Coexisting cervical and lumbar disc degeneration and associated MRI phenotypes: a large-scale population-based study

Abstract

Introduction: It remains unknown whether lumbar disc degeneration and patterns therein along with associated lumbar phenotypes (e.g. Modic changes, disc bulge/extrusion) are associated with coexisting cervical degenerative findings on magnetic resonance imaging (MRI). Furthermore, the risk factors attributing to such a manifestation have not been addressed. As such, the following large-scale population-based study addressed the association coexisting cervical and lumbar disc degeneration and other MRI phenotypes as well as risk factors attributed to their development. Methods: Sagittal T2-weighted MRIs were obtained of the entire spine in 2,762 subjects of a population-based cohort of Southern Chinese origin. Imaging assessment was performed of the cervical and lumbar spine to assess the presence and patterns of disc degeneration and other phenotypes. Lumbar disc degeneration was assessed via the Schneiderman scoring scheme and summated to obtain a DD Score. Subjects were further stratified into two groups: Group 1 entailed individuals with normal cervical spines (n=1,847) and Group 2 consisted of individuals with cervical degenerative findings (n=915). Subject demographics were also assessed. Results: Overall, 39.4% were males and 60.6 % were females with a mean age of 41.1 years. The mean age of Group 1 subjects was 38.8 years and Group 2 individuals was 45.8 years (range: 18.2 - 88.4 years) (p<0.001). The mean age of subjects with no lumbar disc degeneration was 33.9 years and those with cervical findings was 43.9 years (p<0.001). Of those individuals with non-degenerated lumbar discs, 18.5% presented with Group 2 findings. Alternatively, 38.9% of individuals with lumbar disc degeneration had coexisting cervical findings and higher age-adjusted lumbar DD scores (p<0.001). A statistically significant difference was noted between lumbar age-adjusted disc bulge/extrusion, number of involved levels, region-specific disc degeneration, and Modic changes with Group 2 (p<0.05). The most significant factor associated with Group 2 was an increase in the number of levels with lumbar disc degeneration (age & sex-adjusted: 1 level OR: 1.4; 2 levels OR: 1.5; 3 levels OR: 1.8; 4 levels OR 2.7; 5 levels OR: 3.7; p<0.05). Discussion: This is the largest MRI study to address the association of cervical to that of lumbar phenotypes on MRI. The presence and patterns of lumbar disc degeneration were significantly associated with cervical degenerative findings, suggesting that perhaps they share a common pathway of degeneration and findings may be predictive. Understanding the interplay between lumbar and cervical degenerative phenotypes and their associated clinical consequences may assist in understanding the etiology of disease and in designing preventative measures for spine degeneration.