Occipital Lobe Injury and Cortical Visual Outcomes After Neonatal Hypoglycemia

Abstract

Diffusion-weighted imaging studies performed within 6 days after initial hypoglycemia were sensitive in term but not preterm neonates. Diffusion restriction, with low apparent diffusion coefficient values, in the mesial occipital poles may indicate the prognosis for visual outcomes in acute settings after neonatal hypoglycemia.

Brain Injury Patterns in Hypoglycemia in Neonatal Encephalopathy

“…One prospective cohort of 35 subjects with hypoglycemia showed posterior white matter abnormalities in 94% of infants, with other injury of the cortex, white matter hemorrhage, and injury of the basal ganglia, thalamus, and posterior limb of the internal capsule. 21 A retrospective cohort of 45 neonates with hypoglycemia showed occipital diffusion restriction to be limited to Ͻ7 days after initial hypoglycemia in term neonates, 15 and another study of 6 term neonates with hypoglycemia showed restricted diffusion in the parieto-occipital gray and white matter, corpus callosum, and optic radiations. 16 Animal models suggest increased morbidity and mortality when hypoxic-ischemic injury and neonatal hypoglycemia coexist compared with hypoxic-ischemic injury alone or isolated neonatal hypoglycemia.…”

“…4,14 Neuroimaging studies in neonatal hypoglycemia have shown a correlation between hypoglycemia, parieto-occipital injury, and involvement of the underlying white matter tracts, corpus callosum, and thalamus. 8,15,16 However, it is unclear whether the pattern of injury seen in HIE is modified by concurrent hypoglycemia and whether the effects of hypoglycemia in the context of HIE can be reliably recognized by imaging alone. The objective of this study was to identify the predominant imaging patterns and specific radiologic features for neonatal hypoglycemia in the context of NE.…”

Neuroimaging in Patients with Abnormal Blood Glucose Levels

“…44 In the acute phase, there is restricted diffusion with correspondingly reduced ADC values. 14 Some authors think that the degree of restricted diffusion may correlate with parenchymal damage on follow-up.…”

Neonatal Hypoglycemia - Current Concepts

“…Electroencephalographic recordings do not show specific patognomonic features that may result diagnostic . Parieto-occipital diffusion restriction seen on MRI scans have been reported associated with neonatal hypoglycaemia and can result in long-term disability, epilepsy, and visual impairment (Finlan et al, 2006;Tam et al, 2008). The aetiology of this pattern of injury is unclear; however, transient hyperinsulinism may be an independent risk factor.…”

“…Cortical visual impairment happened in a significant proportion of patients with recurrent hypoglycaemia and correlated significantly with low mesial occipital apparent diffusion coefficient values. They concluded that diffusion restriction, with low apparent diffusion coefficient values, in the mesial occipital poles, may indicate poor visual outcomes in acute settings after neonatal hypoglycaemia (Tam et al, 2008). While occipital lobe injury patterns have been widely described, other brain injury patterns have also been identified when studying MRI scans performed on term neonates with symptomatic hypoglycaemia and compared to neurologically normal infants.…”