Does anyone know of any research into its efficacy?
I came accross the following, and it reminded me of this thread.
Bennett, M. and R. Heard (2004). "Hyperbaric oxygen therapy for multiple sclerosis." Cochrane Database Syst Rev(1): CD003057.
MAIN RESULTS: We identified ten reports of nine trials that satisfied selection criteria (504 participants in total). Two trials produced generally positive results, while the remaining seven reported generally no evidence of a treatment effect. None of our three a priori subgroup analyses placed these two trials in the same group and were therefore unable to account for this difference. Three analyses (of 21) did indicate some benefit. For example, the mean Expanded Disability Status Scale (EDSS) at 12 months was improved in the HBOT group (group mean reduction in EDSS compared to sham -0.85 of a point, 95% confidence interval -1.28 to -0.42, P = 0.0001). Only the two generally positive trials reported on this outcome at this time (16% of the total participants in this review). REVIEWER'S CONCLUSIONS: We found no consistent evidence to confirm a beneficial effect of hyperbaric oxygen therapy for the treatment of multiple sclerosis and do not believe routine use is justified. The small number of analyses suggestive of benefit are isolated, difficult to ascribe with biological plausibility and would need to be confirmed in future well-designed trials. Such trials are not, in our view, justified by this review.
You can find the full abstract at http://lansbury.bwh.harvard.edu/ms_reviews_2004.htm
Actually, there is a lot of interesting reading there.