Osmotic Demyelination Syndrome: Central Pontine Myelinolysis and Extrapontine Myelinolysis

Osmotic demyelination syndrome (ODS) refers to central pontine myelinolysis and extrapontine myelinolysis. These disorders are characterized by insults to regions of the brain with anatomical features predisposing white matter tracts to myelin injury in the setting of osmotic disturbances and their attempted correction. Occurring independently or in combination, central pontine myelinolysis and extrapontine myelinolysis share a characteristic timing of onset, but distinct clinical features. Imaging features demonstrate characteristic findings that suggest ODS, but must be correlated with clinical features. Once thought to be universally devastating, ODS currently can have a variable clinical outcome.