Chronic neck pain. An epidemiological, psychological and SPECT study with emphasis on whiplash-associated disorders

Chronic neck pain, a common cause of disability, seems to be the result of several interacting mechanisms. In addition to degenerative and inflammatory changes and trauma, psychological and psychosocial factors are also involved. One common type of trauma associated with chronic neck pain is whiplash injury; this sometimes results in whiplash-associated disorder (WAD), a controversial condition with largely unknown pathogenetic mechanisms. We studied the prevalence of chronic neck pain of traumatic and non-traumatic origin and compared the prevalence of, sociodemographic data, self-perceived health, workload and chronic low-back pain in these groups. In a ready-made questionnaire (MONICA study), we added questions about cervical spine and low-back complaints. 6,000 (72%) completed a self-administered questionnaire. 43% reported neck pain: 48% of women and 38% of men. Women of working age had more neck pain than retired women, a phenomenon not seen in men. 19% of the studied population suffered from chronic neck pain and it was more frequent in women. A history of neck trauma was common in those with chronic neck pain. Those with a history of neck trauma perceived their health worse and were more often on sick-leave. About 50% of those with traumatic and non-traumatic chronic neck pain also had chronic low-back pain. We assessed the subjective and objective neuropsychological functioning in 42 patients with chronic neck pain, 21 with a whiplash trauma, and 21 without previous neck trauma. Despite cognitive complaints, the WAD patients had normal neuropsychological functioning, but the WAD group especially had deviant MMPI results-indicating impaired coping ability and somatization. WAD patients had no alterations in cerebral blood-flow pattern, as measured by rCBF-SPECT and SPM analysis, compared to healthy controls. This contrasts with the non-traumatic group with chronic neck pain, which showed marked blood-flow changes. The blood-flow changes in the non-traumatic group were similar to those described earlier in pain patients but--remarkably enough--were different from those in the WAD group. Chronic neck pain of whiplash and non-traumatic origin appears to be unique in some respects. A better understanding of the underlying pathological mechanisms is a prerequisite for prevention of the development of such chronic pain syndromes and for improvement of the treatment of patients with severe symptoms.