Neuromodulatory Interventions for Traumatic Brain Injury

Long-Term Effects of Neurofeedback and Hyperbaric Oxygen Therapy on Traumatic Brain Injury: A Principal Component Analysis (PCA)-Based Secondary Analysis

Severe traumatic brain injury (TBI) poses significant public health challenges, but treatments like neurofeedback and hyperbaric oxygen therapy (HBOT) show promise in aiding recovery. Neurofeedback enhances brain healing through operant conditioning, while HBOT increases cerebral oxygenation, supporting cognitive recovery. A 33-year-old woman, after suffering a severe TBI in 2018 and a long rehabilitation, began HBOT and neurofeedback in late 2021. By early 2022, she demonstrated significant cognitive, emotional, and social improvements. After numerous sessions, a June 2024 quantitative electroencephalogram (qEEG) revealed substantial brain recovery, with marked gains (Peterson et al.'s initial study) in daily functioning and specific tasks. This secondary analysis conducted in November 2024 used principal component analysis (PCA) on the initial pretest, posttest, and difference score data from the treatment period to explore the neurophysiological effects of the combined therapies. The results showed notable factor structure differences in brainwave patterns and electrode activity from the pretest to the posttest. The simpler structure observed in pretests evolved into a more complex factor structure with posttest and difference scores, indicating neurophysiological adaptations due to the interventions. This study's PCA findings align with the post-treatment qEEG statistical results conducted in June 2024 (Peterson et al.'s initial study), which identified moderate to large improvement effect sizes in the patient's brain's average frequency band parameters (g = 0.612) and small to moderate effect sizes on 19 electrode placement outcomes (uV² g = 0.339 and Hz g = 0.333). The June 2024 results indicated significant progress over a 31-month treatment period. In June 2024, the Disability Rating Scale (DRS) and the Glasgow Outcome Scale Extended (GOSE) showed substantial improvements in cognitive abilities such as feeding, toileting, grooming, and communication skills. According to the qEEG effect sizes, as well as DRS and GOSE scores from the pretest (2021) and posttest (2024), the patient demonstrated meaningful gains in brain recovery and overall quality of life. The cognitive improvements identified in the June 2024 Wilcoxon test were further corroborated by the factor structure analysis conducted in the November 2024 PCA. This alignment between the Wilcoxon test results and the PCA findings underscores the robustness of the observed cognitive gains, providing a comprehensive validation of the patient's progress. The consistency across these distinct analytical methods highlights the significant strides made in cognitive function, reinforcing the efficacy of the treatment regimen over the observed period.

The Role of Neuroinflammation in Shaping Neuroplasticity and Recovery Outcomes Following Traumatic Brain Injury: A Systematic Review

Neuroplasticity and neuroinflammation are variables seen during recovery from traumatic brain injury (TBI), while biomarkers are useful in monitoring injury and guiding rehabilitation efforts. This systematic review examines how neuroinflammation affects neuroplasticity and recovery following TBI in animal models and humans. Studies were identified from an online search of the PubMed, Web of Science, and Embase databases without any search time range. This review has been registered on Open OSF (n) UDWQM. Recent studies highlight the critical role of biomarkers like serum amyloid A1 (SAA1) and Toll-like receptor 4 (TLR4) in predicting TBI patients' injury severity and recovery outcomes, offering the potential for personalized treatment and improved neurorehabilitation strategies. Additionally, insights from animal studies reveal how neuroinflammation affects recovery, emphasizing targets such as NOD-like receptor family pyrin domain-containing 3 (NLRP3) and microglia for enhancing therapeutic interventions. This review emphasizes the central role of neuroinflammation in TBI, and its adverse impact on neuroplasticity and recovery, and suggests that targeted anti-inflammatory treatments and biomarker-based personalized approaches hold the key to improvement. Such approaches will need further development in future research by integrating neuromodulation and pharmacological interventions, along with biomarker validation, to optimize management in TBI.

Non-pharmacological interventions for traumatic brain injury

Heterogeneity and variability of symptoms due to the type, site, age, sex, and severity of injury make each case of traumatic brain injury (TBI) unique. Considering this, a universal treatment strategy may not be fruitful in managing outcomes after TBI. Most of the pharmacological therapies for TBI aim at modifying a particular pathway or molecular process in the sequelae of secondary injury rather than a holistic approach. On the other hand, non-pharmacological interventions such as hypothermia, hyperbaric oxygen, preconditioning with dietary adaptations, exercise, environmental enrichment, deep brain stimulation, decompressive craniectomy, probiotic use, gene therapy, music therapy, and stem cell therapy can promote healing by modulating multiple neuroprotective mechanisms. In this review, we discussed the major non-pharmacological interventions that are being tested in animal models of TBI as well as in clinical trials. We evaluated the functional outcomes of various interventions with an emphasis on the links between molecular mechanisms and outcomes after TBI.

Associations of Nightmares and Sleep Disturbance With Neurobehavioral Symptoms Postconcussion

OBJECTIVE

This study investigates the association of nightmares beyond general sleep disturbance on neurobehavioral symptoms in adults with mild traumatic brain injury (mTBI).

DESIGN

Secondary analysis of a concussion cohort study.

PARTICIPANTS

One hundred and eleven adults older than 20 years with mTBI were recruited from a specialized concussion treatment center.

MAIN MEASURES

Behavioral Assessment Screening Tool, Pittsburgh Sleep Quality Index, and self-report of nightmare frequency in the past 2 weeks.

