What Is Syringomyelia?

Skull and brain deformities and abnormalities are typically congenital and in many cases genetic, except in cases of trauma. Diseases, disorders and abnormal development of skulls, brains and the spine range in severity from easily treatable to fatal. Genetic testing and screenings during pregnancy can help with early detection in cases of congenital abnormalities.

Syringomyelia is a neurological disorder in which a fluid-filled cyst (syrinx) forms within the spinal cord. The syrinx can get big enough to damage the spinal cord and compress and injure the nerve fibers that carry information to and from the brain to the body.

In syringomyelia, the watery liquid known as cerebrospinal fluid (CSF)—which surrounds and protects the brain and spinal cord—builds up within the tissue of the spinal cord, expands the central canal and then forms a syrinx. Generally, a syrinx develops when the normal flow of CSF around the spinal cord or lower brain stem is disturbed. When syrinxes affect the brain stem, the condition is called syringobulbia.

Types of Syringomyelia

There are three types of syringomyelia, the first being linked to congenital brain abnormalities. The second type results from spinal trauma, a tumor or an infection. The third type results from unknown factors and is called idiopathic syringomyelia.

The two most common forms of syringomyelia are:

  • Congenital syringomyelia (also known as communicating syringomyelia) is most often caused by a Chiari malformation and resulting syrinx, usually in the spine's cervical (neck) region. Symptoms typically begin between ages 25 and 40. People with congenital syringomyelia may also have hydrocephalus, a buildup of excess CSF in the brain along with larger-than-normal connected cavities called ventricles. Straining or coughing can increase the pressure within your head and brain, causing you to develop a headache or even lose consciousness. Some people may have a disorder called arachnoiditis—an inflammation of the arachnoid, one of the three membranes that surrounds the spinal cord.
  • Acquired syringomyelia (also known as primary spinal syringomyelia or non-communicating syringomyelia) can be caused by:
    • Spinal cord injury
    • Meningitis (an inflammation of brain and spinal cord membranes usually caused by an infection)
    • Arachnoiditis
    • Tethered cord syndrome (a condition present at birth that causes the spinal cord to abnormally attach to the tissues in the lower spine, limiting its movement)
    • Spinal cord tumor

Causes of Syringomyelia

Syringomyelia may have several possible causes, but most cases are associated with Chiari malformation—an abnormal condition in which brain tissue extends through the hole at the bottom of the skull (foramen magnum) and into the spinal canal, obstructing the flow of cerebrospinal fluid (CSF). Syringomyelia may also be caused by spinal cord injuries, spinal cord tumors and damage caused by inflammation around the spinal cord. In some cases, the cause is unknown (idiopathic).

There are two major forms of syringomyelia:

  • Congenital syringomyelia (also known as communicating syringomyelia) is most often caused by a Chiari malformation and resulting syrinx, usually in the spine's cervical (neck) region. Symptoms typically begin between ages 25 and 40. People with congenital syringomyelia may also have hydrocephalus, a buildup of excess CSF in the brain along with larger-than-normal connected cavities called ventricles. Straining or coughing can increase the pressure within your head and brain, causing you to develop a headache or even lose consciousness. Some people may have a disorder called arachnoiditis—an inflammation of the arachnoid, one of the three membranes that surrounds the spinal cord.
  • Acquired syringomyelia (also known as primary spinal syringomyelia or non-communicating syringomyelia) can be caused by:
    • Spinal cord injury
    • Meningitis (an inflammation of brain and spinal cord membranes usually caused by an infection)
    • Arachnoiditis
    • Tethered cord syndrome (a condition present at birth that causes the spinal cord to abnormally attach to the tissues in the lower spine, limiting its movement)
    • Spinal cord tumor

Studies are underway to better understand the role of genetic factors in Chiari I malformation, the most common cause of syringomyelia. Scientists are studying people with a Chiari I malformation who also have a family member with either the abnormality or syringomyelia to identify the location of the gene(s) responsible for the malformation.

In some cases, birth defects may be associated with brain malformations that can cause syringomyelia. Learning how and when these defects occur during fetal development may help scientists develop strategies that can stop the formation of certain birth defects. Folic acid dietary supplements during pregnancy, for example, can reduce the risk of birth defects of the brain and spinal cord.

Risk Factors for Syringomyelia

Syringomyelia can result from inherited congenital abnormalities called Chiari malformations. In other cases, risk of development have been associated with:

  • Spinal injuries
  • Meningitis
  • A tumor
  • Arachnoiditis
  • A tethered spinal cord
  • A hemorrhage

Screening for & Preventing Syringomyelia

Doctors will use an MRI to determine if a syrinx has developed within your spinal cord, indicating syringomyelia. Early detection may help prevent symptoms becoming worse, but there are no known ways to prevent syringomyelia.

