Differential Diagnosis of Longitudinally Extensive Transverse Myelitis (P02.109)

OBJECTIVE: To report the differential diagnosis of longitudinally extensive transverse myelitis (LETM) patients. BACKGROUND: LETM, a propagate spinal cord (SC) inflammation causing hyper-intensity on T2-weighted magnetic resonance imaging (MRI) over 3 or more vertebral segments, is widely regarded a spectrum of neuromyelitis optica (NMOSD). The broad differential diagnostic of LETM patients is recently discussed, but fairly studied. DESIGN/METHODS: Cross-sectional evaluation of all consecutive patients, admitted at Neurology Department - Sao Paulo University between January 2005 until November 2012, satisfying the straight inclusion criteria: inflammatory transverse myelitis according to transverse myelitis work group (TMWG) and spinal cord lesion extending 3 or more contiguous vertebral segments in MRI. Eligible patients were subjected to complete demographic, clinical, laboratory, spinal fluid analysis, brain and spinal cord MRI. Indirect immunofluorescence assay was used to evaluate aquaporin-4 antibody (NMO-IgG). RESULTS: 128 out of 182 patients were female (70%), 28 caucasian (15%), with 38 mean age (ranging 11 to 72). Differential diagnostic includes: NMO in 84 patients (46,8%), recurrent LETM in 25 (14%), isolated LETM in 30 (16%), MS in 3 (1,6%), infectious in 20 (11%), systemic disease in 8 (4,4%), arterial-venous mal-formation in 8 (4,4%), metabolic in 2 (1%), tumor in 2 (1%) and actinic in 1 patient (0,5%). NMO-IgG sera-positivity was exclusively found in: NMO patients (65%), recurrent LETM (44%) and isolated LETM (20%). LETM associated with rheumatologic, infectious vascular, metabolic, tumoral and actinic etiology were all NMO-IgG negative. CONCLUSIONS: NMOSD is the main diagnosis of LETM in our sample. “Idiopathic” NMO-IgG-negative LETM represent 12%, highlighting the role of other assays to study antiaquaporin-4 antibody, as well as, new antibodies associated with LETM, such as anti-MOG. Furthermore, it is essential to maintain a high index of suspicion for different possible and serious etiologies: infectious and vascular LETM may represent a critical subset with distinct therapeutic and prognosis. Disclosure: Dr. Apostolos-Pereira has received personal compensation for travel grants from Biogen Idec. Dr. Marchiori has nothing to disclose. Dr. Dellavance has nothing to disclose. Dr. Lucato has nothing to disclose. Dr. Jorge has received personal compensation for activities with Novartis and Teva Neuroscience. Dr. Simm has receivedpersonal compensation for activities with Biogen Idec for travel grants. Dr. Sato has received research support from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan and from Ichiro Kanehara Foundation. Dr. Callegaro has received personal compensation for activities with Teva Neuroscience.