SCOTTSDALE, ARIZ. — Physicians in Hawaii have described a mysterious nontraumatic myelopathy in seven young people who became weak and could not stand shortly after taking an otherwise uneventful surfing lesson.
Typically, the novices felt some discomfort or pain during the lesson but continued to surf for 15–20 minutes. They did not notice weakness or paresthesias until 10–60 minutes after the onset of symptoms.
By that time, they were sitting on the beach and could not get up. The patients all had symptoms of neurogenic bladder as well.
“We've done all this imaging to try to see what was going on with them. None of them had back fractures, but they had paraplegia—some for a couple of weeks,” Cherylee W.J. Chang, M.D., said at the annual meeting of the Neurocritical Care Society, where she described the cases in a poster.
All seven patients were treated acutely with methylprednisolone (Solu-Medrol). Over time, six patients improved by 1–3 grades on the Acute Spinal Injury Association impairment scale.
Paraplegia appears to be permanent in the oldest patient, a 31-year-old man from Illinois, according to Dr. Chang of the Queen's Medical Center in Honolulu, where she is medical director of the Neuroscience Institute and neurocritical care director of the stroke center.
Dr. Chang said she first heard of a similar case in 1997. After learning of a third surfer with nontraumatic myelopathy, she began collecting case reports. The four males and three females, aged 15–31 years, described in the poster were hospitalized at the Queen's Medical Center during June 2002 to July 2004.
Only one patient had surfed before. The common factor was a basic maneuver in which they hyperextended from a prone to a standing position on their surfboards. Dr. Chang theorized that the rapid movement probably put substantial pressure on their disks.
Plain films and CT scans did not find any fractures. Serologic and cerebrospinal fluid tests were negative, but lumbar punctures revealed elevated protein, along with increases in red and white blood cells. CT angiograms, done in three patients, showed no aortic dissection.
MRI of the spinal cord produced a clue in all but one patient: changes from T7, T8, or T10 to the conus. Several patients also had loss of disk height or small disk protrusions.
Based on these changes and the young age of the patients, Dr. Chang and her colleagues hypothesized that a rise in disk pressure might have caused extrusion of disk materials into small blood vessels leading to fibrocartilaginous embolization.
“In young people, the disk is still cartilaginous and kind of mushy and wet. In old people, it's probably fiber; if you squish it, it's not going anywhere,” she said, speculating that the cartilage had gotten “squished into the vein and into the spinal cord.”
“I can't prove that, because none of our patients died, thank goodness,” she said. “But it's the theory of why this might be happening.”
Dr. Chang is continuing to follow these patients. She said she has heard of a dozen cases at other hospitals in Hawaii and is curious to learn whether physicians have seen similar patients in other surfing communities.