Acute disseminated encephalomyelitis: a long-term prospective study and meta-analysis

BACKGROUND: There are only a few series in the literature on acute disseminated encephalomyelitis (ADEM) in children. OBJECTIVES AND METHODS: the aims of this study were to perform (i) a prospective clinical/imaging study (1992-2009) on ADEM in children consecutively referred to our institution in Catania, Italy, and (ii) to undertake a systematic review and meta-analysis of published ADEM pediatric cohorts (>10 cases). RESULTS: We identified 17 patients with ADEM (incidence <10 years of age=1.1 per 100 000 person-years). 15 previously published cohorts were compared with our cohort: (i) systematically reviewed (750 cases); and (ii) meta-analyzed (492/750 cases). The 17 patients had the following characteristics: (a) male-to-female ratio, 1.4 (vs. 1.2-1.3 in previous cohorts); (b) mean age at presentation, 3.6 years (vs. 7.1 years in previous cohorts); (c) specific preceding triggering factor, 88% (vs. 69-79% in previous cohorts); (d) the most common initial signs were ataxia, seizures, headache, and thalamic syndrome; (e) brain imaging revealed >3 lesions in 100% (vs. 92% in previous cohorts); (f) the outcome was good in 94% (vs. 70-75% in previous cohorts); and (g) 12% relapsed once (vs. 18% in previous cohorts). CONCLUSIONS: ADEM is generally a benign condition that mosly affects boys more than girls and rarely recurs.