Meningitis Flashcards
Meningitis
Infection and inflammation of meninges
How does meningitis occur
Blood brain barrier usually controls access of potentially toxic metabolites into CSF and tissues.
Failure of this mechanism results in meningitis.
Encephalitis
Infection of the brain parenchyma
Meningo encephalitis
Inflammation of brain + meninges.
Aseptic meningitis
Inflammation of meninges with sterile CSF –caused by viruses
Classification of Meningitis - Duration
Acute: Symptoms present in 24 hrs
Sub acute: Symptoms lasting 1-7 days
Chronic: Symptoms lasting over 7 days
Classification of Meningitis - Etiology
Bacterial meningitis
Fungal meningitis
Viral (aseptic) meningitis
Acute meningitis - Bacteria
Pneumococcus , Meningococcus
Hemophilus influenzae , Group B Streptococcus , Enteric GNB -E.coli
Listeria monocytogenes , Staph. aureus
Acute meningitis - Parasites
Naegleria Fowleri
Angiostrongylus , Acanthamoeba spp.
Strongyloides stercoralis , Entamoeba histolytica .
Chronic meningitis - Bacteria
Mycobacterium tuberculosis
Cryptococcus neoformans
Chronic meningitis - Fungi
Histoplasma , Coccidiodes, Candida, Blastomyces
Chronic meningitis - Others
Toxoplasma , Lyme disease , Syphilis , Cysticerosis.
Transmission - Acute meningitis
Spread via bloodstream
Spread from Para meningeal structures – e.g. Sinusitis
Direct infection to subarachnoid space via fracture
Direct infection
Pathogenesis - meningitis
1) Nasopharyngeal colonization
2) Invasion of epithelium
3) Invasion of blood
4) Further dissemination
5) Cerebrospinal fluid tissues
Symptoms - infant
- Fever
- Not feeding; possible vomiting
- Blank stare
- Lethargic
- Pale, blotchy