Syringomyelia

Key Features

• Destruction of gray and white matter adjacent to the central canal of the cervical spinal cord leads to cavitation and fluid collection within the cord

• Associated with Arnold-Chiari malformation, sometimes with accompanying meningomyelocele

• Cord cavitation may also occur with cord injury or neoplasm at any level of the cord

Clinical Findings

• Cervical lesions

  • Segmental atrophy, 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 in the mid-cervical spinal cord

  • Often there is thoracic kyphoscoliosis

• A pyramidal and sensory deficit may be present in the legs

• Upward extension of the cavitation (syringobulbia) leads to dysfunction of the lower brainstem and thus to bulbar palsy, nystagmus, and sensory loss over one or both sides of the face

Diagnosis

• CT scans reveal

  • Small posterior fossa

  • Enlargement of the foramen magnum

  • Other associated skeletal abnormalities at the base of skull and upper cervical spine

• MRI reveals

  • Syrinx

  • Caudal displacement of the fourth ventricle and herniation of the cerebellar tonsils through the foramen magnum

• Focal cord enlargement is found at myelography or by MRI in patients with cavitation related to past injury or intramedullary neoplasms

Treatment

• 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

• 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