Prognostic value of continuous electroencephalographic recording in full term infants with hypoxic ischaemic encephalopathy.

The prognostic value of early neonatal continuous electroencephalographic recordings in hypoxic ischaemic encephalopathy was evaluated. Thirty seven full term infants with hypoxic ischaemic encephalopathy were studied. The electroencephalogram (EEG) was recorded using four or eight channel Oxford Medilog recorders and was started as soon as possible after birth. The recordings were initially visually analysed and divided into four categories: three in relation to the grade of discontinuity of the background activity (continuous, discontinuous, and maximum depression) and an additional fourth category to include status epilepticus. The EEGs with discontinuous activity were then analysed by computer to obtain a more objective assessment of discontinuity. The results were related to neurological outcome. Continuous background activity was associated with a normal outcome in all but the three infants who had continuous, but asymmetrical EEGs and who developed contralateral hemiplegia. In the eight infants with discontinuous activity, the outcome appeared to be related to the grade of continuity and the presence of clear convulsions on the EEG. The 10 infants with maximum depression and status epilepticus had severe impairment. These preliminary results suggest that continuous recording of EEGs could be used routinely in term infants with hypoxic ischaemic encephalopathy. Computer analysis can improve the value of this technique, allowing the identification of infants who might benefit from early therapeutic intervention.