A B C D E F G H I J K L M N O P R S T U V W

MYELOGRAPHY

Why is Myelography performed ?

The examination is performed if an abnormality of the spinal cord is suspected. It is usually carried out when the simpler tests have failed to give the diagnosis. Myelography is often carried out to diagnose a slipped disc. It is also carried out to investigate more serious conditions such as injuries or possible tumours.

Preparations needed for Myelography

The examination is carried out in the x-ray department of a hospital and usually means at least one night in hospital. You may take a few days to recover from the effects of the test and it may be suggested that you spend a few more nights in hospital and stay off work for a week. You should inform the doctor who arranges the test of any previous allergic reactions to drugs.

What Happens during Myelography

The test is performed by a medically trained specialist (radiologist) who will be assisted by a radiographer and a nurse. You will be brought to the x-ray department and lie on the x-ray table. Adults are given a local anaesthetic, but children and babies may be given a general anaesthetic. General anaesthetic involves an injection in the arm given by an anaesthetist. You will then remember nothing until the test is finished. Adults may be given a sedative injection in the arm before being asked to lie on their side. An injection of local anaesthetic is given into the lower part of the back to make it numb. A second injection, which contains a dye which will show up on x-rays, and which you should not feel, is given through the same area into the cerebrospinal fluid (CSF) which surrounds the spinal cord. There may be a feeling of tightness in the legs after the dye is injected. Yout must keep quite still during the injections. This ensures that the needle does not move. You will then be placed face down on the x-ray table and may be strapped into position. The table is tilted 45 degrees or more in both directions and x-rays are taken at different angles. The movement of the table can be a little alarming but is quite safe as the table is equipped with handles and restraining straps. It takes about 30 minutes to get the full set of x-rays. The whole examination, including the injections, lasts about an hour. In some cases, the initial myelography examination is followed by a CT (computerized tomography) scan of the spinal cord. This enables any abnormal area to be seen in much sharper detail. For this second test, you will be taken from the x-ray room to the CT room, and lie on a narrow table. The table slides so that the relevant part can be placed inside a short tunnel measuring about one foot in length and two feet in diameter. In CT myelography, the body may be scanned at any level between the neck and lower back. The scanning procedure is completely painless. Although you will be alone in the CT room, you will be able to speak to the radiographer through an intercom. Again, you will have to keep quite still while the scan is being taken to avoid blurring the pictures. This type of examination lasts about 30 minutes. After myelography, you will probably be left lying flat for 12 24 hours to reduce the risk of headache and dizziness, which can follow the procedure.

Possible Complications during Myelography

Some patients develop allergic reactions to either the drugs or the dye which is injected during the test. These reactions are readily controlled by treatment, using antihistamines, adrenaline or cortisone-like (steroid) drugs. Backache can be made temporarily worse by the examination. You may develop headache, sickness and dizziness afterwards, especially if you get up and about too soon.

After Myelography

You may have to put up with a slight backache and headache for 12 hours afterwards. This is the reason for the overnight stay in hospital. These symptoms are usually controlled by simple painkilling drugs such as aspirin. You may also feel slightly sick and dizzy for a few hours afterwards. You are likely to be up and about the next day, and return to work and full physical activity within a week. Occasionally, a severe headache will occur and last for several days. This may need powerful painkilling drugs. The sickness and dizziness can also last for several days. These side-effects are unpleasant but not serious. They always resolve within a week but can delay return to work and full physical activity.

If Myelography is not performed

Without the test it may not be possible for the next step of treatment to be planned. The surgeon needs the myelography x-rays and perhaps the CT scan pictures to decide whether and what type of treatment is needed.