Introduction: Congenital Spinal Stenosis (CSS) is a known predisposing factor for Degenerative Cervical Myelopathy (DCM). In a cohort of DCM patients, MRI-based criteria were developed to diagnose pre-existing CSS. Furthermore, patient characteristics and surgical outcomes were compared between patients with and without CSS.
Methods: Study data (including 349 MRIs for quantitative analysis) were derived from two international prospective and multicenter studies. Spinal canal and cord anteroposterior diameters were measured above and below the region of interest at non-compressed sites, and a spinal cord occupation ratio (SCOR) was calculated. A SCOR=70% was used to diagnose patients with CSS. Clinical and MRI factors were compared between patients with and those without CSS using t-tests. Multiple linear regression was used to assess the impact of CSS on surgical outcome.
Results: Calculation of SCOR was feasible in 311/349 patients (89%). Twenty-six patients with CSS were identified (8.4%). Patients with CSS were younger than patients without CSS (50.8 vs. 56.3, p=0.03) and had worse baseline severity as measured by the mJOA (p=0.04), Nurick (p=0.05) and NDI (p<0.01). CSS patients also presented more commonly with T2 cord hyperintensity changes (p=0.09), and worse SF-36 Physical Component scores (p=0.06), though these factors did not reach statistical significance. SCOR was correlated with Torg-Pavlov ratio and spinal canal diameter at C3 but not C5.
Conclusions: CSS patients develop myelopathy at a younger age and have greater impairment and disability than other patients with DCM. Despite this, CSS patients have comparable duration of symptoms, MRI presentations, and surgical outcomes to DCM patients without CSS.
Patient Care: To determine if CSS patients have comparable duration of symptoms, MRI presentations, and surgical outcomes to DCM patients without CSS.
Learning Objectives: In a cohort of DCM patients, MRI-based criteria were developed to diagnose pre-existing CSS