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52 terms

Buxton

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Meningitis: acute septic
Bacterial
Meningitis: aseptic
Viral
Meningitis: chronic
fungal or TB
neck stiffness that prevents flexion
nuchal rigidity
supine position with legs flexed at hip and knee; will resist extension of the leg at the knee
Kernig's sign
passive neck flexion induces flexion of hip and knee
Brudzinski's sign
-inflammation of the meninges
-can be due to non-infectious or infectious causes
meningitis
-fever
-headache
-neck stiffness
-photophobia
-nausea
-vomiting
-cerebral dysfunction +/- (lethargy, confusion, coma)
meningitis
-symptoms evolve over hours to days
-increased NEUTROPHILS in CSF
-Neutrophilic pleocytosis
-Bacterial
Acute Septic Meningitis
-symptoms evolve over hours to days
-increased MONONUCLEAR cells in the CSF
-Lymphocytic pleocytosis
-Bacteria or Fungi are not readily cultured
-usually caused by viruses
Aseptic Meningitis
-symptoms develop over several weeks
-granulomatous inflammatory disease
-MONONUCLEAR cells in CSF
-usually caused by mycobacteria or fungi, occasionally parasites
Chronic Meningitis
-inflammation of brain parenchyma
-manifestations include alterations in level of consciousness, seizures, confusion, personality changes
-primarily of VIRAL etiology
Encephalitis
-both meningeal and encephalitic symptoms are present
-viral, bacterial, or parasitic causes
Meningoencephalitis
causes of bacterial meningitis:
-Group B Streptococcus
-E. coli K1
-Listeria monocytogenes
-Klebsiella
< 1 month
causes of bacterial meningitis:
-Streptococcal pneumoniae
-Neisseria meningitidis
-Haemophilus influenzae
-GBS; E. coli K1
1-23 months
causes of bacterial meningitis:
-Streptococcus pneumoniae
-Neisseria meningitidis
2-50 years
causes of bacterial meningitis:
-Streptococcus pneumoniae
-Neisseria meningitidis
-Listeria monocytogenes
-Aerobic Gram - Rods (E. coli, Klebsiella, Pseudomonas, others)
> 50 years
causes of viral meningitis:
-Enterovirus (most common)
-Arbovirus
-HIV (early infection)
infants and children
causes of viral meningitis:
-HIV (early infection)
-Arbovirus
Adults
causes of chronic meningitis:
-Mycobacterium tuberculosis
-Treponema pallidum
bacterial pathogens
causes of chronic meningitis:
-Cryptococcus neoformans
-Coccidioides immitis
-Histoplasma capsulatum
-other endemic dimorphic _______
fungal pathogens
Pathogenesis of Meningitis: How do organisms access the CNS?
____1____ spread from distant sites of infection or colonization - most often from ____2_____. Must be able to cross the ____3______. The ___4____ is more permeable compared to the rest of the CNS vasculature. Some agents cross following infection of ____5_____ cells.
1) Hematogenous
2) respiratory tract
3) BBB
4) choroid plexus
5) endothelial
Pathogenesis of CNS infection: What are the non-hematogenous routes by which organisms access the CNS?
____1_____ spread following head trauma or secondary to ____2____ or ______3____.
____4____ Route.
1) direct contiguous
2) sinusitis
3) otitis media
4) Neural
Neural spread of CNS infections:
___1____ nerves: Rabies
___2____ nerve: HSV-1, Naegleria fowleri
1) peripheral
2) olfactory
after entry, the trophozoite penetrates the nasal mucosa and migrates along mesaxonal spaces of unmyelinated olfactory nerves, terminating at the olfactory bulb in the subarachnoid space. This space is quite vascularized and is a route of dissemination of trophozoites to other areas of the CNS.
Naegleri fowleri
Pathogenesis of Bacterial Meningitis:
1. Colonization of infection of mucosa at ___1_____.
2) Entry into ____2_____ and evasion of ___3___ and ____4_____
3) ____5_____ in blood
4) Cross the ____6_____
5) Continued replication in the _____7_____and infection of the _____8_____
6) Incite ___9___ response which leads to increased ____10____ of the BBB
7) Edema, increased _____11______, and ____12_____
8) Release of inflammatory mediators, infiltration of ____13______ and edema leads to ___14____ damage.
