CNS infections Flashcards
What can an untreated CNS infection lead to?
Brain herniation and death
Cord compression and necrosis with subsequent permanent paralysis
What are the different types of CNS infections?
Encephalitis Meningitis Meningoencephalitis Encephalomyelitis Epidural abscess Neuritis Sepsis syndrome
What is meningitis?
Inflammation of the meninges
What is encephalitis?
Inflammation of brain parenchyma
What are the different types of meningitis?
Acute pyogenic
Acute aseptic (viral)
Acute focal suppurative (brain abscess, subdural and extradural empyema)
TB
What will pyogenic meningitis show?
Thick layer of suppurative exudate covering the leptomeninges over the surface of the brain
Exudate in the basal and convexity surface
What will meningitis show microscopically?
Neutrophils in the subarachnoid space
Are neutrophils present in viral meningitis?
NO - it is aseptic
What is the basic treatment for bacterial meningitis
Ceftriaxone IV 2g bd
AND
Dexamethasone IV 10mg qds (3ml of 3.3mg/ml base injection)
What are the risk factors for listeria infection?
Over 60 years
Immunocompromised including alcohol dependency and diabetes
What should be added to the empirical antibiotics if there are risk factors for listeria?
Amoxicillin IV 2g hourly
What is used instead of ceftriaxone in penicillin allergy?
Chloramphenicol IV 25mg/kg qds
What is used instead of amoxicillin cover for listeria in penicillin allergy?
Co-trimoxazole IV 120mg/kg divided into 4 doses/day
What should be added to empirical antibiotic therapy if there has been recent travel to a country with high rates of penicillin resistant pneumococci?
Vancomycin IV aiming for a pre dose level of 15-20mg/L OR rifampicin IV/PO 600mg bd
What are countries with high rates of pneumococcal resistance?
Canada China Croatia Pakistan Poland Spain Mexico Italy USA Greece Turkey
Should you continue dexamethasone in the case of a confirmed meningitis that is not pneumococcus?
No - stop
How long should dexamethasone be given?
4 days
What virus commonly causes meningitis?
Enteroviruses Coxsackie HSV VZV Paromyxovirus
How is viral meningitis diagnosed?
Viral stool culture
Throat swab
CSF PCR
What is encephalitis?
Diffusely inflamed cerebral cortex
What are the common signs of encephalitis?
Mental status changes
Confusion
Coma
INSIDIOUS ONSET