Syringomyelia (sih-ring-go-my-E-lee-uh) is the development of a fluid-filled cyst (syrinx) within your spinal cord. Over time, the cyst may enlarge, damaging your spinal cord and causing pain, weakness and stiffness, among other symptoms.

Syringomyelia has several possible causes, though the majority of cases are associated with a condition in which brain tissue protrudes into your spinal canal (Chiari malformation).

Other causes of syringomyelia include spinal cord tumors, spinal cord injuries and damage caused by inflammation around your spinal cord.

If syringomyelia isn't causing any problems, monitoring the condition may be all that's necessary. But if you're bothered by symptoms, you may need surgery.

Syringomyelia symptoms usually develop slowly over time. If your syringomyelia is caused by protrusion of brain tissue into your spinal canal (Chiari malformation), symptoms generally may begin between ages 25 and 40.

In some cases, coughing or straining may trigger symptoms of syringomyelia, although neither causes syringomyelia.

The following early signs and symptoms of syringomyelia may affect the back of your neck, shoulders, arms and hands first:

• Muscle Weakness and wasting (atrophy)
• Loss of reflexes
• Loss of sensitivity to Pain and temperature

Other signs and symptoms of syringomyelia may include:

• Stiffness in your back, shoulders, arms and legs
• Pain in your neck, arms and back
• Bowel and bladder function problems
• Muscle Weakness and spasms in your legs
• Spinal curvature (scoliosis)

When to see a doctor

If you have any of the signs or symptoms associated with syringomyelia, see your doctor. Because many signs and symptoms of syringomyelia can be associated with other disorders, a thorough medical evaluation is important for accurate diagnosis.

If you've experienced a spinal cord injury, watch carefully for signs and symptoms of syringomyelia. Many months to several years may pass after an injury before syringomyelia develops. If you have symptoms, when you go for an evaluation make sure your doctor knows you had a spinal cord injury.

It's unclear exactly how and why syringomyelia happens. When it develops, cerebrospinal fluid — the fluid that surrounds, cushions and protects your brain and spinal cord — collects within the spinal cord itself, forming a fluid-filled cyst (syrinx).

Several conditions and diseases can lead to syringomyelia, including:

• Chiari malformation, a condition in which brain tissue protrudes into your spinal canal
• Meningitis, an inflammation of the membranes surrounding your brain and spinal cord
• Spinal cord tumor, which may interfere with the normal circulation of cerebrospinal fluid
• Conditions present at birth, such as a tethered spinal cord, a condition caused when tissue attached to your spinal cord limits its movement
• Spinal cord injury, which may cause symptoms months or even years after the initial injury

Treatment for syringomyelia depends on the severity and progression of your signs and symptoms.

Monitoring

If syringomyelia is discovered on an MRI scan that's done for an unrelated reason, and syringomyelia isn't causing signs or symptoms, monitoring with periodic MRI and neurological exams may be all that's needed.

Surgery

If syringomyelia is causing signs and symptoms that interfere with your daily life, or if signs and symptoms rapidly worsen, your doctor will usually recommend surgery.

The goal of surgery is to remove the pressure the syrinx places on your spinal cord and to restore the normal flow of cerebrospinal fluid. This can help improve your symptoms and nervous system (neurological) function. The type of surgery you'll need depends on the underlying cause of syringomyelia.

Several types of surgery options are available to reduce pressure on your brain and spinal cord. Surgery types include:

• Treating Chiari malformation. If syringomyelia is caused by Chiari malformation, your doctor may recommend surgery that involves enlarging the opening at the base of your skull (suboccipital craniectomy) and expanding the covering of your brain (dura mater).

  This surgery can reduce pressure on your brain and spinal cord, restore the normal flow of cerebrospinal fluid, and may improve or resolve syringomyelia.

• Draining the syrinx. To drain the syrinx, your doctor will surgically insert a drainage system, called a shunt. It consists of a flexible tube that keeps fluid from the syrinx flowing in the desired direction. One end of the tubing is placed in the syrinx, and the other is placed in another area of your body such as your abdomen.
• Removing the obstruction. If something within your spinal cord, such as a tumor or a bony growth, is hindering the normal flow of cerebrospinal fluid, surgically removing the obstruction may restore the normal flow and allow fluid to drain from the syrinx.
• Correcting the abnormality. If a spinal abnormality is hindering the normal flow of cerebrospinal fluid, surgery to correct it, such as releasing a tethered spinal cord, may restore normal fluid flow and allow the syrinx to drain.

Surgery doesn't always effectively restore the flow of cerebrospinal fluid, and the syrinx may remain, despite efforts to drain the fluid from it.

Follow-up care

Follow-up care after surgery is critical because syringomyelia may recur. You'll need regular examinations with your doctor, including periodic MRIs, to assess the outcome of surgery.

The syrinx may grow over time, requiring additional treatment. Even after treatment, some signs and symptoms of syringomyelia may remain, as a syrinx can cause permanent spinal cord and nerve damage.

Genes that neighbor SMN1, called SMN2 genes, are similar in structure to SMN1 genes. They can sometimes help offset the SMN protein deficiency, but the number of SMN2 genes fluctuates from person to person. So the type of SMA depends on how many SMN2 genes a person has to help make up for their SMN1 gene mutation. If a person with chromosome 5–related SMA has more copies of the SMN2 gene, they can produce more working SMN protein. In return, their SMA will be milder with a later onset than someone who has fewer copies of the SMN2 gene.