Encephelitis

Question 1

aetiology and risk factors of encephelitis

Answer 1

Inflammation of the brain- due to many causes

Mainly
VIRAL- most common- HSV,
Bacterial - N. Menigitides
Fungal - Cryptococcus
Parasite- Toxoplasmosis
Autoimmune/paraneoplastic- Anti-Hu, anti-NMDA, Prion

Question 2

Presentation of encephelitis

Answer 2

Medical emergency-
Under 1 or over 65, (or 30 if AID)
Rapid Onset if infection
Slower if autoimmune (but faster than–dementia)
Often immunocompromised so check

major criteria- Altered brain status (Drowsy -> coma)

minor-
seizures
Cognitive changes- personality, labile, etc
fevers (depends on cause)
Focal neurology- aphasia, Hemiparesis, visual nerve changes, facial nerve changes, ataxia, tremors, etc)
Meningism common (neck stiff, photophobia,

Autoimmune take 3-4 month to develop, and has ++ psych sx

other sx–
rashes COMMON
Previous viral illness, travel
parotitis

Question 3

Investigation of encephelitis

Answer 3

Any altered conscious status with focal neuro- think immediate LP (care of herniation-check with CT/MRI)

LP - same as meningitis results - viral (Lympho +), bacterial (sugar -, prot +, Leukocyte +, cloudy, Opening pressure +)
autoimmune- check ABs, Prot +

MRI is modality of choice

Question 4

Management of encephalitis

Answer 4

A-E approach as emergency

admit to ITU and ISOLATE
CT head in case of LP contraindication
then LP

usually immediate start on Aciclovir and Abx (do LP first if possible)
rarely add steroids (controvertial), but do if ICP +

Non- infective-
rituximab, cylcophosphamide