Syringomyelia, often referred to as SM, is a chronic disorder involving the spinal cord.
For reasons that are only now being understood, cerebrospinal fluid enters the
spinal cord, forming a cavity known as a syrinx. (Doctors sometimes use other
words such as cyst, hydromyelia or syringohydromyelia) This syrinx often
expands and elongates over time, destroying the center of the spinal cord. As
the nerve fibers inside the spinal cord are damaged, a wide variety of symptoms can
occur, depending upon the size and location of the syrinx.
There are two major types of SM. In most cases it is related to a congenital
malformation involving the hindbrain (cerebellum) called a Chiari I Malformation,
named after the physician who first described it. This malformation occurs during fetal
development and is characterized by downward displacement of the lower part of the
brain (cerebellar tonsils) beneath the foramen magnum, into the cervical spinal canal.
This displacement blocks the normal flow of cerebrospinal fluid. When normal flow is
obstructed, a syrinx can then form in the spinal cord. Not all patients with Chiari
Malformations will develop a syrinx, however.
The second major type of SM occurs as a complication of trauma, meningitis, tumor,
or arachnoiditis. In these cases the syrinx forms in the section of the spinal cord
damaged by these conditions. As more people are surviving spinal cord injuries, more
cases of post-traumatic SM are being diagnosed as the syrinx can form years after the
What are the symptoms?
The symptoms of SM are numerous and a person may have various combinations of
different symptoms. Symptoms tend to develop slowly, although sudden onset may
occur with coughing and straining. Some common symptoms include: loss of
sensitivity, especially to hot and cold, muscle weakness and spasticity, motor
impairment, loss of bowel and bladder control, as well as osteoporosis and scoliosis.
The majority of patients suffer from headaches and chronic pain. Syringomyelia may
eventually result in severe, disabling handicaps such as paraplegia and quadriplegia.
How is Syringomyelia diagnosed?
In the past diagnosis was difficult. Many doctors were unfamiliar with SM so patients
went from one doctor to another while their condition degenerated. Now, with the use
of Magnetic Resonance Imaging technology, the timeliness of diagnosis can be vastly
improved. The images taken show body structures such as the brain and spinal cord in
vivid detail. This test will show the syrinx clearly and any other spinal conditions or
abnormalities. MRI is safe and painless.
This information from American Syringomyelia Alliance Project Inc.