Syringomyelia is a disorder in which a fluid-filled cyst (called a syrinx) forms within the spinal cord.
If this syrinx enlarges over time, it can damage the spinal cord. It does this by compressing and injuring the nerve fibres that transmit information to and from the brain to the rest of the body.
Generally, a syrinx develops when the normal flow of cerebrospinal fluid around the spinal cord or lower brain stem is disturbed. When syrinxes affect the brain stem, the condition is called syringobulbia. Symptoms of syringomyelia arise from damage to the spinal cord. Symptoms develop slowly over time. They also vary among individuals according to the position of syrinx formation and the extent of its size.
Symptoms may include:
Syringomyelia may have several possible causes. In most cases it is associated with a condition called Chiari malformation. This is where brain tissue extends through the hole at the bottom of the skull (foramen magnum) and into the spinal canal, obstructing CSF flow.
Syringomyelia may also be caused by spinal cord injuries, spinal cord tumours, and damage caused by inflammation around the spinal cord.
Your physician will make the diagnosis of syringomyelia after reviewing your medical history and the results of a physical exam focusing on neurological function. The physician will also probably order imaging of the spine or brain. Sometimes, syringomyelia may be found during diagnostic imaging for another disorder.
Magnetic resonance imaging (MRI) is the most reliable way to diagnose syringomyelia. Using this test, a physician will determine if there is a syrinx in the spine or another abnormality, such as a tumour. In some cases, the physician may perform a dynamic MRI may to show the flow of fluid around the spinal cord and within the syrinx.
The type of treatment for syringomyelia depends on the severity and progression of an individual’s symptoms and the underlying cause of the abnormality. In the absence of symptoms, syringomyelia is usually not treated. It may still need to be carefully monitored for progression by periodic clinical and radiological reviews. People with an associated Chiari malformation are prone to experience headaches with straining.
Surgery is usually recommended for individuals with symptomatic or progressive syringomyelia. There are two general forms of treatment: restoration of normal CSF flow around the spinal cord and direct drainage of the syrinx. The type of treatment depends on what is causing the symptoms. It can include:
All can help restore the normal flow of CSF.
Medications such as gabapentin (Neurontin) may help decrease the painful sensation of the shoulders and arms that frequently occur with syringomyelia. Sometimes syringomyelia can recur even after surgery. Regular medical check-ups with the physician, including periodic scans, to assess surgery outcome is needed. The syrinx may regrow over time and would require additional treatment. Even after treatment, some signs and symptoms of syringomyelia can remain. This is because a syrinx can cause permanent spinal cord and nerve damage.
Some critical research is taking place in this field.
The National Institute of Neurological Disorders and Stroke (NINDS) is conducting studies to better understand the role of genetic factors in Chiari I malformation. This is the most common cause of syringomyelia. The research focuses on identifying the gene(s) responsible for the malformation in individuals with a Chiari malformation who also have a family member with either the abnormality or syringomyelia.
Studies to learn how and when certain birth defects occur is also underway. This is focused on those defects associated with brain malformations that cause syringomyelia during fetal development. It is worth mentioning that the use of folic acid dietary supplements during pregnancy has been found to reduce the risk of birth defects of the brain and spinal cord, including malformations of the skull, brain and spine.