Extreme hypernatremia as a cause of extrapontine myelinolysis

Hypernatremia is a potentially lethal condition and can cause osmotic demyelination, rhabdomyolysis, and encephalopathy. Extrapontine myelinolysis, a fairly common metabolic disorder, is associated with neurological complications. Central pontine and extrapontine myelinolysis are commonly recognized with rapid correction of sodium for hyponatremia. Myelinolysis, however, has rarely been described with hypernatremia. One such patient is described in this article. A young adult female with restricted water intake during the postpartum period presented with a history of progressive weakness, generalized slowing of movement, slurred speech, and difficulty in swallowing. On examination, the patient was conscious and quadriparetic with signs of dehydration. Investigations revealed hypernatremia and features suggestive of extrapontine myelinolysis on magnetic resonance imaging of the brain. After correcting hypernatremia, there was a gradual but steady improvement in the neurological symptoms of the patient over 5 days and the patient was discharged in hemodynamically stable state. Although the exact etiological factor is unknown, a ritual in some communities in India, that is, to restrict the water intake for females in the postpartum period, may exacerbate dehydration.