Extrapontine myelinolysis resulting in transient cortical blindness.
Central pontine myelinolysis and extrapontine myelinolysis are characterized by symmetric demyelination subsequent to rapid shifts in serum osmolality. Described here is a novel case of transient cortical blindness in association with imaging features of extrapontine myelinolysis, which occurred in a child with carbamoyl phosphate synthetase deficiency after rapid correction of hyperammonemia. Serum sodium levels were within normal limits at presentation and throughout the period of ammonia correction. A potential pathogenic mechanism of osmotic demyelination in the setting of acute treatment for hyperammonemia in a patient with a urea cycle abnormality includes disruption of the blood-brain barrier and re-equilibration of organic osmolytes, particularly glutamine.
Langer
Jennifer E
JE
Department of Neurology, University of Virginia Health System, Charlottesville, Virginia, USA.
Wilson
William G
WG
Raghavan
Prashant
P
Rust
Robert S
RS
Goodkin
Howard P
HP
D019575:Blindness, Cortical / Q000175:diagnosis* / Q000209:etiology*; D002675:Child, Preschool; D006801:Humans; D008297:Male; D017590:Myelinolysis, Central Pontine / Q000150:complications* / Q000175:diagnosis*