Signs & Symptoms of Syringomyelia

Symptoms of damage to the spinal cord vary among individuals depending on where the syrinx forms, how large it is and how long it extends. Symptoms develop slowly over time, worsen over many years, and may occur on one or both sides of the body. Symptoms can include:

  • Pain (potentially chronic)
  • Progressive weakness in arms and legs
  • Stiffness in the back, shoulders, neck, arms or legs
  • Headaches
  • Loss of sensitivity to pain or hot and cold, especially in the hands
  • Numbness or tingling
  • Loss of balance
  • Loss of bowel and bladder control
  • Problems with sexual function
  • Curvature of the spine (scoliosis); may be the only symptom in children

Diagnosing Syringomyelia

A physician will review your medical history, perform a physical exam focusing on neurological function, and 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 can determine if there is a syrinx in the spine or another abnormality, such as a tumor. In some cases, multiple MRI images may be taken in rapid succession (called dynamic MRI) to show the flow of fluid around the spinal cord and within the syrinx. You might receive an injection of a dye or contrast agent to enhance the MRI images.

Ongoing NIH-funded research is aimed at improving diagnostic imaging techniques to better visualize conditions in the spine, including syringomyelia, even before symptoms appear.

In addition, NINDS has developed common data elements for Chiari I malformation. This allows researchers to communicate in a common scientific language, improve data quality and explore research opportunities that compare and combine data from multiple institutions.

Treating Syringomyelia

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

If your syringomyelia doesn't show symptoms, it is usually not treated, but you should be carefully monitored by a neurologist or neurosurgeon as symptoms can worsen over time. A physician may recommend not treating the condition if you are of advanced age or if there is no progression of symptoms. If you have syringomyelia, you should avoid activities that involve straining (e.g., lifting heavy objects, jumping) since these actions can trigger symptoms. If you have an associated Chiari malformation, you may experience a headache with straining.

The goal of surgery for syringomyelia is to eliminate the syrinx and prevent further spinal cord injury. Surgery is usually recommended for cases of symptomatic or progressive syringomyelia. There are two general forms of treatment: restoration of normal CSF flow around the spinal cord, and directly draining the syrinx. The type of treatment depends on what is causing your symptoms. The following are some options:

  • Treating the Chiari malformation: The main goal of Chiari surgery is to provide more space at the base of the skull and upper neck. This reduces pressure on the brain and spinal cord, restoring the normal flow of CSF. Surgery can allow the syrinx to drain, sometimes becoming smaller or even disappearing entirely. Symptoms may improve even if the syrinx remains the same size or is reduced only slightly. You should get treated sooner rather than later because delaying treatment can cause irreversible spinal cord damage. Syringomyelia can recur after surgery, making additional operations necessary.
  • Preventing a syrinx from forming or expanding after an injury: The primary strategy is to prevent a trauma-related syrinx from developing or growing in the first place. A somewhat controversial procedure (expansive duraplasty) involves removing scar tissue around the spinal cord and sometimes adding a patch to expand the dura (membrane surrounding the spinal cord). By clearing and expanding the space around the spinal cord, the normal flow of CSF may be restored.
  • Removing the obstruction: Surgically removing obstructions such as scar tissue, bone from the spinal canal, or tumors can help restore the normal flow of CSF. If a tumor is causing your syringomyelia, removing it almost always eliminates the syrinx. Occasionally, radiation may be used to shrink the tumor.
  • Draining the syrinx: If there is no associated Chiari malformation or tumor, it may be necessary to drain the syrinx. This is usually done in cases where the syrinx is growing, or the cause of the CSF obstruction cannot be identified. A surgeon will insert a drain called a stent or shunt to allow the fluid to flow to another part of the body where it can be absorbed. Draining the syrinx can halt the progression of symptoms and relieve headache.

Living with Syringomyelia

Cysts may enlarge over time causing more damage and increased pain. Additionally, secondary conditions may arise in tandem with syringomyelia, which may adversely affect daily quality of life. Some are diagnosed with fibromyalgia, chronic fatigue syndrome or arthritis. Physical therapy may help with decreased mobility and stiffness, weak muscles and general pain, though avoid overly exerting yourself with heavy lifting or jumping, as they may exacerbate symptoms.

To further your understanding of your diagnosis and to contribute to cutting-edge research, consider participating in a clinical trial so clinicians and scientists can learn more about causes, symptoms, treatment and prevention. Clinical research uses human volunteers to help researchers learn more about a disorder and perhaps find better ways to safely detect, treat or prevent disease.

All types of volunteers are needed—those who are healthy or may have an illness or disease—of all different ages, sexes, races and ethnicities to ensure that study results apply to as many people as possible, and that treatments will be safe and effective for everyone who will use them.

For information about participating in clinical research, visit NIH Clinical Research Trials and You. Learn about clinical trials currently looking for participants at Clinicaltrials.gov.