Pediatric central nervous system inflammatory demyelination: acute disseminated encephalomyelitis, clinically isolated syndromes, neuromyelitis optica, and multiple sclerosis

Abstract

We review the recent consensus definitions for acute disseminated encephalomyelitis,clinically isolated syndromes, neuromyelitis optica, and multiple sclerosis (MS) in children. We also discuss the importance of clinically defined consistency, the need for biomarker-based patient delineation, the likelihood of subsequent MS diagnosis following acute demyelination, and current therapeutic options. Studies of children after a first episode of demyelination have identified disease onset in adolescence, intrathecal oligoclonal bands and optic neuritis as associated with a higher MS risk, whereas prepubertal onset, presence of polyfocal features with encephalopathy, and transverse myelitis have been associated with a lower risk of subsequent MS. The relapsing-remitting form of MS accounts for over 96% of all MS in children. Neuromyelitis optica appears to be a distinct clinical and biological entity for which neuromyelitis optica IgG provides a high degree of specificity. Neuroimaging plays a key role in the diagnosis of acute demyelination, and serial imaging can provide evidence of lesion dissemination in time that can confirm a diagnosis of MS even in the absence of clinical relapse. Although clinical definitions, increased awareness, and MRI have contributed to the increasing identification of acute demyelination and MS in children, challenges remain in predicting MS risk. Identification of reliable biomarkers or application of more advanced neuroimaging techniques would serve as invaluable tools to distinguish monophasic demyelination from the first attack of MS.