Brain Stimulation Combined With Watching Hand Movements to Improve Hand Recovery in Chronic Stroke

The participation duration for each participant is 10 weeks, including the assessment period.

Group 1 tDCS + AOT (intervention): tDCS will be administered at the outpatient clinic for 20 minutes per session, for a total of 10 sessions over two consecutive weeks. During the tDCS sessions, each participant will engage in AOT for 30 minutes under the supervision of a therapist. Subsequently, each participant will continue performing AOT at home for 30 minutes per session, once a day, five days per week, for 8 consecutive weeks.

Group 2 tDCS alone (control): tDCS will be administered at the outpatient clinic for 20 minutes per session, for a total of 10 sessions over two consecutive weeks. During the tDCS sessions, each participant will watch a landscape video for 30 minutes. Subsequently, each patient will continue watching the landscape video at home for 30 minutes per session, once a day, five days per week, for 8 consecutive weeks.

Group 3 AOT alone (control): placebo tDCS will be administered at the outpatient clinic for 20 minutes per session, for a total of 10 sessions over 2 consecutive weeks. During the placebo tDCS sessions, each participant will engage in AOT for 30 minutes under the supervision of a therapist. Following the clinic sessions, each patient will continue performing AOT at home for 30 minutes per session, once a day, five days per week, for 8 consecutive weeks.

The principal investigator will visit each research site throughout the duration of the study. All participants will attend the outpatient rehabilitation setting five times a week for 30 minutes per session, for 2 consecutive weeks, and continue intervention at home for five days a week for 8 consecutive weeks. The total intervention duration consists of 10 consecutive weeks. For each session in the hospital, there will be a physiotherapist to monitor participants' compliance with the interventions and to ensure that the training is conducted as per protocol. Level of participation would be measured by Rating of Perceived Exertion Scale of 3-5 (light activity to somewhat hard). If the subject attended the session but refuse to participate in the intervention, the subject would be excluded from the study.

Inclusion criteria

• Adults aged 18 to 59 years
• Single episode of unilateral stroke and weakness in hand muscles 6 to 24 months post-stroke
• No excessive spasticity of the upper limb, defined as grade two or less on Modified Ashworth Scale

Exclusion criteria

• Patients diagnosed with posterior circulation infarction
• Unable to follow commands due to poor cognitive function
• Unilateral neglect
• Homonymous hemianopia
• Other existing neurological disorders that lead to poor hand function
• Grade four or five hand muscle strength.