The use of hyperbaric oxygen for veterans with PTSD: basic physiology and current available clinical data.

Post-traumatic stress disorder (PTSD) affects up to 30% of veterans returning from the combat zone. Unfortunately, a substantial proportion of them do not remit with the current available treatments and thus continue to experience long-term social, behavioral, and occupational dysfunction. Accumulating data implies that the long-standing unremitting symptoms are related to changes in brain activity and structure, mainly disruption in the frontolimbic circuit. Hence, repair of brain structure and restoration of function could be a potential aim of effective treatment. Hyperbaric oxygen therapy (HBOT) has been effective in treating disruptions of brain structure and functions such as stroke, traumatic brain injury, and fibromyalgia even years after the acute insult. These favorable HBOT brain effects may be related to recent protocols that emphasize frequent fluctuations in oxygen concentrations, which in turn contribute to gene expression alterations and metabolic changes that induce neuronal stem cell proliferation, mitochondrial multiplication, angiogenesis, and regulation of the inflammatory cascade. Recently, clinical findings have also demonstrated the beneficial effect of HBOT on veterans with treatment-resistant PTSD. Moderation of intrusive symptoms, avoidance, mood and cognitive symptoms, and hyperarousal were correlated with improved brain function and with diffusion tensor imaging-defined structural changes. This article reviews the current data on the regenerative biological effects of HBOT, and the ongoing research of its use for veterans with PTSD.

Cognitive enhancement of healthy older adults using hyperbaric oxygen: a randomized controlled trial.

More than half of community-dwelling individuals sixty years and older express concern about declining cognitive abilities. The current study's aim was to evaluate hyperbaric oxygen therapy (HBOT) effect on cognitive functions in healthy aging adults.A randomized controlled clinical trial randomized 63 healthy adults (>64) either to HBOT(n=33) or control arms(n=30) for three months. Primary endpoint included the general cognitive function measured post intervention/control. Cerebral blood flow (CBF) was evaluated by perfusion magnetic resonance imaging.There was a significant group-by-time interaction in global cognitive function post-HBOT compared to control (p=0.0017). The most striking improvements were in attention (net effect size=0.745) and information processing speed (net effect size=0.788).Voxel-based analysis showed significant cerebral blood flow increases in the HBOT group compared to the control group in the right superior medial frontal gyrus (BA10), right and left supplementary motor area (BA6), right middle frontal gyrus (BA6), left middle frontal gyrus (BA9), left superior frontal gyrus (BA8) and the right superior parietal gyrus (BA7).In this study, HBOT was shown to induce cognitive enhancements in healthy aging adults via mechanisms involving regional changes in CBF. The main improvements include attention, information processing speed and executive functions, which normally decline with aging.

Hyperbaric oxygen therapy improves neurocognitive functions of post-stroke patients - a retrospective analysis.

BACKGROUND: Previous studies have shown that hyperbaric oxygen therapy (HBOT) can improve the motor functions and memory of post-stroke patients in the chronic stage. OBJECTIVE: The aim of this study is to evaluate the effects of HBOT on overall cognitive functions of post-stroke patients in the chronic stage. The nature, type and location of the stroke were investigated as possible modifiers. METHODS: A retrospective analysis was conducted on patients who were treated with HBOT for chronic stroke (>3 months) between 2008-2018. Participants were treated in a multi-place hyperbaric chamber with the following protocols: 40 to 60 daily sessions, 5 days per week, each session included 90 min of 100% oxygen at 2 ATA with 5 min air brakes every 20 minutes. Clinically significant improvements (CSI) were defined as > 0.5 standard deviation (SD). RESULTS: The study included 162 patients (75.3% males) with a mean age of 60.75±12.91. Of them, 77(47.53%) had cortical strokes, 87(53.7%) strokes were located in the left hemisphere and 121 suffered ischemic strokes (74.6%).HBOT induced a significant increase in all the cognitive function domains (p < 0.05), with 86% of the stroke victims achieving CSI. There were no significant differences post-HBOT of cortical strokes compared to sub-cortical strokes (p > 0.05). Hemorrhagic strokes had a significantly higher improvement in information processing speed post-HBOT (p < 0.05). Left hemisphere strokes had a higher increase in the motor domain (p < 0.05). In all cognitive domains, the baseline cognitive function was a significant predictor of CSI (p < 0.05), while stroke type, location and side were not significant predictors. CONCLUSIONS: HBOT induces significant improvements in all cognitive domains even in the late chronic stage. The selection of post-stroke patients for HBOT should be based on functional analysis and baseline cognitive scores rather than the stroke type, location or side of lesion.

