Syringomyelia

This chapter discusses syringomyelia, which is dilation of the spinal canal. It can be either congenital or post-traumatic. It is associated with central pain characteristics of predominantly neuropathic pain. Headaches may be present in patients with syringomyelia associated with type 1 Arnold-Chiari malformation. The size of the syrinx does not correlate to the severity of pain. Damage to the deeper layers of the dorsal horn causes an imbalance between the inhibitory and excitatory stimuli with upregulation of substance P. Electromyography shows a mixture of shortened and prolonged action potentials in syringomyelia. Somatosensory-evoked potential may be useful in the electrodiagnosis of syringomyelia. MRI plays a key role in the diagnosis of syringomyelia. Medical treatment is multifaceted and may be unsuccessful in treating the neuropathic pain. Surgery is the definitive treatment, although symptoms of pain may persist after resection. Spinal cord stimulation may offer relief to some patients and can be considered, as long as the dimensions of the vertebral canal are not significantly compromised.