ABSTRACT
OBJECTIVE: To study the characteristics of amplitude integrated electroencephalography (aEEG) in preterm infants and changes of maturation with gestational age. METHODS: aEEG monitoring was done within 3 days of age with domestically produced digital aEEG set (CFM3000). Duration of each recording was at least 4 hours. The continuity, sleep-wake cycle, voltage and bandwidth of all aEEG tracing were analyzed. RESULTS: The percent of continuity background increased from 30% of 28 weeks to 85.7% of 36 weeks (χ(2) = 28.2, P = 0.026); the percent of mature sleep-wake cycle increased from 10% of 28 weeks to 100% of 36 weeks (χ(2) = 192.4, P < 0.01). Low bound voltage increased with gestational age, from (6.8 ± 1.7) µV (28 w) to 9.7 - 10.1 µV (35 - 36 w) (F = 11.4, P < 0.01). Bandwidth of the narrow band decreases gradually with gestational age, from 1.45 cm (28 w) to (0.86 ± 0.24) cm (36 w) (F = 8.731, P < 0.01). The correlation coefficient for continuity, sleep-wake cycle, low bound voltage and bandwidth of narrow band, and total scores were 0.32, 0.81, 0.38, 0.55 and 0.78 respectively (P < 0.05). CONCLUSION: The older the gestational age of infants at birth, the more mature the aEEG pattern, manifested as increased continuity and sleep-wake cycle, the higher low bound voltage and more narrowed bandwidth with increased gestational age.
Subject(s)
Electroencephalography , Infant, Premature/physiology , Age Factors , Female , Humans , Infant, Newborn , MaleABSTRACT
OBJECTIVE: To study the changes of the amplitude-integrated electroencephalography (aEEG) tracings within 6 hours after birth in term infants with hypoxic-ischemic encephalopathy (HIE) and explore the value of aEEG in early diagnosis and prediction of neurological outcome in term infants. METHODS: From May 2003 to February 2005, 33 term infants with HIE at the Division of Neonatology, Pediatric Hospital of Fudan University were studied by aEEG within 6 hours after birth. The results of aEEG were categorized into three groups (normal, mildly abnormal and severely abnormal aEEG), while HIE was clinically classified into three grades (mild, moderate and severe) and the neurological outcomes at 18 months were assessed (normal, disabled and dead). The correlation between the results of aEEG, severity of HIE and neurological outcome at 18 months were analyzed, respectively. The values of aEEG on early diagnosis and neurological outcome prediction of HIE were analyzed. RESULTS: Among the 33 term infants with HIE, 20 infants had normal aEEG (normal amplitude aEEG), 5 had mildly abnormal aEEG (4 with mildly abnormal amplitude aEEG, 1 with normal amplitude and seizure) and 8 had severely abnormal aEEG (2 with mildly abnormal aEEG and seizures, 4 with severely abnormal amplitude and 2 with severely abnormal amplitude and seizures), respectively. Seventeen infants (51.5%) had mild HIE, 19 moderate (27.3%) and 7 (21.2%) severe HIE, respectively. Twenty-five cases were followed up, which showed that 19 had normal neurological outcome, 1 had disability and 5 died. By CMH square analysis and Spearman rank correlation analysis, the results of aEEG classification were correlated with the severity of HIE and the neurological outcome of term infants. Abnormal aEEG could predict the severity of HIE in term infants with a sensitivity of 100%, specificity of 81.3%, positive predictive value of 85.0% and negative predictive value of 100%, respectively. Abnormal aEEG could predict the neurological outcome of term infants with HIE, which showed a sensitivity of 100%, specificity of 90.9%, positive predictive value of 93.3% and negative predictive value of 100%, respectively. Severely abnormal aEEG could predict the severe HIE in term infants with sensitivity of 96.2%, specificity of 100%, positive predictive value of 100% and negative predictive value of 87.5%, respectively. Severely abnormal aEEG could predict the neurological outcome of term infants with HIE, which showed sensitivity of 94.7%, specificity of 100%, positive predictive value of 100% and negative predictive value of 85.7%, respectively. CONCLUSIONS: Monitoring with aEEG in term infants with HIE within 6 hours after birth could predict the severity of HIE and its neurological outcome at 18 months.