Infections of the nervous system Flashcards
What is brain parenchyma?
Functional tissue in the brain
The involvement of what structure is hallmark of encephalitis?
In encephalitis the brain parenchyma is inflamed
What are the classifications of meningitis?
- Acute pyogenic (bacterial) meningitis
- Acute aseptic (e.g. viral, non-infectious) meningitis
- Acute focal suppurative infection (brain abscess, subdural/extradural empyema)
- Chronic bacterial infection (TB)
- Acute encephalitis (brain parenchyma)
How does pyogenic meningitis appear under a microscope?
Neutrophils in subarachnoid space
What antibiotics are given for pyogenic meningitis?
Ceftriaxone + Dexamethasone
If listeria add Amoxicillin 4 hourly
When do you give steroids in pyogenic meningitis?
10mg IV 15-20 mins before or with first dose of antibiotics and then every 6 hours for 4 days
What is a contra-indication for giving steroids to a patient with meningitis?
- post-surgical meningitis
- Meningococcal
- Septic shock
- Patients hypersensitive to steroids
What type of pyogenic meningitis benefits most from steroid treatment?
Pneumococcal meningitis
When is viral meningitis most often seen?
Late summer / autumn
What aspect of a patients history gives a big clue to viral meningitis?
Travel history
What organisms cause viral meningitis?
Enteroviruses e.g. ECHO virus
How is viral meningitis diagnosed?
Viral stool PCR + culture, throat swab & CSF PCR
What is the treatment for viral meningitis?
Supportive as the condition tends to be self limiting
What are some symptoms of encephalitis?
- Mental status change
- Confusion
- Obtundation or coma
- Seizure
- Behavioral & speech disturbance
- Focal or diffuse neurological signs
What are some symptoms of Meningo-encephalitis?
- Headache
- fever
- Neck stiffness
+
encephalitis features
Is the cerebral cortex affected by encephalitis?
Yes
Does encephalitis tend to have a insidious or sudden onset?
Most likely insidious
What investigations are done for encephalitis?
- Lumbar puncture (1st line)
- EEG
- MRI