HBOT Conversations:

This is a Phase II randomized trial designed to describe the magnitude of change between
baseline and follow-up outcomes for symptom surveys and a battery of neuropsychological tests
administered at time points corresponding before and after 10 weeks over observation in four
groups:

– A military population with post-concussion syndrome (mTBI) receiving local standard care

– A military population with post-concussion syndrome (mTBI) receiving local standard care
and sham hyperbaric oxygen sessions

– A military population with post-concussion syndrome (mTBI) receiving local standard care
and hyperbaric oxygen at 1.5 atmospheres sessions

– A otherwise similar group with PTSD but no history of TBI receiving local standard care
Differences and variability of the tests will be used for determining the optimum
primary endpoint(s) for future trial, as well as for refinement of sample size and power
calculations for these studies. The groups undergoing hyperbaric sessions will be
assigned to receive HBO2 or sham using a randomized, double blind design.

Active duty military (Army, Marine, Navy, Air Force) men and non-pregnant women residing in
the United States and who will remain in the military for the entire study period, aged 18-65
years who have been deployed one or more times to the US Central Command since the initiation
of Operation Enduring Freedom (October 7, 2001) who either:

– have been diagnosed with Post Traumatic Stress Disorder (PTSD) as a result of traumatic
events that occurred during the qualifying CENTCOM deployment, but have no diagnosed or
suspected lifetime brain injuries resulting in loss or alteration of consciousness; OR

– have been diagnosed with at least one mild brain injury (mTBI) with persistent (> 4
months) symptoms sustained during one or more of those deployments