2003 Volume 40 Issue 9 Pages 610-616
A concussion describes the brief loss of consciousness after head injury, but if this loss of consciousness lasts longer than 6 hours, it is presumed that there was brain tissue injury, and the term “Diffuse Axonal Injury (DAI)” is used. CAT scan evidence of DAI is provided by punctuate hemorrhage, with little edema. A MRI may show some signs of DAI even when a CT scan does not. An EEG is not as useful as an emergency examination, but it aids in prognosis. Areas of focal damage to the cortex may show evidence of abnormal activity (slowing and spike activity) for weeks or months after the injury. We evaluated 15 patients (6 months after brain injury) who are in post acute rehabilitation in our center to examine how EEG can provide us with clinical information in the chronic phase after brain injury. Six patients with normal EEG findings were in a coma for significantly less time after injury and had a higher alpha frequency than the nine patients who showed EEG abnormalities (p<0.01). Three patients who showed severe higher brain dysfunction showed EEG abnormalities, such as focal slow waves. Some patients who showed normal EEG findings had higher brain dysfunction, so we must be careful in clinical situations, since the EEG may look normal. We showed the clinical significance of EEG exanimation 6 months or longer after brain injury in patients with DAI; and that EEGs can provide important information during post acute rehabilitation.