Improvement of memory impairments in poststroke patients by hyperbaric oxygen therapy.

OBJECTIVE: Several recent studies have shown that hyperbaric oxygen (HBO2) therapy carry cognitive and motor therapeutic effects for patients with acquired brain injuries. The goal of this study was to address the specific effects of HBO2 on memory impairments after stroke at late chronic stages. METHOD: A retrospective analysis was conducted on data of 91 stroke patients 18 years or older (mean age ∼60 years) who had either ischemic or hemorrhagic stroke 3-180 months before HBO2 therapy (M = 30-35 months). The HBO2 protocol included 40 to 60 daily sessions, 5 days per week, 90 min each, 100% oxygen at 2ATA, and memory tests were administered before and after HBO2 therapy using NeuroTrax's computerized testing battery. Assessments were based on verbal or nonverbal, immediate or delayed memory measures. The cognitive tests were compared with changes in the brain metabolic state measured by single-photon emission computed tomography. RESULTS: Results revealed statistically significant improvements (p < .0005, effect sizes medium to large) in all memory measures after HBO2 treatments. The clinical improvements were well correlated with improvement in brain metabolism, mainly in temporal areas. CONCLUSIONS: Although further research is needed, the results illustrate the potential of HBO2 for improving memory impairments in poststroke patients, even years after the acute event.

Hyperbaric oxygen therapy can improve post concussion syndrome years after mild traumatic brain injury - randomized prospective trial.

BACKGROUND: Traumatic brain injury (TBI) is the leading cause of death and disability in the US. Approximately 70-90% of the TBI cases are classified as mild, and up to 25% of them will not recover and suffer chronic neurocognitive impairments. The main pathology in these cases involves diffuse brain injuries, which are hard to detect by anatomical imaging yet noticeable in metabolic imaging. The current study tested the effectiveness of Hyperbaric Oxygen Therapy (HBOT) in improving brain function and quality of life in mTBI patients suffering chronic neurocognitive impairments. METHODS AND FINDINGS: The trial population included 56 mTBI patients 1-5 years after injury with prolonged post-concussion syndrome (PCS). The HBOT effect was evaluated by means of prospective, randomized, crossover controlled trial: the patients were randomly assigned to treated or crossover groups. Patients in the treated group were evaluated at baseline and following 40 HBOT sessions; patients in the crossover group were evaluated three times: at baseline, following a 2-month control period of no treatment, and following subsequent 2-months of 40 HBOT sessions. The HBOT protocol included 40 treatment sessions (5 days/week), 60 minutes each, with 100% oxygen at 1.5 ATA. "Mindstreams" was used for cognitive evaluations, quality of life (QOL) was evaluated by the EQ-5D, and changes in brain activity were assessed by SPECT imaging. Significant improvements were demonstrated in cognitive function and QOL in both groups following HBOT but no significant improvement was observed following the control period. SPECT imaging revealed elevated brain activity in good agreement with the cognitive improvements. CONCLUSIONS: HBOT can induce neuroplasticity leading to repair of chronically impaired brain functions and improved quality of life in mTBI patients with prolonged PCS at late chronic stage. TRIAL REGISTRATION: ClinicalTrials.gov NCT00715052.