The testing available at the Neurodiagnostic Lab allows physicians to view how a patient's brain and/or nervous system is actually working...dynamic information not available through traditional imaging techniques such as MRI and CT scans. These tests aid in the diagnosis of some of the more serious neurological problems including Epilepsy, Multiple Sclerosis, Strokes, Parkinson's Disease and other neurological disorders, as well as common ones such as Carpal Tunnel Syndrome. The Neurodiagnostic Lab provides various tests of the Central, Peripheral and Autonomic nervous systems. Some of these tests require special instructions and preparation, which will be given along with the test description.
All tests must be ordered by a doctor (MD, DO), Physician Assistant (PA) or Nurse Practitioner (APRN). Orders may be faxed to our office 444-4777. Once we receive the order, your appointment will be scheduled. To preregister for your appointment, please call 442-0711, x2090, x2489, or x2187.
Electroencephalograms (EEG):
EEG, the "brainwave" test, shows the electrical function of the brain (like EKGs show dynamic testing of the heart). EEG is useful in detecting seizures, strokes, syncopal episodes, tumors, and processes that affect the brain diffusely (such as a metabolic problem or encephalopathy). Electrodes, which are gold cups attached to long wires, are pasted onto the scalp, and a computer captures the tiny electrical signals the brain makes over the course of 30 minutes. It doesn't hurt at all. The more relaxed you are, the better the test; we will even try to get you to sleep! The test takes a total of about 1-1/2 hours. Your doctor may ask you to come sleep deprived (no more than 4-5 hours sleep the night before). Sleep deprivation actually helps to enhance your test. Please avoid caffeine and stimulants before the test, but eat and take medications as you normally would. Please have clean, dry hair without hairspray or styling gel.
Ambulatory EEG records the brainwaves, and sometimes EKG as well, continuously for a period of 24 or more hours. It is useful in diagnosing seizures, especially during sleep, and blackout spells. The electrodes are glued onto the scalp, and the activity is captured on a computer card that is in a recorder that you can carry around while carrying out basic routine activities. The set up takes about an hour, and you'll need to come back the following day to have the equipment removed. It will be helpful to wear a button front shirt so that you are not pulling clothes over your head which may pull off an electrode. Sleep, eat, and take medications as you normally would.
Pediatric EEG is offered for children under 15. Sometimes, depending on the age or development of the child, sedation is necessary along with sleep deprivation. Sedation may involve diet restrictions. When an appointment is made, this can be explained and worked out. For very young children, you may want to bring familiar objects (bottle, pacifier, blanket, pillow, stuffed animals, etc) if this will put them at ease and help them to sleep for the test. Plan to be here for 2 hours. Please leave siblings at home if possible. as we need a quiet environment to encourage sleep. Pediatric EEGs are read by a pediatric neurologist who has special training, since childrens' brainwaves are very different than adults.
Evoked Potentials (EP):
The evoked potential measures how long it takes an impulse to travel from a point of stimulation to the brain, to determine if a problem is in the peripheral or central nervous system. Electrodes are applied to the scalp, a stimulus is given to one of the sensory pathways, and brain waves are recorded and averaged, then measured. The test doesn't hurt, but may seem very repetitive. Testing takes anywhere from 1/2 to 1 1/2 hours. Eat and take medications as you normally would, and have clean skin and hair. Do not use any lotions.
Three types of evoked potential testing are offered:
Visual Evoked Potentials (VERs): detect abnormalities of the visual system of the brain, useful for differentiating optic nerve from brain problems. Each eye is tested independently. The stimulus is a checkerboard screen that switches from black/white to white/black many times while you focus on a target. It is important that you are rested and alert, since your attention is needed to stay focused. Bring glasses or contact lenses if you normally use them for distance.
Brainstem Auditory Evoked Potentials (BAERs): detect problems with hearing, disorders of balance, tumors and auditory nerve problems. Each ear is tested independently. Headphones are put on; in the ear being tested, you will hear a rapid clicking noise. In the other will be a masking "seashell" noise. You can relax, and even sleep, through this test.
