ARI Publication 40 – 2013 Version
CGI, ABC, and ATEC scales, but the differences between treatment and placebo groups were not
Rossignol DA, et al: Hyperbaric treatment for children with autism: a multicenter, randomized, doubleblind, controlled trial BMCPediatr 2009, 9:21.
Another randomized, double-blind, placebo-controlled study involved 46 children with autism
undergoing 80 sessions (1.3 atm, 24% oxygen, 6-10 sessions/week). 34 participants completed the
study (most of the withdrawals were due to travel time to the clinic, not adverse effects). In this
study both groups were also receiving intensive ABA therapy (109 hours/month). This study
involved extensive pre and post assessment of autistic symptoms, including both direct observations
of behavior and standardized questionnaires. Overall, there was no difference in improvement in
any of the behavioral assessments, suggesting that HBOT therapy was not significantly beneficial.
Granpeesheh D, et al, Randomized trial ofhyperbaric oxygen therapy for children with autism.
Research in Autism Spectrum Disorders 2010, 4:268-275.
Research on decreased blood flow in brains of children with autism:
Many studies have investigated blood flow in the brains of individuals with autism with brain scans
(PET, SPECT, and fMRI), and they have generally found decreased blood flow (hypoperfusion) in
several parts of the brain. Only one study (Zilbovicius et al 1992) was negative, possibly due to
lower quality of the imaging available at that time. Most of these studies involved small numbers of
participants and even fewer controls, but in total they provide substantial evidence for
hypoperfusion existing in most individuals with autism. One small study included children and
adults with autism, and found that the older individuals had worse hypoperfusion than the younger
ones. One study of 45 children with autism found that the degree of decreased blood flow in one
part of the brain (left superior temporal gyrus) correlated modestly with more severe autism scores
(primarily with restricted/repetitive behaviors). One study (Ohnishi et al 2000) found that
impairments in communication and social interactions correlated with decreased blood flow in one
part of the brain, and that “obsessive desire for sameness” correlated with decreased blood flow in
another part of the brain. Overall, hypoperfusion seems to be a very common problem in children
and adults with autism, and likely has a large effect on their symptoms and cognitive function. The
cause of the hypoperfusion is unknown, but may relate to inflammation of blood vessels leading to
restricted blood flow. Effective treatments for this problem are sorely needed.
Zilbovicius M, etal, Regional cerebral bloodflow in childhood autism: a SPECTstudy. Am J Psychiatry
1992, 149(7):924-930. (21 children with autism and 14 controls)
Zilbovicius Met al., Temporal lobe dysfu,nction in childhood autism: a PET study. Positron emission tomography.
Am J Psychiatry 2000, 157(12):1988-1993. (21 children with autism compared to JO children with mental
Ohnishi T, et al, Abnormal regional cerebral blood flow in childhood autism. Brain 2000, 123(Pt
9):1838-1844. (23 children with autism compared to 26 non-autistic controls matched for age and
Starkstein SE, et al., SPECTfindings in mentallyret;Jrdedautisticindividuals, J Neuropsyd’JiatryGin
Neurasci. 20lXJSummer;143′:370-5. (30 children with autism and mental retardation compared to 14 children
with mental retardation).
Wilcox J, et al, Brain perfusion in autism varies with age. Neuropsychobiology. 2002;46(1):13-6. (14
individuals with autism age 3-37years and 14 age-matched controls)
Meresse G;. etal, Autism severity and temporal lobe functional abnormalities. Ann Neural 2005
Sep;58(3):466-9. (45 children with autism)