Which populations are at increased risk for osmotic demyelinating syndromes?

Osmotic demyelinating syndrome (ODS) primarily occurs due to rapid changes in serum osmolality, particularly related to sodium levels. Populations that are at increased risk for this condition are those who undergo significant electrolyte disturbances.

Malnourished individuals and alcohol abusers frequently face deficiencies in essential nutrients and electrolytes, leading to a susceptibility to alterations in serum osmolality. When these individuals receive treatment that involves rapid correction of hyponatremia (low sodium levels), they are at a greater risk of developing ODS. This occurs because the brain, which adapts to low sodium levels by losing intracellular osmoles, may not be able to adjust quickly enough if sodium levels increase rapidly, resulting in demyelination.

In contrast, healthy young adults and athletes typically have balanced dietary intakes, which would not lead to the same level of nutritional deficiencies or rapid shifts in serum sodium. Individuals with hypertension may experience sodium fluctuations, but their risk for osmotic demyelination is not as pronounced as that seen in malnourished populations or those who abuse alcohol.