Encephalitis and meningitis

hrhodes's version from 2015-10-14 10:08

General encephalitis

Question Answer
What is encephalitis ?Viral inflammation of the brain parenchyma resulting in diffuse or focal neuropsychological dysfunction. Meningitis and Encephalitis often coexist.
What forms of viral encephalitis can be treated? HSV and VZV Encephalitis.
Which viral encephalitis is common in immunocompromised?CMV and VZV
What do ticks and mossies infect with?arbovirus.
How does the virus cause its mischief?Virus replicates outside the CNS->travels via blood stream, neurons or Olfactory pathways-> enters neural cells-> disruption in cell function, inflammatory response and haemorrhage
Does HSV affect grey or white matter more?HSV affects grey > white matter.
What causes more white > grey after demyelination?Postinfective encephalitis (EBV, CMV, measles)


Question Answer
What is HSE untreated mortality and long term disability rates?50-75% ; 100% long term disabilities.
In PIE secondary to measles, what is the mortality rate?40%
What are the mortality rates in VZV in normal and IC patients?100% mortality in immunocompromised, 15% otherwise 8% mortality and 12% morbidity
Name 3 types of encephalitis that have 100% mortality in immunocompetant?Rabies and acute disseminated encephalitis. Subacute sclerosing Panencephalitis (second to measles)


Question Answer
Name two categories of encephalitis?Infectious and post infectious
List infectious causesHSV/VZY, EBV, CMV, entero- and adenovirus, rabies, tick and mossie born diseases (arbo)
List post-infectious causesInfluenza, Measles, Rubella, VZV, HIV, post immunisation Bact./Others: Ricketsia, Leptospirosis, Amoebic, Listeria,


Question Answer
Describe the most common presentation of encephalitisMinor illness with headache (URTI)-> nausea, headache, fever, neck-stiffness -> neurological symptoms -> lethargy, confusion, hallucinations, ACS, seizures

Investigations :

Question Answer
Which investigations would you order?FBE (?Eosinophilia, WCC), U&E, CRP, ESR, INR (pre LP and sepsis related), LFT, viral serology, blood cultures
What do you expect from the LP result?pressure normal or slightly high, clear or slightly turbid, WCC 50-500, rotein mild up, normal glucose
What do you send CSF for?Usual, HSV, VZV, EBV, CMV, Japanese encephalitis-PCR and M/C/S
When dos you get a CT head? pre LP if possible
What does CT head show?mass effect in 80%, often only subtle changes
What other tests would you like if money and time not an object?MRI and EEG
What is the gold standard for diagnosis?Brain Biopsy (96% sens 100% spec)


Question Answer
How do you manage these patents?Supportive care mainly with management of complications (seizures, ACS) Aciclovir/Famciclovir, Dexamethasone