title: Extrapontine myelinolysis associated with severe hypernatremia in infancy.
abstract: Extrapontine myelinolysis (EPM) is an uncommon disorder in children, with few pediatric cases reported to date. We report the first case of an infant with EPM without central pontine myelinolysis (CPM) presenting with severe hypernatremia. On admission, the infant had impaired consciousness, mild dehydration, and severe hypernatremia (190 mmol/L). The following day, the patient developed abnormal involuntary movements. Brain magnetic resonance imaging (MRI) confirmed EPM without CPM. He recovered without sequelae, and clinical examinations were within normal limits approximately 6 months after discharge. Brain MRI at 1 year after onset showed complete disappearance of the previous EPM regions. To the best of our knowledge, this represents the youngest patient with EPM without CPM presenting with severe hypernatremia. Given that treatment for osmotic demyelination syndrome (ODS) is yet to be established, preventing the development of ODS is crucial.
authors.affiliation: Department of Pediatrics and Child Health, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Ryoji
authors.initials: R
authors.lastname: Aoki
authors.affiliation: Department of Pediatrics and Child Health, Nihon University School of Medicine, Tokyo, Japan. t-morimoto@hosp.tohoku-mpu.ac.jp.
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Morimoto
authors.affiliation: Department of Pediatrics and Child Health, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Yuno
authors.initials: Y
authors.lastname: Takahashi
authors.affiliation: Department of Pediatrics and Child Health, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Saito
authors.affiliation: Department of Pediatrics and Child Health, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Fuchigami
authors.affiliation: Department of Pediatrics and Child Health, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Shori
authors.initials: S
authors.lastname: Takahashi
mesh_terms: D006801:Humans; D006955:Hypernatremia / Q000097:blood / Q000175:diagnosis / Q000209:etiology*; D007223:Infant; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D017590:Myelinolysis, Central Pontine / Q000150:complications* / Q000175:diagnosis; D012720:Severity of Illness Index; D012964:Sodium / Q000097:blood*
chemical_list: D012964:Sodium
keywords: central pontine myelinolysis; extrapontine myelinolysis; hypernatremia; osmotic demyelination syndrome