Scientists say they have discovered that breathing low oxygen levels in short bursts could help improve the mobility of people with spinal cord injuries. This is according to a study published in the journal Neurology.
Spinal cord injury (SCI) is defined as disruption to the nerves attached to the spinal cord in the back. When the nerves are damaged, this can lead to reduced feeling in the body and loss of mobility, such as the inability to walk.
According to the National Spinal Cord Injury Statistical Center (NSCISC), there are approximately 12,000 new cases of spinal cord injury in the US every year.
Randy D. Trumbower, of Emory University in Atlanta, GA, and a study author of this most recent research, says that around 59% of all spinal injuries are incomplete. This means damage to the spinal cord is not absolute, so there is potential for the spinal cord to recover.
"Unfortunately, usually a person affected by this type of spinal injury seldom recovers the ability to walk normally," Trumbower adds.
But the investigators believe their new research may give promise to those who have lost mobility as a result of spinal cord injuries.
Patients exposed to hypoxia treatment
To reach their findings, the investigators analyzed 19 individuals who suffered spine injuries between levels C2 (in the neck) and T12 (in the thoracic vertebrae) of the spine.
Participants had no joint shortening, some controlled ankle, knee and hip movements, and they had the ability to walk a minimum of one step without human help.
The subjects were split into two groups. In the first group, nine people were exposed to either hypoxia - short periods of breathing low oxygen levels - or a sham treatment (control treatment) in which they received only normal oxygen levels. After 2 weeks, they received the other treatment.
The hypoxia treatment involved subjects breathing low oxygen levels through a mask for 90 seconds, followed by 60 seconds of normal oxygen levels, and they were required to do this for 40 minutes a day for 5 days.
The second group received either the hypoxia or sham treatment, then they were asked to walk as fast as they could for 30 minutes within 1 hour of the treatment. They were also switched to the other treatment 2 weeks later.
The researchers monitored the participants' walking speed and endurance before the study began, on the first and fifth days of treatment, and 1 and 2 weeks after treatment ceased.
Endurance 'increased by 250%'
The findings revealed that on a 10-meter walking test, participants who received the hypoxia treatment walked an average of 3.8 seconds faster, compared with when they breathed only normal oxygen levels.
On a test of how far subjects could walk in 6 minutes, those who received the hypoxia treatment plus walking increased their endurance by an average of 100 meters - a 250% increase, compared with those who received sham treatment plus walking.
Overall, it was found that all participants showed improved walking ability. In detail, over 30% increased their walking speed by a minimum of 1/10 of a meter per second, and 70% increased their endurance by at least 50 meters.
In an editorial linked to the study, Michael G. Fehlings, of the University of Toronto in Canada, hypothesizes how the hypoxia treatment may work:
"One question this research brings to light is how a treatment that requires people to take in low levels of oxygen can help movement, let alone in those with compromised lung function and motor abilities.
A possible answer is that spinal serotonin, a neurotransmitter, sets off a cascade of changes in proteins that help restore connections in the spine."
The investigators warn that chronic or sustained hypoxia should only be carried out by trained individuals within a supervised medical environment, or it could cause serious injury.
Medical News Today recently reported on a study detailing the creation of a prosthetic bladder that could help urine control for individuals with spinal cord injury.