Meningoencephalitis

Meningoencephalitis (; from Greek: meninges- membranes; enkephalos brain; and -itis inflammation) is a medical condition that simultaneously resembles both meningitis, which is an infection or inflammation of the meninges, and encephalitis, which is an infection or inflammation of the brain.

Causes

Causative organisms include protozoans, viral and bacterial pathogens.

Specific types include:

Bacterial

• Listeria monocytogenes
• Neisseria meningitidis
• Rickettsia prowazekii
• Mycoplasma pneumoniae
• Tuberculosis
• Borrelia (Lyme disease)
• Leptospirosis

Viral

• Tick-borne meningoencephalitis
• West Nile virus
• Measles
• Epstein-Barr virus
• Varicella-zoster virus
• Enterovirus
• Herpes simplex virus type 1
• Herpes simplex virus type 2
• Mumps, a relatively common cause of meningoencephalitis. However, most cases are mild, and mumps meningoencephalitis generally does not result in death or neurologic sequelae.^[1]
• HIV, a very small number of individuals exhibit meningoencephalitis at the primary stage of infection.^[2][3]

Other/multiple

• Granulomatous meningoencephalitis
• Antibodies targeting amyloid beta peptide proteins which have been used during research on Alzheimer's disease.^[4]
• The fungus, Cryptococcus neoformans, can be symptomatically manifested within the CNS as meningoencephalitis with hydrocephalus being a very characteristic finding due to the unique thick polysaccharide capsule of the organism.
• Anti-N-methyl-D-aspartate (anti-NMDA) receptor antibodies, which are also associated with seizures and a movement disorder
• Vasculitis

Protozoal

• Primary amoebic meningoencephalitis, e.g., Naegleria fowleri, Balamuthia mandrillaris, Sappinia diploidea
• Trypanosoma brucei
• Toxoplasma gondii (sporozoa)

Ameobic pathogens exist as free-living protozoans. Nevertheless, these pathogens cause rare and uncommon CNS infections. N. fowleri produces primary amebic meningoencephalitis (PAM). The symptoms of PAM are indistinguishable from acute bacterial meningitis. Other amebae cause granulomatous amebic encephalitis (GAE), which is a more subacute and can even a non-symptomatic chronic infection. Ameobic meningoencephalitis can mimic a brain abscess, aseptic or chronic meningitis, or CNS malignancy.^[5]

Animal

• Halicephalobus gingivalis

Animal pathogens exist as facultative parasites. They are an exceptionally rare cause of meningoencephalitis.^[6]

Prognosis

The disease is associated with high rates of mortality and severe morbidity.

Notable cases

It was cause of death of the popular British TV presenter Christopher Price.^[7]

In May, 2009 former Premier of New South Wales (Australia) Morris Iemma was admitted to hospital with meningoencephalitis.^[8]

Recent medical research indicates that it was the cause of Mary Ingalls' (older sister of Laura Ingalls) blindness (not scarlet fever as the book indicates).^{[9][10][11][12]}

In popular culture

In the 2011 film Contagion, the pandemic disease kills when it causes meningoencephalitis in patients. The film's virus is named Meningoencephalitis Virus One (MEV-1).

In the 'House' episode Euphoria (Part 2), primary amoebic meningoencephalitis was the cause of Foreman's symptoms.

See also

• Meningitis
• Meningism
• Primary amoebic meningoencephalitis
• Encephalitis

References