Abstract
Osmotic demyelination syndrome (ODS) is a disorder characterised by the widespread development of demyelination in both pontine and extrapontine regions. It has been recognised as a complication arising from the rapid correction of hyponatraemia. This study presents the case of a 20-year-old Thai female patient at 10 weeks gestation, exhibiting an initial presentation of catatonia - an uncommon manifestation of ODS. The patient developed symptoms following the rapid correction of hyponatraemia in the context of hyperemesis gravidarum. Magnetic resonance imaging (MRI) of the brain revealed a trident or bat-wing-shaped pattern in T2-weighted and fluid-attenuated inversion recovery (FLAIR) sequences at the central pons. The patient underwent five cycles of plasmapheresis and received rehabilitation, leading to clinical improvement. LEARNING POINTS: Osmotic demyelination syndrome (ODS) is a rare but potentially devastating neurological complication, such as catatonia, resulting from the correction of hyponatraemia.Pregnancies complicated by hyperemesis gravidarum tend to exhibit hyponatraemia and hypokalaemia, which serve as contributing risk factors for ODS.Plasmapheresis is considered as an option in the treatment of ODS for the removal of inflammatory substances.