Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Observational Study
. 2018 May:82:36-43.
doi: 10.1016/j.pediatrneurol.2018.02.004. Epub 2018 Apr 2.

Cerebral Autoregulation and Conventional and Diffusion Tensor Imaging Magnetic Resonance Imaging in Neonatal Hypoxic-Ischemic Encephalopathy

Melisa Carrasco  1 , Jamie Perin  2 , Jacky M Jennings  2 , Charlamaine Parkinson  3 , Maureen M Gilmore  3 , Raul Chavez-Valdez  3 , An N Massaro  4 , Raymond C Koehler  5 , Frances J Northington  3 , Aylin Tekes  6 , Jennifer K Lee  7
Affiliations
Observational Study

Cerebral Autoregulation and Conventional and Diffusion Tensor Imaging Magnetic Resonance Imaging in Neonatal Hypoxic-Ischemic Encephalopathy

Melisa Carrasco et al. Pediatr Neurol. 2018 May.

Abstract

Background: Deviation of mean arterial blood pressure (MAP) from the range that optimizes cerebral autoregulatory vasoreactivity (optimal MAP) could increase neurological injury from hypoxic-ischemic encephalopathy (HIE). We tested whether a global magnetic resonance imaging (MRI) brain injury score and regional diffusion tensor imaging (DTI) are associated with optimal MAP in neonates with HIE.

Methods: Twenty-five neonates cooled for HIE were monitored with the hemoglobin volume index. In this observational study, we identified optimal MAP and measured brain injury by qualitative and quantitative MRIs with the Neonatal Research Network (NRN) score and DTI mean diffusivity scalars. Optimal MAP and blood pressure were compared with brain injury.

Results: Neonates with blood pressure measurements within optimal MAP during rewarming had less brain injury by NRN score (P = 0.040). Longer duration of MAP within optimal MAP during hypothermia correlated with higher mean diffusivity in the anterior centrum semiovale (P = 0.008) and pons (P = 0.002). Blood pressure deviation below optimal MAP was associated with lower mean diffusivity in cerebellar white matter (P = 0.033). Higher optimal MAP values related to lower mean diffusivity in the basal ganglia (P = 0.021), the thalamus (P = 0.006), the posterior limb of the internal capsule (P = 0.018), the posterior centrum semiovale (P = 0.035), and the cerebellar white matter (P = 0.008). Optimal MAP values were not associated with the NRN score.

Conclusions: The NRN score and the regional mean diffusivity scalars detected injury with mean arterial blood pressure deviations from the optimal MAP. Higher optimal MAP and lower mean diffusivity may be related because of cytotoxic edema and limited vasodilatory reserve at low MAP in injured brain. DTI detected injury with elevated optimal MAP better than the NRN score.

Keywords: Blood pressure; Brain hypoxia ischemia; Cerebrovascular circulation; Magnetic resonance imaging; Newborn.

PubMed Disclaimer

Conflict of interest statement

Conflicts of interest

JKL, FJN, and RC-V received research support from Medtronic for a separate study. JKL was also a paid advisory board member for Medtronic. This arrangement has been reviewed and approved by the Johns Hopkins University in accordance with its conflict of interest policies. Medtronic had no role in the current study’s design, data collection and analysis, interpretation of the results, writing, or decision to submit our manuscript for publication.

Figures

FIGURE 1
FIGURE 1
Examples of identifying the optimal MAP with the most robust autoregulatory vasoreactivity. The arrows denote optimal MAP during hypothermia (A), rewarming (B), and normothermia (C) at the HVx nadir. When a nadir in HVx was not present, the neonate was coded as having an unidentifiable optimal MAP (D). HVx, hemoglobin volume index; MAP, mean arterial blood pressure.
FIGURE 2
FIGURE 2
The distribution of time that neonates spent at each level of mean arterial blood pressure. Whiskers are fifth to ninety-fifth percentiles.
See this image and copyright information in PMC

References

    1. Azzopardi D, Strohm B, Marlow N, et al. Effects of hypothermia for perinatal asphyxia on childhood outcomes. N Engl J Med. 2014;371:140–149. - PubMed
    1. Shankaran S, Pappas A, McDonald SA, et al. Childhood outcomes after hypothermia for neonatal encephalopathy. N Engl J Med. 2012;366:2085–2092. - PMC - PubMed
    1. Ohshima M, Tsuji M, Taguchi A, Kasahara Y, Ikeda T. Cerebral blood flow during reperfusion predicts later brain damage in a mouse and a rat model of neonatal hypoxic-ischemic encephalopathy. Exp Neurol. 2012;233:481–489. - PubMed
    1. Massaro AN, Govindan RB, Vezina G, et al. Impaired cerebral autoregulation and brain injury in newborns with hypoxic-ischemic encephalopathy treated with hypothermia. J Neurophysiol. 2015;114:818–824. - PMC - PubMed
    1. Tekes A, Poretti A, Scheurkogel MM, et al. Apparent diffusion coefficient scalars correlate with near-infrared spectroscopy markers of cerebrovascular autoregulation in neonates cooled for perinatal hypoxic-ischemic injury. AJNR Am J Neuroradiol. 2015;36:188–193. - PMC - PubMed

Publication types