Thoracic radiculopathy is due to spinal nerve insult, usually secondary to intervertebral disc pathology (herniation, discitis). Special situations present in diabetic truncal or thoracoabdominal radiculopathy and postherpetic neuralgia.
Myelopathy has been associated with thoracic disc herniation (TDH), disc calcification, posterior longitudinal ligament and/or ligamentum flavum ossification, spinal stenosis, and anterior spinal cord herniation with prolapse through the dura mater. Hereditary and congenital anomalies include: alkaponuria, syringomyelia, diastematomyelia, tethered cord, X-linked hypophosphatemic rickets, epidural or vertebral vascular malformations, and neurofibromatosis.
Infectious diseases include: vertebral osteomyelitis, vertebral tuberculosis (Pott's disease), discitis, epidural abscess, human T-lymphotropic virus 1 (HTLV-1), syphilis; schistosomiasis. Compression from intradural or extradural neoplasias can cause myelopathy.
Iatrogenic ischemic thoracic myelopathy can follow inadvertent intravascular injection of particulate steroids during transforaminal epidural injections, causing embolization and paraplegia. Thoracic myelopathy may result from ligature during lumbar sympathectomy, prolonged clamping during aortic aneurysm surgery, or transoperative microembolization of the anterior spinal cord artery. Dissecting aneurysms can interrupt blood supply to the thoracic cord.Intrathecal catheters can develop granulomas at the tip causing devastating compressive myelopathy. Radiation therapy can cause demyelination, focal necrosis and vasculitic changes of the thoracic spinal cord.1,2