An EEG records the electrical activity of the brain. Highly sensitive and accurate computerized digital monitoring systems record the activity through an array of electrodes placed at measured intervals on the patient's scalp. EEGs are the only available diagnostic tool to diagnose seizure disorder. Read the frequently asked questions for more information.
The test is non-invasive and painless for the patient. Sensors are placed on the scalp with a lanolin type conductive paste that washes off with ease. While testing, the patient may be asked to do a deep breathing exercise (hyperventilate) and may be shown a strobe light that flashes at various frequencies. These activities are helpful in revealing brain patterns useful for diagnosis. The test takes about 90 minutes and the patient is asked to remain still, relaxed and is made as comfortable as possible.
Physicians may also want to observe brain patterns that occur during sleep. For this purpose the patient may be scheduled for a Sleep Deprived EEG or an Ambulatory EEG.
The Sleep Deprived EEG requires that the patient stay awake most of the night prior to the testing. In testing children, we ask that the child be kept up as late as possible and wake as early as possible. In some cases a mild sedative may be given, but only if ordered by the referring physician and scheduled with Pediatrics prior to testing.
The Digital Ambulatory EEG
The Digital Ambulatory EEG is recorded on a mini hard disc for a minimum of 24 consecutive hours of brain wave activity. Our new state-of-the-art equipment offers prolonged EEG recording, more channels, ease of reading, and voice recognition for patient reporting events. This brings higher yield in identifying seizure activity. The patient (or spouse, caretaker, etc.) speaks into a microphone to inform the reader of any events he or she may be having.
Long-term Digital Video Monitoring
Long-term Video Monitoring is useful in diagnosing patients with frequent events. This test is a simultaneous recording of EEG (brain waves) and audio/visual behavior of a patient over an extended period of time. Sensors are applied to the scalp with a glue-like substance that is removed following the test period.
Evoked Potentials (EP)
Evoked Potentials are useful in evaluating neurological problems, including acoustic neuroma, optic neuritis, spinal cord injuries, and multiple sclerosis. They record electrical activity from the brain in response to external stimulation.
Three types of Evoked Potentials are done in our lab: the visual evoked potentials (VEP), the Brainstem Auditory Evoked Potentials (BSAEP), and the Somatosensory Evoked Potentials (SSEP).
The VEP requires the patient to stare at a pattern on a screen while sensors are applied to the scalp using conductive paste. This test is used to evaluate the optic nerves.
The BSAEP evaluates the acoustic nerve and brainstem auditory pathways. sensors are applied to the scalp and either earphones or ear inserts (much like foam earplugs) are used to deliver a series of clicks to each ear separately.
Somatosensory EP Median or Post-tibial EP's
Sensors are applied to the scalp, spinal column as well as other places on the body, and a small electrical current (creating a tingling sensation) is applied to the skin over the specific nerves on the arms or legs. This test is used to assess the pathways from the nerves in the arms (median) or legs (post-tibial) through the spinal cord. Sometimes, patients having surgical procedures involving the spinal cord or acoustic nerve will have Evoked Potential monitoring throughout their operation to assist in nerve function