When using the EEG as a clinical tool, one should always keep in mind that the EEG recording is simply a random sampling of the person’s brain electric activity taken at a particular period of time. Hence, in those neurologic disorders that produce transient abnormalities in the EEG, an EEG may be interpreted as normal unless the time of occurrence of the abnormality coincides with the time of recording. This issue becomes particularly important in investigations of seizure disorders. Contrary to the notions of the uninitiated, a normal EEG in no way “rules out” a genuine seizure disorder, as interictal epileptiform abnormalities may or may not have been present at the time of recording. One of the ways that is employed to mitigate this problem is to increase the probability of occurrence of abnormalities during the recording period. This may be achieved by using various activation procedures that can elicit or enhance certain normal as well as abnormal activity in the EEG. It must be understood, however, that while activation procedures are most valuable in the case of seizure disorders, they may also be useful in the study of many other neurologic disorders.
KeywordsSleep Deprivation Seizure Disorder Absence Seizure Activation Procedure Slow Activity
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