[P3-103] Prediction of brain rhythm recovery after cardiopulmonary resuscitation: Cortical evoked potential study in a boy
Electrophysiological tests such as electroencephalography (EEG), brain stem or somatosensory evoked potential (BSEP. SSEP), event related potential (ERP), and mismatch negativity (MMN) have been used for prediction of cerebral recovery after cardiopulmonary resuscitation (CPR). However, very low voltage EEG less than 20μV is usually considered as a precursor of electrocerebral silence (ECS), and ECS is considered in brain death determination. Here, we report an experience of MMN study in a 9-year-old boy who was in persistent vegetative state after CPR with markedly suppressed EEG, and slowly regained cerebral activity. The patient originally had cerebral palsy and Lennox-Gastaut syndrome. He was admitted to the intensive care unit for status epilepticus provoked by mycoplasma and enteroviral infection. During admission, sudden unexpected pneumothorax caused cardiorespiratory arrest and a few hours of CPR were done. Despite this previous event, his cardiac functions rapidly recovered. However, his EEG showed marked generalized suppression at 3 weeks after CPR. At the same period of time, cortical evoked potential using passive auditory oddball with larger tone difference (2,000Hz deviant and 1,000 Hz standard stimuli) than conventional MMN stimuli (under 10% of difference) showed rudimentary cortical response to deviant auditory tones. 18 days later, 2nd MMN showed more increased MMN amplitude with faster latency. 17 days after the 2nd MMN, his routine EEG showed more recovered cortical activity and even showed epileptic discharges. We conclude that cortical evoked potential reflects the primitive cortical function and can predict the electrocerebral recovery. This result can be applied to neurocritical care of children.