Osmotic Demyelination Syndrome due to Severe Hyponatremia Mimicking Hypoxic Encephalopathy

Abstract

Hyponatremia and its rapid correction is a well-known cause of osmotic demyelination most commonly affecting the pons. We report on a case of severe hyponatremia likely due to psychogenic polydipsia resulting in hypotonic hyperhydration with resulting cortical laminar necrosis on initial imaging, mimicking hypoxic brain damage. Pontine myelinolysis became apparent on follow-up imaging, illustrating the diagnostic challenges of extrapontine manifestations of severe hyponatremia.

Zusammenfassung

Der schnelle Ausgleich einer Hyponatriämie ist eine bekannte Ursache osmotischer Demyelinisation, typischerweise in Form der zentralen pontinen Myelinolyse. Wir berichten von einem Fall schwerer Hyponatriämie, bei dem der rasche Ausgleich des Natriumspiegels zu einer kortikalen, laminären Nekrose in der initialen MRT-Bildgebung geführt hat, ein Befund, der einer hypoxischen Hirnschädigung gleicht. Spätere Bildgebung zeigte dann zusätzlich eine pontine Myelinolyse. Unser Fallbericht illustriert die diagnostischen Herausforderungen bei extrapontinen Manifestationen schwerer Hyponatriämie.

Key words

osmotic demyelination syndrome - central pontine myelinolysis - hyponatremia - cortical laminar necrosis

Schlüsselwörter

osmotisches Demyelinisationssyndrom - zentrale pontine Myelinolyse - Hyponatriämie - kortikale laminäre Nekrose

• References

• 1 Kleinschmidt-Demasters BK. Norenberg MD. Rapid correction of hyponatremia causes demyelination: relation to central pontine myelinolysis. Science 1981; 211: 1068-1070
• 2 Gocht A. Colmant HJ. Central pontine and extrapontine myelinolysis: a report of 58 cases. Clin Neuropathol 1987; 6: 262-270
• 3 Nardone R. McCoy M. Kunz AB. et al. Hyponatremic encephalopathy mimicking hypoxic-ischemic encephalopathy. Clin Neuroradiol 2010; 20: 243-246
• 4 Calakos N. Fischbein N. Baringer JR. et al. Cortical MRI findings associated with rapid correction of hyponatremia. Neurology 2000; 55: 1048-1051
• 5 Liu X. Zhao X. Yang J. et al. Cortical laminar necrosis following the rapid correction of drug-induced hyponatremia. Neurol Sci 2015; 36: 1725-1727
• 6 DeLuca GC. Nagy Z. Esiri MM. et al. Evidence for a role for apoptosis in central pontine myelinolysis. Acta Neuropathol 2002; 103: 590-598
• 7 Ashrafian H. Davey P. A review of the causes of cental pontine myelinosis: yet another apoptotic illness?. Eur J Neurol 2001; 8: 103-109
• 8 Singh TD. Fugate JE. Rabinstein AA. Central pontine and extrapontine myelinolysis: a systematic review. Eur J Neurol 2014; 21: 1443-1450
• 9 Ruzek KA. Campeau NG. Miller GM. Early diagnosis of central pontine myelinolysis with diffusion-weighted imaging. Am J Neuroradiol 2004; 25: 210-213
• 10 McNamee T. Forsythe S. Wollmann R. et al. Central pontine myelinolysis in a patient with classic heat stroke. Arch Neurol 1997; 54: 935-936
• 11 Okeda R. Kitano M. Sawabe M. et al. Distribution of demyelinating lesions in pontine and extrapontine myelinolysis. Acta Neuropathol 1986; 69: 259-266
• 12 Gutierrez LG. Rovira A. Portela LA. et al. CT and MR in non-neonatal hypoxic–ischemic encephalopathy: radiological findings with pathophysiological correlations. Neuroradiology 2010; 52: 949-976
• 13 Fraser CL. Arieff AI. Epidemiology, pathophysiology, and management of hyponatremic encephalopathy. Am J Med 1997; 102: 67-77
• 14 Cho A. Choi CG. Lee SA. Cortical laminar necrosis associated with osmotic demyelination syndrome. J Clin Neurol 2005; 1: 174-176