Effect of transcranial direct current stimulation in combination with robotic therapy in upper limb impairments in people with stroke: a systematic review

Background Stroke is a devastating condition, which not only affects patients' activity, but also is a primary reason for the psychosocial impact on them, their caregivers, and the healthcare system. Transcranial direct current stimulation (tDCS) modulates cortical activity, encouraging neuro-modulation and motor recovery in stroke rehabilitation. Robotic therapy (RT) provides repetitive, high-intensity, interactive, task-specific intervention and can measure changes while providing feedback to people with stroke. Objectives This study aimed to evaluate and summarize the scientific literature systematically to investigate the combined effect of tDCS and RT in patients with stroke. Methods Four databases (MEDLINE, Web of Science, ScienceDirect, & PEDro) were searched for clinical trials investigating the effect of RT and tDCS in stroke patients with upper limb impairment. PEDro scale was used for the quality assessment of included studies. Results The search yielded 208 articles. A total of 213 patients with stroke who had upper limb impairment were studied. In the majority of the trials, RT combined with tDCS lead to positive improvement in various measures of upper limb function and spasticity. Conclusions RT along with tDCS is an effective mode of rehabilitation, although no additional effects of tDCS plus RT in comparison with RT alone were reported. Large, robust studies are needed, so that health care providers and researchers can make better decisions about merging tDCS and RT in stroke rehabilitation settings in the future.