Acquired Brain Injury (TBI) is a serious medical and health problem in the US. Individuals with an acquired brain injury due to stroke and Traumatic Brain Injury (TBI) commonly suffer from upper extremity physical impairments that persist even after years of injury; these deficits are attributed to the damage to brain structure and changes in structural and functional connectivity. Although the conventional rehabilitation approaches are helpful in assisting motor recovery often there is a complaint of fatigue due to the repetitive tasks and also, nearly half of the ABI survivors do not regain their ability to use their arms for daily activities.

To address this issue, Dr. Shenoy's proposed study will investigate the combined use of individually targeted non-invasive brain stimulation and music-assisted video game-based hand exercises to achieve functional recovery. Further, the project will also investigate how the intervention modulates brain activity (recorded using EEG) in terms of brain connectivity before- and after the -intervention. In the end, this study will allow us to understand the cortical dynamics of ABI rehabilitation upon brain stimulation. Extending further, this could pave the way to advance the knowledge of behavioral and neural aspects of motor control in patients with different types of neuromuscular disorders.

Persistent physical deficits associated with upper extremities including motor weakness, spasticity, and the lack of bimanual coordination of fingers, hands, and arms are particularly problematic as it results in serious disruption of many instrumental activities of daily living. Conventional physical and occupational therapy help improve motor recovery in ABI but nearly 50% of the patients still suffer from a significant level of upper limb motor impairment following rehabilitation, undermining the need for novel therapeutic approaches to improve recovery. Non-invasive brain stimulation (NIBS) techniques such as Transcranial Direct Current Stimulation (tDCS) have shown great promises as adjuvant means to improve the efficacy of neurorehabilitation in Stroke. However, the benefit of combining NIBS with regular motor training has not been extensively studied in the TBI population.

One of the inherent challenges with the approach in dealing with the heterogeneity of the TBI population in terms of the type of injury and the location of the affected cortical region which warrants personalized intervention than a one-size-fits-all approach. Therefore, we propose to develop an individually targeted high-definition tDCS (HD-tDCS) protocol to optimize its effect and achieve maximal upper limb motor recovery in each patient by stimulating the hand knob region which is close to precentral gyrus. HD-tDCS will be combined with MusicGlove exercises (music-assisted repetitive finger movements) to improve the neuroplasticity (adaptation and reorganization to compensate for the initial insult and to attempt to restore function) and fine motor learning while keeping patients engaged. Using a double-blind design, 24 individuals with an acquired brain injury will be randomized to either receive real or sham HD-tDCS during MusicGlove therapy to assess the added benefit of HD-tDCS. In addition, we aim to investigate the underlying neural mechanism of HD-tDCS on motor recovery by studying change in EEG based brain connectivity because of the intervention.

The short-term significance of this project will be to validate the effectiveness of HD-tDCS in ABI neurorehabilitation and help better understand the underlying cortical mechanism of the improvement. In the long-term, the findings of this pilot study will contribute toward the development of an optimal patient-specific rehabilitation therapy to maximize motor recovery in individuals with neuromuscular disorders.

Inclusion Criteria:18 and 75 years

• Confirmed diagnosis of Acquired brain injury (individuals with stroke or Traumatic Brain Injury)
• At least 6 months post-injury
• Complaints of weak movement of hands and fingers
• Ability to understand the instructions that are part of the tDCS-MusicGlove testing and intervention
• Willingness and ability to participate in and travel to Kessler Foundation for the baseline assessment visits, 10 training visits, and post-training follow-up visits
• Ability to sit and be active for 2 hours on a chair (or wheelchair) without cardiac, respiratory and/or pain disturbances as assessed during the screening visit.
• Willingness to give written informed consent.
• Medically stable and not planning for a major change in medications for at least 4 months

Exclusion Criteria:

• Unable to move the hand because of muscle stiffness (scoring 3 or more on the Ashworth scale)
• Have lost the sensation of hand movement
• Have a history of alcohol abuse and/or illicit drug use
• Have a problem with the eyesight that would make it difficult to notice the changing instructions on a computer screen
• Currently enrolled in another research study that might affect this research study
• A history of epilepsy (including family members who are diagnosed with epilepsy)
• An active history of migraine or chronic headache
• A history of mental illness (e.g. schizophrenia, anxiety, depression, and PTSD)
• Past or current history of treated ringing in the ears known as tinnitus or severe hearing problems
• Have a tattoo with metal-based ink in the head or neck.
• Have severe skin damage on the scalp
• Afraid of confined spaces (claustrophobic)
• Have metallic implants, including intracranial electrodes, surgical clips, shrapnel or a pacemaker.
• Currently taking medications that increase the risk of seizures
• Pregnant

double-blinded (participant and the investigator are blinded from knowing the HD-tDCS allocation sequence)