Meningitis Flashcards
What is bacterial meningitis?
An acute purulent infection within the subarachnoid space, considered a medical emergency.
What are the most common causes of bacterial meningitis in adults?
Streptococcus pneumoniae (50%), Neisseria meningitidis (25%), and Listeria monocytogenes (10%).
What is the classic triad of bacterial meningitis?
Fever, headache, and nuchal rigidity.
What is Kernig’s sign?
A sign of meningeal irritation where the patient experiences pain when the leg is extended at the knee while the hip is flexed.
What is Brudzinski’s sign?
A sign of meningeal irritation where flexion of the neck causes involuntary flexion of the hips and knees.
What is the most common cause of meningitis in neonates?
Group B streptococci and Listeria monocytogenes.
What is the mortality rate of pneumococcal meningitis despite antibiotic therapy?
0.2
What is the role of dexamethasone in bacterial meningitis?
It reduces the rate of hearing loss and neurologic complications when given before or with the first dose of antibiotics.
What is the most common complication of bacterial meningitis?
Increased intracranial pressure (ICP).
What is the most common cause of viral meningitis?
Enteroviruses (e.g., echoviruses, coxsackieviruses).
What is the typical CSF profile in viral meningitis?
Lymphocytic pleocytosis (25-500 cells/μL), normal glucose, and slightly elevated protein.
What is the most common symptom of viral meningitis?
Headache, often frontal or retro-orbital, with photophobia.
What is the treatment for HSV meningitis?
Intravenous acyclovir.
What is the most common cause of encephalitis in immunocompetent adults?
Herpes simplex virus (HSV-1).
What is the diagnostic test of choice for HSV encephalitis?
CSF PCR for HSV DNA.
What is the most common focal finding in HSV encephalitis?
Frontotemporal lobe involvement.
What is the most common cause of brain abscess?
Streptococcus spp. (40%), Enterobacteriaceae (25%), and anaerobes (30%).
What is the most common source of otogenic brain abscess?
Otitis media and mastoiditis, often affecting the temporal lobe.
What is the typical presentation of a brain abscess?
Headache, fever, and focal neurologic deficits.
What is the treatment for brain abscess?
Combination of high-dose antibiotics (e.g., ceftriaxone, metronidazole) and neurosurgical drainage.
What is the most common complication of brain abscess?
Seizures, occurring in 15-35% of patients.
What is the most common cause of fungal meningitis?
Cryptococcus neoformans.
What is the diagnostic test for cryptococcal meningitis?
CSF cryptococcal antigen test (CrAg).
What is the treatment for cryptococcal meningitis?
Amphotericin B plus flucytosine.
