Thoracic spinal cord lesions are influenced by the degree of cervical spine involvement in multiple sclerosis

Study design: Cross-sectional analyses. Objective: To determine whether cervical spinal cord lesions predict the presence of thoracic cord lesions in multiple sclerosis (MS) patients. Setting: Single MS Clinic, AZ, USA. Methods: All MS patients, with MRI studies of the brain, cervical and thoracic spine obtained during a single scanning session, were acquired during a 1-year period. Clinical, demographic and imaging covariates were used in a multivariate regression model to refine predictors of thoracic cord involvement. Results: A total of 687 patients were evaluated, and patients were excluded because of a diagnosis of other neurological disorders, not meeting the 2010 McDonald criteria for MS (n= 222) or incomplete neuraxis imaging (n= 339). The study cohort comprised 126 patients. There was an increase in the odds ratio (OR) of thoracic spine involvement when any cervical spine lesion was present (OR=6.08, 95% confidence interval (2.21-16.68), P<0.001). The multivariate logistic regression model demonstrated a substantial and significant increase in the odds of thoracic spine involvement when more than two cervical spine lesions were present, two lesions (OR 4.44, (0.91-21.60), P=0.06), three lesions (OR 19.76, (3.51-111.17), P=0.001), four or more lesions (OR 20.49, (1.97-213.23), P=0.012) and diffuse lesions (OR 71.94, (5.28-979.88), P=0.001), when adjusting for significant covariates including clinical symptoms, brain lesions, disease duration and treatment exposure. Conclusions: Thoracic spinal cord lesions appear to be predicated on the degree of cervical spine involvement in patients with MS, a risk that appears to be independent of brain findings or clinical features.