Viral meningitis/Encephilitis Flashcards
Define meningitis
inflammation of the meninges
Define encephalitis
inflammation of the brain
Define meningo-encephalitis
inflammation of the brain and meninges
What is the commonest cause of aseptic meningitis?
viruses
What is the basic infectious particle of a virus?
virion
What is the commonest viral cause of viral meningitis?
enteroviruses
Describe the pathogenesis of viral meningitis
- colonisation of mucosal surfaces
- invasion of epithelial surface
- replication in cells
- dissemination and CNS invasion
- symptoms due to inflammatory response in CNS
What are the general features of clinical presentation of viral meningitis?
- fever
- meningism (headache, stiff neck, photophobia)
- sometimes viral prodrome
What is Kernig’s sign?
flex hip and knee to 90 degrees, knee cannot extend due to pain and stiffness
What is Brudzinski’s sign?
felxing the neck causes the hips and knees to flex
Define nuchal rigidity
resistance to flexion of the neck
What do you test in a lumbar puncture sample for suspected meningitis?
MC&S, protein, glucose (must check blood glucose at same time), viral PCR
Define pleocytosis
white cells in CSF
What would you expect to see in the WBC count of someone with viral meningitis?
lyphocytic (
What is the first treatment for suspected meningitis?
start IV antibiotics if any risk of bacterial meningitis
What is Mollaret’s meningitis?
- recurrent aseptic meningitis
- wide differentil but major cause is HSV2
What symptoms would you get in enteroviral meningitis?
fever, vomiting, anorexia, rash, URTI,
What abnormal features are seen in people with mumps meningitis?
abdominal pain and orchitis
What are the associated features of mengitis as part of primary infection in HIV?
fever, lymphadenopathy, pharyngitis, rash
What is the cause of the majority of viral encephalitis?
HERPES SIMPLEX VIRUS (90% HSV1)
What is the clinical presentation of viral encephalitis?
-ALTERED MENTAL STATE
-fever
-headache
-meningism
(also may have seizures, weakness, dysphagis, cranial nerve palsy and ataxia)
How would you treat viral encephalitis?
- high dose IV acyclovir
- oral switch not recommended
What are the CSF findings in viral encephalitis compared with that of viral meningitis?
the same
What is acute disseminated encephalomyelopathy?
immune mediated CNS demyelination