RESULTS

Among adults with mTBI, nightmares accounted for the greatest amount of variability in negative affect (β = .362, P < .001), anxiety (β = .332, P < .001), and impulsivity (β = .270, P < .001) after adjusting for age and sex. Overall sleep disturbance had the strongest association with depression (β = .493, P < .001), fatigue (β = .449, P < .001), self-reported executive dysfunction (β = .376, P < .001), and overall burden from concussive symptoms (β = .477, P < .001).

CONCLUSIONS

Nightmares and sleep disturbance are differentially associated with variance in neurobehavioral symptoms. Nightmares were independently associated with neurobehavioral symptoms representing an excess of normal functioning (eg, anxiety, impulsivity), while general sleep disturbance was associated with neurobehavioral symptoms representing functioning below normal levels (eg, depression, fatigue, self-reported executive dysfunction). Clinical and research implications are discussed.

Optimising recovery of consciousness after coma. From bench to bedside and vice versa

BACKGROUND

Several methods have been proposed to foster recovery of consciousness in patients with disorders of consciousness (DoC).

OBJECTIVE

Critically assess pharmacological and non-pharmacological treatments for patients with chronic DoC.

METHODS

A narrative mini-review, and critical analysis of the scientific literature on the various proposed therapeutic approaches, with particular attention to level of evidence, risk-benefit ratio, and feasibility.

RESULTS AND DISCUSSION

Personalised sensory stimulation, median nerve stimulation, transcranial direct current stimulation (tDCS), amantadine and zolpidem all have favourable risk-benefit ratios and are easy to implement in clinical practice. These treatments should be proposed to every patient with chronic DoC. Comprehensive patient management should also include regular lifting, pain assessment and treatment, attempts to restore sleep and circadian rhythms, implementation of rest periods, comfort and nursing care, and a rehabilitation program with a multi-disciplinary team with expertise in this field. More invasive treatments may cause adverse effects and require further investigation to confirm preliminary, encouraging results and to better define responders' intervention parameters. Scientific studies are essential and given the severity of the disability and handicap that results from DoC, research in this area should aim to develop new therapeutic approaches.

Interventions Facilitating Recovery of Consciousness Following Traumatic Brain Injury: A Systematic Review

People who experience disorders of consciousness (DoC) following a severe traumatic brain injury (TBI) have complex rehabilitation needs addressed by occupational therapy. To examine the effectiveness of interventions to improve arousal and awareness of people with DoC following a TBI. For this systematic review, we followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched six databases in collaboration with a research librarian. Twenty-seven studies were included and grouped thematically. Multimodal sensory stimulation, familiar voices telling structured stories, and transcranial direct current stimulation had a moderate level of evidence. Multimodal sensory stimulation had the strongest evidence in support of its use in clinical practice. Occupational therapy practitioners should administer multimodal stimuli frequently as studies reported administering these interventions at least twice daily. Occupational therapy practitioners should incorporate personally relevant, meaningful, salient stimuli into interventions when treating patients with DoC.

Neuromodulation Therapies in Pre-Clinical Models of Traumatic Brain Injury: Systematic Review and Translational Applications

Traumatic brain injury (TBI) has been associated with several lasting impairments that affect quality of life. Pre-clinical models of TBI have been studied to further our understanding of the underlying short-term and long-term symptomatology. Neuromodulation techniques have become of great interest in recent years as potential rehabilitative therapies after injury because of their capacity to alter neuronal activity and neural circuits in targeted brain regions. This systematic review aims to provide an overlook of the behavioral and neurochemical effects of transcranial direct current stimulation (tDCS), transcranial magnetic stimulation (TMS), deep brain stimulation (DBS), and vagus nerve stimulation (VNS) in pre-clinical TBI models. After screening 629 abstracts, 30 articles were pooled for review. These studies showed that tDCS, TMS, DBS, or VNS delivered to rodents restored TBI-induced deficits in coordination, balance, locomotor activity and improved cognitive impairments in memory, learning, and impulsivity. Potential mechanisms for these effects included neuroprotection, a decrease in apoptosis, neuroplasticity, and the restoration of neural circuit abnormalities. The translational value, potential applicability, and the interpretation of these findings in light of outcome data from clinical trials in patients with TBI are discussed.

Effect of neuroanatomy on corticomotor excitability during and after transcranial magnetic stimulation and intermittent theta burst stimulation

Individual neuroanatomy can influence motor responses to transcranial magnetic stimulation (TMS) and corticomotor excitability after intermittent theta burst stimulation (iTBS). The purpose of this study was to examine the relationship between individual neuroanatomy and both TMS response measured using resting motor threshold (RMT) and iTBS measured using motor evoked potentials (MEPs) targeting the biceps brachii and first dorsal interosseus (FDI). Ten nonimpaired individuals completed sham‐controlled iTBS sessions and underwent MRI, from which anatomically accurate head models were generated. Neuroanatomical parameters established through fiber tractography were fiber tract surface area (FTSA), tract fiber count (TFC), and brain scalp distance (BSD) at the point of stimulation. Cortical magnetic field induced electric field strength (EFS) was obtained using finite element simulations. A linear mixed effects model was used to assess effects of these parameters on RMT and iTBS (post‐iTBS MEPs). FDI RMT was dependent on interactions between EFS and both FTSA and TFC. Biceps RMT was dependent on interactions between EFS and and both FTSA and BSD. There was no groupwide effect of iTBS on the FDI but individual changes in corticomotor excitability scaled with RMT, EFS, BSD, and FTSA. iTBS targeting the biceps was facilitatory, and dependent on FTSA and TFC. MRI‐based measures of neuroanatomy highlight how individual anatomy affects motor system responses to different TMS paradigms and may be useful for selecting appropriate motor targets when designing TMS based therapies.