chronic, progressive disease characterized principally by the development of a cyst, called a syrinx, near the spinal cord or brain stem. Symptoms include gradual dissociated sensory loss, muscle wasting, and spasticity. The cause of the disease is unknown but is thought to be a developmental defect. Symptoms ordinarily appear between 10 and 30 years of age; males are affected more often than females.

The onset of syringomyelia is slow. Initial symptoms may include weakness of the hand muscles, a lateral curvature of the spine ( scoliosis), or injuries, such as burns, with lack of pain. The loss of pain and temperature sensation has a shawl-like distribution over the arms and shoulders. Syringobulbia, the formation of a cyst on the brainstem, may develop in association with syringomyelia. Symptoms include atrophy of the tongue, difficulty in swallowing ( dysphagia), loss of pain and temperature sensation in the face, and a variety of other neurological disorders.

There is no cure for syringomyelia; treatment may include surgical drainage of the cyst. Patients may live as long as 40 years after the onset of the disease.