MAGNETIC-RESONANCE-IMAGING FINDINGS IN 22 CASES OF MYELITIS - COMPARISON BETWEEN PATIENTS WITH AND WITHOUT MULTIPLE-SCLEROSIS

We reviewed the magnetic resonance imaging (MRI) database of the Dent Neurologic Institute to study the abnormal findings in myelitis. We id entified 22 patients, and compared non-MS-related acute transverse mye litis (ATM, n = 9), to myelitis associated with multiple sclerosis (MS -myelitis, n = 13). The ATM patients were significantly older than MS patients at the time of the myelitis diagnosis (mean age 46 vs 35, p < 0.05). ATM appeared as a ''longitudinal myelitis'', with fusiform cor d expansion on T-1-weighted images and intramedullary increased signal on T-2-weighted images, each involving multiple spinal levels (mean = 7-8). However, MS-myelitis lesions appeared focal, involving signific antly fewer spinal levels (mean = 1-2, p < 0.001), although the lesion s were equally likely to expand the cord. Four (42%) of the ATM lesion s showed abnormal, variable enhancement, whereas none of the MS myelit is lesions enhanced. Cranial MRI was more likely to be normal in ATM ( 78%) than in MS-myelitis patients (15%, p < 0.001). Although readily d istinguishable from lesions due to MS, the various etiologies for ATM, including post-infectious (n = 2), post-vaccination (n = 3), and idio pathic (n = 4) were indistinguishable on MRI. The MRI findings of an e xtensively lesioned, swollen cord, suspicious for an intramedullary tu mor and providing a temptation for a biopsy, may reflect a non-neoplas tic inflammatory disorder.