Post-traumatic syringomyelia and tethered spinal cord can occur following spinal cord injury. It can occur from two months to many decades after injury. The results can be devastating, causing new levels of disability long after a person has had successful rehabilitation. The clinical symptoms for syringomyelia and tethered spinal cord are the same and can include progressive deterioration of the spinal cord, progressive loss of sensation or strength, profuse sweating, spasticity, pain and autonomic dysreflexia (AD).
In post-traumatic syringomyelia (sear-IN-go-my-EE-lia) a cyst or fluid-filled cavity forms within the cord. This activity can expand over time, extending two or more spinal segments from the level of SCI.
Tethered spinal cord is a condition where scar tissue forms and tethers, or holds, the spinal cord to the dura, the soft tissue membrane that surrounds it. This scar tissue prevents the normal flow of spinal fluid around the spinal cord and impedes the normal motion of the spinal cord within the membrane. Tethering causes cyst formation. Tethered cord can occur without evidence of syringomyelia, but post-traumatic cystic formation does not occur without some degree of cord tethering.
Magnetic resonance imaging (MRI) easily detects cysts in the spinal cord, unless rods, plates or bullet fragments are present.
Post-traumatic tethered cords and syringomyelia are treated surgically. Untethering involves a delicate surgery to release the scar tissue around the spinal cord to restore spinal-fluid flow and the motion of the spinal cord. In addition, a small graft is placed at the tethering site to fortify the dural space and decrease the risk of re-scarring. If a cyst is present, a tube, or shunt, is placed inside the cavity to drain the fluid from the cyst. Surgery usually leads to improved strength and reduced pain; it does not always bring back lost sensory function.
In experiments at the University of Florida, people with spinal cord cysts were treated with injections of fetal tissue. It is unlikely this technique will find its way to the clinic any time soon, but the tissue did grow and it filled the cavities preventing further loss of function.
Syringomyelia also occurs in people who have congenital abnormality of the brain called a Chiari malformation – during development of the fetus, the lower part of the cerebellum protrudes from the back of the head into the cervical portion of the spinal canal. Symptoms usually include vomiting, muscle weakness in the head and face, difficulty swallowing, and varying degrees of mental impairment. Paralysis of the arms and legs may also occur. Adults and adolescents with Chiari malformation who previously showed no symptoms may show signs of progressive impairment, such as involuntary, rapid, downward eye movements. Other symptoms may include dizziness, headache, double vision, deafness, an impaired ability to coordinate movement and episodes of acute pain in and around the eyes.
Syringomyelia can also be associated with spina bifida, spinal cord tumors, arachnoiditis and idiopathic (cause unknown) syringomyelia. MRI has significantly increased the number of diagnoses in the beginning stages of syringomyelia. Signs of the disorder tend to develop slowly, although sudden onset may occur with coughing or straining.
Surgery results in stabilization or modest improvement in symptoms for most people. Delay in treatment may result in irreversible spinal cord injury. Recurrence of syringomyelia after surgery may make additional operations necessary; these operations may not be completely successful over the long-term. Up to one half of those treated for syringomyelia have symptoms return within five years.
Source: National Institute of Neurological Disorders and Stroke, American Syringomyelia Alliance Project.
For more information on syringomyelia, contact American Syringomyelia Alliance Project (ASAP) P.O. Box 1586, Longview, TX 75606-1586; toll-free 1-800-ASAP-282; or visit the Internet site: www.asap.org