Syringomyelia Information - symptom, cause, picture, treatment of
Destruction or degeneration of gray and white matter adjacent to the central canal of the cervical spinal cord leads to cavitation and accumulation of fluid within the spinal cord. The precise pathogenesis is unclear, but many cases are associated with Arnold-Chiari malformation, in which there is displacement of the cerebellar tonsils, medulla, and fourth ventricle into the spinal canal, sometimes with accompanying meningomyelocele. In such circumstances, the cord cavity connects with and may merely represent a dilated central canal. In other cases, the cause of cavitation is less clear. There is a characteristic clinical picture, with segmental atrophy and areflexia and loss of pain and temperature appreciation in a "cape" distribution owing to the destruction of fibers crossing in front of the central canal (see illustration). Thoracic kyphoscoliosis is usually present. With progression, involvement of the long motor and sensory tracts occurs as well, so that a pyramidal and sensory deficit develops in the legs. Upward extension of the cavitation (syringobulbia) leads to dysfunction of the lower brain stem and thus to bulbar palsy, nystagmus, and sensory impairment over one or both sides of the face.
More Information on Syringomyelia
Syringomyelia, ie, cord cavitation, may also occur in association with an intramedullary tumor or following severe cord injury, and the cavity then does not communicate with the central canal.
In patients with Arnold-Chiari malformation, there are commonly skeletal abnormalities on plain x-rays of the skull and cervical spine. CT scans show caudal displacement of the fourth ventricle. MRI or positive contrast myelography may demonstrate the malformation itself. Focal cord enlargement is found at myelography or by MRI in patients with cavitation related to past injury or intramedullary neoplasms.
Treatment of Syringomyelia
Treatment of Arnold-Chiari malformation with associated syringomyelia is by suboccipital craniectomy and upper cervical laminectomy, with the aim of decompressing the malformation at the foramen magnum. The cord cavity should be drained, and if necessary an outlet for the fourth ventricle can be made. In cavitation associated with intramedullary tumor, treatment is surgical, but radiation therapy may be necessary if complete removal is not possible. Posttraumatic syringomyelia is also treated surgically if it leads to increasing neurologic deficits or to intolerable pain.