A clinical trial testing hyperbaric
oxygen (HBO) treatment on persistent postconcussion symptoms (PCS)
in U.S. military service members showed no benefits over a sham
procedure in an air-filled chamber, but symptoms did improve in both
the HBO and sham treatment groups compared with a group of patients
who received no supplemental air chamber treatment, according to a
report published online by JAMA Internal Medicine.
Most service members who sustain mild traumatic brain injury (mTBI)
fully recover within 30 days but some patients report chronic
symptoms, which can include headaches, balance issues, sleep
disturbance, forgetfulness and irritability. Some anecdotal evidence
suggests HBO treatment can improve PCS. Those anecdotes prompted the
Department of Defense and the Department Veterans Affairs to create
a clinical research program to evaluate the efficacy and safety of
HBO in a series of randomized, sham-control trials.
Researcher R. Scott Miller, M.D., of the Uniformed Services
University of the Health Sciences, Bethesda, Md., and colleagues
report on the outcomes from one of these preliminary clinical
trials. The Hyperbaric Oxygen Therapy for Persistent Postconcussive
Symptoms after Mild
Traumatic Brain Injury (HOPPS) trial was designed for three
groups of patients: patients who received routine PCS care in the
Department of Defense, patients with routine PCS care supplemented
with HBO for 60 minutes for 40 sessions, and patients who received
routine PCS supplemented with 40 otherwise identical sham sessions
in an air-filled chamber at a level that masked the pressurization
process. Scores on a postconcussion symptoms questionnaire were the
primary outcome measure.
The study included 72 military service members at military hospitals
in Colorado, North Carolina, California and Georgia. The routine
care group had 23 patients, while 24 patients were enrolled in the
HBO group and 25 in the sham group. The median age of patients was
31 years old, 96 percent of the patients were male and they had, on
average, sustained three lifetime mTBIs.
Findings indicate that no differences were seen between groups for
improvement of at least two points (the definition of clinically
significant) on part of the symptoms scale (25 percent in the
routine care/no intervention group met the prespecified 2-point
change as did 52 percent in the HBO group and 33 percent in the sham
group). However, compared with the no intervention group (average
change score, 0.05), both groups with supplemental chamber
procedures showed improved symptoms on a total score (average change
score, 5.4 in the HBO group and 7.0 in the sham group). No
difference between the HBO group and the sham group was seen. All
the chamber sessions were well tolerated.
"Among service members with PCS, HBO showed no benefits over an air
sham compression procedure, but symptoms in both groups improved
compared with mTBI care without supplemental chamber interventions.
This outcome suggests that the observed improvements were not oxygen
mediated but may reflect nonspecific improvements related to placebo
effects. Taken with results from other concurrent investigations,
our study does not support phase 3 trials of
HBO for the treatment of PCS at this time," the study concludes.
Commentary: Hyperbaric Oxygen, Lesson for Postconcussion Symptoms
Treatment
In a related commentary, Charles W. Hoge, M.D., of the Walter Reed
Army Institute of Research, Silver Spring, Md., and Wayne B. Jonas,
M.D., of the Samueli Institute, Alexandria, Va., write: "Although
this trial was technically a pilot investigation designed to produce
data necessary for a pivotal study and will not likely end debate on
this topic (given tenacious advocacy by HBO proponents), these
results are consistent with two other sham-controlled clinical
trials among service members and veterans involving a range of HBO
doses. Given the outstanding methods, consistency in results, and
lack of dose response across these studies, it is increasingly hard
to argue that a phase 3 trial of HBO for the treatment of
postconcussion symptoms (or PTSD) is warranted."
"This conclusion is disappointing for service members and veterans
experiencing war-related symptoms but offers important lessons and
an opportunity to engage in renewed dialogue concerning the
priorities for future interventions. This dialogue requires us to
begin by acknowledging that no new treatments for persistent blast
or impact-related postconcussion symptoms have been identified,
despite the extensive investment to date," they note.
