Infectious Disorders of the CNS Flashcards
Bacterial meningitis empirical Abx - Neonates
Ampicillin + Cefotaxime
Bacterial meningitis, empirical Abx - Children/Adults, 2-50 years
Vancomycin AND Ceftriaxone/Cefotaxime
Bacterial meningitis, empirical Abx - Adults > 50
Vancomycin AND Ampicillin AND Ceftriaxone/Cefotaxime
Bacterial meningitis, empirical Abx - Immunocompromised/Nosocomial/Head Trauma/Neurosurgery
Cefepime AND Vancomycin
+/- Ampicillin
Which HSV causes meningitis vs. encephalitis in adults?
HSV-2 generally causes meningitis
HSV-1 generally causes encephalitis
What are the two most common causes of viral encephalitis?
HSV-1
WNV
Classic MRI finding of herpes encephalitis
Fronto-temporal hyperintensity???
Treatment for herpes encephalitis
Acyclovir
Bacterial meningitis - most common organism, neonates < 2 months
Group B Strep (50%)
Bacterial meningitis - most common organism, children 2 months - 2 years
Streptococcus pneumoniae (50%)
Bacterial meningitis - 2 most common organisms, children/adults 2-34 years
Neisseria meningitides (40%)
Streptococcus pneumonia (40%)
Bacterial meningitis - most common organism, adults > 35 years
Streptococcus pneumonia (50-70%)
Common organism causing bacterial meningitis in adults > 60
Listeria monocytogenes
Viral meningitis - CSF
Elevated WBCs (10-2,000/mL), primarily lymphocytes
Normal Glucose
Normal - slightly elevated protein
PCR amplification of viral genomic material from CSF
Elevated ratio of CSF/serum antibody titer (IgM)
Viral meningitis - 2 most common pathogens
Enterovirus (70%)
HSV-2
Classic Triad of Bacterial Meningitis
Fever
Headache
Nuchal rigidity
Accounts for 45% of all cases
+ AMS, any 2/4 is 95% sensitive
Etiologies of bacterial meningitis
Hematological spread (most common)
Adjacent intracranial infection (sinusitis, mastoiditis, otitis)
Skull/spinal defects (congenital, traumatic, surgical)
Goal of bacterial meningitis treatment
Initiation of antibiotic therapy within 60 minutes of patient arrival in the ER
LP findings in bacterial meningitis
Elevated WBCs (100-10,000/mL) - majority (>80%) neutrophils
Elevated Protein (>50g/dL)
Low glucose (<0.4
Bacterial culture positive in 70-85%
Indications for imaging before LP
Focal deficits / AMS
Signs of increased ICP (papilloedema)
Suspected focal CNS infection/lesion
Immunocompromised
*Get blood cultures and start immediate empiric antibiotics first!
Streptococcal meningitis - demographics and treatment
Children 2 years - adults > 35 years
Vancomycin + 3rd generation cephalosporin
10-14 days
Meningococcal meningitis - demographics and treatment
Children/adults 2-34 years
Vancomycin + 3rd generation cephalosporin
> 7 days
Listeria monocytogenes - demographics and treatment
Adults > 60 years
Ampicillin +/- aminoglycoside
> 21 days
Brudzinski Sign
With the patient supine, forced flexion of the neck elicits a reflex flexion of the hips
+ in meningitis
Kernig sign
With the patient supine and hip and knee both flexed at 90 degrees, subsequent extension of the knee past 90 degrees is painful
+ in Meningitis
