Topography of maturational changes in EEG burst spectral power of the preterm infant with a normal follow-up at 2years of age

Objective

To quantify the electroencephalography (EEG) burst frequency spectrum of preterm infants by automated analysis and to describe the topography of maturational change in spectral parameters.

Methods

Eighteen preterm infants <32 weeks gestation and normal neurological follow-up at 2 years underwent weekly 4-h EEG recordings (10–20 system). The recordings (n = 77) represent a large variability in postmenstrual age (PMA, 28–36 weeks). We applied an automated burst detection algorithm and performed spectral analysis. The frequency spectrum was divided into δ1 (0.5–1 Hz), δ2 (1–4 Hz), θ (4–8 Hz), α (8–13 Hz) and β (13–30 Hz) bands. Spectral parameters were evaluated as a function of PMA by regression analysis. Results were interpolated and topographically visualised.

Results

The majority of spectral parameters show significant change with PMA. Highest correlation is found for δ and θ band. Absolute band powers decrease with increasing PMA, while relative α and β powers increase. Maturational change is largest in frontal and temporal region.

Conclusions

Topographic distribution of maturational changes in spectral parameters corresponds with studies showing ongoing gyration and postnatal white matter maturation in frontal and temporal lobes.

Significance

Computer analysis of EEG may allow objective and reproducible analysis for long-term prognosis and/or stratification of clinical treatment.