MHBOT can be effective in improving SPECT as well as attention and reaction times

In some cases less is more :

Of the 111 children diagnosed with CP (aged 4 to 12 years), only 75 were suitable for neuropsychological testing, assessing attention, working memory, processing speed, and psychosocial functioning. The children received 40 sessions of HBOT or sham treatment over a 2-month period. Children in the active-treatment group were exposed for 1 h to 100% oxygen at 1.75 atmospheres absolute (ATA), whereas the sham group received only air at 1.3 ATA. Children in both groups showed better self-control and significant improvements in auditory attention and visual working memory compared with the baseline.

However, no statistical difference was found between the two treatments. Furthermore, the sham group improved significantly on eight dimensions of the Conners’ Parent Rating Scale, whereas the active treatment group improved only on one dimension. Most of these positive changes persisted for 3 months. No improvements were observed in either group for verbal span, visual attention, or processing speed. Unfortunately, the Collet study increased the pressure to 1.75 ATA of 100% oxygen for 60 min (40 treatments) and to 1.3 ATA in the control group breathing air for 60 min, i.e., a 30% increase in oxygen for the controls.

This dose of HBOT had not been used previously in Cerebral Palsy patients and was possibly an overdose (Harch 2001) and likely inhibited the HBOT group’s gains. Evidence for this was seen in the GMFM data where five of the six scores increased in the HBOT group from immediate post HBOT testing to the 3-month retest versus three of six scores in the controls. Some of the negative effects of 1.75 ATA likely had worn off by this time. Results of the Collet study showed significant improvements in both groups, but no difference between groups. The serendipitous flaw in the study was the 1.3 ATA air control group, which also improved significantly. This underscored the fact that the ideal dose of HBOT is unknown in chronic pediatric brain injury, but it suggested that oxygen signaling may occur at very low pressures.