Hyperbaric oxygen therapy treatment has broad beneficial molecular effects in neurological diseases, underscoring the exciting therapeutic potential of this treatment. Hyperbaric oxygen therapy treatment from a therapeutic perspective in human clinical studies focusing on neurological disorders.
ASD is a group of developmental disorders characterized by inhibition of social behavior and anxiety, among other symptoms. Interestingly, some of the molecular abnormalities exhibited by ASD, such as mitochondrial dysfunction, white matter changes, and hypoperfusion, have been associated with dysfunctions potentially treatable by hyperbaric oxygen therapy. Therefore, hyperbaric oxygen therapy treatment is expected to improve some symptoms of ASD.
A different study by Rossignol et al. The efficacy of two different hyperbaric oxygen therapy protocols was examined: 1.5 ATA with 100% oxygen or 1.3 ATA with 24% oxygen. Inflammation, as measured by reduced levels of C-reactive protein expression and improvements in clinical aspects, including speech and cognitive awareness, was reduced in both groups compared to before treatment. We note that this study was an open-label trial in which subjects were not randomly assigned to their groups. Three additional studies found that clinical and behavioral improvements after HBO therapy included social and cognitive improvements. Unfortunately, these studies did not have a control group, complicating interpretation of the results.
Furthermore, several studies investigating hyperbaric oxygen therapy treatment in the context of ASD have found no major improvements in the aforementioned aspects. In a study conducted by Granpeesheh et al., human ASD subjects were divided into two groups: one group received 1.3 ATA in 24% oxygen, and the other was a sham group that received an ATA room air (21% oxygen). Although clinician and parent ratings did not match on several behavioral tests, no significant differences were found between the two groups in most aspects. We note that in several studies of hyperbaric oxygen therapy treatment, the use of slightly elevated pressures was observed to constitute some form of treatment; therefore, its use as treatment in the control group may pose a problem.
studied the effects of hyperbaric oxygen therapy treatment in a mouse model of fragile X syndrome, a disorder closely associated with ASD, and found improvements in social and anxiety-like behaviors. Since ASD is a sizable spectrum, we believe that more fine-tuned research is needed in this area, focusing on specific groups on the spectrum that may have similar etiologies. In particular, ASD subpopulations known to have mitochondrial dysfunction represent 5% of the overall ASD population and share certain clinical and molecular features. This makes them prime candidates for such studies, in large part because hyperbaric oxygen therapy has been shown to have a positive effect on mitochondrial activity.