Syringomyelia

What is syringomyelia?

Syringomyelia is a rare condition in which a fluid-filled cyst, called a syrinx, forms inside your spinal cord. Over time, the cyst can press on the nerves in your spine and cause pain, weakness or numbness.

What are the symptoms of syringomyelia?

Symptoms usually build up slowly, often over months or years, and can vary depending on where the syrinx sits and how big it is. You may notice:

• weakness, pain or stiffness in your back, shoulders, arms or legs
• an inability to feel very hot or cold temperatures, especially in your hands
• a loss of pain sensation
• headaches
• muscle spasms, weakness or wasting in your arms or legs
• difficulty walking or balance problems
• problems with sexual function
• loss of bladder or bowel control

A classic sign is a loss of feeling for pain and temperature across your shoulders and upper arms, sometimes described as a 'cape-like' pattern, while your sense of touch and joint position stays normal. Children may develop scoliosis (a curve in the spine) or walk on their toes.

What causes syringomyelia, and who is at risk?

Doctors don't know the exact reason a syrinx forms, but most believe it happens when the normal flow of cerebrospinal fluid, the fluid that cushions your brain and spinal cord, is changed or blocked.

This can happen because of:

• a Chiari malformation, where the lower part of the brain sits lower than usual and blocks the normal flow of fluid; this is the most common cause
• a tethered spinal cord, or spina bifida, present from birth
• a spinal cord injury, sometimes months or years earlier
• a spinal cord tumour
• inflammation of the lining around the spinal cord (arachnoiditis) or meningitis

Sometimes no cause can be found; this is called idiopathic syringomyelia. The condition can affect anyone, but most people are diagnosed between the ages of 20 and 50.

Are there different types of syringomyelia?

Yes. Doctors classify syringomyelia by how the cyst forms and what it connects to:

• communicating syringomyelia, where the cyst connects to a fluid-filled space in the brain and often occurs alongside hydrocephalus (extra fluid around the brain)
• non-communicating syringomyelia, which doesn't connect to the brain's fluid spaces and is usually linked to a Chiari malformation, past injury, or inflammation

Your doctor may also describe your syringomyelia by its underlying cause, for example as 'Chiari-related' or 'post-traumatic'.

How is syringomyelia diagnosed?

Your doctor will ask about your symptoms and carry out a physical and neurological examination, checking your strength, feeling, reflexes, balance and coordination.

The most important test is an MRI scan, which shows the syrinx, its size and position, and can reveal an underlying cause such as a Chiari malformation or tumour. A special type of MRI, called a cine flow scan, may be used to look at how fluid moves around your brain and spinal cord. If you can't have an MRI, for example because of a pacemaker or certain metal implants, a CT myelogram (a scan combined with an injected dye) may be used instead.

How is syringomyelia treated?

Treatment aims to relieve pressure on your spinal cord and improve the flow of cerebrospinal fluid. What's recommended depends on your symptoms and the underlying cause.

Non-surgical treatment

• observation, with regular check-ups and repeat MRI scans, if your syrinx is small, stable or not causing symptoms; some syrinxes, especially in children, can shrink or disappear on their own
• avoiding activities that increase pressure in your head or neck, such as heavy straining, holding your breath, or high-impact activities like trampolines, roller coasters and contact sports
• physical therapy, occupational therapy, or pain medication, to ease discomfort and improve movement

Surgical treatment

Surgery is often needed to treat the underlying cause rather than the syrinx itself. Options include:

• surgery to create more space at the back of the skull (decompression), if you have a Chiari malformation; this usually reduces the size of the syrinx
• laminectomy and duraplasty, to free up the flow of cerebrospinal fluid across an area of scarring
• a shunt, a thin tube that drains fluid away from the syrinx, usually kept as an option if other treatments haven't worked, as it can sometimes need repeating if the syrinx returns

Surgery is often helpful, and many people see improvements in strength and movement, especially when the syrinx is in the neck area, though pain or numbness may not fully go away. Because a syrinx can return, regular follow-up appointments and scans are important.

When should I see a doctor?

See a doctor as soon as possible if you or your child has symptoms that could suggest syringomyelia, since early treatment may help prevent permanent nerve damage.

Get immediate medical attention if you have:

• loss of bladder or bowel control, or new problems with either
• sudden or new weakness in your arms or legs
• trouble walking or frequent falls

If you've had surgery, contact your care team straight away if you notice a fever, severe pain, swelling, or pus or drainage from the wound.