BASICS
Meningoencephalomyelitis associated with aberrant and unusual helminth and insect parasitic invasion of nervous tissues.
- Aberrant migration of parasitic organisms of other species or organ systems
- Helminth and arthropod parasites identified from the equine CNS include nematodes (Strongylus vulgaris, Strongylus equinus, Angiostrongylus cantonensis, Halicephalobus gingivalis, Setaria spp., and Draschia megastoma) and fly larvae (Hypoderma spp.)
- The clinical signs result from physical tissue destruction, hemorrhage, and inflammation, or a space-occupying effect, depending on the parasite. S. vulgaris is the most pathogenic of the large strongyles and can form fibrinoparasitic emboli that directly block cerebral vasculature
- An additional immune-associated inflammatory response may contribute to the pathophysiologic picture
CNS and other specific tissues associated with the more common parasitic migration pattern.
Much decreased with the introduction of modern anthelmintics.
Multifocal neurologic signs that can be attributed to brainstem, cerebellum, or spinal cord involvement. History and physical examination signs are associated with the migratory pattern in each specific case and can include progressive:
- Ataxia
- Ascending paresis
- Decreased perineal tone
- Cranial nerve deficits variable, e.g. decreased menace response, ptosis, dropped lips
- Intention head tremor
- Muscle wasting
- Pyrexia
DIAGNOSIS
TREATMENT
MEDICATIONS
FOLLOW-UP
MISCELLANEOUS