Prospective ten-year follow-up study comparing patients with whiplash-associated disorders and asymptomatic subjects using magnetic resonance imaging

Study Design: A prospective 10-year follow-up study of patients with whiplash-associated disorders (WAD) and asymptomatic volunteers. Objective: To clarify long-term impact of whiplash injury on patient's symptoms and on magnetic resonance imaging (MRI) findings of the cervical spine. Summary of background data: Long-term prognosis of WAD has not been fully elucidated. Methods: Between 1993 and 1996, we conducted cross-sectional comparative study of 508 acute WAD patients and 497 asymptomatic volunteers, all of whom underwent MRI of the cervical spine. For this follow-up study, 133 WAD patients and 223 control subjects were recruited again. All participants underwent follow-up MRI and physical examination, and answered to questionnaires regarding neck symptoms. Evaluation of MRI included decrease in signal intensity of discs, posterior disc protrusion, disc space narrowing, and foraminal stenosis using 2 to 4 numerical grades. Increase in the numerical grades by one or more was considered to be progression of degenerative changes. Results: Progression of decrease in signal intensity was observed in 109 WAD patients (82.0%), and 132 control subjects (59.2%), (age, sex adjusted odds ratio [OR]: 3.06), posterior disc protrusion in 101 (75.9%) and in 155 (69.5%) (OR = 1.46), disc space narrowing in 33 (24.8%) and in 59 (26.5%) (OR = 0.98), and foraminal stenosis in 6 (4.5%), and in 20 (9.0%) (OR = 0.52), respectively. Neck pain was observed in 34 WAD patients (25.6%) and 22 control subjects (9.9%) (P < 0.0001). There was no statistically significant correlation between neck pain and progression in each MR finding in either group. Conclusion: The results of this study suggest that, although some WAD patients are more likely to suffer from long-lasting neck pain, MRI findings cannot explain the symptoms.