Seasonal postpartum hypernatremic encephalopathy with osmotic extrapontine myelinolysis and rhabdomyolysis

Abstract

Background Neurological manifestations secondary to extrapontine myelinolysis and rhabdomyolysis caused by hypernatremia are infrequently reported. Occurrence of neurological manifestations due to spontaneous hypernatremia during postpartum period producing rhabdomyolysis and cerebral parenchymal MRI changes has not been previously reported. Objective Evaluation of clinical and radiological profile of postpartum hypernatremia. Methods Clinical, laboratory and radiological data of eleven women in postpartum period presenting with hypernatremic encephalopathy with or without muscle weakness were reviewed. Results Eleven puerperal women presented with encephalopathy due to hypernatremia from 2007 to 2009. Consciousness was altered in all the patients ranging from confusion to deep coma. Nine patients had quadriparesis, eight had corticospinal and corticobulbar dysfunction, six had ataxia, and seizures occurred in four patients. The patients had hypernatremia ranging from 158 to 199 mEq/l with hyperchloremia, markedly elevated serum CK levels (2572 to 61,107 U) and azotemia. Ten patients underwent MRI which revealed hyperintensity of corpus callosum in all the patients in T2, FLAIR and diffusion weighted sequences. Symmetrical hyperintensities were seen also in internal capsule, corona radiata, cerebellar peduncles and hippocampus in various combinations. Seven patients improved neurologically with reduction of serum sodium and CK levels while four patients died. Conclusion Hypernatremia is a potentially lethal condition which can produce encephalopathy, osmotic demyelination and rhabdomyolysis. Prompt identification and appropriate management can improve the outcome in these patients.