pathogenesis
Last reviewed 01/2018
Syrinxes, or tube-like cavities, form within the grey commissure behind the central canal of the spinal cord.
The syrinxes enlarge into the dorsal horns and white matter of the cord affecting especially dorsal and lateral columns. Destruction of grey and white matter occurs as fluid within the syrinx causes pressure atrophy. Syrinxes may extend to the brainstem - syringobulbia.
The incidence of difficult childbirth is higher in patients with syringomyelia than in controls. It is possible that abnormal pressures in the cervical spine and fourth ventricle during delivery can rupture the ependymal lining of the central canal of the spinal cord and start a syrinx. The hydrostatic theory is supported by the observation that symptoms occasionally progress following a bout of coughing.