Relationship Between Cerebral Glucose Metabolism and Neurodevelopmental Outcomes in Very-Low-Birth-Weight Infants without Structural Abnormalities

Abstract

Purpose: Very-low-birth-weight (VLBW) infants are more likely to have poor neurodevelopmental outcomes, even if structural abnormalities are not observed during brain magnetic resonance imaging (MRI). The purpose of the present study was to determine whether cerebral glucose metabolism is correlated with neurodevelopmental outcomes in VLBW infants without structural abnormalities.

Methods: Twenty-seven VLBW infants (birth weight < 1,500 g) without structural abnormalities were prospectively enrolled. All infants underwent F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) examinations at term-equivalent ages, and the regional glucose metabolic ratios were calculated. Neurodevelopmental outcomes were assessed using the Mental Development Index (MDI) and the Psychomotor Development Index (PDI) of the Bayley Scales of Infant Development-II at a corrected age of 18–24 months. Poor neurodevelopmental outcomes were defined as an MDI or PDI score < 85.

Results: The glucose metabolic ratio in the right central region of the brain was significantly correlated with the MDI score (r = 0.505, p = 0.007). The glucose metabolic ratios in the right central region and right insula in the poor-neurodevelopmental-outcome group were significantly lower than those in the good-neurodevelopmental-outcome group (1.03 ± 0.02 vs. 1.08 ± 0.04, p = 0.004, and 1.08 ± 0.05 vs. 1.13 ± 0.05, p = 0.018, respectively). Furthermore, the right central region and insula exhibited large extent of metabolic connectivity in infants with good neurodevelopmental outcome than that in infants with poor neurodevelopmental outcome.

Conclusions: Cerebral glucose metabolism was correlated with the neurodevelopmental outcomes of VLBW infants at a corrected age of 18–24 months.