Syringomyelia

Syrinx is an ancient Greek word meaning “reed, pipe or tube” from which we get the word syringe.

The brain and spine are protected by fluid called cerebrospinal fluid (CSF). In syringomyelia, the CSF collects in the tissue of the spinal cord, expands the central canal and a fluid-filled cyst called a syrinx is formed. A syrinx can grow to a size which can damage the spinal cord causing a clinical myelopathy.

Syringobulbia, is the condition when the syrinx expands into the brainstem affecting the voice and swallow. Hydromyelia is a variant of normal with persistence of the embryological narrow CSF space within the spinal cord.

Syringomyelia is typically found in patients between the ages of 25 and 40, but it can also develop in young children and people older than 40. Syringomyelia is very rare and affects approximately 8 in 100,000 people.

Syringomyelia is caused by conditions which affect the flow of CSF within the spinal canal. This most often occurs in patients with a Chiari malformation where part of the brain called the cerebellar tonsil protrudes through the big hole (foramen magnum) at the base of the skull where the brainstem becomes the spinal cord.

However, syringomyelia can also be caused by spinal cord injuries, meningitis, inflammation of the arachnoid membrane and spinal cord tumours.

In most patients the syrinx is discovered as an incidental finding on a scan. The symptoms caused by a syrinx can vary depending on where the syrinx forms and how large it is. Usually, the symptoms appear slowly but can worsen over the years if the syrinx expands.

Symptoms of Syringomyelia include:

• Headaches- if there is associated hydrocephalus (water on the brain).
• Pain- recumbent axial back pain.
• Weakness of the limbs.
• Stiffness of the limbs, back or shoulders.
• Balance issues.
•  Incontinence.
•  Scoliosis (curving of the spine).
• Loss of sensitivity to hot and cold.
•  Altered sexual functions.

Your consultant will refer you for an MRI scan of the brain and spine, which will identify the location and size of the syrinx. A scan with contrast is often required to exclude a spinal cord tumour.

Incidental Syringomyelia is managed conservatively with an interval scan to ensure no change.

If the syrinx is secondary to another problem (Chiari malformation, tumour, scar tissue etc.) the first reaction is to treat the cause of the syrinx. For example a foramen magnum decompression (FMD) often causes the associated syrinx to collapse. Symptoms can be helped with pain management, medication and physiotherapy.

If the syrinx persists then other treatments can be considered such as surgery to open the syrinx (marsupialisation) or shunt surgery to drain the syrinx.