Intrinsic disorders include spinal cord infarction, hemorrhage, transverse myelitis, HIV infection, poliovirus infection, West Nile virus infection, syphilis (which can cause tabes dorsalis), COVID-19, trauma, vitamin B12 deficiency (which causes subacute combined degeneration), decompression sickness, lightning injury (which can cause keraunoparalysis [transient paralysis and sensory deficits with ischemia]), radiation therapy (which can cause myelopathy), syrinx, and spinal cord tumor.