Abstract: We report results of an observational cohort study investigating long-term follow-up in participants from two completed United States military trials of hyperbaric oxygen (HBO₂) for persistent post-concussive symptoms (PCS), as well as challenges in...
Traumatic Brain Injury (TBI)
Linear analysis of heart rate variability in post-concussive syndrome.
Heart rate variability (HRV) represents measurable output of coordinated structural and functional systems within the body and brain. Both mild traumatic brain injury (mTBI) and HRV are modulated by changes in autonomic nervous system function. We present baseline HRV results from an ongoing mTBI clinical trial. HRV was assessed via 24-hour ambulatory electrocardiography; recordings were segmented by physiological state (sleep, wakefulness, exercise, standing still). Time, frequency, and spatial domain measures were summarized and compared with symptoms, sleep quality, and neurological examination. Median low frequency/high frequency (LF/HF) ratio exceeded 1.0 across segments, indicating prevalence of sympathetic modulation. Abnormal Sharpened Romberg Test was associated with 29% LF/HF decrease (95% CI [2.1, 47.7], p=0.04); pathological nystagmus associated with decreased standard deviation of electrocardiogram R-R interval (SDNN) index (25% decrease, 95% CI [0.8, 43.4], p=0.04). Increased sympathetic modulation was associated with increased anger scores (19% LF/HF increase with 5-point State Trait Anger Expression Inventory-2 trait anger increase (95% CI [1.2, 39.1], p=0.04)). A 13% HF increase (95% CI [2.1, 25.7], p=0.02) was observed with increased Pittsburgh Sleep Quality Index scores. These results support autonomic nervous system dysfunction in service members after mTBI.
TBI study questioned: Dr. Weaver response.
Abstract: Weaver, Lindblad, Wilson, Churchill, Deru, , , , (). TBI study questioned: Dr. Weaver response. Undersea & hyperbaric medicine : journal of the Undersea and Hyperbaric Medical Society, Inc, ;44(1):82-85. https://www.ncbi.nlm.nih.gov/pubmed/28768093
Sleep assessments for a mild traumatic brain injury trial in a military population.
Baseline sleep characteristics were explored for 71 U.S. military service members with mild traumatic brain injury (mTBI) enrolled in a post-concussive syndrome clinical trial. The Pittsburgh Sleep Quality Index (PSQI), sleep diary, several disorder-specific questionnaires, actigraphy and polysomnographic nap were collected. Almost all (97%) reported ongoing sleep problems. The mean global PSQI score was 13.5 (SD=3.8) and 87% met insomnia criteria. Sleep maintenance efficiency was 79.1% for PSQI, 82.7% for sleep diary and 90.5% for actigraphy; total sleep time was 288, 302 and 400 minutes, respectively. There was no correlation between actigraphy and subjective questionnaires. Overall, 70% met hypersomnia conditions, 70% were at high risk for obstructive sleep apnea (OSA), 32% were symptomatic for restless legs syndrome, and 6% reported cataplexy. Nearly half (44%) reported coexisting insomnia, hypersomnia and high OSA risk. Participants with post-traumatic stress disorder (PTSD) had higher PSQI scores and increased OSA risk. Older participants and those with higher aggression, anxiety or depression also had increased OSA risk. The results confirm poor sleep quality in mTBI with insomnia, hypersomnia, and OSA risk higher than previously reported, and imply sleep disorders in mTBI may be underdiagnosed or exacerbated by comorbid PTSD.
Traumatic Brain Injury and Attempted Suicide Among Veterans of the Wars in Iraq and Afghanistan
Abstract Studies of the association between traumatic brain injury (TBI) and suicide attempt have yielded conflicting results. Furthermore, no studies have examined the possible mediating role of common comorbid psychiatric conditions in this association. This study...
Chronic Diseases as Barriers to Oxygen Delivery: A Unifying Hypothesis of Tissue Reoxygenation Therapy.
