Relationship between prolonged neural suppression and cerebral hemodynamic dysfunction during hypothermia in asphyxiated piglets.
Brain Dev
; 40(8): 649-661, 2018 Sep.
Article
in En
| MEDLINE
| ID: mdl-29789202
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, nâ¯=â¯3), control with HT (C-HT, nâ¯=â¯3), HI insult with NT (HI-NT, nâ¯=â¯10), and HI insult with HT (HI-HT, nâ¯=â¯10). TRS and aEEG were performed in all groups until 24â¯h after the insult. Piglets in the HI-HT group were maintained in a hypothermic state for 24â¯h after the insult.RESULTS:
There was a positive linear correlation between changes in CBV at 1, 3, 6, and 12â¯h after the insult and low-amplitude aEEG (<5⯵V) duration after insult in the HI-NT group, but a negative linear correlation between these two parameters at 6 and 12â¯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 ANDCONCLUSION:
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.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Brain
/
Hypoxia-Ischemia, Brain
/
Hemodynamics
/
Hypothermia, Induced
Type of study:
Prognostic_studies
Limits:
Animals
Language:
En
Journal:
Brain Dev
Year:
2018
Document type:
Article
Affiliation country: