Eighty four patients with multiple sclerosis were treated in monoplace chambers with either hyperbaric oxygen at 2 atmospheres absolute or placebo. Comprehensive double blind assessment was carried out before, immediately after, and one month after treatment. There was no clinically important or significant benefit in any of the four major criteria of outcome–namely, the patient’s subjective opinion, the examiner’s opinion, the score on the Kurtzke disability status scale, or the time taken to walk 50 m. Out of 40 other clinical variables assessed, two (the sensory scale and timed writing with the left hand) showed a significant improvement without any subjective clinical correlate or change in any of seven other tests of left hand function. No group of symptoms was perceived by the patients as having improved more after treatment with hyperbaric oxygen than placebo. It is concluded that there is no basis for recommending hyperbaric oxygen in the treatment of multiple sclerosis.

Wiles, Clarke, Irwin, Edgar, Swan, , , , (1986). Hyperbaric oxygen in multiple sclerosis: a double blind trial. British medical journal (Clinical research ed.), 1986 Feb;292(6517):367-71. https://www.ncbi.nlm.nih.gov/pubmed/3080173