EEG patterns in 10 extreme premature neonates with normal neurological outcome: qualitative and quantitative data.
The aim of this prospective study was to describe and quantify EEG patterns in 10 very premature infants (24 weeks 2 days- 26 weeks 4 days GA) without neonatal neurological pathology and with a normal outcome at 3 years of age for nine of them. EEG and eye movements were recorded in the first 5 days of life. All tracings were discontinuous; EEG inactivity (<15 microV) never exceeded 1 min, representing 45.3% of total recording time. The EEG bursts, mainly synchronous, could last up to 83 s when >50 microV and to 197 s when >15 microV. High voltage delta waves (0.5 Hz; up to 330 microV), either smooth or superimposed with 7-12 Hz rhythms, were the most typical and frequent figures, mainly in temporal (mean number 257.2 +/- 73.3) and occipital (237.7 +/- 65.8 per hour recording) areas. In temporal areas, they appeared mainly in clusters; more often unilateral than bilateral (P < 0.05). Occipital delta waves were as often bilateral and synchronous as unilateral. The two distinct frontal delta waves were significantly less numerous than other delta waves (P < 0.05). Bursts of hypersynchronous high voltage delta waves and of diffuse sharp theta waves were less numerous than other waves (P < 0.01). Considering periods with or without eye movements, the mean percentage and the mean longest period of EEG activity (< or =50 microV) were significantly greater (P < 0.01) when eye movements were present, indicating a rough sleep state differentiation as early as 25 weeks CA. These EEG patterns are qualitatively and quantitatively reproducible. They constitute standards of normality and a basis for the determination of neurological prognosis.
Vecchierini
Marie-Françoise
MF
Laboratoire d'Explorations Fonctionnelles, Centre Hospitalier Universitaire Bichat-Claude Bernard, AP-HP/Université Paris VII, Paris, France.
d'Allest
Anne-Marie
AM
Verpillat
Patrice
P
D004569:Electroencephalography; D005069:Evaluation Studies as Topic; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D008297:Male; D010043:Outcome and Process Assessment, Health Care; D011247:Pregnancy; D011446:Prospective Studies; D012015:Reference Standards; D012894:Sleep Stages / Q000502:physiology; D014894:Weights and Measures