Facilities

EEG & EP Lab

What's an EEG?

An EEG or electroencephalogram is a diagnostic test that gives a physician information about the brain's activity. Basically, it's an electrical picture of the brain. Small devices called electrodes are placed in precise locations on the scalp and attached by wires to an electroencephalograph or an EEG machine. Electrical activity (brainwaves) is collected and recorded as a pattern of wavy lines. A neurologist then interprets these lines to determine if there are abnormal patterns caused by brain disease or dysfunction. EEG
A precision tool
Most EEGs are recorded on long strips of paper. At UVa, our EEGs are digital recordings displayed on large computer monitors. This computerization allows for even more precise readings and analysis.

Because UVa's EEGs are captured digitally and analyzed on a computer, they can be stored, displayed and interpreted more conveniently and accurately.

Most importantly, UVa's EEGs are done by trained, single-purpose technologists and interpreted by physicians who have formal and licensed training in neurophysiology. The sheer number of adult and pediatric electrophysiology studies done by our technologists and physicians gives them the experience with difficult-to-interpret studies of common and unusual maladies.

What an EP?
EP (evoked potential) testing uses an EEG to measure the electrical activity of nerves or to determine areas of the brain, brain stem, or spinal cord serving an individual nerve. An EP measures the time it takes for a nerve impulse generated by a specific stimulus to reach the brain as determined by an EEG. Evoked potentials may also serve as a guide during the surgical removal of tumors growing around important nerves. There are three common types of EP: EP
  • Visual evoked potential: In this test, the stimulus is a computer-generated visual test pattern that measures the speed and quality of nerve pathways from the eye to the visual regions of the brain.
  • Sensory evoked potential: The stimulus is generated by an electrode that is placed on one of the patient's limbs. The test measures the intactness of sensory pathways from the limb, through the spinal cord, and into sensory regions of the brain.
  • Brain stem auditory evoked potentials: The stimulus is an audible click that tests the integrity of sound sensation from the ears to the brainstem.

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