Is repetitive peripheral magnetic stimulation (rPMS) effective for improving everyday activities in people after stroke?
Stroke, the most common cause of disability, occurs when a blood clot blocks a blood vessel in the brain. Two types of stroke are known: ischaemic, due to lack of blood flow, and haemorrhagic, due to bleeding. Paralysis of the arm or leg after stroke causes problems with everyday activities and functions, including showering, dressing, and walking. Stroke patients with hemiparesis require physical rehabilitation: training of upper and lower limbs, exercise focused on activities of daily living, and fitting of walking aids (e.g. cane chosen appropriately). However, effective treatments are currently limited. rPMS is a painless method of stimulation that has been used to try to improve movement in people with brain or nerve disorders.
We found three trials of rPMS (two individual RCTs and one cross-over trial) involving a total of 121 participants. One study compared rPMS against 'sham’ stimulation (a very weak form of stimulation or a sound only). Two studies compared rPMS plus rehabilitation versus rehabilitation alone.
We found limited evidence for use of rPMS to improve activities of daily living, muscle strength, upper limb function, and spasticity (unusual stiffness of muscles) in people after stroke. Although rPMS plus rehabilitation slightly reduced spasticity of the elbow compared with rehabilitation alone, it remains unclear what type of rPMS should be performed, and on which part of the body. No information was available on lower limb function. The included trials reported no impact on death.
Quality of the evidence
We classified the quality of the evidence as low for improving activities of daily living, mainly because one study had a small sample size. Additional trials with larger sample sizes are needed to determine a suitable rPMS protocol for treating people after stroke.
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.
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.