Each year, thousands of Americans come to trauma centers across the country with devastating spinal cord injuries, often as the result of an automobile accident. Many die before they reach the hospital; for the survivors, recovery can vary significantly. Once a patient is stabilized after injury, the next question is invariably whether he or she will walk again. A study published in the March 19 issue of The Lancet suggests four simple measures may help physicians predict ambulation outcomes in these individuals with greater than 95 percent accuracy.
Making predictions now
In 2009, Riley Martin, 17, was riding his motorcycle when a large truck pulled out in front of him on the highway. Unable to stop in time, Martin hit the back of the pickup, fracturing his ribs, shoulder, and collar bone and completely severing his spinal column. Martin was taken to a local trauma center where his extensive injuries kept him unconscious for several days. Once he woke up, one of the first questions he remembers asking doctors is whether he would walk again.
It is a common scenario, says Charles Tator, a neurosurgeon at the Toronto Western Hospital in Toronto, Canada. Spinal cord injuries rarely occur alone—and those other injuries, as well as other factors, can make it difficult for doctors to accurately predict whether a person will walk again.
“There are many factors to consider. If the patient has a head injury, a concussion or perhaps a blood clot, if the patient is drunk, on drugs or uncooperative, if there are broken bones, or if the patient is unconscious or medicated by hospital staff, these are all things that can interfere with an accurate prognosis about ambulation,” he says.
Currently, the standard for predictions is an impairment scale created by the American Spinal Injury Association (PDF). Doctors test 20 muscles across the body and rate how well they are working.
“We ask the patient to exert maximum force on a particular muscle—for example, the knee extensor muscle—and then give it a grade of 1 to 5,” says Tator. “There are specific criteria for each grade but a 5 means the muscle is working normally.”
The scores for each muscle are summed to make an ASIA grade. A person who falls in the ASIA category A shows no preserved motor or sensory function and is unlikely to walk again, whereas an ASIA E has complete function and will probably make a full recovery. The ASIA scale is comprehensive, but it usually needs to be conducted several times over the course of a few weeks before doctors can make a strong prediction regarding outcome.
“This scale was established nearly 20 years ago and is a reasonably good method of assessing whether a patient will walk again,” says Tator. “By reasonably good, I mean it’s not perfect. We can’t be 100 percent sure what is going to happen. And neurological status can change dramatically after the first few days of injury. We keep testing so we can get the most accurate neurological picture.”
Some doctors have hoped to discover a simpler and less time-consuming method of predicting a patient's chances of walking again. In a recent pan-European study of more than 1,400 people with serious spinal cord injury, Joost van Middendorp, now a spinal trauma research fellow at the Princess Alexandra Hospital in Brisbane, Australia, determined that a motor assessment of the quadriceps and calf muscles, as well as a sensation test at the inside of the knee and outside of the ankle demonstrated greater than 95 percent accuracy in predicting whether the patient would be walking a year later.
“The ASIA Impairment Scale has been used to estimate the chance of recovery and walking function. The predictions were fairly accurate for very severe and mild cord injuries but not as much for those in the middle,” says van Middendorp. He argues that the four measures identified in his study were better at predicting ambulation outcomes for people who scroe the more ambiguous ASIA grades of B and C.
“Using this mix of motor and sensation measures, physicians can predict walking outcomes better than ever before,” says van Middendorp. “Patient counseling can start early and be based on highly accurate data.”
“There’s always hope”
Tator says while the van Middendorp study is interesting, it’s not going to stop him or his staff from conducting the entire ASIA scale. “It’s a very interesting analysis,” says Tator. “But there’s more to a spinal cord injury prognosis than just walking. Will these four measures predict the return of sexual function? Of bladder function or bowel control? The results of the whole examination help us to make prognoses about these things, too.”
Martin was ultimately classified as an ASIA grade A—a difficult prognosis suggesting he would never walk unassisted again.
“I remember asking every doctor who looked at me, ‘Is there even a chance I’ll walk again?’” he says. “They all said no except one. There was one doctor told me that he’s seen it happen before. There’s always a chance I might walk again.” He is now a client at Project Walk, a recovery and rehabilitation program in Carlsbad, CA, and plans to get out of his wheelchair someday no matter what doctors may say.
“Every case is different. That’s what I focus on,” he says. “I know these predictions help the doctors figure out recovery plans. But no matter what, I’m never going to give up hope. No one should.”
A clinical prediction rule for ambulation outcomes after traumatic spinal cord injury: a longitudinal cohort study.
Dr Joost J van Middendorp MD, Allard JF Hosman MD, A Rogier T Donders PhD, Martin H Pouw MD, Prof John F Ditunno MD, Prof Armin Curt MD, Prof Alexander CH Geurts MD, Hendrik Van de Meent MD, for the EM-SCI Study Group.
The Lancet - 19 March 2011 ( Vol. 377, Issue 9770, Pages 1004-1010 )
Correction: An earlier version of this story incorrectly reported the year of Rily Martin's accident and his age at that time. Reporting about what he remembered from that time also has been changed.