The Full form of ADS is Acquired Demyelinating Syndrome. ADS are immune-mediated demyelinating disorders of the central nervous system in children. An acute (abrupt) onset of inflammatory demyelination of the central nervous system (CNS) is called acquired demyelinating syndrome (ADS). A nationwide, multicentre and prospective cohort study was initiated in the Netherlands in 2006, with a reported ADS incidence of 0.66/100,000 per year and MS incidence of 0.15/100,000 per year in the period between 2007 and 2010. The first attack of multiple sclerosis (MS) in childhood can appear very different from one child to another. The demyelination can occur in a single location (unifocal) or in more than one location (polyfocal) in the CNS. In this study, we provide an update on the incidence and the long-term follow-up of ADS in the Netherlands. Children below 18 years with a first attack of demyelination were included consecutively from January 2006 to December 2016. Diagnoses were based on the International Paediatric MS study group consensus criteria. Outcome data were collected by neurological and neuropsychological assessments, and telephone call assessments. The reported incidence of ADS in Dutch children has increased since 2010. Residual deficits are common in this group, even in monophasic patients. Therefore, long-term follow-up in ADS patients is warranted.