EEG is a real time test.
“The principal role of the EEG, however, is in the evaluation of persons with epilepsy. First of all, it must be remembered that about 50 per cent of those who have had an undoubted tonic-clonic seizure will have a normal EEG. It follows that a normal EEG does not prove or disprove a diagnosis of epilepsy.”
Hopkins, Clinical Neurology, ©Oxford University Press, 1993
The concussions that disable, are almost always more symptomatic at 24 hours, than at the 2-4 hour time frame when injured persons are evaluated in the emergency room. Brain injury symptoms escalate over the first 24 hours, because brain injury involves a cascade of events. It is critical that if you are still symptomatic the day after your injury, go back to the same Emergency Room, don’t wait for a doctors appointment. It is critical that the Emergency Room personnel see that the symptoms still persist or have gotten worse.