Wataru Jinnai1, Shinji Nakamura2, Kosuke Koyano3, Satoshi Yamato1, Takayuki Wakabayashi2, Yinmon Htun2, Yasuhiro Nakao2, Takashi Iwase2, Makoto Nakamura2, Saneyuki Yasuda3, Masaki Ueno4, Takanori Miki5, Takashi Kusaka6. 1. Department of Pediatrics, Faculty of Medicine, Kagawa University, Kagawa, Japan; Division of Neonatology, Shikoku Medical Center for Children and Adults, Kagawa, Japan. 2. Department of Pediatrics, Faculty of Medicine, Kagawa University, Kagawa, Japan. 3. Maternal Perinatal Center, Faculty of Medicine, Kagawa University, Kagawa, Japan. 4. Department of Pathology and Host Defense, Faculty of Medicine, Kagawa University, Kagawa, Japan. 5. Department of Anatomy and Neurobiology, Faculty of Medicine, Kagawa University, Kagawa, Japan. 6. Department of Pediatrics, Faculty of Medicine, Kagawa University, Kagawa, Japan. Electronic address: kusaka@med.kagawa-u.ac.jp.
Abstract
OBJECTIVES: Hypothermia (HT) improves the outcome of neonatal hypoxic-ischemic encephalopathy. Here, we investigated changes during HT in cortical electrical activity using amplitude-integrated electroencephalography (aEEG) and in cerebral blood volume (CBV) and cerebral hemoglobin oxygen saturation using near-infrared time-resolved spectroscopy (TRS) and compared the results with those obtained during normothermia (NT) after a hypoxic-ischemic (HI) insult in a piglet model of asphyxia. We previously reported that a greater increase in CBV can indicate greater pressure-passive cerebral perfusion due to more severe brain injury and correlates with prolonged neural suppression during NT. We hypothesized that when energy metabolism is suppressed during HT, the cerebral hemodynamics of brains with severe injury would be suppressed to a greater extent, resulting in a greater decrease in CBV during HT that would correlate with prolonged neural suppression after insult. METHODS: Twenty-six piglets were divided into four groups: control with NT (C-NT, n = 3), control with HT (C-HT, n = 3), HI insult with NT (HI-NT, n = 10), and HI insult with HT (HI-HT, n = 10). TRS and aEEG were performed in all groups until 24 h after the insult. Piglets in the HI-HT group were maintained in a hypothermic state for 24 h after the insult. RESULTS: There was a positive linear correlation between changes in CBV at 1, 3, 6, and 12 h after the insult and low-amplitude aEEG (<5 µV) duration after insult in the HI-NT group, but a negative linear correlation between these two parameters at 6 and 12 h after the insult in the HI-HT group. The aEEG background score and low-amplitude EEG duration after the insult did not differ between these two groups. DISCUSSION AND CONCLUSION: A longer low-amplitude EEG duration after insult was associated with a greater CBV decrease during HT in the HI-HT group, suggesting that brains with more severe neural suppression could be more prone to HT-induced suppression of cerebral metabolism and circulation.
OBJECTIVES:Hypothermia (HT) improves the outcome of neonatal hypoxic-ischemicencephalopathy. Here, we investigated changes during HT in cortical electrical activity using amplitude-integrated electroencephalography (aEEG) and in cerebral blood volume (CBV) and cerebral hemoglobin oxygen saturation using near-infrared time-resolved spectroscopy (TRS) and compared the results with those obtained during normothermia (NT) after a hypoxic-ischemic (HI) insult in a piglet model of asphyxia. We previously reported that a greater increase in CBV can indicate greater pressure-passive cerebral perfusion due to more severe brain injury and correlates with prolonged neural suppression during NT. We hypothesized that when energy metabolism is suppressed during HT, the cerebral hemodynamics of brains with severe injury would be suppressed to a greater extent, resulting in a greater decrease in CBV during HT that would correlate with prolonged neural suppression after insult. METHODS: Twenty-six piglets were divided into four groups: control with NT (C-NT, n = 3), control with HT (C-HT, n = 3), HI insult with NT (HI-NT, n = 10), and HI insult with HT (HI-HT, n = 10). TRS and aEEG were performed in all groups until 24 h after the insult. Piglets in the HI-HT group were maintained in a hypothermic state for 24 h after the insult. RESULTS: There was a positive linear correlation between changes in CBV at 1, 3, 6, and 12 h after the insult and low-amplitude aEEG (<5 µV) duration after insult in the HI-NT group, but a negative linear correlation between these two parameters at 6 and 12 h after the insult in the HI-HT group. The aEEG background score and low-amplitude EEG duration after the insult did not differ between these two groups. DISCUSSION AND CONCLUSION: A longer low-amplitude EEG duration after insult was associated with a greater CBV decrease during HT in the HI-HT group, suggesting that brains with more severe neural suppression could be more prone to HT-induced suppression of cerebral metabolism and circulation.
Authors: Dianne G Kleuskens; Filipe Gonçalves Costa; Kim V Annink; Agnes van den Hoogen; Thomas Alderliesten; Floris Groenendaal; Manon J N Benders; Jeroen Dudink Journal: Front Pediatr Date: 2021-02-02 Impact factor: 3.418