ODS

Q 44 years old homeless male was admitted to the ICU with severe hyponatremia a week ago, due to psychogenic polydipsia. Unfortunately, after five days of treatment, patient developed dysarthria, quadriparesis, behavioral disturbances, and seizures. Patient required intubation. It was determined that patient has probably developed osmotic demyelination syndrome (ODS) due to rapid correction of sodium. In osmotic demyelination syndrome, the initial severity of the illness is a good predictor of long-term prognosis.

A) True

B) False

Answer: B 

There are three objectives of this question.

First, to emphasize that in ODS, formerly called central pontine myelinolysis (CPM), symptoms can be delayed up to six days.

Second, although conventionally, ODS has been thought to be an irreversible process, evidence has shown that, with good support, meaningful recovery is possible up to eight weeks after the event.

Third, the initial severity of the illness is not predictive of long-term prognosis.

The most dreaded outcome of ODS is the potential "locked-in" syndrome.

#electrolytes

#neurology

References:

1. Lambeck J, Hieber M, Dreßing A, Niesen WD. Central Pontine Myelinosis and Osmotic Demyelination Syndrome. Dtsch Arztebl Int. 2019 Sep 2;116(35-36):600-606. doi: 10.3238/arztebl.2019.0600. PMID: 31587708; PMCID: PMC6804268.

2. Sterns RH, Riggs JE, Schochet SS Jr. Osmotic demyelination syndrome following correction of hyponatremia. N Engl J Med 1986; 314:1535.

3. Menger H, Jörg J. Outcome of central pontine and extrapontine myelinolysis (n = 44). J Neurol 1999; 246:700.

4. Louis G, Megarbane B, Lavoué S, et al. Long-term outcome of patients hospitalized in intensive care units with central or extrapontine myelinolysis*. Crit Care Med 2012; 40:970.