What is a Syrinx?

A syrinx is a fluid-filled neurological cavity, or cyst, found in the spine. It may result from a number of causes, including congenital disorder of the spine, a spinal tumor or traumatic injury. The cyst may develop months to years after spinal injury or scarring due to spinal surgery. If the syrinx occurs in the spinal cord, the condition is referred to as syringomyelia. If it occurs in the brain stem, it is termed syringobulbia.

The most common cause of syrinx formation is a congenital disorder called Chiari malformation. This causes the tissue of the cerebellum and brain stem to be pushed downwards into the spine. The syrinx creates a blockage to the normal flow of cerebrospinal fluid (CSF). It may develop at any stage of life and, depending on how rapidly it expands, symptoms may take a long time to appear.

Initial symptoms may be mild and often go unnoticed. Most commonly the cervical region of the spine is affected; this is the part of the spine directly below the skull. A loss of temperature and pain sensitivity may be the first sign of syringomyelia, and it has often been recognized by a painless burn or cut, prompting the person to seek medical advice. Weakness, muscle wasting or atrophy, and loss or weakening of reflexes may all be progressive symptoms.

Other signs may include pain and stiffness of the back, arms and legs, facial numbing or pain, bowel and bladder problems, or spasticity of the legs. Scoliosis, or curvature of the spine, and joint deformation of the shoulders, elbows or wrists may also be seen. All of these symptoms, while characteristic of syringomyelia, may also be signs of other medical conditions, so medical advice should be sought for correct diagnosis.

A magnetic resonance image (MRI) will likely be done by the doctor to diagnose the condition. This uses radio waves and magnetic fields to produce a three-dimensional image of the spine and allows easy recognition of the syrinx. Multiple MRIs may be done to track its progress throughout treatment.

There is no medication to treat syringomyelia. In most cases surgery will be performed to either drain the syrinx; remove the obstruction causing it to correct the underlying malformation; or insert a shunt to allow normal flow of the CSF. Close follow-up is recommended as a syrinx may recur. Despite surgical intervention and rehabilitation therapy, some of the neurological symptoms of syringomyelia may not ever resolve.