[Multiple sclerosis in children: clarifying its place among the demyelinating spectrum]

Multiple sclerosis (MS) is an autoimmune disease caused by the destruction of the myelin layer and the nervous fibers, and secondary by a progressive neuronal damage. It is characterized by episodes of demyelination disseminated in time and space in different areas of the white matter of the CNS which includes periventricular region, spinal cord, brain stem, cerebellum and optical nerve. Due to the confusing differential diagnosis of MS in children with other demyelinating diseases such as ADEM, it is important to reach this diagnosis when there is proof of white matter lesions disseminated in time and space that cannot be explained by any other mechanisms or pathologies. The goal of this paper is to review the diagnostic parameters used for MS in the pediatric age, the dilemmas regarding the validity of diagnostic criteria, clinical manifestations, differentiation of other demyelinating diseases, and the diagnostic process. MS although infrequent, is a valid diagnosis among the spectrum of childhood inflammatory demyelinating diseases. The clinical presentation might be indistinguishable from a multifocal acute disseminated encephalopathy or could be presented with just focal signs. A reasonable clinical judgment and the practice of laboratory tests confirm or rule out the diagnosis. It is not possible to differentiate between ADEM and MS in a first episode, nor by the clinical, the CSF, neither the neuroimaging. There are still needed consensus criteria both clinical and laboratory test. There are many question still to be answered using prospective studies, and standardized clinical measures that will allow the delimitation of the demographic, neurological, and neuropsychological aspects of the MS and other form of acquired demyelinating diseases in children.