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Have an Electroencephalogram (EEG)


An electroencephalogram (EEG) is a noninvasive diagnostic test to measure the electrical activity of the brain. 

If your need an electroencephalogram in the Bay Area, Dignity Health is here to help. Our hospitals and imaging centers offer complete neurological diagnostic testing, including EEG. Find a Doctor near you today.

Why We Perform Electroencephalograms

At Dignity Health, your doctor may use an electroencephalogram test to diagnose or monitor several neurological conditions. An EEG test is commonly used to detect or monitor: 

  • Brain diseases such as encephalopathy
  • Brain tumors
  • Effects of anesthesia on brain activity during brain surgery
  • Head injuries
  • Infections
  • Sleep disorders
  • Seizures, including those caused by epilepsy
  • Unexpected changes in brain function, including coma

What to Expect During an EEG 

The electroencephalogram is a minimally invasive test that can be done in a Dignity Health hospital or doctor’s office. It usually is performed by an experienced EEG technician, who sends the test results to your doctor. Depending on the purpose of the test, an EEG typically takes one to three hours. In some cases, extended monitoring is necessary.

Prior to receiving an EEG test, your doctor will give you specific instructions on how to prepare. In general, you should:

  • Avoid caffeine for eight hours before the test. 
  • Continue taking all prescribed medications unless instructed otherwise by your doctor.
  • Shampoo your hair the night before, but do not apply any conditioner or other hair products.

During your EEG test, the technician will place adhesive-backed electrodes on your scalp and possibly your face. The electrodes connect to a machine that records your brain activity. You will be asked to lie still with your eyes closed. You may also be asked to perform certain activities during the test, such as breathing fast or looking at a flashing strobe light.

An EEG test is generally safe. However, the EEG technician is trained to respond if parts of the procedure trigger a seizure, such as viewing a strobe light.

Recovery after Electroencephalogram

You may return to normal activities following an EEG. If you experience a seizure during the test, the technician will give you specific instructions about how to proceed.

The electroencephalogram test can help your doctor determine if you have a seizure disorder or other brain condition. Once this diagnosis has been established, your Dignity Health neurological team can create your personalized treatment plan.

Dignity Health offers advanced neurological diagnostic testing, including electroencephalogram, in the Bay Area.