Bilateral Arm Training versus unilateral Arm Training for Severely Affected Stroke Patients: Exploratory Single-Blinded Randomized Controlled Trial

Abstract Objective To compare the effects of unilateral and bilateral arm training on arm impairment in severely affected stroke patients. Design Single-blinded, randomized, controlled trial. Setting Inpatient rehabilitation center. Participants Sixty-nine first time subacute patients with stroke and a non-functional hand. Patients were stratified according to lesion location post-hoc. Interventions Repetitive bilateral arm training on an “arm-cycle” followed by synchronized bilateral repetitive distal hand training, or an identical unilateral arm training performed by the paretic limb only. Both unilateral and bilateral trainings were administered twice daily over six weeks. Main outcome measures The primary outcome measure was the Fugl-Meyer Score for the arm (FMA), and secondary measures were biomechanical parameters measuring isometric force and rate of force generation. Outcome measures were assessed before, at the end of, and two weeks after intervention. Results Patients were homogeneous at study onset. All patients improved regarding the FMA and most biomechanical parameters after intervention. Yet the post-hoc analysis stratifying patients according to lesion location showed that patients with pure subcortical stroke, but not patients with cortical involvement of stroke, showed a significantly (p=0.022) greater improvement following the bilateral training in FMA (from 6.8±5.7 to 17.8±15.8) compared to unilateral training (from 6.5±7.8 to 8.7±8.6). Conclusion The benefit of bilateral arm training followed by repetitive bilateral hand training for motor control of the severely paretic upper limb may depend on lesion location. Further studies with larger sample size are required for the validation of these results.