Diffusion Tensor Imaging to Predict Neurodevelopmental Impairment in Infants after Hypoxic–Ischemic Injury

Abstract

Objective Magnetic resonance imaging (MRI) is the standard of care for evaluation of brain injury after hypoxic–ischemic encephalopathy (HIE) in term newborns. This study utilizes diffusion tensor imaging (DTI) to (1) identify infants at highest risk of development of cerebral palsy (CP) following HIE and to (2) identify regions of the brain critical to normal fidgety general movements (GMs) at 3 to 4 months of postterm. Absence of these normal, physiological movements is highly predictive of CP. Study Design Term infants treated with hypothermia for HIE from January 2017 to December 2021 were consented for participation and had brain MRI with DTI after rewarming. The Prechtl's General Movements Assessment was performed at 12 to 16 weeks of age. Structural MRIs were reviewed for abnormalities, and DTI data were processed with the FMRIB Software Library. Infants underwent the Bayley Scales of Infant and Toddler Development III test at 24 months. Results Forty-five infant families were consented; three infants died prior to MRI and were excluded, and a fourth infant was excluded due to diagnosis of a neuromuscular disorder. Twenty-one infants were excluded due to major movement artifact on diffusion images. Ultimately, 17 infants with normal fidgety GMs were compared with 3 infants with absent fidgety GMs with similar maternal and infant characteristics. Infants with absent fidgety GMs had decreased fractional anisotropy of several important white matter tracts, including the posterior limb of the internal capsule, optic radiations, and corpus callosum (p < 0.05). All three infants with absent fidgety GMs and two with normal GMs went on to be diagnosed with CP. Conclusion This study identifies white matter tracts of the brain critical to development of normal fidgety GMs in infants at 3 to 4 months of postterm using advanced MRI techniques. These findings identify those at highest risk for CP among infants with moderate/severe HIE prior to hospital discharge. Key Points