Organism | Likely mechanism of myelopathy | Typical location of myelopathy |
Viruses |
Cytomegalovirus | Viral infection with or without vasculitis | Typically conus and cauda equina |
Dengue virus | Usually parainfectious or postinfectious demyelination; rarely acute compressive myelopathy from hematoma | Multifocal leukomyelitis |
Enterovirus D68 | Infection of anterior horn cells | Cervical cord is the most common location |
Epstein-Barr virus | Unknown: detection of Epstein-Barr virus DNA in CSF argues for infiltration of infected inflammatory cells | Typically longitudinally extensive intrinsic cord involvement |
Herpes simplex virus type 2 | Combination of reactivation of infection and inflammation | Conus and cauda equina |
HIV type 1 | Many mechanisms, most commonly white matter vacuolization; no evidence of medullary viral replication | Thoracic cord, corticospinal tracts, and dorsal columns |
Human T-cell lymphotropic virus type I | Immune-mediated infiltration of infected white blood cells into the meninges, microvasculature, and parenchyma | Thoracic cord, particularly lateral white matter tracts |
Poliovirus | Viral infection and cell death | Anterior horn cells |
Varicella-zoster virus | Combination of reactivation of infection and inflammation with or without a vasculitic component | Usually thoracic cord dorsal horn; parenchymal extension beyond affected dermatome is common |
West Nile virus | Viral infection with or without concomitant inflammation | Roots, anterior horn cells |
Bacteria |
Borrelia burgdorferi | Lymphocytic meningovascular inflammatory reaction to endoneurial and connective tissue infection | Roots at any level |
Mycobacterium tuberculosis | Compressive due to Pott disease; granulomatous if intrinsic | Any level but commonly thoracic for Pott disease |
Mycoplasma pneumoniae | Unknown: infection versus inflammatory versus toxin-mediated | Typically longitudinally extensive intrinsic cord involvement |
Pyogenic bacteria | Mass effect of pyogenic abscess | Typically epidural, most commonly thoracic or lumbar spine |
Treponema pallidum | Most commonly inflammation involving meninges and periphery of spinal cord with accompanying atrophy; vasculitic infarct, pachymeningeal inflammation, and dorsal column atrophy less common | Cervical and thoracic cord |
Parasites |
Schistosoma haematobium, Schistosoma mansoni | Infection-mediated granuloma formation; eggs stimulate granulomatous inflammatory reaction, venous congestion | Lower spinal cord and conus medullaris |
Taenia solium | Mass effect of infectious cysts | Typically extramedullary, although intramedullary also reported |
Fungi |
Coccidioides immitis | Mass effect of abscess; also arachnoiditis | Cervical cord for intramedullary abscess |