Amplitude Integrated Electroencephalography in the Full-Term Newborn

To study perioperative amplitude-integrated electroencephalography (aEEG) as an early marker for new brain injury in neonates requiring cardiac surgery for critical congenital heart disease (CHD).

This retrospective observational cohort study investigated 76 neonates with critical CHD who underwent neonatal surgery. Perioperative aEEG recordings were evaluated for background pattern (BGP), sleep-wake cycling (SWC), and ictal discharges. Spontaneous activity transient (SAT) rate, inter-SAT interval (ISI), and percentage of time with an amplitude <5 µV were calculated. Routinely obtained preoperative and postoperative magnetic resonance imaging of the brain were reviewed for brain injury (moderate-severe white matter injury, stroke, intraparenchymal hemorrhage, or cerebral sinovenous thrombosis).

Preoperatively, none of the neonates showed an abnormal BGP (burst suppression or worse) or ictal discharges. Postoperatively, abnormal BGP was seen in 18 neonates (24%; 95% CI, 14%-33%) and ictal discharges was seen in 13 neonates (17%; 95% CI, 8%-26%). Abnormal BGP and ictal discharges were more frequent in neonates with new postoperative brain injury (P = .08 and .01, respectively). Abnormal brain activity (ie, abnormal BGP or ictal discharges) was the single risk factor associated with new postoperative brain injury in multivariable logistic regression analysis (OR, 4.0; 95% CI, 1.3-12.3; P = .02). Postoperative SAT rate, ISI, or time <5 µV were not associated with new brain injury.

Abnormal brain activity is an early, bedside marker of new brain injury in neonates undergoing cardiac surgery. Not only ictal discharges, but also abnormal BGP, should be considered a clear sign of underlying brain pathology.

Seizures in newborns are the most frequent manifestation of an acute neurologic dysfunction, but sometimes they can be the early onset of an epileptic encephalopathy, mainly of genetic origin. When neonatal seizures are suspected, a video-encephalographic (EEG) recording is fundamental for correct interpretation of the clinical phenomena to avoid unnecessary anticonvulsant therapy. After a diagnosis of seizures, continuous monitoring is necessary to evaluate seizure burden, to diagnose status epilepticus, to monitor efficacy of anticonvulsant medications, and to form a differential diagnosis with the uncoupling phenomenon. Although the outcome of newborns depends mostly on the underlying etiology, the presence of seizures seems to have a negative prognostic value, especially if the seizures are prolonged. The most common antiepileptic drugs are only partially effective. Phenobarbital is the most used first-line drug with no differences between preterm and full-term newborns. Moderate to severe abnormal background EEG activity and electrographic-only seizures seem to be associated with a lack of response to phenobarbital. Moreover, seizures management in newborns has not significantly changed if the etiology is acute symptomatic. However, evidence of promising therapeutic approaches for neonatal epilepsy encephalopathies is growing. An accurate and prompt diagnosis of seizures is required for early management to avoid the potential detrimental effects of seizures on the immature brain.

To evaluate the predictive value of pre- and postoperative amplitude-integrated electroencephalography (aEEG) on neurodevelopmental outcomes in children operated for congenital heart disease (CHD).

Prospectively enrolled cohort of 60 infants with CHD who underwent cardiac surgery with cardiopulmonary bypass in the first 3 months of life. Infants with a genetic comorbidity were excluded. aEEG was assessed for 12 hours pre- and 48 hours postoperatively. Background pattern was classified by the use of standard categories, and the presence of seizures and sleep-wake cycles (SWCs) was noted. Outcome at 1 and 4 years of age was assessed with standardized developmental tests.

