If medical professionals can intervene quickly enough, the heart can be restarted after a person has officially died, but the resulting brain damage often means they struggle to return to their former motor function and neurological capacity. Now, doctors at LSU Health New Orleans and the University of North Dakota have successfully reversed the brain damage of a two-year-old drowning victim using oxygen therapy techniques.

The doctors explain that the girl's heart stopped after she drowned in a swimming pool, but she was later resuscitated at the Arkansas Children's Hospital. When MRI scans were performed, they revealed deep gray matter injury, and the loss of both gray and white matter. She could no longer speak, walk or respond to voices, and she couldn't stop squirming and shaking her head.

To treat the girl, Dr Paul Harch, the Director of Hyperbaric Medicine at LSU Health, proposed hyperbaric oxygen therapy (HBOT), which involves administering pure oxygen to a patient lying in a pressurized chamber. That wasn't available in the girl's location, so to prevent permanent tissue damage, Harch began a bridging treatment of normobaric oxygen therapy – essentially the same thing, but at a normal pressure, equal to that at sea level.

The normobaric treatment began 55 days after the drowning incident, and involved two 45 minute sessions a day. This continued for about three weeks, and during that time significant improvements were seen. The girl became more alert, stopped squirming, and regained some movement in her arms and hands. She could laugh, eat, track motion with her eyes, and her speech began to return.

The patient and her family then traveled to a hyperbaric oxygen therapy center in New Orleans, where her treatment continued for a further eight weeks. From day 79 after the injury, the girl was placed in a hyperbaric chamber at 1.3 atmospheres of pressure and given pure oxygen for 45 minutes a day, five days a week.

The girl's condition improved throughout the treatment. After 40 sessions and some physical therapy, the doctors reported that she had normal cognition and near-normal motor function, she could speak better than she could before the accident, and could walk with assistance. An MRI taken four weeks after the end of the treatment also showed that the brain damage had almost completely reversed, leaving only mild residual injury.

While it's no doubt a promising and encouraging story, the doctors acknowledge that there are a lot of unknowns still surrounding the treatment and admit their success in this case may be largely due to the girl's young age.

"The startling regrowth of tissue in this case occurred because we were able to intervene early in a growing child, before long-term tissue degeneration," says Harch. "Although it's impossible to conclude from this single case if the sequential application of normobaric oxygen then HBOT would be more effective than HBOT alone, in the absence of HBOT therapy, short duration, repetitive normobaric oxygen therapy may be an option until HBOT is available. Such low-risk medical treatment may have a profound effect on recovery of function in similar patients who are neurologically devastated by drowning."

The report was published in the journal Medical Gas Research.