CSA 2 – Answer

Initial trace
Change in trace

Abnormal beta activity – the raw EEG recorded during one of these spikes is in keeping with beta activity (frequency – 13 to 30 Hz). As the patient is deeply sedated this beta activity is abnormal (beta activity normally occurs in awake patients). Common causes of abnormal beta activity in PICU include underlying brain injury and as in this case the use of midazolam for sedation (explaining why it was unresponsive to midazolam boluses). This can be differentiated from seizure activity by the appearance of the raw EEG during the episode and also by the fact that only the frequency increased during the episodes and not the power (seizure activity is sudden onset increase in both frequency and power).