What are some diagnostic tests for nervous system disorders?
Evaluating and diagnosing damage to the nervous system can be very complicated. Many of the same symptoms occur in different combinations among the different disorders. To further complicate the diagnostic process, many disorders do not have definitive causes, markers, or tests.
Neurological tests to evaluate children may include:
Computed tomography scan (also called a CT or CAT scan). A diagnostic imaging procedure that uses a combination of X-rays and computer technology to produce horizontal, or axial, images (often called slices) of the body. A CT scan shows detailed images of any part of the body, including the brain, bones, muscles, fat, and organs. CT scans are more detailed than general X-rays.
Electroencephalogram (EEG). A procedure that records the brain's continuous, electrical activity by means of electrodes attached to the scalp.
Magnetic resonance imaging (MRI). A diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body.
Electrodiagnostic tests (for example, electromyography and nerve conduction velocity). Studies that evaluate and diagnose disorders of the nerves, muscles and motor neurons. Electrodes are inserted into the muscle, or placed on the skin overlying a nerve, muscle, or muscle group, and electrical activity and muscle response are recorded.
Positron emission tomography (PET) scan. A computer-based imaging technique that provides a picture of the brain's activity rather than its structure by measuring levels of an injected with a tracer molecule, most often glucose.
Arteriogram (also called angiogram). A procedure that provides an image of arteries and/or veins going to and through the brain. CT angiography, a newer and less invasive technique, is sometimes used.
Cerebral spinal fluid analysis (also called spinal tap or lumbar puncture). A procedure used to make an evaluation or diagnosis by examining the fluid withdrawn from the thecal sac, the sac of fluid positioned below where the spinal column has come to an end.
Evoked potentials. Procedures that record the brain's electrical response to visual, auditory, and sensory stimuli.
Myelogram. A procedure that uses dye injected into the spinal canal to make the structure clearly visible on X-rays. Though once common, this is rarely used.
Ultrasound (also called sonography). A diagnostic imaging technique that uses high-frequency sound waves and a computer to create images of blood vessels, tissues, and organs. Ultrasounds are used to view internal organs as they function, and to assess blood flow through various vessels.
Neurosonography. A procedure that uses ultra high-frequency sound waves that enable the doctor to evaluate structures of the nervous system, including the brain, spinal cord, and other structures.
How should I prepare my child for neurological testing?
Infants. You cannot explain the examination to an infant, but you can help your baby feel more secure during the test by bringing a special blanket, toy, or pacifier. For many of the studies, sedation or anesthesia is performed, which requires the child to fast before the procedure. You may breastfeed your baby or give him or her a bottle of juice or formula once the technician tells you your baby can eat.
Toddlers and preschool-aged children. Young children remember things for only a short time, so the best time to talk about the test is right before you are ready to come to the hospital. Explain to your child that you are going to the hospital to have some pictures taken that the doctor needs in order to help him or her get better. Try to use simple words. For tests that require the child to be still, such as a CT, MRI, or lumbar puncture, sedation or anesthesia may be used to ensure a good quality image and prevent pain.
It is important to be honest with your child. If the test will be uncomfortable, be sure to talk about and tell him or her it is okay to cry. Because children at this age are afraid of being separated from their parent, let him or her know that mom or dad will stay with him or her as much as possible. When you come to the hospital, bring a favorite book, toy, or blanket.
School-aged children. School-aged children have good imaginations. If you do not tell them the truth, they may imagine something much worse than the actual test. The day of the test, tell your child that he or she will be going to the hospital to have some pictures taken. Tell him or her that the pictures will help the doctor decide how to make him or her better. Use simple words. Be honest. Try to tell your child exactly what will happen. If your child's test is going to be uncomfortable, be sure to tell him or her it is okay to cry. When you come to the hospital, bring along a favorite book, toy, or game. Depending on the age and emotional maturity of the child, sedation, or anesthesia may be used.