Common Neurological Tests
Image or sound wave tests
tomography or computer assisted tomography (CT or CAT scan)
This test uses x-rays and computers to create two-dimensional pictures of
selected body parts. Dye may be injected into a patient's vein to obtain a
better picture. Other than needle insertion for the dye, this test is painless.
resonance imaging (MRI)
An MRI is an advanced way of taking pictures of the inner brain. It is
harmless and involves magnetic fields and radio waves. It is performed when a
patient is lying in a small chamber for about 30 minutes. Because MRI utilizes a
very strong magnet, if you have metal in your body other than dental fillings,
notify your physician. Be sure to tell your physician if you suffer from
claustrophobia (fear of closed areas). A physician can offer recommendations
that can help you relax. This test is painless.
activity or response tests
Nerve Conduction Studies
NCSs test how well signals travel along a nerve and can help find the cause of abnormal nerve function.
Signals are made to travel along the nerve by applying small electric pulses to the nerve at one site and
recording the response at a different place along the nerve. The small electric pulses cause a short, mild
tingling feeling. The nerve's response is picked up by a recording instrument and then is measured by the physician
or technologist performing the test. Several nerves may need to be tested depending on the type of problem.
Needle Examination (EMG or
During the needle EMG portion of the examination, the physician inserts a small needle into a muscle to record the
electrical activity of the muscle. The electrical activity of the muscle is fed into the recording instrument and the
physician then analyzes it by looking at a signal on the scope and listening to the sounds the activity makes through the
speaker. This test can help determine if there are abnormalities in the muscle or the nerve going to it.
There may be mild discomfort when the need is inserted into the muscle. The needles are discarded after use
to prevent the transmition of infections.
You should inform the physician prior to the examination if you are on blood thinners or have hemophilia. The physician should
also be informed if you have a cardiac pacemaker or use a transcutaneous electrical nerve
stimulator(TENS) unit. Avoid using skin
lotions the day of the test. If you have myasthenia gravis you should ask your physician whether or not to take medications, such as
Mestinon, before the examination.
When the examination is completed, the eclectrodiagnostic medicine consultant will analyze the results and report them to the physician
who referred you for the tests. Your referring physician will use the test results to help decide on proper
EEG measures the electrical activity of the brain. It is primarily used in
the evaluation of seizures and other transient alterations of awareness and
consciousness. Activity of the brain is passively recorded, no electrical
stimulation is given. The test typically takes 20-30minutes. You may be asked
to take deep breaths and may be exposed to flashing lights during the EEG. Once
the technician completes the recording, a physician will review the test and
send a report to your doctor.
Involve tests that diagnose specific causes of sleep problems. To perform the
tests, it is often necessary for a patient to spend the night in a sleep
laboratory. Brain wave activity, heart rate, electrical activity of the heart,
breathing and oxygen in the blood are all measured during the sleep test. The
test is painless.
Another common test
Cerebral spinal fluid analysis (Spinal tap or lumber
This test is used to check for bleeding, hemorrhage, infection or other
disorder of the brain, spinal cord and nerves. In this test the lower back is
numbed with local anesthesia, and a thin needle is placed into the space that
contains the spinal fluid. The amount of spinal fluid needed to diagnose the
specific problem is removed and the needle is withdrawn. Discomfort may be
associated with this test.