Osmotic Demyelination Syndrome Presenting with Parkinsonism

Osmotic demyelination syndrome (ODS) is a condition which occurs due to rapid osmotic changes which result in myelinolysis of the nervous system. Uncommonly the myelinolysis could involve areas beyond the pons resulting in extrapontine myelinolysis (EPM). We report a 70-year-old gentleman who presented with a 2-week history of reduced interaction and altered behavior with parkinsonism following oral correction of severe hyponatraemia. Magnetic resonance imaging (MRI) of the brain revealed hyperintensities in the T2-weighted FLAIR images involving the pontine region with no involvement of basal ganglia. This case illustrates the significance of adhering to recommended protocols when correcting hyponatraemia and the importance of timing brain imaging in ODS.