Hyperbaric oxygen therapy (HBOT) can lead to significant neurological improvements in post stroke patients, sometimes months or years after their attack, according to new research.

HBOT is currently approved in the United States for decompression sickness (the bends), wound healing, carbon monoxide poisoning, skin grafts and thermal burns, among other applications, according to the authors.

All participants in the study suffered an ischemic or hemorrhagic stroke between 6 and 36 months earlier, and none had shown improvements in their condition for at least a month. Half of the group received 90-minute sessions of oxygen therapy five days a week for two months while the other half received no treatment for two months and then started the oxygen therapy.

Brain imaging performed before and after HBOT showed improvements in brain activity. Some patients showed impressive functional improvements.

Investigators believe oxygen therapy also may be able to help people with other neurological conditions, such as Alzheimer’s, and are currently studying it in patients with traumatic brain injury.