There are numerous causes of meningoencephalomyelitis including:
Some specific diseases, which have one or more components of meningoencephalomyelitis, include granulomatous meningoencephalomyelitis, pug dog meningoencephalitis and necrotizing meningoencephalitis of Yorkshire terriers and Maltese dogs.
Infectious causes may be viral, bacterial, fungal or parasitic and are identified by either direct observation of the organism in the cerebrospinal fluid (CSF), culture of the CSF or serologic testing of the blood, CSF or other body fluid affected by the pathogen.
Exposure to virus can occur through insect bites, food, water, skin contact or decomposing material.
Rickettsial and arbovirus diseases can be carried by mosquitoes or ticks while protozoal diseases such as neospora and toxoplasmosis are spread by fecal contamination.
When a specific cause of meningoencephalomyelitis is not found, it is called idiopathic, which means it has no known cause, although unidentified viral and immune-mediated causes are commonly suspected.
If an infectious cause invades the brain, it can cause inflammation of the brain, spinal cord and coverings. White blood cells invade the brain tissue as they try to fight off the infection. The brain tissue swells and can cause destruction of nerve cells, bleeding within the brain and brain damage.
