Influence of CNS T2-focal lesions on cervical cord atrophy and disability in multiple sclerosis

Mechanisms associated with cervical spinal cord (CSC) and upper thoracic spinal cord (TSC) atrophy in multiple sclerosis (MS) are poorly understood.

To assess the influence of brain, CSC and TSC T2-hyperintense lesions on cord atrophy and disability in MS.

Thirty-four MS patients underwent 3T brain, cervical and thoracic cord magnetic resonance imaging (MRI) and Expanded Disability Status Scale (EDSS) score assessment. CSC/TSC lesion number and volume (LV), whole-brain and cortico-spinal tract (CST) LVs were obtained. Normalized whole CSC and upper TSC cross-sectional areas (CSAn) were also derived. Age- and sex-adjusted regression models assessed associations of brain/cord lesions with CSAn and EDSS and identified variables independently associated with CSAn and EDSS with a stepwise variable selection.

CSC CSAn (β = -0.36, p = 0.03) and TSC CSAn (β = -0.60, p < 0.001) were associated with CSC T2 LV. EDSS (median = 3.0) was correlated with CSC T2 LV (β = 0.42, p = 0.01), brain (β = 0.34, p = 0.04) and CST LV (β = 0.35, p = 0.03). The multivariate analysis retained CSC LV as significant predictor of CSC CSAn (R² = 0.20, p = 0.023) and TSC CSAn (R² = 0.51, p < 0.001) and retained CSC and CST LVs as significant predictors of EDSS (R² = 0.55, p = 0.001).

CSC LV is an independent predictor of cord atrophy. When neurological impairment is relatively mild, central nervous system (CNS) lesion burden is a better correlate of disability than atrophy.