In February last year, a 2-year-old girl called Eden suffered cardiac arrest and brain damage after she fell into a 5°C (41°F) pool outside and drowned for 10 to 15 minutes.

A team of doctors now claim they have effectively "reversed" the brain damage of the toddler after starting normobaric oxygen and hyperbaric oxygen therapy 55 days post-incident.

Despite these miraculous-sounding results, the treatment still needs further evidence to confirm its efficacy in "similar patients who are neurologically devastated by drowning." The recent case study was published this week in the journal Medical Gas Research.

The theory goes that hyperbaric oxygen therapy increases the amount of oxygen in your blood. This, therefore, improves oxygen delivery for tissue functions to help fight infection or minimize injury.

After the little girl was resuscitated, brains scans revealed significant brain damage involving deep gray matter injury and cerebral atrophy with gray and white matter loss. She was left in a state of constant squirming and head shaking, and was unable to talk, walk, and remained unresponsive to commands.

Dr Paul Harch, clinical professor and director of hyperbaric medicine at LSU Health New Orleans, suggested she try hyperbaric oxygen therapy. However, since the treatment center was not near where the family lived, they began a “bridge” treatment in an attempt to stop further degeneration of brain tissues.

This initial treatment, starting 55 days after the incident, involved breathing in 100 percent normobaric oxygen (oxygen at sea level) for 45 minutes twice a day through the nose. The immediate results appeared to be phenomenal.

“Within hours the patient was more alert, awake, and stopped squirming,” the study notes. Over the next 23 days, the doctors reported the girl laughing, making short sentences, and increasing the movement of her limbs.

By day 78, the family traveled to New Orleans to begin the full hyperbaric oxygen therapy (HBOT), where she had to lay in a hyperbaric chamber for 45 minutes a day, five days a week for 40 sessions. Towards the end of this treatment, she was able to talk more fluently than before the incident, displayed normal cognition, near-normal motor function, and showed an improvement on almost all of her neurological abnormalities.

"Such low-risk medical treatment may have a profound effect on recovery of function in similar patients who are neurologically devastated by drowning,” Dr Paul Harch said in a statement. As Dr Harch also points out, this is just one case.

HBOT is typically used to treat decompression sickness suffered by divers. In recent years, many have claimed it also treats a range of diseases and conditions, but much of these remain unconfirmed by proper clinical trials and the FDA has still not cleared the use of hyperbaric chambers to treat many illnesses.

In 2013, the FDA released a statement called “Hyperbaric Oxygen Therapy: Don't Be Misled”, which explains: “HBOT has not, however, been proven to be the kind of universal treatment it has been touted to be on some Internet sites.”

Results such as Eden's are hard to argue with, but more evidence is needed before HBOT can live up to some of its larger than life claims.