Alternative Names
Electroencephalogram; Brain wave test
Normal Values:
Brain waves have normal frequency and amplitude, and other characteristics are typical.
What abnormal results mean:
Abnormal findings may suggest the following:
- Seizure disorders (such as epilepsy or convulsions)
- Structural brain abnormality (such as a brain tumor or brain abscess)
- Head injury
- Attention deficit problems
- Encephalitis (inflammation of the brain)
- Hemorrhage (abnormal bleeding caused by a ruptured blood vessel)
- Cerebral infarct (tissue that is dead because of a blockage of the blood supply)
- Sleep disorders (such as narcolepsy)
- Drug or alcohol abuse
- Migraines (in some cases)
- Hallucinations
- Syncope
- Vertigo
EEG may confirm brain death in someone who is in a coma. Note: a normal EEG does not mean that a seizure did not occur.
Additional conditions under which the test may be performed: