Spring 2004 Volume 16, Number 3	Whiplash Pain? A Solid Reason at Last
	Pain, lawsuits, social withdrawal, malingering. The inability to pin whiplash down, to predict who needs extensive treatment opens a pandora's box of miseries. Many who've undergone the characteristic neck-snapping are OK in a few months. Headache, neck stiffness and other pain gradually ease. But around 20 percent still suffer a half-year later or more. And it's that group that prompted neurosurgeon Donlin Long, M.D., Ph.D., and colleagues to test a hunch on what causes the pain and follow it up with treatment.
"It's hard to define what goes wrong in whiplash. Imaging studies show nothing that's diagnostic," says Long. "Nor does a physical exam." Add whiplash's history of lawsuits and the fact that some studies show many patients stop coming to the doctor once they settle in court, and it's easy to conclude the problem smacks of malingering or that it's psychosomatic. But Long cites figures for non-litigious nations such as Switzerland -- they, too, show 20 percent have persistent pain -- that keep him from dismissing the troubles. The real basis, he believes, is largely musculo-ligamentous. And in a study about to be published, Long is specific: Much lasting whiplash pain comes from rupture of ligaments that longitudinally connect the flat, facet joints of adjacent vertebrae in the upper neck. "You can't see the damage," he says, "because the ligments are just under the visual threshold of what an MRI can image." But in the study he used an indirect technique to sort things out: In blinded, random order, team members injected upper cervical facet joints and their nearby nerve roots with a local anesthetic. Then they watched. "We wanted the needle placement to reproduce patients' pain, to hear them say, That's exactly what I feel." Then, after the anesthetic, eyes should roll heavenward in relief. "We aimed for 100 percent pain blockage. A side study used provocative discography-distending vertebral discs slightly with dye before the anesthesia-to rule out lower cervical disc trouble as a cause. "With diagnostic blocking, you can't say 'Aha, the joint is causing the pain' or 'Aha, it's the disc.' But you can pinpoint a particular vertebral segment as the problem's likely source." Assessing results took skill and experience, Long says. "But then we knew we could offer surgery with reasonable confidence." Of the 67 patients in the study, all who'd searched at least a year for relief, none had whiplash pain stemming from disc problems. "That's important," he adds, "because patients commonly get disc surgery for this pain!" And roughly half undergoing the diagnostic blocking saw their symptoms confirmed and then blocked. For them, Long went on to recommend fusion of the offending vertebrae. Forty-four had surgery-which indeed revealed a high level of ligament damage-and most are pain-free three years later. The take-home message: Here's a solid explanation for whiplash pain that doesn't go away. "If you've got this problem," Long assures, "there's potentially real benefit from fusion surgery." For more information, call 410-955-2251