Grade II Whiplash and Cervical Radiculopathy Similar in Presentation

Whiplash-associated disorders are medical problems that result from having had whiplash, which is caused by having your head suddenly pitched forward forcefully and then jerking backwards at the same rate. Whiplash, of course, results in severe pain, as well as weakness in the arms for some people.

Another painful neck disorder, cervical radiculopathy, is a condition where there is a herniated or bulging disc in the neck that is pressing on the root nerve, causing severe pain. This type of condition is probably the most common neuropathic (nerve-related) pain issue that involves the neck and arms.

Researchers have thought that generalized sensory hypersensitivity (extra strong sensitivity) is the result of how pain is processed in our brain and different sensations are associated with different nerve dysfunction. Now, there is some evidence that people with whiplash-associated disorders and cervical radiculopathy may be experiencing the same type of pain and, therefore, similar pain processing.

The authors of this article wanted to compare patients with chronic whiplash-associated disorders to those with cervical radiculopathy, using a test called Quantitative Sensory Testing. To do this, they recruited 50 patients who had complaints of neck pain for between three months and three years as a result of a motor vehicle accident. According to the whiplash classification called the Quebec Task Force Classification criteria of WAD II, the patients had no loss in muscle power or reflexes. Thirty eight patients with cervical radiculopathy were also included. These patients had to have pain or other symptoms such as numbness past the elbow and sensory or reflex problems that corresponded with the nerve in the neck that was affected. Finally, 31 health volunteers participated as a comparison, or control, group.

The researchers measured the patients' pressure pain thresholds (PPTs) using an instrument called an algometer. Cold pain thresholds were measured using a device that was applied over the skin on both the neck and the hand. The brachial plexus provocation test was also done. The brachial plexus is a network of nerves that go from the neck part of the spine, running down to the shoulder, arm, hand, and fingers.

Other tests included vibration thresholds (VT), thermal (hot, cold) detection thresholds, and current perception thresholds (CPTs). All patients and volunteers completed a questionnaire called the Neck Disability Index (NDI), which measures pain and disability. They also completed the Symptom Check List. At the beginning of the study, all the patients (not the control group) had physical exams.

When gathering the results, the researchers found that there weren't any significant differences between the two pain groups when measuring from side to side for any of the measurements. In the radiculopathy group, the patients had higher detection thresholds for several of the tests on the sides with the injuries, but there was no difference between the radiculopathy and whiplash groups on the sides without the injury. However, both groups had higher detection thresholds (pain, temperature) than the control group.

The authors wrote that it was clear that the two injuries were similar in how the sensitivity was felt. An interesting finding was that people with more severe pain showed greater levels of central pain processing.



References: Andy Chien, B.Phty (Hons) et al. Whiplash (Grade II) and Cervical Radiculopathy Share a Similar Sensory Presentation: An Investigation Using Quantitative Sensory Testing. In Clinical Journal of Pain September 2008. Vol. 24. No. 7. Pp. 595-603.