Cervical spinal cord atrophy

Objective To assess whether cervical spinal cord atrophy heralds the onset of progressive MS. Methods We studied 34 individuals with radiologically isolated syndrome (RIS) and 31 patients with relapsing-remitting MS (RRMS) age matched to 25 patients within a year of onset of secondary progressive MS (SPMS). Two raters independently measured (twice per rater) the cervical spinal cord average segmental area (CASA) (mm) of axial T2-weighted images between C2 and C7 landmarks. The midsagittal T2-weighted image from the end of C2 to the end of C7 vertebra was used tomeasure the cervical spine (c-spine) length (mm). Sex, age at cervical MRI, number and location of cervical spinal cord lesions, c-spine length, and diagnoses were analyzed against the outcome measures of CASA and C2 and C7 slice segmental areas. Results Intrarater and interrater agreement was excellent (intraclass correlation coefficient >0.97). The CASA area (p = 0.03) and C7 area (p = 0.002) were smaller in SPMS compared with RRMS. The C2 area (p = 0.027), CASA (p = 0.004), and C7 area (p = 0.003) were smaller in SPMS compared with RIS. The C2 area did not differ between SPMS and RRMS (p = 0.09). The C2 area (p = 0.349), CASA (p = 0.136), and C7 area (p = 0.228) did not differ between RIS andMS (SPMS and RRMS combined). In the multivariable model, ≥2 cervical spinal cord lesions were associated with the C2 area (p = 0.008), CASA (p = 0.009), and C7 area independent of disease course (p = 0.017). Progressive disease course was associated with the C7 area independent of the cervical spinal cord lesion number (p = 0.004). Conclusion Cervical spinal cord atrophy is evident at the onset of progressive MS and seems partially independent of the number of cervical spinal cord lesions. Classification of evidence This study provides Class III evidence that MRI cervical spinal cord atrophy distinguishes patients at the onset of progressive MS from those with RIS and RRMS. From the Department of Neurology (B.Z., X.G., B.M.K., B.G.W., J.-M.T., O.H.K.), Department of Radiology (B.Z., K.K.), and Department of Health Sciences Research (E.J.A.), Mayo Clinic College of Medicine, Rochester, MN; Department of Neurology (X.G.), The affiliated ZhongShan Hospital of DaLian University, LiaoNing, China; Multiple Sclerosis Center (D.P., C.J.A.), Keck School of Medicine, University of Southern California, Los Angeles; Department of Neurology (C.L.-F.), Hopital Pasteur, Nice, France; Cerrahpasa School of Medicine (A.S.), Istanbul University, Turkey; and Department of Neurology & Neurotherapeutics (D.T.O.), Clinical Center for Multiple Sclerosis, University of Texas Southwestern Medical Center,