The effect of combining transcranial direct current stimulation with robot therapy for the impaired upper limb in stroke

Neurological rehabilitation technologies such as Robot Therapy (RT) and noninvasive brain stimulation (NIBS) can promote motor recovery after stroke. The novelty of this research was to explore the feasibility and the effect of the combination method of NIBS called transcranial Direct Current Stimulation (tDCS) with uni-lateral and three-dimensional RT for the impaired upper limb (UL) in people with sub-acute and chronic stroke. This thesis involved three studies: (a) systematic review with meta-analyses (b) a pilot double-blinded randomised controlled trial with a feasibility component and (c) a reliability study of the measurement of Motor Evoked Potential (MEP) response using Transcranial Magnetic Stimulation in healthy adults. The first study involved a review of seven papers exploring the combination of tDCS with rehabilitation programmes for the UL in stroke. For the second study, stroke participants underwent 18 x one hour sessions of RT (Armeo®) over eight weeks during which they received 20 minutes real tDCS or sham tDCS. Outcome measures were applied at baseline, post-intervention and at three-month follow-up. The qualitative component explored the views and experiences of the participants of RT and NIBS using semi-structured interviews. The third study involved age-matched healthy adults exploring intrarater and test-retest reliability of the TMS assessment. Results of the three studies were the following: Seven papers were reviewed and a small effect size was found favouring real tDCS and rehabilitation programmes for the UL in stroke. 22 participants (12 sub-acute and 10 chronic) completed the pilot RCT. Participants adhered well to the treatment. One participant dropped out of the trial due to painful sensations and skin problems. The sub-acute and chronic groups showed a clinically significant improvement of 15.5% and 8.8% respectively in UL impairments at post-intervention from baseline. There was no difference in the effects of sham and anodal tDCS on UL impairments. Participants found the treatment beneficial and gave suggestions how to improve future research. In summary, the TMS assessment showed excellent reliability for measurement of resting motor threshold but poor to moderate reliability for MEP amplitude. In conclusion, it was indicated that RT may be of benefit in sub-acute and chronic stroke however, adding tDCS may not result in an additive effect on UL impairments and dexterity. The present study provided a power calculation for a larger RCT to be carried out in the future.