Myelopathy associated with age-related cervical disc herniation: a retrospective review of magnetic resonance images

BACKGROUND: Cervical intervertebral disc herniation can lead to myelopathy. Aging is an established variable related to spondylotic myelopathy. Studying this association will help in controlling the increase in spondylotic myelopathy with age. OBJECTIVES: To study the association between cervical disc level, its direction, and the frequency of myelopathy with age, and to assess the epidemiology of age-related cervical disc herniation and myelopathy. DESIGN: Retrospective review of magnetic resonance (MR) images. SETTING: Tertiary referral hospital. PATIENTS AND METHODS: We studied the MR images of adults patients (> 18 years of age) referred to our department between 2001 and 2012 for suspected cervical spondylopathy. The direction and severity of herniation and the presence of myelopathy was determined for spinal levels C2 to C7. MAIN OUTCOME MEASURE(S): Relationship between age-related cervical disc herniation and myelopathy. RESULTS: We studied 6584 patient MR images, which included 2402 males (39.1%) and 3737 females (60.9%). The frequency of myelopathy increased with age from 0.6% in patients < 20 years of age, reaching 9.1% in patients > 70 years of age. The most common level affected by myelopathy was C5-C6. In elderly patients (> 60 years), the C3-C4 level became the predominant level affected by myelopathy. Likewise, the frequency of central disc herniation increased significantly (P <.001) with age at all cervical levels. Furthermore, upper cervical levels showed a higher frequency of central disc herniation than lower cervical levels in the elderly. CONCLUSION: The increased frequency of central disc herniation with age suggest an important, and probably a cause-effect relationship, between herniation and myelopathy.