Data on cranial MRI findings in infants with hypernatremic dehydration is scanty. We present the findings of 21 infants with hypernatremic dehydration.

Materials and methods: This was a retrospective study of infants with hypernatremic dehydration admitted to   a teaching hospital in Central India between April 2015 and May 2018. All infants whose MRI brain was done were included into the study. The patterns of abnormalities on brain MRI were recorded and outcomes analyzed.

Results: Of the 21 infants (12 male) included in our study, 17 were neonates.    Mean serum sodium was 174.79 meq/L .   MRI abnormalities were documented in 19. There were 4 patterns noted.   In the first pattern seen in 15 infants, there was symmetrical diffusion restriction in bilateral internal capsule, along white matter tracts in brain stem, in bilateral ventro-lateral thalami and  cerebellar peduncles.  The second pattern of bleeds was seen in 5 patients .  This included multiple microbleeds in periventricular white matter in 2, subdural haemorrhage in 2, sub arachnoid haemorrhage in 1. The third pattern was a serpiginous T1 hyperintense signal abnormality in grey white matter junction. The fourth abnormality was a sagittal sinus thrombosis seen in one patient. Of the 21 patients 15 were discharged with no  apparent deficits, two were discharged with some neurodeficit and 4 had bad outcomes.

Conclusion: In this series of 21 infants with hypernatremic dehydration we have described 4 patterns of cranial MRI abnormalities with good outcomes in 71.4%.