Neuromodulation for Mild Traumatic Brain Injury Rehabilitation: A Systematic Review

Abstract

Background: Mild traumatic brain injury (mTBI) results from an external force to the head or body causing neurophysiological changes within the brain. The number and severity of symptoms can vary, with some individuals experiencing rapid recovery, and others having persistent symptoms for months to years, impacting their quality of life. Current rehabilitation is limited in its ability to treat persistent symptoms and novel approaches are being sought to improve outcomes following mTBI. Neuromodulation is one technique used to encourage adaptive neuroplasticity within the brain.Objective: To systematically review the literature on the efficacy of neuromodulation in the mTBI population.Method: A systematic review was conducted using Medline, Embase, PsycINFO, PsycARTICLES and EBM Review. Preferred Reporting Items for Systematic Reviews and the Synthesis Without Meta-analysis reporting guidelines were used and a narrative review of the selected studies was completed. Fourteen articles fulfilled the inclusion criteria which were published in English, investigating an adult sample and using a pre- and post-intervention design. Studies were excluded if they included non-mild TBI severities, pediatric or older adult populations.Results: Thirteen of fourteen studies reported positive reductions in mTBI symptomatology following neuromodulation. Specifically, improvements were reported in post-concussion symptom ratings, headaches, dizziness, depression, anxiety, sleep disturbance, general disability, cognition, return to work and quality of life. Normalization of working memory activation patterns, vestibular field potentials, hemodynamics of the dorsolateral prefrontal cortex and excessive delta wave activity were also seen. The studies reviewed had several methodological limitations including small, heterogenous samples and varied intervention protocols, limiting generalisability. Further research is required to understand the context in which neuromodulation may be beneficial.Conclusions: While these positive effects are observed, limitations included unequal representation of neuromodulation modalities in the literature, and lack of literature describing the efficacy of neuromodulation on the development or duration of persistent mTBI symptoms. Better clarity regarding neuromodulation efficacy could have a significant impact on mTBI patients, researchers, clinicians, and policy makers, facilitating a more productive post-mTBI population. Despite the limitations, the literature indicates that neuromodulation warrants further investigation. PROSPERO registration number: CRD42020161279.

Oculomotor Deficits and Symptom Severity Are Associated With Poorer Dynamic Mobility in Chronic Mild Traumatic Brain Injury

“…Use of virtual reality to encourage motor and cognitive pairing while simulating outdoor environments can provide more realistic models of training. If exercises by themselves are not adequate to induce neuroplasticity in the chronic stage of mTBI, pairing neuromodulation with exercise strategies may provide opportunities to improve functional outcomes ( 93 ).…”

Developing Novel Therapies for Degenerative Cervical Myelopathy [AO Spine RECODE-DCM Research Priority Number 7]: Opportunities From Restorative Neurobiology

“…Neuromodulation is broadly defined by the International Neuromodulation Society as ‘the alteration of nerve activity through targeted delivery of a stimulus, such as electrical stimulation or chemical agents, to specific neurological sites in the body’. 97 Electrical neuromodulation is used in the treatment of conditions and symptoms including but not limited to chronic pain, 98 , 99 movement disorders, 100 - 102 epilepsy, 102 - 104 psychiatric disorders, 105 , 106 stroke, 107 , 108 traumatic brain injury 109 , 110 and sensory deficits. 111 , 112 A variety of devices have been developed to deliver stimulation to the target of interest, with some being invasive such as deep brain stimulation and spinal cord stimulation (SCS) and others noninvasive such as transcranial Direct Current Stimulation (tcDCS), repetitive Transcranial Magnetic Stimulation (rTMS) and peripheral surface electrode Neuromuscular Electrical Stimulation (NMES) or Functional Electrical Stimulation (FES).…”

Use of Novel Concussion Protocol With Infralow Frequency Neuromodulation Demonstrates Significant Treatment Response in Patients With Persistent Postconcussion Symptoms, a Retrospective Study

“…In a 30-month follow up study, 12 of 15 Vietnam veterans with combat-related PTSD did not experience a relapse after receiving alpha-theta brainwave NF compared to 14 veterans receiving treatment as usual who all experienced a relapse ( Peniston and Kulkosky, 1991 ). A report on different neuromodulation techniques for mTBI described positive findings in 13 of 14 papers reviewed, concluding that neuromodulation warrants further investigation ( Buhagiar et al, 2020 ).…”