Wesley's Neurodiagnostic Lab provides inpatient and outpatient testing to diagnose disorders of the brain and nervous system. Testing procedures can be tailored to meet the specific needs of each patient. Equipment and procedures are state-of-the-art; and tests are of the highest quality and conform to national standards. Test include:
An EEG records the brain's electrical activity, using electrodes that are placed on the patient's scalp. The test is not painful and takes about 90 minutes while the patient remains still and relaxed. The patient may be asked to take repeated deep breaths (hyperventilate) and may be shown a strobe light that flashes at different speeds. Both activities can help reveal different brain patterns that are useful in diagnosis. If observation of brain patterns that occur during sleep are needed, the patient may be asked to stay awake most of the night prior to the EEG appointment.
EEGs assist physicians in the diagnosis of a variety on neurological problems, from common headaches and dizziness to seizure disorders, strokes, and degenerative brain disease. The EEG is also used to look for organic causes of psychiatric symptoms and disabilities in children and can assist physicians in determining irreversible brain death.
EP (evoked potential)
The EP is a digital recording of electrical activity from the brain, spinal nerves or sensory receptors in response to specific external stimulation. After electrodes are applied to the scalp and other areas of the body, a series of stimuli is introduced and a computer records the neurological responses. Hundreds of responses are received, amplified and averaged by a computer. The final response is plotted on a graph and interpreted by a physician who looks for particular waveforms and the time it takes them to occur.
Evoked potentials are helpful in evaluating a number of different neurological problems, including spinal cord injuries, acoustic neuroma and optic neuritis. Each type of EP looks at different neurological pathways. The three most common types are brainstem auditory evoked potential (BAEP), visual evoked potential (VEP), and somatosensory evoked potential (SSEP).
The AEP assists in evaluating the auditory nerve pathways from the ears through the brainstem. Electrodes are attached to the scalp and earlobes, and earphones are placed over the ears. The earphones deliver a series of clicks or tones to each ear separately.
The VEP evaluates the visual nervous system from the eyes to the occipital (visual) cortex of the brain. Electrodes are applied to the scalp, and the patient is usually asked to stare at a pattern on a video screen while remaining fully alert. Each eye is tested separately.
The SSEP assesses pathways from nerves in the arms or legs, through the spinal cord to the brainstem or cerebral cortex. After electrodes are placed on the scalp and along the spinal cord, a small electrical signal is applied to the skin overlying nerves on the arms and legs. This current creates a tingling sensation that is not painful. Each leg or arm is tested separately.
Long-term EEG with video monitoring
Long-term monitoring is the simultaneous recording of EEG and videotaped behavior over extended periods of time. It is helpful in diagnosing patients with intermittent or infrequent disturbances. These lengthy tests are performed in the lab, using special computers.