Ultrasound Predicts White Matter Integrity after Hypothermia Therapy in Neonatal Hypoxic-Ischemic Injury

Electroencephalogram background and head ultrasound together stratify seizure risk in neonates undergoing hypothermia

The benefits of continuous electroencephalography (cEEG) monitoring in the intensive care unit (ICU) are increasingly appreciated, though expanding indications for cEEG may strain resources. The current standard of care in babies with hypoxic-ischemic encephalopathy (HIE) undergoing therapeutic hypothermia (TH) includes cEEG monitoring throughout the entire TH and rewarming process (at least 72 h). Recent cEEG data demonstrate that most seizures occur within the first 24 h of monitoring. We hypothesized that abnormal head imaging and EEG background could stratify seizure risk in babies with HIE undergoing TH to identify candidates for early cEEG discontinuation. In this retrospective review of 126 neonates undergoing TH and cEEG, we identified seizures in 38 (30%) neonates, 33 (87%) of whom seized within the first 24 h of cEEG monitoring. EEG background was graded and demonstrated that 90% of neonates with seizures had a moderately/markedly abnormal background versus 33% of neonates who did not seize (p < 0.0001). Additionally, while head ultrasound (HUS) obtained before EEG did not stratify seizure risk alone, no neonates with both a normal/mildly abnormal EEG background and a normal HUS (0/25) experienced seizures in contrast to 60% (24/40) neonates with both an abnormal EEG background and an abnormal HUS (p < 0.0001). Our data suggest that neonates with abnormal EEG backgrounds and abnormal HUS should be monitored for seizures throughout TH and rewarming, while neonates with normal/mildly abnormal EEG backgrounds and normal HUS are at low risk of seizures after 24 h of monitoring, and thus would be candidates for early cEEG discontinuation.

Value of cranial ultrasound at initiation of therapeutic hypothermia for neonatal encephalopathy

OBJECTIVE

There is variation in the clinical practice for the use of cranial ultrasound (cUS) at the time of initiation of therapeutic hypothermia (TH) for neonatal encephalopathy. The role of cUS in selecting patients who may benefit from TH or excluding those where TH may impose risk is unknown.

STUDY DESIGN

A retrospective study was conducted on infants who received TH at a single tertiary center. Findings from cUS at initiation of TH were compared to findings from MRI following the completion of TH.

RESULTS

One hundred and eight infants were studied. Of the 55 with abnormalities on early cUS, 50 did not have corresponding MRI abnormalities. In contrast, 16 infants had some degree of intracranial hemorrhage detected on their MRI that was not noted on earlier cUS.

CONCLUSIONS

This study challenges whether cUS is an essential universal screening tool prior to the commencement of TH.

Serum brain injury biomarkers are gestationally and post-natally regulated in non-brain injured neonates

BACKGROUND

To determine the association of gestational age (GA) and day of life (DOL) with the circulating serum concentration of six brain injury-associated biomarkers in non-brain injured neonates born between 23 and 41 weeks' GA.

METHODS

In a multicenter prospective observational cohort study, serum CNS-insult, inflammatory and trophic proteins concentrations were measured daily in the first 7 DOL.

RESULTS

Overall, 3232 serum samples were analyzed from 745 enrollees, median GA 32.3 weeks. BDNF increased 3.7% and IL-8 increased 8.9% each week of gestation. VEGF, IL-6, and IL-10 showed no relationship with GA. VEGF increased 10.8% and IL-8 18.9%, each DOL. IL-6 decreased by 15.8% each DOL. IL-10 decreased by 81.4% each DOL for DOL 0-3. BDNF did not change with DOL. Only 49.67% of samples had detectable GFAP and 33.15% had detectable NRGN. The odds of having detectable GFAP and NRGN increased by 53% and 11%, respectively, each week after 36 weeks' GA. The odds of having detectable GFAP and NRGN decreased by 15% and 8%, respectively, each DOL.

CONCLUSIONS

BDNF and IL-8 serum concentrations vary with GA. VEGF and interleukin concentrations are dynamic in the first week of life, suggesting circulating levels should be adjusted for GA and DOL for clinically relevant assessment of brain injury.

IMPACT

Normative data of six brain injury-related biomarkers is being proposed. When interpreting serum concentrations of brain injury biomarkers, it is key to adjust for gestational age at birth and day of life during the first week to correctly assess for clinical brain injury in neonates. Variation in levels of some biomarkers may be related to gestational and postnatal age and not necessarily pathology.