The study authors interviewed and examined 141 patients with whiplash-related pain, and 40 patients with acute ankle injury as a control. Patients were seen at 1 week, and 1, 3, 6, and 12 months after their injury. All patients scored their pain intensity on a 100-point scale, from no pain to unbearable pain. Patients were asked to rate their overall upper-body pain (thus excluding ankle and leg pain), and separately rate pain in the lower back, the neck, the shoulders and arms, and headache pain.
Both groups reported initial similar global pain from their injuries, but pain was more frequent in the whiplash-injured patients. Surprisingly there was no significant difference in the intensity of pain between the two groups in their global pain ratings, despite the confinement of the ratings to the upper body. A significant difference was seen over time, however. Pain in ankle-injured patients declined rapidly, falling from an initial average of 15 to near zero within the first month. In contrast, pain in whiplash-injured patients fell from an average of 20 initially to only 14 after one year. The greatest difference between the groups was seen in shoulder and arm pain, and there was no difference in back pain.
The investigators also found that patients with more pain also had more non-painful neurological complaints, including forgetfulness, irritability, and dizziness. This correlation was not found in ankle-injured patients.
After one year, all ankle-injured patients, and 90 percent of whiplash-injured patients, had returned to work.
"Pain in the neck, head, shoulder, arm, and lower part of the back are frequent complaints in the first year after whiplash injury," said lead study author Helge Kasch, a neurologist at the Aarhus University Hospital in Denmark. However, he said, the benign nature of most whiplash injury is demonstrated by the return to work of most patients within one year.
"This study was not explicitly designed to explore whether whiplash-associated handicap is a physical or psychological phenomenon," he noted. "Although psychological factors may play a role, previous studies have found normal psychological functions, besides distress" in both acute and chronic whiplash patients.
Regarding the unexpectedly high frequency of upper body pain in ankle-injured patients, Kasch noted that specifically inquiring about such symptoms may increase the frequency with which they are reported.
This study was supported by the Danish Society of Polio and Accident Victims; Insurance and Pensions in Denmark; the Danish Medical Research Council; the Danish Pain Research Center; and the Danish Rheumatism Association.
The American Academy of Neurology, an association of more than 18,000 neurologists and neuroscience professionals, is dedicated to improving patient care through education and research.
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Journal
Neurology