SCUBA DIVING MAY HOLD PROMISE FOR PARAPLEGICS

Doctors at the John Hopkins Hospital and the Kennedy Krieger Institute have been busy presenting the data they collected in a small study in May.  They found that paraplegics showed improvement after a few days of scuba diving—improvement normally expected only after months of therapy, if at all.

Although the findings must be scientifically scrutinized and explained, they’re offering rare hope for those who have used a wheelchair for years.  More research could lead to new therapies to improve function and quality of life for those paralyzed through accident or disease, even years after the paralysis occurred.

“There is no treatment for people with chronic spinal cord injury, and many believe once you’ve lost the communication between the brain and the extremities, there is nothing you can do to restore lost function,” said Dr. Adam Kaplin, an assistant professor of psychiatry and behavioral science at Hopkins’ School of Medicine.  “What we saw in the water strongly suggests there is some scuba-facilitated restoration of neurological and psychological function in paraplegics.”

The doctors began their study with standard mental and physical tests on veterans paralyzed for an average of 15 years, as they sought scuba diving certification in nine dives over four days in the Cayman Islands.  They retested the group and nine “dive buddies” afterward, and each vet showed temporary improvement on at least one test, while the buddies had no changes.

The changes might not seem significant outside of medical circles, but continued therapy could mean permanent life improvements, said co-director Dr. Daniel Becker.  He is head of pediatric restoration therapy at Kennedy Kreiger’s international Center for Spinal Cord Injury and an assistant professor of neurology at Hopkins.

Scuba diving falls into an area called exercise therapy, which generally is becoming accepted as a means of improving function for paraplegics, said Kim Anderson-Erisman, a researcher and director of education at the Miami Project to Cure Paralysis at the University of Miami School of Medicine.

She said studies in recent years have shown that activities can not only improve function, but also can reduce complications from infection and other bone, skin, and heart problems, particularly in those with “incomplete” injury, or those who have some sensation below the injury site.  The scuba study and other research could help determine how long past an injury a person can improve, and how much, she said.

The doctors can’t yet explain it, and haven’t yet published their data in a medical journal or found much in the way of existing studies on scuba.  But they have a theory that has to do with the effect of nitrogen in the air and pressure from the water on the central nervous system.

Because of pressure at greater depths, more nitrogen is dissolved into blood and body tissues.  An effect of that process is a large increase in serotonin production in the brain and spinal cord tissues.  Serotonin, a neurotransmitter found in the central nervous system, regulates mood and sleep and contributes to cognitive function.

Doctors speculate that all the extra serotonin impacts the central pattern generator in the spinal cord, which acts like a microprocessor and may activate dormant pathways—and restore some function in systems not working properly.

The short-term boost is not a true repair, which may be why the benfits to the vets wore off after a few weeks.  But the doctors say treatment at regular intervals may lead to more and longer lasting mental and physical improvements that might in turn lead to true repair of broken spinal cord pathways.

“It’s just a theory, but it’s testable,” says Becker.