Quantitative EEG (qEEG), also known as brain mapping, is a noninvasive test that uses transitional EEG data and specialized computer digitization to display the diagnostic information as topographic color-coded maps of the cerebral cortex. The computer analyzes EEG signals for amplitude and distribution of alpha, beta, theta, and delta frequencies and displays the analysis as a color map. Specific or minute abnormalities are enhanced and allow comparison with normal data. This methodology is used for assessing cognitive function and for evaluating patients with migraine headaches, trauma, or episodes of vertigo or dizziness. Persons who lose periods of time and select patients with generalized seizures, dementia of organic origin, ischemic abnormalities, or certain psychiatric disorders are also candidates for this testing. With this procedure, it is possible to localize a specific area of the brain that may otherwise show up as a generalized area of deficit in the conventional EEG. Children or adults who demonstrate hyperactivity, dyslexia, dementia, or Alzheimer disease may benefit from evaluation through brain mapping.

1. Ensure that the patient is rested and awake for the test so that no sleep signals appear as indicators of beta wave activity.

2. Place a sensor cap on the patient's head.

3. Place the patient in a recumbent position and instruct the patient to keep the eyes closed and to refrain from any movement.

4. Follow guidelines in Chapter 1 for safe, effective, informed intratest care.

Abnormal brain maps can pinpoint the following conditions:

1. Areas of focal seizure discharge in persons who experience generalized seizures

2. Areas of focal irritation in persons with migraine

3. Areas of ischemia

4. Areas of dysfunction in states of dementia

5. Areas of possible brain abnormalities associated with schizophrenia or other psychotic states

Pretest Patient Care

1. Explain test purpose and procedure. There are no known risks. Emphasize the fact that electrical impulses pass from the patient to the machine and not the opposite.

2. Tell the patient that food and fluids can be taken before testing. However, no coffee, tea, or caffeinated drinks should be ingested for at least 8 hours before test.

3. Ensure that tranquilizers are not taken before testing (check with healthcare provider). Other prescribed medications such as antihypertensive medications and insulin may be taken. If in doubt, contact the testing laboratory for guidelines.

4. Follow guidelines in Chapter 1 for safe, effective, informed pretest care.

1. Tranquilizers may alter results.

2. Eye and body movements cause changes in signals and wave patterns.

Normal

• Normal frequency signals and evoked responses presented as a color-coded map of electrical brain activity