A football player lies motionless after having made a tackle. He's conscious but has no sensation in his arms or legs. Everyone in the stadium holds his or her breath as the trainers -- and the stretcher-bearers -- rush onto the field.
The player likely is suffering from what trainers and sports medicine physicians call spinal shock, a term they use to describe a concussion-like injury to the spinal cord that leads to a temporary loss of feeling and motor reflexes below the area of injury.
This doesn't happen often -- only about one athlete in 100,000 experiences it, according to Dr. Tanya Hagen, a sports medicine physician for UPMC -- but it's frightening when it does.
"This kind of thing is the scariest thing I've ever had to deal with," said Dr. Hagen, who has provided medical assistance at dozens of local high school football games. "We can deal with blood and bones and other traumatic injuries, but when it comes to the spine ...
"We take it seriously when it happens," said Dr. Jack Wilberger, chair of the department of neurosurgery at Allegheny General Hospital. "But as it turns out, fortunately, it's a scary problem but relatively benign."
What Dr. Hagen calls spinal shock really ought to be called spinal concussion, said Dr. Adam Kanter, a neurosurgeon who is director of UPMC's Minimally Invasive Spine program.
"Spinal shock and spinal concussion are often used interchangeably, but they shouldn't be," Dr. Kanter said. "Spinal shock involves loss of sensation, motor paralysis and reflexes that is often the result of a spinal cord injury. This does not typically recover."
Spinal concussion, on the other hand, "by definition is transient in nature," he said. "It often involves the immediate onset of sensory and motor deficits in the arms or the legs that fully resolve in 15 or 30 minutes or so."
The problem with the neurosurgeon's definition from a sports medicine physician's perspective, Dr. Hagen said, is that the sports medicine physician can't tell at the time of the injury whether it's the really, really bad thing (spinal shock) or the less serious deal (spinal concussion).
"There is no way to tell how severe the injury is, based on a physical exam alone," Dr. Hagen said. That requires hospital tests.
Dr. Wilberger works a lot with athletes. So although he makes the same distinction Dr. Kanter does, he is comfortable with the more broadly used definition.
Spinal shock, Dr. Wilberger said, "is basically like a concussion to the brain. A temporary loss of function, usually with a stinger-like sensation. Usually resolved in a short period of time."
Four out of five athletes who get spinal concussions recover completely and will show no abnormalities on tests, Dr. Wilberger said.
But in about 20 percent of athletes who experience spinal concussions, "more so in college and the pros because they've been banged around longer," tests will indicate spinal stenosis, a narrowing of the space available to the spine, Dr. Wilberger said.
"Stenosis may have no consequences," he said. But if stenosis is extremely severe, "it can cause problems with spinal cord functioning. People might not be able to walk as a result of it."
Because it is so rare, and because most who experience it recover quickly and fully, much less research has been done on spinal concussion than on brain concussions.
"We don't have an experimental model for spinal concussion," Dr. Kanter said. "Therefore, it is very poorly studied."
Such research as has been done indicates that otherwise healthy individuals who suffer a spinal concussion are not at greater risk, Dr. Hagen said.
"If one has had a spinal concussion, it does not necessarily predispose to having another spinal concussion," she said.
"While people say that those who have this injury are prone to having it multiple times, they are not prone to having it turn into a serious injury," Dr. Wilberger said.
But athletes who suffer from spinal stenosis, disc herniations or spinal contusions -- bruising of the spine, causing inflammation and bleeding from blood vessels near the injury -- are at greater risk for a second spinal concussion, with more serious consequences, Dr. Kanter said.
This is why "anybody who has [spinal concussion] should be seen by a spine professional and receive X-rays and an MRI," Dr. Kanter said.
The good news about spinal concussions is that they are rare. The better news is that they are getting more rare.
"Usually we see five or six cases in the course of a football season," Dr. Wilberger said. "So far, we haven't seen any."
Dr. Hagen noted the decline in the number of spinal concussion cases has coincided with a ban on spear tackling, which is leading with the helmet. She thinks poor tackling technique may be a greater contributor to the injury than congenital spine defects.
Jack Kelly: email@example.com or 412-263-1476.