Brain Abscesses and other CNS Infections Flashcards
What is a brain abscess?
A focal suppurative process in the brain parenchyma
What microbes (polymicrobial) are Brain abscesses associated with?
> Streptococcus (60-70%)
Staphylococcus Aureus (10-15%) - usually after surgery
Gram -ve enteric bacteria
Others e.g fungi, TB, too gondii, nocardia, actinomyces.
In what 4 settings do Brain abscesses develop?
1) Direct (contiguous) suppurative focus - From ear, teeth, 40% sinuses
2) Distant focus haematogenous spread - Endocarditis, Bronchiectasis, Multiple abscesses
3) Trauma - open cranial fracture
4) Cryptogenic (No focus)
What is the most common clinical symptom of Brain abscess?
Headache
What are the other clinical symptoms of brain abscess?
> Fever > Stiffness > Neck stiffness > Focal neurological deficit > Nausea > Vomiting > Dizziness > Seizures > Confusion > Coma
How does the concentration of antic’s differ if you need it to reach CSF than brain tissue?
Needs to be higher conc.
What are the complications of Brain abscess?
> Rupture –> Vasculitis
> Raised ICP can = coning.
What is a Subdural Empyema?
Infection between dura and arachnoid mata.
What are the microbes that cause a Subdural Empyema? (Polymicrobial)
> Streptococci
Anaerobes
Aerobic gram -ve bacili.
Where do Subdural empyemas mostly develop from?
Sinuses (50-80%)
Middle ear and mastoid (10-20%)
Distant site (5%, haematogenous)
Following surgery/trauma.
What are the symptoms of Subdural Empyema?
> Headache > Fever > Focal neurological deficit > Confusion > Seizure > Coma
What is the management of Subdural Empyema?
Pus drainage
How are EVDs and VP shunt infections diagnosed?
CSF microscopy and culture.
What is the most common cause of EVDs/VP infection?
Coagulase-negative staphylococci
What is the management of EVDs/VP infection?
> Remove the device
> IV Antib’s
