Neuroimaging Spectrum of Severe Hypernatremia in Infants with Neurological Manifestations

Neuropediatrics. 2021 Aug;52(4):316-325. doi: 10.1055/s-0041-1730938. Epub 2021 Jun 30.

Abstract

Background: Variable neurological manifestations and imaging findings have been described in children with severe hypernatremia. We aimed to describe the spectrum of neuroimaging changes in infants with severe hypernatremia.

Methods: This retrospective study included infants with severe hypernatremia (serum sodium >160 mEq/L), abnormal neurological examination, and an abnormal magnetic resonance imaging (MRI) of the brain over a period of 2 years in a tertiary care hospital. Relevant clinical data, including the feeding practices, clinical features, complications, and biochemical and radiological parameters, were entered in a structured pro forma. MRI findings were classified as vascular (hemorrhages and cerebral sinus venous thrombosis), osmotic demyelination syndrome (pontine and extrapontine myelinolyses), and white matter changes.

Results: The common clinical features in the neonates were poor feeding (n = 4) and decreased urine output (n = 4); the older infants presented with gastrointestinal losses (n = 5). All cases had dehydration with encephalopathy. The patterns of radiological injury were vascular (hemorrhages, n = 5 and venous thrombosis, n = 3), osmotic demyelination (n = 8), and white matter changes (n = 7). Coagulopathy was correlated with the vascular complications (r = 0.8, p < 0.0001); the degree of dehydration was correlated with the venous thrombosis (r = 0.7, p < 0.04) and acute kidney injury (r = 0.8, p < 0.001). Neurological sequelae were seen in four cases and correlated with hypernatremia (r = 0.6, p = 0.03) and hyperosmolarity (r = 0.6, p = 0.03).

Conclusion: Characteristic neuroimaging findings are vascular changes in the form of venous thrombosis and hemorrhages, osmotic demyelination and white matter tract injury, and/or mostly combinations of these findings. Severe hypernatremia and resulting hyperosmolarity frequently cause neurological sequelae in neonates and infants.

MeSH terms

  • Child
  • Humans
  • Hypernatremia* / complications
  • Hypernatremia* / etiology
  • Infant
  • Infant, Newborn
  • Magnetic Resonance Imaging / methods
  • Myelinolysis, Central Pontine* / diagnosis
  • Myelinolysis, Central Pontine* / etiology
  • Myelinolysis, Central Pontine* / pathology
  • Neuroimaging / adverse effects
  • Retrospective Studies