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23 Cards in this Set
- Front
- Back
What are the usual defense mechanisms of the CNS?
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-Blood brain barrier
-Its central anatomical location |
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What 3 infections usually present with a CNS specimen?
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1. Meningitis
2. Brain abcess 3. Encephalitis |
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What are the 2 most common causes of meningitis?
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1. 2ndary infection disseminated from upper resp tract infection.
2. Trauma |
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What types of symptoms accompany meningitis?
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Severe headache
Fever Stiff neck |
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What types of WBC counts are seen in bacterial versus viral meningitis?
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Bacterial: PMNs
Viral: Lymphocytes |
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What CSF Glu and Protein levels are seen in bacterial versus viral meningitis?
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Bacterial: low glu, high protein
Viral: normal glu, slightly high protein. |
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What do CSF direct smears and cultures produce for bacterial versus viral meningitis?
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Bacterial: positive
Viral: negative - can't grow on artificial media. |
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What usually causes brain abcesses?
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1. Infection somewhere else
2. Skull trauma |
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What 3 types of infections often are causes of brain abcess?
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1. Otitis media
2. Sinusitis 3. Lung infection |
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Is encephalitis usually bacterial or viral?
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viral
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What should CSF normally look like?
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Clear and straw colored. if cloudy, suspect infection.
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What is a CSF specimen ALWAYS?
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STAT - these are bad infections.
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What do you inoculate a CSF specimen to, and how do you incubate it?
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CA, BA, Thioglycollate.
-37'C, CO2 atmosphere. |
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Should you do a direct smear for a CSF? Why?
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Yes - b/c plates take 24 hrs, and there's no normal flora in the CSF.
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What 2 STAT direct smears should be done for a CSF specimen?
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-Gram stain
-Capsule stain (for Cryptococcus neoformans) |
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How is CSF processed before inoculating plate media?
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Centrifuged because bacteria are usually in low numbers. Then inoculate with the sediment.
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What are probable pathogens in Meningitis of newborns?
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-Beta strep grp B
-Listeria -Chryseobacterium meningoseptic. -E. coli |
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What are probable pathogens in Meningitis of kids under 5 yrs?
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H. influenzae type B
N. meningitidis S. pneumonia |
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What are probable pathogens in Meningitis of adults?
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Neisseria meningitidis
S. pneumonia |
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What are 2 common pathogns in brain abcesses?
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-Streptococci
-Anaerobes |
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What 3 parasites cause CNS infections?
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-Naegleria fowleri
-Acanthamoeba -Toxoplamsa |
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What yeasts cause CNS infections?
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Cryptococcus neoformans.
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What molds cause CNS infections?
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-Coccidiodes immitis
-Nocardia |