Preoperatively, infants either showed continuous normal voltage (n = 56) or discontinuous normal voltage (n = 4). Postoperatively, abnormal background pattern (flat trace, burst suppression, or continuous low voltage) was detected in 7 (12%), discontinuous normal voltage in 37 (61%), and continuous normal voltage in 16 (27%) infants. Nineteen infants (32%) did not return to normal SWCs within the recording period. Seizures were detected in 4 infants preoperatively and in another 4 postoperatively. After we controlled for surgical and postoperative risk factors, abnormal postoperative background pattern and lack of return to SWCs independently predicted poorer intelligence quotient at 4 years (P = .03 and P = .04 respectively) but was not related to motor outcome.

aEEG is a useful bedside tool that helps to predict outcome in infants undergoing open-heart surgery for CHD. Abnormal postoperative background pattern and lack of return to SWCs are markers for subsequent impaired cognitive development.

To analyze whether in term neonates during immediate transition after birth low cerebral activity measured by amplitude-integrated EEG (aEEG) is linked to cerebral regional oxygen saturation (crSO₂) measured by near-infrared spectroscopy (NIRS). Additionally, the cerebral fractional tissue oxygen extraction (cFTOE) was calculated to analyze whether cerebral activity is linked to cFTOE.

A total of 244 term neonates delivered by primary cesarean section were studied. In addition to routine monitoring with pulse oximetry, aEEG and NIRS measurements were performed during the first 15 min after birth. The mean minimum (V_min) and maximum (V_max) amplitude of the cerebral activity as well as crSO₂ and cFTOE for each minute was determined. Neonates with initial V_min < 5 μV or V_max < 10 μV, which normalized during transition (study group) were compared to neonates with normal aEEG values throughout the whole monitoring period (control group).

9 neonates fulfilled inclusion criteria to the study group and were compared to 50 neonates in the control group. V_min, V_max, crSO₂, SpO₂ and cFTOE were compared from the 4th to 15th min after birth. During our study period, V_min and V_max were significantly lower in the study group than in the control group. crSO₂ was significantly lower in the study group until minute 11, dropping below the 10th centile in minute 8. cFTOE was significantly higher in the study group until minute 10, rising above the 90th centile in minutes 8 and 9. SpO₂ was within normal ranges in both groups. crSO₂ and cFTOE were within normal ranges in the control group.

The present study demonstrates that neonates with initially low cerebral activity during immediate transition after birth concurrently showed low crSO₂ (<10th percentile), but increased cerebral oxygen extraction (cFTOE > 90th percentile). Cerebral monitoring with aEEG and NIRS might provide useful information on the neonates’ condition during immediate transition.

The study aims are to evaluate cerebral background patterns using amplitude-integrated electroencephalography in newborns with critical congenital heart disease, determine if amplitude-integrated electroencephalography is predictive of preoperative brain injury, and assess the incidence of preoperative seizures. We hypothesize that amplitude-integrated electroencephalography will show abnormal background patterns in the early preoperative period in infants with congenital heart disease that have preoperative brain injury on magnetic resonance imaging.

Twenty-four newborns with congenital heart disease requiring surgery at younger than 30 days of age were prospectively enrolled within the first 3 days of age at a tertiary care pediatric hospital. Infants had amplitude-integrated electroencephalography for 24 hours beginning close to birth and preoperative brain magnetic resonance imaging. The amplitude-integrated electroencephalographies were read to determine if the background pattern was normal, mildly abnormal, or severely abnormal. The presence of seizures and sleep-wake cycling were noted. The preoperative brain magnetic resonance imaging scans were used for brain injury and brain atrophy assessment.

Fifteen of 24 infants had abnormal amplitude-integrated electroencephalography at 0.71 (0-2) (mean [range]) days of age. In five infants, the background pattern was severely abnormal. (burst suppression and/or continuous low voltage). Of the 15 infants with abnormal amplitude-integrated electroencephalography, 9 (60%) had brain injury. One infant with brain injury had a seizure on amplitude-integrated electroencephalography. A severely abnormal background pattern on amplitude-integrated electroencephalography was associated with brain atrophy (P = 0.03) and absent sleep-wake cycling (P = 0.022).

Background cerebral activity is abnormal on amplitude-integrated electroencephalography following birth in newborns with congenital heart disease who have findings of brain injury and/or brain atrophy on preoperative brain magnetic resonance imaging.