Study design: Prospective longitudinal study, mean follow-up period; 11.7 +/- 0.8 years was conducted from 1995 to 2007.
Objective: To clarify normal aging process of cervical spine and correlation between progression of disc degeneration and development of clinical symptoms.
Summary of background data: Aging of the cervical spine can inevitably occur in anyone. Long-term longitudinal studies following the same individuals are necessary to elucidate the accurate aging processes of the cervical spine.
Methods: Two hundred twenty-three subjects of 497 original cohorts (123 men, 100 women, mean age: 39.0 +/- 15.0, follow-up rate: 44.9%). Subjects, who underwent MRI 10 years ago, underwent another MRI, neurologic examination, and questionnaire survey regarding symptoms related to cervical spine and life style. Following 5 MR findings representing intervertebral disc degeneration were evaluated: (1) decrease in signal intensity of disc, (2) anterior compression of dura and spinal cord, (3) posterior disc protrusion (PDP), (4) disc space narrowing (DSN), and (5) foraminal stenosis (FS).
Results: Progression of degenerative findings was observed in 189 subjects (81.1%). Progression of decrease in signal intensity of disc was observed in 59.6%, anterior compression of dura and spinal cord in 61.4%, PDP in 70.0%, DSN in 26.9%, and FS in 9.0%. Logistic regression analysis revealed that incidence of progression of PDP, DSN, FS was higher in elderly subjects. There were no correlations between any degenerative MR findings and sex, smoking, alcohol, sport, or body mass index. Neck pain, shoulder stiffness, and numbness in upper extremities were recognized in 9.9%, 30.0%, and 4.0% of subjects, and 1 or more clinical symptoms have developed in 34.1% during 10 years.
Conclusion: Progression of degeneration of cervical spine on MRI was frequently observed during 10-year period, with development of symptoms in 34% of subjects. No factor related to progression of degeneration of cervical spine was identified except for age.