March 25, 2013
A 52-year-old patient with alcoholism presents with altered mental status, pseudobulbar palsy, and hyponatremia.
Osmotic Demyelination Syndrome (ODS)
- ODS is a neurologic disorder caused by rapid correction of hyponatremia. It is characterized by demyelination that affects the central portion of the base of pons. There are no inflammatory changes, and blood vessels are normal. This condition classically occurs in alcoholics, malnourished, or chronically debilitated adults.
- Clinical presentation: spastic tetraparesis, pseudobulbar paralysis, and acute changes in mental status.
- Key Diagnostic Features: Confluent T2 hyperintensity involving central pons. Typically, the peripheral aspect of pons and corticospinal tracts are spared. Sometimes, a trident-shaped central signal abnormality is seen. Diffusion restriction can be seen in the acute setting. There is no enhancement seen following contrast administration. Extrapontine sites include basal ganglia and cerebral white matter. Peripheral cortex and hippocampii are uncommonly involved.
- DDx: Ischemia, tumor, demyelination, metabolic diseases
- Rx: Restrict fluids, discontinue diuretics. Steroids, plasmapharesis.