1) distant sites
2) bloodstream
3) complement
4) antibody
5) replication
6) BBB
7) CSF
8) meninges
9) Inflammatory
10) permeability
11) intracranial pressure
12) pleocytosis
13) WBCs
14) neuronal
Gross: the leptomeninges contain abundant, creamy, purulent exudate; most prominently over the superior surface of the cerebellum. The underlying brain is swollen and the vessels are congested.
Acute Septic Meningitis
Histo: Subarachnoid space is filled with neutrophils, plasma cells, and lymphocytes. Brain tissue looks normal.
Acute Septic Meningitis
CSF: Gram positive cocci = _______1____, treat with _____2_____
1) Strep pneumo
2) Vancomycin + ceftriaxone
CSF: Gram negative cocci = ____1______, treat with ___2______ or ____3____ if resistant
1) Neisseria meningitidis
2) Penicillin G
3) ceftriaxone
CSF: Gram positive rod = ______1____, treat with ____2______ plus an ____3______
1) Listeria monocytogenes
2) Ampicillin
3) Aminoglycoside (ex. gentamycin)
CSF: Gram negative rod = ____1_____, treat with __2_____ plus an _____3_____
1) E. coli or HIB (influenza B)
2) Ceftriaxone
3) Aminoglycoside
-Cell count: 100-5,000
-Neutrophils
-decreased Glucose
-elevated Protein
Bacterial meningitis
-Cell count: 10-500
-Lymphocyte
-normal Glucose
-Elevated Protein
Viral meningitis
-Cell count: 0-1,000
-Lymphocytes
-decreased Glucose
-elevated Protein
TB meningitis
-Cell count: 0-500
- Lymphocytes
-normal to decreased Glucose
-Elevated Protein
Fungal meningitis
normal protein levels < ________mg/dl
40
normal glucose level _______mg/dl
40-70
normal WBC level ________
0-5
-Growth on blood agar
-alpha hemolytic
-optochin sensitive
-Bile soluble
Streptococcus pneumoniae
causes:
-meningitis
-pneumonia
-sinusitis
-otitis media
Strep pneumo
-leading cause of serious infections worldwide
-widespread antibiotic resistance
-meningitis (any age group, but mostly in children-very serious)
-nasopharyngeal colonization common (5-20% healthy adults, 20-40% healthy children)
-human reservoir: direct person to person transmission
-90 different serotypes
-member of viridans groups
Strep pneumo
empiric treatment of meningitis caused by strep pneumo:
vancomycin + 3rd generation cephalosporin
Resistance of Strep pneumo:
MIC <0.1 micrograms/ml Penicillin: ___1____
MIC 0.1-1 :____2______
MIC >1: _____3_____
MIC >2 :____4____
1) susceptible
2) intermediate
3) resistant
4) highly resistant
Strep Pneumo vaccine:
-Recommended for >65 years and individuals lacking functional spleen, institutionalized, immune suppressed
23 valent vaccine
Strep pneumo vaccine:
-infants and toddlers
-4 doses @ 2,4,6, and 12-15 months
13 valent conjugate vaccine
-no growth on blood agar, except as satellite colonies around Staph aureus
-tiny colonies grown on chocolate agar
-growth on Thayer Martin agar
Hib
one national multi-center surveillance reported Beta-lactamase production in 36% of isolates of ________
Hib
empiric therapy for Hib meningitis :(2)
1) vancomycin + 3rd generation cephalosporin
2) Dexamethasone
Hib specific target therapy:
if Beta lactamase negative: _____1_____
Beta lactamase positive: ____2______
1) Ampicillin
2) 3rd generation cephalosporin
_______ vaccine consists of a capsular polysaccharide covalently bound to a protein (varies with manufacturer)
Hib
capsular polysaccharide of Hib only stimulates ____1____ with no ____2____. Attachment to protein stimulates ____3____ response. Use of Hib vaccine has decreased the incidence of Hib meningitis by >_____4____%
1) IgM
2) memory
3) IgG memory
4) 90