TABLE 11-11. MAJOR USES OF THE ELECTROENCEPHALOGRAM
- Diagnosis of epilepsy.
- Paroxysmal spikes, sharp waves, and/or slow waves may be diagnostic of epilepsy. The EEG can help identify the type of seizure disorder, and it may help localize a seizure focus.
- Focal slowing in the EEG may help localize a lesion. The EEG pattern is not specific for any particular type of pathology.
- Slowing is seen with most metabolic encephalopathies. Again the EEG pattern is not helpful in diagnosing the type of encephalopathy.
- Barbiturates and minor tranquilizers frequently produce an excessive amount of low-voltage fast activity.
- Unusual EEG patterns are seen in a number of degenerative diseases (SSPE and Creutzfeldt-Jakob disease, for example). In the others, the EEG changes are nonspecific and often very slight.
- Two flat EEGs taken 24 hours apart are diagnostic of cerebral death in the absence of hypothermia or drug overdose.