title: Mechanisms and therapy of osmotic demyelination.
abstract: Central pontine myelinolysis (CPM) is a rare but serious demyelinative disease that is associated with rapid correction of chronic hyponatremia. Disruption of the blood-brain barrier (BBB) following a rapid increase in serum sodium concentration is considered to play a critical role in the pathogenesis of osmotic demyelination. We investigated the protective effect of dexamethasone (DEX) on osmotic demyelination in rats. After rapid correction of chronic hyponatremia, rats displayed serious neurologic impairments and demyelinative lesions were observed in various brain regions. Conversely, DEX-treated rats exhibited minimal neurologic impairments and demyelinative lesions were rarely seen in the brain. A marked extravasation of endogenous immunoglobulin G and Evans blue dye were observed in the brains of rats that did not receive DEX, indicating disruption of the BBB, but this was not observed in DEX-treated rats. These results indicate that DEX is effective in preventing osmotic demyelination by inhibiting BBB disruption, and suggest that DEX might be useful for the prevention of CPM in clinical practice.
authors.affiliation: Department of Teratology and Genetics, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan. tmurase@riem.nagoya-u.ac.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Murase
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Sugimura
authors.forename: Seiko
authors.initials: S
authors.lastname: Takefuji
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Oiso
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Murata
mesh_terms: D000818:Animals; D001812:Blood-Brain Barrier / Q000187:drug effects*; D003907:Dexamethasone / Q000494:pharmacology*; D004195:Disease Models, Animal; D005070:Evans Blue / Q000378:metabolism; D005938:Glucocorticoids / Q000494:pharmacology; D007074:Immunoglobulin G / Q000378:metabolism; D017590:Myelinolysis, Central Pontine / Q000378:metabolism / Q000503:physiopathology* / Q000517:prevention & control*; D009995:Osmosis / Q000187:drug effects; D051381:Rats
chemical_list: D005938:Glucocorticoids; D007074:Immunoglobulin G; D005070:Evans Blue; D003907:Dexamethasone