Abstract: Modern medical practice has resulted in the accumulation of a growing number of incurable chronic diseases, many of which are inflammatory in nature. Inflammation establishes a hypoxic microenvironment within tissues, a condition of inflammatory hypoxia...
Erythropoietin in patients with traumatic brain injury and extracranial injury-A post hoc analysis of the erythropoietin traumatic brain injury trial.
Abstract: Erythropoietin (EPO) may reduce mortality after traumatic brain injury (TBI). Secondary brain injury is exacerbated by multiple trauma, and possibly modifiable by EPO. We hypothesized that EPO decreases mortality more in TBI patients with multiple trauma,...
Immediate and delayed hyperbaric oxygen therapy as a neuroprotective treatment for traumatic brain injury in mice.
Abstract: Traumatic brain injury is the most common cause of death or chronic disability among people under-35-years-old. There is no effective pharmacological treatment currently existing for TBI. Hyperbaric oxygen therapy (HBOT) is defined as the inhalation of pure...
Hyperbaric Oxygen Therapy Can Induce Angiogenesis and Regeneration of Nerve Fibers in Traumatic Brain Injury Patients.
Background: Recent clinical studies in stroke and traumatic brain injury (TBI) victims suffering chronic neurological injury present evidence that hyperbaric oxygen therapy (HBOT) can induce neuroplasticity. Objective: To assess the neurotherapeutic effect of HBOT on prolonged post-concussion syndrome (PPCS) due to TBI, using brain microstructure imaging. Methods: Fifteen patients afflicted with PPCS were treated with 60 daily HBOT sessions. Imaging evaluation was performed using Dynamic Susceptibility Contrast-Enhanced (DSC) and Diffusion Tensor Imaging (DTI) MR sequences. Cognitive evaluation was performed by an objective computerized battery (NeuroTrax). Results: HBOT was initiated 6 months to 27 years (10.3 ± 3.2 years) from injury. After HBOT, DTI analysis showed significantly increased fractional anisotropy values and decreased mean diffusivity in both white and gray matter structures. In addition, the cerebral blood flow and volume were increased significantly. Clinically, HBOT induced significant improvement in the memory, executive functions, information processing speed and global cognitive scores. Conclusions: The mechanisms by which HBOT induces brain neuroplasticity can be demonstrated by highly sensitive MRI techniques of DSC and DTI. HBOT can induce cerebral angiogenesis and improve both white and gray microstructures indicating regeneration of nerve fibers. The micro structural changes correlate with the neurocognitive improvements.
Neuroprotective effect of hyperbaric oxygen therapy in a juvenile rat model of repetitive mild traumatic brain injury.
Repetitive mild traumatic brain injury (rmTBI) is an important medical concern for adolescent athletes that can lead to long-term disabilities. Multiple mild injuries may exacerbate tissue damage resulting in cumulative brain injury and poor functional recovery. In the present study, we investigated the increased brain vulnerability to rmTBI and the effect of hyperbaric oxygen treatment using a juvenile rat model of rmTBI. Two episodes of mild cortical controlled impact (3 days apart) were induced in juvenile rats. Hyperbaric oxygen (HBO) was applied 1 hour/day × 3 days at 2 atmosphere absolute consecutively, starting at 1 day after initial mild traumatic brain injury (mTBI). Neuropathology was assessed by multi-modal magnetic resonance imaging (MRI) and tissue immunohistochemistry. After repetitive mTBI, there were increases in T2-weighted imaging-defined cortical lesions and susceptibility weighted imaging-defined cortical microhemorrhages, correlated with brain tissue gliosis at the site of impact. HBO treatment significantly decreased the MRI-identified abnormalities and tissue histopathology. Our findings suggest that HBO treatment improves the cumulative tissue damage in juvenile brain following rmTBI. Such therapy regimens could be considered in adolescent athletes at the risk of repeated concussions exposures.