Encephalitis Flashcards
what is encephalitis?
Inflammation of brain tissue
difference from the clinical presentation of meningitis?
Increased incidence of fitting
Acute personality change
Which virus transferred by vectors including birds and mosquitoes is becoming a leading cause of encephalitis world wide ?
West Nile virus
Name a bacterial cause of encephalitis ?
Listeria
Which organisms can cause encephalitis via local invasion ?
Amoebae (found in warm water)
Which organism causes encephalitis via oral route ? (Eating cat poo 🤮)
Toxoplasmosis- e.g toxoplasma gonadii
Most common cause of viral encephalitis in UK
Herpes
most serve form?
herpes still
but Most easily treatable
Rapid progression to loss of consciousness and coma
which cause about 60-70% of brain abscesses?
Streptococcus anginosus group and mixed gram negative anaerobes
1° focus: mouth, gut or female genital tract infection
which cause about 10-15%?
Staphylococcus aureus
Following endocarditis or ivdu
which causes about 20-30%?
Pseudomonas and enterobacteriaceae
Following middle ear infection or immunodeficiency
Why are brain abscesses dangerous?
Dangerous sincecause death due to pressure-related issues
What is the most common route of entry for organisms causing brain abscess ?
Another route?
Local extension e.g from mastoiditis or sinusitis
Other route:haematogenously
non invasive diagnosis of brain abscess?
CT or MRI scan show mass in brain
why would a lumbar puncture be performed?
CSF sample
Possible small increase in WCC
But polymorphs or lymphocytes may be raised
Culture: often negative
whats a more helpful invasive diagnostic test?
CT guided aspiration abscess contents
Microscopy and culture (including anaerobic culture)
how are brain abcesses treated?
Aspiration
Broad spectrum antibiotics that penetrate BBB
Name a common spinal infection ?
Pyogenic vertebral osteomyelitis
If left untreated, it can lead to permanent neurological deficits, significant spinal deformity, or DEATH
Herpes meningitis vs herpes encephalitis
Herpes meningitis does NOT need therapy BUT herpes encephalitis is a MEDICAL EMERGENCY
encephalitis diagnosis from CSF?
White cell count
- About 100/mm3 lymphocytic predominance
other methods?
Viral cell culture
Slow and positive in only 4%
PCR
Highly sensitive and specific
why would a brain biopsy be performed?
seldom performed now
For viral cell culture
Antigen detection with labelled antibodies
PCR
