Mielitis. Diferencias entre esclerosis múltiple y otras etiologías

espanolIntroduccion Un primer brote de mielitis puede ocurrir en el contexto de enfermedades desmielinizantes, inflamatorias sistemicas o infecciosas. Nuestro objetivo fue analizar las diferencias entre mielitis asociadas a esclerosis multiple (EM) y mielitis por otras etiologias. Metodos Analisis retrospectivo, unicentrico, de pacientes con primer brote de mielitis (2000-2013). Se analizaron variables demograficas, etiologicas, clinicas, radiologicas y pronosticas, y se compararon entre mielitis por EM y mielitis por otras etiologias. Resultados Se incluyo un total de 91 pacientes. Tiempo medio de seguimiento: 7 anos. Diagnosticos: EM 57 (63%), mielitis transversa idiopatica 22 (24%), asociada a enfermedades sistemicas 6 (7%), otros diagnosticos (6%). Mielitis por EM: menor edad de inicio (35 ± 11 vs .41 ± 13; p = 0,02), mayor afectacion esfinteriana (40,4 vs. 27,3%; p = 0,05), mayor afectacion multifocal en la RM medular (77,2 vs. 26,5%; p = 0,001), menor extension de la lesion (segmentos vertebrales 2,4 vs. 1,4; p = 0,001), localizacion cervical (82,5 vs. 64,7%; p = 0,05) y localizacion posterior (89,5 vs. 41,2%; p = 0,001). Mielitis por otras etiologias: mayor localizacion anterior (47,1 vs. 24,6%; p = 0,02) y centromedular (47,1 vs. 14,1%; p = 0,001) y mejor recuperacion al ano (EDSS 2,0 vs. 1,5; p = 0,01). Analisis multivariante: la afectacion multifocal medular (OR 9,38; IC 95%: 2,04-43,1) y del cordon posterior (OR 2,16; IC 95%: 2,04-2,67) se asociaron de forma independiente al diagnostico de EM. Conclusiones Un alto porcentaje de pacientes con un primer brote de mielitis seran diagnosticados de EM. La presencia de lesiones medulares multifocales y en el cordon posterior se asocian de forma significativa a este diagnostico. EnglishBackground Myelitis can appear as an initial symptom in the context of demyelinating diseases, systemic inflammatory diseases, and infectious diseases. We aim to analyse the differences between myelitis associated with multiple sclerosis (MS) and myelitis resulting from other aetiologies. Methods Single-centre, retrospective analysis of patients with initial myelitis (2000-2013). Demographic, aetiological, clinical, radiological and prognostic variables were analysed and compared between patients with myelitis from MS and those with myelitis due to other aetiologies. Results We included 91 patients; mean follow-up was 7 years. Diagnoses were as follows: MS 57 (63%), idiopathic transverse myelitis 22 (24%), associated systemic diseases 6 (7%), and other diagnoses (6%). Myelitis due to MS was associated with younger age of onset (35 ± 11 vs. 41 ± 13; P = .02), more pronounced sphincter involvement (40.4 vs. 27.3%; P=.05), greater multifocal involvement in spinal MRI (77.2 vs. 26.5%; P=.001), shorter lesion extension (2.4 vs. 1.4 vertebral segments; P=.001), cervical location (82.5 vs. 64.7%; P=.05) and posterior location (89.5 vs. 41.2%; P=.001). Myelitis due to other aetiologies more frequently showed anterior location (47.1 vs. 24.6%; P=.02), and central cord involvement (47.1 vs. 14.1%; P=.001), with better recovery at one year of follow up (EDSS 2.0 vs. 1.5; P=.01). Multivariate analysis showed that multifocal spinal cord involvement (OR 9.38, 95% CI: 2.04-43.1) and posterior cord involvement (OR 2.16, 95% CI: 2.04-2.67) were independently associated with the diagnosis of MS. Conclusions A high percentage of patients with an initial myelitis event will be diagnosed with MS. The presence of multifocal and posterior spinal cord lesions was significantly associated with the diagnosis of MS.