Amplitude spectral analysis of maturational changes of delta waves in preterm infants

The aim of this study is to clarify the usefulness of amplitude spectral analysis for an evaluation of maturational changes of delta activities in preterm infants. We chose each ten healthy infants without complications who were 29-30, 31-32, and 33-34 weeks of post-conceptional age (PCA) at electroencephalogram (EEG) recordings. Fast Fourier transform algorithm was applied for amplitude spectral analysis. The analyzed data were divided into four frequency bands; D1 0.53-1, D2 1-2, D3 2-3, and D4 3-4Hz. The average amplitude of six segments with high voltage slow waves was calculated in each frequency band. A significant reduction of the amplitude along with PCA was present in all leads in D1 band. On the other hand, a significant negative correlation with PCA was observed only in the occipital leads in D2, D3 or D4 bands. In conclusion, maturational EEG changes assessed by amplitude spectral analysis were prominent in the occipital areas, and in the frequency less than 1Hz.

[1]  A. Okumura,et al.  Background electroencephalographic (EEG) activities of very preterm infants born at less than 27 weeks gestation: a study on the degree of continuity , 2001, Archives of disease in childhood. Fetal and neonatal edition.

[2]  G. Holmes,et al.  Prognostic value of background patterns in the neonatal EEG. , 1993, Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society.

[3]  Schulte Fj,et al.  Maturation of EEG activity during sleep in premature infants. , 1968, Electroencephalography and clinical neurophysiology.

[4]  J. Eyre,et al.  The Neurophysiological Examination of the Newborn Infant , 1992 .

[5]  F. Torres,et al.  The EEG of the early premature. , 1985, Electroencephalography and clinical neurophysiology.

[6]  P. Mccullagh,et al.  Variation in power spectral analysis of the EEG with gestational age. , 1991, Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society.

[7]  C T Lombroso,et al.  Neonatal Polygraphy in Full‐Term and Premature Infants: A Review of Normal and Abnormal Findings , 1985, Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society.

[8]  Akihisa Okumura,et al.  Neonatal EEG: a powerful tool in the assessment of brain damage in preterm infants , 1999, Brain and Development.

[9]  Kazuyoshi Watanabe,et al.  Dysmature EEG pattern in EEGs of preterm infants with cognitive impairment: maturation arrest caused by prolonged mild CNS depression , 1997, Brain and Development.

[10]  Kazuyoshi Watanabe,et al.  Physical condition of preterm infants with periventricular leukomalacia , 2001, Brain and Development.

[11]  T. Negoro,et al.  [Developmental changes of topographic EEG features in the newborn]. , 1984, No to hattatsu = Brain and development.