SATURDAY, Sept. 17 (HealthDay News) -- Paralyzed veterans who learned to scuba dive experienced both physical and mental improvements, a new study suggests.

Researchers brought 10 paralyzed veterans and nine healthy participants to the Cayman Islands in May for a four-day scuba certification course.

Before the dives, researchers did a series of neurological and psychological tests, measuring muscle spasticity, motor control and sensitivity to pinprick and light touch, as well as symptoms of depression, obsessive-compulsive disorder, hostility and post-traumatic stress disorder (PTSD).

Participants did nine dives over four days. Eight of the 10 paraplegics were able to complete the dives.

Afterward, researchers ran the tests again.

The results: those who dived experienced an average 15 percent drop in muscle spasticity; a 10 percent improvement in sensitivity to light touch; and a 5 percent improvement in the ability to feel a pinprick. In some cases tone, sensation and motor function went up as much as 20 percent to 30 percent.

Psychologically, participants also experienced a drop in obsessive-compulsive symptoms, depression and post-traumatic stress disorder (PTSD).

By contrast, the healthy divers experienced no improvement of any kind.

"We saw dramatic changes in a matter of days in a number of people with spinal cord injury who went scuba diving," said study co-author Dr. Daniel Becker, head of pediatric restoration therapy at the International Center for Spinal Cord Injury at Kennedy Krieger Institute and an assistant professor of neurology at Johns Hopkins University School of Medicine in Baltimore. "This is just a pilot study, but to see such a restoration of neurological function and significant improvement in PTSD symptoms over such a short period of time was unprecedented."

The findings were to be presented Saturday at the Paralyzed Veterans of America conference in Orlando, Fla. Because this study was presented at a medical meeting, the conclusions should be viewed as preliminary until published in a peer-reviewed journal.

Researchers said the next step is determining what about scuba diving may be beneficial in a larger sample of participants, and whether those improvement are lasting.

They also acknowledged that being on a Caribbean vacation may have helped injured veterans' mental state.

More information

For more on spinal cord injuries, visit the U.S. National Institute of Neurological Disorders and Stroke.