Continuous EEG monitoring in patients with traumatic brain injury reveals a high incidence of epileptiform activity.
BACKGROUND
EEG is the only available method for real time monitoring of the brain and is therefore of great interest in the neurointensive care. The present study describes our experiences from implying continuous EEG monitoring as a routine method. We also present EEG patterns observed on patients with traumatic brain injury (TBI).


METHODS
Seventy TBI patients requiring neurointensive care were included. Digital EEG was recorded continuously. Five minutes every hour were analysed off-line.


RESULTS
Twenty-three patients (33%) developed seizures, 74+/-47 h after trauma. The seizures were brief, responding to phenytoin, or persistent, requiring propofol or barbiturate sedation. Six out of eight patients with persistent seizures had intracerebral contusions. Eighteen patients (26%) displayed focal high frequency activity that proceeded to seizures in eight cases. Twelve patients (17%) developed recurrent paroxysmal delta activity. The patients in the seizure group were significantly older (62+/-12 vs. 28+/-17 years) and more often exposed to low energy trauma (87% vs 22%) compared to the paroxysmal delta pattern group.


CONCLUSIONS
TBI implies high risk for development of epileptiform activity, with a time lag between trauma and seizure onset. TBI patients also displayed other EEG pattern that should be investigated further in order to obtain a better understanding of posttraumatic mechanisms.
Ronne-Engstrom
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Department of Neurosurgery, Division of Neuroscience, University Hospital, Uppsala, Sweden. elisabeth.ronne.engstrom@akademiska.se
Winkler
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D000328:Adult; D000367:Age Factors; D000368:Aged; D000927:Anticonvulsants / Q000627:therapeutic use; D001930:Brain Injuries / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology*; D002540:Cerebral Cortex / Q000293:injuries* / Q000503:physiopathology*; D004569:Electroencephalography; D004827:Epilepsy / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000627:therapeutic use; D015994:Incidence; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D011237:Predictive Value of Tests; D012307:Risk Factors; D013997:Time Factors
D000927:Anticonvulsants; D006993:Hypnotics and Sedatives