A rare medullar disease defined as a development of a fluid-filled cavity or syrinx within the spinal cord due to blockage of cerebrospinal fluid circulation (for example due to basal arachnoiditis, meningeal carcinomatosis, various mass lesions), spinal cord injury (for example due to trauma, radiation necrosis, spinal abscess), spinal dysraphism or intramedullary neoplasm. It presents with neuropathic pain, numbness, muscular weakness, changes in tone or spasticity or autonomic changes (hyperhidrosis, heart rate or blood pressure instability). Selective loss of pain and temperature with relative preservation of dorsal column function (touch and pressure) are classic findings. [from
SNOMEDCT_US]