Somatosensory Evoked Potentials (SERs): detect disorders of the spinal cord, and are useful in differentiating spinal cord from peripheral nerve problems. The stimulus are series of multiple, low level electrical pulses at the feet or hands which produce twitching in the toes or fingers. We will help you to relax through this test. Loose, comfortable clothes are recommended so that we can access your limbs. It is especially important that you have clean, lotion-free skin.
Nerve conductions (NCV) and Electromyography (EMG):
Nerve conductions determine how well individual nerves transmit a stimulus by calculating the speed it travels and measuring the time it takes from point to point, as well as how many fibers are working. EMGs give information on the condition of the nerves in specific muscles, and may point to a problem with a nerve root exiting the spinal cord. These tests are useful in detecting disorders such as carpal tunnel syndrome, cervical or lumbar nerve problems and peripheral nerve entrapments or damage from diabetes. They are also useful in testing various muscle disorders. They can help evaluate recovery in peripheral nerve lesions. NCVs involve series of small electric "shocks" at different sites on the limbs which usually cause a twitch of the fingers or feet. Most people describe the feeling as "weird", and tolerate it very well. EMGs use a thin needle electrode to help the physician listen to and watch the nerve activity within muscles to see if there has been an injury. This can be uncomfortable from the pinprick, but is tolerable.
Most tests are about 30 minutes long. Please dress comfortably for your test, keeping in mind we need to get to your arms or legs. Loose clothes are best. Avoid lotions on your skin. Eat and take medications as you normally do.
Transcranial Doppler (TCD):
TCD is an ultrasound of the arteries in the brain. An ultrasound transducer is held against the head in various places, to pick up and measure the blood flow of the arteries to make sure they are not blocked or in spasm. Eat and take medications as you normally would. The test takes about 1 hour.
Autonomic Testing:
This series of tests evaluates the autonomic nervous system by measuring heart rates while at rest and with some exertion, pupil change with light, blood pressures lying and standing, sympathetic skin response, etc. Plan to be here for about 45 minutes. Please reschedule your appointment if you have been sick within 48 hours before your appointment. A list of your medications, especially betablockers, is important.
Infant Hearing Screening:
Connecticut and Rhode Island require that all newborns have their hearing tested by otoacoustic emission or AABR; we provide this service on the maternity unit. We also test infants up to 6 months who have been "missed", or who need followup for retesting or high risk criteria (genetic history in the family, various syndromes, staying in NICU for an extended period of time, etc.). Infants older than 6 months are referred to the audiology department. Infants should ideally be sleeping for the test, as it goes much quicker and the tests don't rely on interpreting behavior. Sometimes bottles or pacifiers help keep the infant happy enough to get the test done.
Therapeutic Injections:
Sometimes injections of medications can help to reduce symptoms from a pinched nerve or a dystonia. Localized steroids can be successful in reducing the inflammation around the Median nerve for Carpal Tunnel Syndrome. Botox is used for various dystonias secondary to cerebral palsy, stroke, and traumatic brain injury as well as "writers cramp". The Botox acts to locally chemodenervate, or paralyze, muscles that are in spasm to help them relax.
Our Location within the Hospital
You may enter the hospital and pick up directions at any entrance, but please be aware that the Faire Harbour entrance information desk closes at 3 pm. The hospital provides free valet parking service at the main entrance. If you have not preregistered for your appointment, please come through the Outpatient entrance where the registrars will take your insurance and other information. Take the green elevators to the 4th floor, exit left off the elevator, and left into the hallway. You will see our waiting room on the right, Room 4.153 with the large glass window. When you arrive in the waiting room, use either phone to call x2334 to check in. A technician will be with you shortly.
Billing
All testing will be billed from L&M Hospital. Many of the tests will have professional fees billed by the reading physician, with the exception of pediatric EEGs. Adult EEGs, Evoked Potentials, and Autonomic Studies will be billed from the NeuroGroup, 350 Montauk Avenue, New London. 443-1891. Nerve conductions/EMGs will be billed from Associated Physiatrists. It is suggested you contact the reading physician's office before your appointment to make sure their office participates with your insurance, or you may be held responsible for that portion of your bill.
Factsheet: Thoracic Outlet Syndrome
Factsheet: Carpal Tunnel Syndrome
Pediatric EEG appt. info
Additional Neurology Information
Yahoo Neurology Directory
NeuroGuide
Neurology Channel