Bilateral Robotic Rehabilitation in Chronic Stroke

Efficacy and Neurophysiological Correlates of a Bilateral Robotic Treatment for Patients With Chronic Stroke Outcomes

This study investigated the effectiveness and neurophysiological correlates of Bilateral Robot-Assisted Training (BRAT) in right-handed individuals with chronic unilateral stroke, focusing on how lesion side (dominant vs. non-dominant hemisphere) influences recovery. Twenty-four participants (>6 months post-stroke) completed a three-week BRAT program using the ALEx-RS robotic exoskeleton integrated with cognitively engaging serious games involving symmetric and asymmetric upper limb tasks.

Clinical outcomes (Fugl-Meyer Assessment, Bimanual Activity Test, Motricity Index) and kinematic measures (movement smoothness, movement duration) were assessed at baseline, post-treatment, and at two-month follow-up. Significant improvements (p < 0.05) in all outcomes were observed after training and maintained at follow-up.

Patients with left hemiparesis (non-dominant side affected) showed greater gains in movement smoothness and bimanual task quality, suggesting recovery of more physiological motor patterns. Conversely, those with right hemiparesis (dominant side affected) improved mainly in movement speed, indicating compensatory strategy use. Greater baseline impairment predicted larger kinematic gains, particularly in the left hemiparesis group.

These findings support BRAT as an effective intervention for chronic stroke and underscore the importance of lesion side in shaping recovery profiles, with implications for personalized rehabilitation planning.

Inclusion Criteria:

• first-ever unilateral stroke event;
• upper limb paresis with the ability to perform at least antigravity movements of the upper limb;
• right- hand dominance.

Exclusion Criteria:

• impossibility to provide informed consent;
• cognitive impairment limiting the ability to understand the therapist's directions (screening Mini-Mental State Examination score <24/30);
• hemispatial neglect, severe memory/attention impairment or severe aphasia;
• degree of spasticity of the upper limb such as to make the use of robotic devices impossible (Modified Ashworth Scale score > 3).