Response to the Harch Group's "A phase I study of low-pressure hyperbaric oxygen therapy for blast-induced post-concussion syndrome and post-traumatic stress disorder"

Effect of hyperbaric oxygenation therapy on post-concussion syndrome

The present review evaluated the effect of hyperbaric oxygenation (HBO) therapy on post-concussion syndrome (PCS). Searches for publications from the earliest date possible up until the first week of 2016 were conducted using the electronic databases Cochrane, EBSCOhost, Embase, Ovid MEDLINE, PubMed and Web of Science. Additional trials were identified through reference list scanning. Randomized controlled trials assessing the effectiveness of HBO therapy in PCS were selected and tested for eligibility for inclusion in the present review. Two independent reviewers conducted data extraction and the Cochrane Collaboration's recommended method was used to assess the risk of bias in each study included. Review Manager 5.3 software was used for data synthesis and analysis and the standardized mean difference (SMD) or mean difference (MD) was estimated with a fixed or random effects model using a 95% confidence interval (CI). A total of 127 articles were identified, 4 of which were eligible for final analysis. The meta-analysis identified no difference in the Rivermead Post-Concussion Symptoms Questionnaire (MD=1.23; 95% CI, -3.47-5.94; P>0.05; I2=35%) or Post-Traumatic Stress Disorder Checklist (PCL) scores (SMD=0.12; 95% CI, -0.31-0.54; P>0.05; I2=0%) scores between groups receiving different oxygen doses. The differences in PCL scores (SMD=-0.13, 95% CI, -0.80-0.53; P>0.05; I2=63%) and neurobehavioral symptoms (SMD=-1.00, 95% CI, -2.58-0.58; P>0.05; I2=92%) between the HBO and sham groups were not significant. The current study demonstrated that HBO therapy has no significant effect on PCS compared with the sham group. Therefore, it was determined that effective design and execution of a large clinical trial, which includes treatment, control and sham groups is required in the future.

Case control study: hyperbaric oxygen treatment of mild traumatic brain injury persistent post-concussion syndrome and post-traumatic stress disorder

Mild traumatic brain injury (TBI) persistent post-concussion syndrome (PPCS) and post-traumatic stress disorder (PTSD) are epidemic in United States Iraq and Afghanistan War veterans. Treatment of the combined diagnoses is limited. The aim of this study is to assess safety, feasibility, and effectiveness of hyperbaric oxygen treatments (HBOT) for mild TBI PPCS and PTSD. Thirty military subjects aged 18-65 with PPCS with or without PTSD and from one or more blast-induced mild-moderate traumatic brain injuries that were a minimum of 1 year old and occurred after 9/11/2001 were studied. The measures included symptom lists, physical exam, neuropsychological and psychological testing on 29 subjects (1 dropout) and SPECT brain imaging pre and post HBOT. Comparison was made using SPECT imaging on 29 matched Controls. Side effects (30 subjects) experienced due to the HBOT: reversible middle ear barotrauma (n = 6), transient deterioration in symptoms (n = 7), reversible bronchospasm (n = 1), and increased anxiety (n = 2; not related to confinement); unrelated to HBOT: ureterolithiasis (n = 1), chest pain (n = 2). Significant improvement (29 subjects) was seen in neurological exam, symptoms, intelligence quotient, memory, measures of attention, dominant hand motor speed and dexterity, quality of life, general anxiety, PTSD, depression (including reduction in suicidal ideation), and reduced psychoactive medication usage. At 6-month follow-up subjects reported further symptomatic improvement. Compared to Controls the subjects' SPECT was significantly abnormal, significantly improved after 1 and 40 treatments, and became statistically indistinguishable from Controls in 75% of abnormal areas. HBOT was found to be safe and significantly effective for veterans with mild to moderate TBI PPCS with PTSD in all four outcome domains: clinical medicine, neuropsychology, psychology, and SPECT imaging. Veterans also experienced a significant reduction in suicidal ideation and reduction in psychoactive medication use.

Clinical utility of SPECT neuroimaging in the diagnosis and treatment of traumatic brain injury: a systematic review

Purpose

This systematic review evaluated the clinical utility of single photon emission computed tomography (SPECT) in traumatic brain injury (TBI).

Methods

After defining a PICO Statement (Population, Intervention, Comparison and Outcome Statement), PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) criteria were applied to identify 1600 articles. After screening, 374 articles were eligible for review. Inclusion for review was focus on SPECT in the setting of mild, moderate, or severe TBI with cerebral lobar specificity of SPECT findings. Other inclusion criteria were comparison modalities in the same subjects and articles in English. Foreign language articles, SPECT studies that did not include comparison modalities, and case reports were not included for review.

Results

We identified 19 longitudinal and 52 cross-sectional studies meeting inclusion criteria. Three longitudinal studies examined diagnostic predictive value. The first showed positive predictive value increases from initial SPECT scan shortly after trauma to one year follow up scans, from 59% to 95%. Subsequent work replicated these results in a larger cohort. Longitudinal and cross sectional studies demonstrated SPECT lesion localization not detected by CT or MRI. The most commonly abnormal regions revealed by SPECT in cross-sectional studies were frontal (94%) and temporal (77%) lobes. SPECT was found to outperform both CT and MRI in both acute and chronic imaging of TBI, particularly mild TBI. It was also found to have a near 100% negative predictive value.

Conclusions

This review demonstrates Level IIA evidence (at least one non-randomized controlled trial) for the value of SPECT in TBI. Given its advantages over CT and MRI in the detection of mild TBI in numerous studies of adequate quality, and given its excellent negative predictive value, it may be an important second test in settings where CT or MRI are negative after a closed head injury with post-injury neurological or psychiatric symptoms.