Seventeen patients with definite and progressive multiple sclerosis entered a double-blind randomized placebo-controlled therapeutic trial of hyperbaric oxygen (HBO). Exposure in monoplace chamber was 90 minutes long each time, 5 days a week, for 4 weeks. The treatment and placebo groups received 100% oxygen at 1.5 bar constant pressure or normal air at 0.1-0.2 bar, respectively. The clinical status of the patients in both groups were compared until one year after treatment. There was no benefit of HBO versus placebo according to the Kurtzke disability status scale. A lesser proportion of patients with deterioration of bowel/bladder function 12 months after therapy was the only benefit of HBO versus placebo according to Kurtzke functional systems scales. On the whole however, HBO is useless in the management of progressive forms of multiple sclerosis.

Confavreux, Mathieu, Chacornac, Aimard, Devic, , , , (1986). [Ineffectiveness of hyperbaric oxygen therapy in multiple sclerosis. A randomized placebo-controlled double-blind study]. Presse medicale (Paris, France : 1983), 1986 Sep;15(28):1319-22. https://www.ncbi.nlm.nih.gov/pubmed/2950392