Call me cynical, but since hyperbaric chambers are being purchased by doctors for their offices, for example for autism to name but one, i think we would be hearing more about people being offered these treatments if it worked for many peoples PN. Once a doctor makes an investment in equipment, they want to use it as much as possible to make their money back. It may work for some, either because of their cause or makeup, or at the point they caught it, but i doubt it works for many. I wish it did.