Dynamic magnetic resonance imaging findings in the early stages of neonatal hypoglycemic brain injury

Abstract

Hypoglycemia is common among neonates and can cause neurological dysfunction. This study aimed to identify the specific time window to perform diffusion-weighted imaging (DWI) for detecting early brain injury in neonatal hypoglycemia and assess the clinical characteristics and neurological outcomes of different patterns of brain injury in neonatal hypoglycemia. We conducted a retrospective analysis of the changes in conventional magnetic resonance imaging (MRI) and DWI at different time points and clinical characteristics in 86 neonates with hypoglycemic brain injury. Among 139 DWI scans, 84 showed injury site hyperintensities within 7 days after hypoglycemia. Thirty-nine scans revealed low DWI and abnormal T1-/T2-weighted imaging signals within 11-23 days after onset, of which 21 showed DWI hyperintensities in the corpus callosum. Abnormal signals were undetected in the second scans of 13 infants within 9-20 days after onset. Vulnerable sites comprised the occipital lobe (98%), splenium of the corpus callosum (60%), and parietal lobe (30%). Compared with focal injury (n = 66), extensive injury (n = 20) had higher involvement of the internal capsule, basal ganglia, and thalamus (P < 0.05); higher incidence of recurrent convulsions, respiratory failure, and coma (P < 0.01); and a higher proportion of death and severe neurodevelopmental impairment (P < 0.05).

Conclusions: Neonatal hypoglycemic brain injury was most common in the occipital lobes. Severe clinical symptoms were significantly associated with extensive brain injury involving the internal capsule, basal ganglia, and thalamus, which could be attributed to hypoxia-ischemia and lead to a poor prognosis.

What is known: • There is no clear neurological safe threshold for hypoglycemia in neonates. Studies suggest that symptomatic hypoglycemia can be related to brain injury.

What is new: • Severe clinical symptoms are significantly associated with extensive brain injury on MRI scans. Extensive brain injuries involving the internal capsule, basal ganglia, and thalamus, which could be due to associated hypoxia-ischemia and lead to a poor prognosis.

Keywords: Brain injuries; Diffusion-weighted imaging; Hypoglycemia; Magnetic resonance imaging; Newborn.