chevron-left chevron-right chevron-up chevron-right chevron-left arrow-back star phone quote checkbox-checked search wrench info shield play connection mobile coin-dollar spoon-knife ticket pushpin location gift fire feed bubbles home heart calendar price-tag credit-card clock envelop facebook instagram twitter youtube pinterest yelp google reddit linkedin envelope bbb pinterest homeadvisor angies

Electoencephalography (EEG)

Electroencephalography ( EEG) Electroencephalography (EEG) is the recording of electrical activity along the scalp produced by the firing of neurons within the brain. In clinical contexts, EEG refers to the recording of the brain’s spontaneous electrical activity over a short period of time, usually 20–40 minutes, as recorded from multiple electrodes placed on the scalp. In neurology, the main diagnostic application of EEG is in the case of epilepsy, as epileptic activity can create clear abnormalities on a standard EEG study. A secondary clinical use of EEG is in the diagnosis of coma, encephalopathies, and brain death. EEG used to be a first-line method for the diagnosis of tumors, stroke and other focal brain disorders, but this use has decreased with the advent of anatomical imaging techniques such as MRI and CT.

Doctor meeting a new patient

EEG Testing

  • An EEG is a painless test that measures electrical activity of the brain. It helps in the diagnosis of numerous conditions related to the brain. It is similar to an EKG or Heart Test, but it is done on the head.
  • An EEG takes approximately one hour. A technician will mark and measure your head with a measuring tape and a non-toxic grease pencil. Small metal electrodes are placed on the scalp with adhesive paste. You will be resting in a reclining chair in a dark and quiet room while recording. During the test, you will feel no sensation at all from the electrodes. You will be asked to do certain things during the recording, such as breathe deeply and rapidly for several minutes or look at a bright flickering light.
  • The recording machine converts the electrical signals into a series of wavy lines that are recorded by the computer. These signals are then studied and interpreted by the physician.

How to Prepare for the Test

Routine EEG
  1. You will need to wash your hair the night before the test.
  2. You should not use any oils, sprays or conditioner on your hair before the test.
  3. We ask that you do not wear makeup or put lotion on your face.
  4. You may also continue your usual medicines unless instructed otherwise by your doctor.
Sleep-Deprived EEG
  1. You will need to wash your hair the night before the test.
  2. You should not use any oils, sprays or conditioner on your hair before the test.
  3. You should not wear makeup or put lotion on your face.
  4. You need to either: (1) Get up at 3 a.m. on the morning of the test, OR (2) Do not go to bed until 2 a.m. The goal is to be tired and ready to fall asleep at the time of the test.
  5. You can eat before the test; however, you should avoid all stimulants (e.g., coffee, tea, soda, chocolate, smoking, etc) for 8 hours prior to the test.
  6. You may also continue your usual medicines unless instructed otherwise by your doctor.
  7. Because you may be sleepy, please have someone else drive you to and from the test.