This sheet describes possible tests used to diagnose and gather information about neurologic disorders in children. Your child’s healthcare provider will tell you which of these tests your child's needs:
Angiogram (also called an arteriogram). A procedure that checks the health of the blood vessels (arteries or veins) going to and inside the brain. During the procedure, a catheter (thin plastic tube) is placed in a blood vessel. Fluid called contrast dye is used to make the blood vessels show up clearly on X-rays. Specialized angiograms can also be done in combination with CT or MRI (see below). The amount of time required for these tests can vary. Speak to your healthcare provider beforehand so that you can anticipate how long the test will take as your child will need to lie still for this test. Your child may need sedation or general anesthesia in order to complete this exam.
CT (computed tomography) scan. A test that combines X-rays and computer technology to form detailed pictures of the brain. Radiation is used during the test. Your child will need to lie still throughout this exam but they are generally quick and many children will be able to complete these exams without much assistance. Sedation of anesthesia may be needed.
EEG (electroencephalography). A test that records the electrical activity of the brain. During the test, round discs with wires (electrodes) are placed on the scalp with glue or paste. The electrodes send electrical signals that record electrical brain activity. Sometimes this test is done while your child is asleep. Sometimes it is done while awake. Occasionally it is performed while your child is under video surveillance in order to coordinate brain wave activity with physical activity.
EMG (electromyography). A test done to check muscle and nerve function in the arms and legs. During the test, small needle electrodes are placed in certain muscles. As your child rests and tightens these muscles, the electrical activity is recorded. Your child will therefore need to cooperate with the technician performing the test and be able to follow simple directions. This test is often done with a nerve conduction study (see below).
Evoked potentials. Tests that check how fast and well the body’s nerves respond to specific types of sensory stimulation. These can include flashing lights, loud sounds, or electrical signals sent to the arms and legs. During the test, electrodes are placed on the skin. The electrical activity is then recorded. Your child needs to be awake and cooperative throughout this exam.
MRI (magnetic resonance imaging) scan. A test that uses strong magnets, radio waves, and computer technology to form detailed pictures of the brain. No radiation is used during the test. Because of the magnets you need to let your healthcare provider know if your child has any metal in his or her body. Your child cannot have an MRI because of the metal since it may impact the quality of the study. Your child cannot undergo MRI imaging if they have any metal in their body, including braces. Check with your healthcare provider before your test date if your child has any reasons not to have an MRI. MRI machines are also very noisy. Some young children may have difficulty lying still for this exam due to the noise and the time needed to complete the exam, which can often be longer than 20 minutes. Speak to your healthcare provider if you think your child will need sedation for this exam.
NCS (nerve conduction study). A test that checks the function of the nerves in the arms and legs. During the test, electrodes are placed on the skin along the pathways of certain nerves. An electrical current is then used to stimulate these nerves. The electrical activity is recorded.
PET (positron emission tomography). A test that uses computer technology to take a picture of brain activity rather than brain structure. During the test, a glucose-based compound is injected into the bloodstream. The compound helps highlight areas of high and low brain activity in the picture. Therefore, this test requires the placement of an IV in your child's arm before the test.
Spinal tap (also called a lumbar puncture). A procedure that checks the health of the brain, meninges, and spinal cord by analyzing the cerebrospinal fluid (CSF). During the test, the low back is numbed. A needle is then inserted into the spinal canal and a sample of CSF is drawn for analysis. This procedure takes only a few minutes, but your child must remain completely still without moving.
Transcranial Doppler (TCD). A test that uses high-frequency sound waves to show the flow of blood through the blood vessels in the brain. There is no radiation involved during this test. Your child will need to remain still although a little movement is OK throughout this exam.
Ultrasound. A test that uses sound waves to form a picture of the brain. There is no radiation involved during this test. This test is only effective in imaging the brain in infants when the soft spot in the skull (fontanelle) is still open. Once this fuses, at a few months of age, ultrasound is not an effective way to image the brain because sound waves cannot penetrate the skull.
Many hospitals have people trained in helping children cope with their medical care or hospital experience. These people are often called child life specialists. Check with your child’s healthcare provider if child life programs or other similar services are available for your child. There are also things you can do to help your child prepare for a test or procedure. How best to do this depends on your child’s needs. Start with the tips below:
Use brief and simple terms to describe the test to your child and why it’s being done. Younger children tend to have a short attention span, so do this shortly before the test. Older children can be given more time to understand the test in advance.
Tell your child what to expect in the hospital during the test. For instance, you could mention who will be performing the test and what the hospital room will look like.
Make sure your child understands which body parts will be involved in the test.
As best you can, describe how the test will feel. For instance, an electrode may be placed on the skin. The electrode is round and may feel sticky.
Allow your child to ask questions and answer these questions truthfully. Your child may feel nervous or afraid. He or she may even cry. Let your child know that you’ll be nearby during the test.
Use play when telling your child about the test, if appropriate. With younger children, this can involve role-playing with a child’s favorite toy or object. With older children, it may help to read books or show pictures of what happens during the test.
Most of these tests require children to remain still without moving. Some children are unable to do this. If you are concerned that your child will not be able to lay still for the required time speak with your healthcare provider. Specialized pediatric centers often provide pediatric sedation services that can help your child remain calm and not move throughout these tests.