Spinal cord and brain corticospinal tract lesions are associated with motor progression in tumefactive multiple sclerosis

•Spinal cord lesions correlate with progressive disease in typical relapsing remitting MS.•Tumefactive demyelinating lesions occur in ∼2% of MS population.•Tumefactive MS (TMS) presents with signs/symptoms of a cerebral mass.•Progressive disease is uncommon in TMS.•Progression in TMS typically leads to motor impairment. Spinal cord lesions have been associated with progressive disease in individuals with typical relapsing remitting MS (RRMS). In the current study, we aimed to determine if progressive disease is associated with spinal cord lesions in those with tumefactive multiple sclerosis (MS). Retrospective chart review of individuals presenting to Mayo Clinic with tumefactive MS with spinal cord MRIs available (n=159). Clinical data were extracted by chart review. Brain and spinal cord MRIs were reviewed to characterize the tumefactive demyelinating lesion(s) and assess the burden of spinal cord disease. A total of 69 (43%) had spinal cord lesions. Progressive demyelinating disease was documented in 13 (8%); the majority (11/13) with secondary progressive disease. The method of progression was myelopathic in 8/13 (62%), cognitive in 3/13 (23%), motor from a supratentorial lesion in 2/13 (16%). EDSS at last follow-up was higher in those with progression than those without (median 6.0 (2.0-10.0) vs. 2.5 (0-10.0), p = < 0.001). Progressive demyelinating disease occurred in a minority. Patients with progression typically experienced progressive motor impairment, and this occurred exclusively in individuals with lesions in the corticospinal tracts of the brain and/or the spinal cord.