Encephalitis Flashcards
What is encephalitis?
Inflammation of the brain parenchyma associated with neurological dysfunction
How does encephalitis differ from meningitis?
Inflammation of the brain tissue vs inflammation of the meninges
In what percentage of cases of encephalitis is an aetiological agent identified?
~50%
What is the most common type of causative organism of encephalitis?
Viruses
Other than viruses, what else can cause encephalitis?
- Other organisms
- Toxins
- Autoimmune disorders
What are the two types of viral encephalitis?
- Acute viral encephalitis
- Post-infectious encephalitis
What is acute viral encephalitis?
Direct viral infection of the brain
What is post-infectious encephalitis?
An autoimmune process that occurs following infection elsewhere in the body
What is the most common viral cause of encephalitis?
HSV
What other viruses can cause encephalitis?
- CMV
- Adenovirus
- Influenza virus
- Rabies
What are the bacterial causes of encephalitis?
- TB
- Mycoplasma
- Listeria
- Lyme disease
- All causes of bacterial meningitis
What fungi can cause encephalitis?
- Histoplasmosis
- Candidiasis
What parasites can cause encephalitis?
- Toxoplasmosis
- Schistosomiasis
What are the risk factors for encephalitis?
- Age <1
- Age >65
- Immunodeficiency
- Travel to endemic locations
What is the clinical hallmark of acute encephalitis?
Triad of:
- Fever
- Headache
- Altered mental status
What do most patients with viral encephalitis initially present with?
Symptoms of meningitis