Pain
Myelography is a low-risk routine procedure. Only the injection of the contrast medium in the lumbar region (between L3 and L4) can cause risks for the patient. A rare complication is the occurrence of pain during the examination.
These occur due to injury to nerve fibers during puncture with the myelography needle. Patients often report headache and back pain. In addition, sensory disturbances and paralysis can also occur due to the injury to the nerve.
Depending on the patient, the symptoms may persist for several days after the examination, but in most cases they subside completely. Headaches can also be caused by the additional withdrawal of cerebrospinal fluid during the examination. The reduced cerebrospinal fluid content compensates by dilating the vessels supplying the meninges, which causes headaches in the patient.
Contrast medium
Myelography is typically performed with X-rays. A contrast medium containing iodine is injected into the spinal cord to better distinguish it from the surrounding cerebrospinal fluid. This results in a stronger contrast between the spinal cord and the cerebrospinal fluid space.
Possible masses in the space can thus be better visualized. Myelography is therefore not possible if the patient is known to be allergic to iodine-containing substances. There is a risk of severe allergic reactions. In addition, the functionality of the thyroid gland should always be checked before the examination, since iodine is an important starting substance for the production of thyroid hormones.
Complications
Myelography complications are very rare.The most common “complication” is a temporary headache. Serious complications can occur:
- Post-bleeding: In the worst case, injury to a blood vessel can lead to bleeding into the spinal canal (epidural hematoma), which can damage spinal nerves.
- Nerve injury: A misplacement of the myelography needle can injure outgoing spinal nerves. These cannot avoid the needle because they are no longer swimming in the water of the nerves.
Pain, loss of sensation and paralysis can be the result.
- Infection: Due to a germ carry-over (bacteria), both a superficial and a deep infection of spinal structures (intervertebral disc, vertebrae, spinal cord) is possible. In the worst case, an ascending spinal meningitis can occur.
- Continuous loss of spinal fluid: If the puncture site of the spinal cord skin (dura) does not close on its own, as is usually the case, spinal fluid can seep outwards continuously. A surgical procedure to close the hole is then often necessary.
- Allergic reaction: An allergic reaction to the contrast medium can in extreme cases lead to an allergic shock (circulatory arrest).
- Disorders in the function of the mucosal glands: The absorption of the iodine contained in the X-ray contrast medium into the thyroid gland can in certain cases lead to dangerous hyperthyroidism.
