Acute disseminated encephalomyelitis (ADEM) is an immunologically mediated inflammatory disease of the central nervous system that typically occurs after a viral infection or recent vaccination, and is most commonly seen in the pediatric population. In 2007 the International Pediatric Multiple Sclerosis Study Group proposed a consensus definition for ADEM for application in research and clinical settings. This article gives an overview of ADEM in children, focusing on differences that have emerged since the consensus definition was established. Although the focus is on neuroimaging in these patients, a synopsis of the clinical features, immunopathogenesis, treatment, and prognosis of ADEM is provided.

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Acute neurological changes in sickle cell disease (SCD) patients often raise the suspicion for stroke. Posterior reversible encephalopathy syndrome (PRES) can mimic stroke in its clinical presentation. We aimed to (i) review the PRES literature in SCD patients including clinical presentation, risk factors, pathophysiology, and management and (ii) elucidate the distinction between PRES and stroke in SCD. The exact pathophysiology of PRES in SCD remains elusive but is likely multifactorial and related to sickling, ischemia, and chronic anemia predisposing to vasogenic edema. PRES and stroke in SCD are distinguishable conditions. Our review may help elucidate a clinical approach to this distinction.

SHQ1 is essential for biogenesis of H/ACA ribonucleoproteins, a class of molecules important for processing ribosomal RNAs, modifying spliceosomal small nuclear RNAs, and stabilizing telomerase. Components of the H/ACA ribonucleoprotein complex have been linked to neurological developmental defects. Here we report two sibling pairs from unrelated families with compound heterozygous variants in SHQ1. Exome sequencing was used to detect disease causing variants which were submitted to ‘matching’ platforms linked to MatchMaker Exchange. Phenotype comparisons supported these matches. The affected individuals present with early-onset dystonia, with individuals from one family displaying additional neurological phenotypes, including neurodegeneration. As a result of CSF studies suggesting possible abnormal dopamine metabolism, a trial of levodopa replacement therapy was started but no clear response was noted. We show that fibroblasts from affected individuals have dramatic loss of SHQ1 protein. Variants from both families were expressed in S. cerevisiae, resulting in a strong reduction in H/ACA snoRNA production and remarkable defects in rRNA processing and ribosome formation. Our study identifies SHQ1 as associated with neurological disease, including early-onset dystonia, and begins to delineate the molecular etiology of this novel condition.

Cognitive dysfunction is common in pediatric-onset multiple sclerosis, but long-term data on cognitive maturation in these patients are sparse. We report the clinical features and cognitive trajectories in 4 pediatric-onset multiple sclerosis patients who were 10 years or younger at first attack and were followed between 1998 and 2010. Relapses in all 4 patients were frequent early in the disease and became infrequent or absent over time. Declines on neuropsychological testing were most pronounced on measures of processing speed, specifically visuomotor speed, and executive control requiring mental sequencing and set shifting, whereas global intellectual ability and phonemic fluency remained stable or improved over time. These case studies demonstrate a negative impact of multiple sclerosis on cognitive development in the long term and suggest that continued observation into adulthood is required to appreciate the vocational consequences of pediatric-onset multiple sclerosis.

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ObjectiveTo describe the phenotypic spectrum in patients with MBD5-associated neurodevelopmental disorder (MAND) and seizures; features of MAND include intellectual disability, epilepsy, psychiatric features of aggression and hyperactivity, and dysmorphic features including short stature and microcephaly, sleep disturbance, and ataxia.MethodsWe performed phenotyping on patients with MBD5 deletions, duplications, or point mutations and a history of seizures.ResultsTwenty-three patients with MAND and seizures were included. Median seizure onset age was 2.9 years (range 3 days–13 years). The most common seizure type was generalized tonic-clonic; focal, atypical absence, tonic, drop attacks, and myoclonic seizures occurred frequently. Seven children had convulsive status epilepticus and 3 nonconvulsive status epilepticus. Fever, viral illnesses, and hot weather provoked seizures. EEG studies in 17/21 patients were abnormal, typically showing slow generalized spike-wave and background slowing. Nine had drug-resistant epilepsy, although 3 eventually became seizure-free. All but one had moderate-to-severe developmental impairment. Epilepsy syndromes included Lennox-Gastaut syndrome, myoclonic-atonic epilepsy, and infantile spasms syndrome. Behavioral problems in 20/23 included aggression, self-injurious behavior, and sleep disturbance.ConclusionsMBD5 disruption may be associated with severe early childhood-onset developmental and epileptic encephalopathy. Because neuropsychiatric dysfunction is common and severe, it should be an important focus of clinical management.

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