic reviews have assessed the findings of available trials. The effect and safety of this intervention for people after stroke currently remain uncertain.
To assess the effect of rPMS for improving activities of daily living and functional ability in people after stroke.
We searched the Cochrane Stroke Group Trials Register (August 2016), the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 8) in the Cochrane Library (August 2016), MEDLINE Ovid (November 2016), Embase Ovid (August 2016), the Cumulative Index to Nursing and Allied Health Literature (CINAHL) in Ebsco (August 2016), PsycINFO Ovid (August 2016), the Allied and Complementary Medicine Database (AMED) Ovid (August 2016), Occupational Therapy Systematic Evaluation of Evidence (OTseeker) (August 2016), the Physiotherapy Evidence Database (PEDro) (October 2016), and ICHUSHI Web (October 2016). We also searched five ongoing trial registries, screened reference lists, and contacted experts in the field. We placed no restrictions on the language or date of publication when searching the electronic databases.
We included randomised controlled trials (RCTs) conducted to assess the therapeutic effect of rPMS for people after stroke. Comparisons eligible for inclusion were (1) active rPMS only compared with 'sham' rPMS (a very weak form of stimulation or a sound only); (2) active rPMS only compared with no intervention; (3) active rPMS plus rehabilitation compared with sham rPMS plus rehabilitation; and (4) active rPMS plus rehabilitation compared with rehabilitation only.
Two review authors independently assessed studies for inclusion. The same review authors assessed methods and risk of bias and extracted data. We contacted trial authors to ask for unpublished information if necessary. We resolved all disagreements through discussion.
We included three trials (two RCTs and one cross-over trial) involving 121 participants. Blinding of participants and physicians was well reported in all trials, and overall risk of bias was low. We found no clear effect of rPMS on activities of daily living at the end of treatment (mean difference (MD) -3.00, 95% confidence interval (CI) -16.35 to 10.35; low-quality evidence) and at the end of follow-up (MD -2.00, 95% CI -14.86 to 10.86; low-quality evidence). Investigators in one study with 63 participants observed no statistical difference in improvement of upper limb function at the end of treatment (MD 2.00, 95% CI -4.91 to 8.91) and at the end of follow-up (MD 4.00, 95% CI -2.92 to 10.92). One trial with 18 participants showed that rPMS treatment was not associated with improved muscle strength at the end of treatment (MD 3.00, 95% CI -2.44 to 8.44). Another study reported a significant decrease in spasticity of the elbow at the end of follow-up (MD -0.48, 95% CI -0.93 to -0.03). No studies provided information on lower limb function and death. Based on the GRADE approach, we judged the certainty of evidence related to the primary outcome as low owing to the small sample size of one study.
Available trials provided inadequate evidence to permit any conclusions about routine use of rPMS for people after stroke. Additional trials with large sample sizes are needed to determine an appropriate rPMS protocol as well as long-term effects. We identified three ongoing trials and will include these trials in the next review update.