Research

© Neurorecovery Lab

NeuroRecovery Lab: Advancing Neurorehabilitation through Neuromodulation

At the NeuroRecovery lab, we aim to understand the mechanisms of recovery from brain injury by modulating neural activity, stimulating brain plasticity, and enhancing recovery from brain injury, whether moderate, such as concussion, or severe, such as coma, using neuromodulation techniques. Developing innovative yet translational therapeutic strategies in neurorehabilitation to advance clinical research is our primary goal.

The different ongoing projects at the NeuroRecovery Lab convey to the same objective: to develop new neuromodulation strategies using integrated methodologies aiming at unveiling mechanisms of recovery following a brain injury. Using this approach, we aim to enhance brain plasticity, functional connectivity, and recovery of patients with acquired brain injury.

Brain injury

Mild traumatic brain injury (mTBI), commonly known as a concussion, occurs when a head injury leads to functional changes in the brain and possible damage to its microstructures. Notably, mTBI typically does not present with visible structural lesions on conventional imaging, such as CT scans or MRIs. However, cognitive impairments following mTBI are well-documented and can persist in up to 10-30% of patients. These symptoms often interfere with daily activities, can delay return to school or work, and may significantly impact patients’ quality of life. As a result, some individuals with mTBI remain unemployed one year after the injury. Over the past five years, our hospital's emergency unit has admitted over 3,000 patients with head injuries, yet the majority were discharged without further monitoring or guidance, highlighting a critical gap in the appropriate care and long-term management of mTBI. Therefore, in close collaboration with the CHU Liège, we developed a concussion care pathway (more info on the CHU NeuroRehab & Consciousness Clinic can be found here) with the objective to provide a holistic management of mTBI suffering from persistent symptoms. Currently, several research projects are underway to characterize neural alterations associated with mTBI and to develop targeted therapeutic strategies for patients with persistent post-concussive symptoms.

On the other side of the spectrum, severe brain injuries can lead to conditions commonly referred to as post-coma patients with disorders of consciousness (DoC). Patients with DoC, including vegetative/unresponsive wakefulness syndrome and minimally conscious state, may remain in this condition for days, months, or even years. At present, there are no evidence-based guidelines regarding the treatment of patients with DoC. However, some recent studies demonstrated the potential therapeutic effect of different pharmacological and non-pharmacological interventions. Nevertheless, the mechanisms of recovery are still largely unknown and the current effect size of tested pharmacological and non-pharmacological interventions remain limited. We hence need to develop new yet implementable therapeutic options to promote DoC patients’ recovery.

Taken together, we need to improve our understanding of brain-injured recovery, both mild and severe, which could guide scientists and clinicians to develop novel, individualized and complementary treatment options.  

Non-invasive brain stimulation

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that uses low electrical currents to modulate neuronal activity. tDCS has been applied to improve cognitive functions not only in healthy individuals but also in patients with brain injuries. While the exact neurophysiological mechanisms of tDCS remain unclear, it is believed to enhance neuronal excitability by facilitating the release of action potentials, potentially influencing synaptic plasticity. Short-duration stimulation (typically lasting several minutes) can induce aftereffects that persist for hours, while long-term protocols can have long-lasting neurophysiological and clinical effects. Over the past decade, tDCS has been increasingly used in both research and clinical settings, including stroke rehabilitation, chronic pain management, and depression treatment. Compared to other brain stimulation techniques like transcranial magnetic stimulation (TMS) and deep brain stimulation (DBS), tDCS is often considered safer and more feasible for clinical application.

Transcranial alternating current stimulation (tACS) is another form of non-invasive brain stimulation used to modulate neural activity. Because tACS can target brain oscillations at specific frequencies, it has become a valuable tool for neural entrainment (i.e., brain oscillations can synchronize themselves to an external stimulation). This technique holds promise in enhancing brain network connectivity and could be particularly useful for modulating cortical rhythms involved in cognition, motor function, and sensory processing.

Another approach in NIBS is transcutaneous auricular vagus nerve stimulation (taVNS), which targets the vagus nerve through its auricular branch. taVNS is also thought to have the potential to affect the thalamocortical pathway. In short, by modulating this system in a “bottom-up” manner, taVNS could influence brain regions involved in higher-order functions. One of the key areas affected by taVNS is the default mode network, a network of brain regions that is typically active when a person is at rest and not focused on the outside world. The default mode network is often disrupted in patients with severe brain injuries, such as those in DoC, and in individuals with post-concussion syndrome. By stimulating this network, taVNS could help restore normal brain activity, potentially improving cognitive and attentional function in these patients.

Considering the pathophysiology of brain injuries and the neuromodulatory mechanisms of non-invasive brain stimulation (NIBS), as well as the privileged access to neurophysiology and neuroimaging tools at the GIGA, ULiege and CHU Liege, the team aims to develop new neuromodulation strategies for optimizing neurorehabilitation. This multidisciplinary approach aims to unveil underlaying mechanisms of brain injury, enhance brain plasticity, functional connectivity, and recovery of brain-injured patients.

Clinics

The NRL is part of the CHU NeuroRehab & Consciousness Clinic, Neurology Department, CHU Liege (Pr Lejeune).

The lab also closely collaborates with various departments at the hospital, including the departments of physical medicine and rehabilitation (Pr Kaux), nuclear medicine (Pr Hustinx), radiodiagnostic (Pr Tshibanda) and neuropsychology (Mr Vincent).

Our values

In our lab, the key elements are respect and ethics—toward our work, our colleagues and participants. We aim to provide a work environment that balances autonomy and collaboration, encouraging independent ideas alongside collective scientific contributions.

We value empathy and altruism, recognizing that scientific progress is the fruit of a strong team work and mutual support.

Our work is driven by our determination, enthusiasm and curiosity, which we believe are essential to advancing science and patients care.