Neuro: 17.3: Meningitis Flashcards
Which HSV type is more associated with viral meningitis?
HSV-2
If the meningitis is due to a viral cause, what will the LP findings be?
- high WBCs (lymphocytes)
- normal glucose
- normal/increased protein
- normal/increased opening pressure
Organism?
- gram positive
- lancet-shaped diplococci
- encapsulated
Strep. pneumo
What layer of the meninges is tightly attached to the brain?
the pia mater
Organism?
- family = picornavirus
- envelope = no
- genome = ss positive sense linear
- capsid = icosahedral
Coxsackievirus
What is the tx for Listeria monocytogenes meningitis?
ampicillin
Dx?
- CSF findings = high lymphocytes, low glucose
fungal meningitis
What are the 3 most common causes of meningitis in a neonate?
- Group B strep
- E. coli
- Lysteria monocytogenes
Organism?
- 5–10 μm with narrow budding
- Heavily encapsulated yeast
- Not dimorphic
Cryptococcus neoformans
What special media is Haemophilus influenzae cultured on? Why?
- chocolate agar
- contains factor V (NAD+) and X (hematin)
Dx?
- CSF findings = high lymphocytes, normal glucose
viral meningitis
What is the tx for Haemophilus influenzae meningitis?
ceftriaxone
What is the main virulence factor for Strep. pneumo?
the capsule
Organism?
- gram positive cocci
- beta-hemolytic
- Hippurate positive
- produces CAMP factor
Group B strep
Organism?
- gram negative rod
- fimbriae
- K-capsule
- LPS endotoxin
E. coli
What is the prophylaxis for Haemophilus influenzae meningitis?
rifampin
What is the standard treatment for meningitis? What if Listeria is suspected?
- ceftriaxone and vancomycin empirically
- add ampicillin if Listeria is suspected
What is the most common causative agent of meningitis in nonvaccinated infants?
H. influenzae
Haemophilus influenzae: IgA protease positive or negative?
positive
Neisseria meningiditis: IgA protease positive or negative?
positive
What is the gram stain and morphology of Listeria monocytogenes?
- gram positive rod
- “rocket tails”
- tumbling
Organism?
- gram positive rod
- “rocket tails”
- tumbling
Listeria monocytogenes
Name 5 viral causes of meningitis.
- enteroviruses (coxsackie)
- HSV-2
- HIV
- West Nile
- VZV
Where should you place the needle when performing an LP? Why? What is the landmark to help you?
- place needle btw L3-L4 or L4-L5
- the spinal cord ends at L2
- landmark = the level of the iliac crest
- *** “to keep the cord alive, keep the needle between L3 and L5”
Strep. pneumo: optochin sensitive or resistant?
sensitive
What is the gram stain and morphology of Haemophilus influenzae?
- gram negative coccobacillary rod
What does Neisseria meningiditis ferment?
- maltose and glucose
- *** “MeninGococci ferment Maltose and Glucose”
What is the most common causative agent of meningitis in adults and elderly pts?
Strep. pneumo
Where is the arachnoid mater found?
btw the dura (on the skull) and the pia (on the brain)
Why does meningitis cause nuchal rigidity?
bend neck = stretch meninges = pain
What is the most common causative agent of meningitis in children and teenagers?
Neisseria meningiditis
What is the diagnostic test for meningitis?
lumbar puncture
What are the leptomeninges?
the light meninges- the Pia and arachnoid together
If the meningitis is due to a fungal cause, what will the LP findings be?
- high WBCs (lymphocytes)
- low glucose
- increased protein
- increased opening pressure
What is the tx for Neisseria meningiditis?
- ceftriaxone
- penicillin G
What layer of the meninges is tightly attached to the skull?
the dura mater
Photophobia is a more common symptom in meningitis due to ______.
viruses
What is the prophylaxis for Neisseria meningiditis?
- Rifampin
- ciprofloxacin
- ceftriaxone
What is the prophylactic tx for mothers testing positive for Group B strep?
intrapartum penicillin
What is the gram stain and morphology of Strep. pneumo?
- gram positive lancet-shaped diplococci
- encapsulated
What is the tx for cryptococcal meningitis?
- amphotericin B
- with/without flucytosine
If the meningitis is due to a bacterial cause, what will the LP findings be?
- high WBCs (neutrophils)
- low glucose
- increased protein
- increased opening pressure
- positive gram stain and culture
What is the gram stain and morphology of Group B strep?
- gram positive cocci
- beta-hemolytic
Organism?
- “Rusty” sputum
Strep. pneumo
Organism?
- gram negative coccobacillary rod
- grows on chocolate agar
Haemophilus influenzae
Organism?
- gram negative diplococci
- polysaccharide capsule
- ferments maltose and glucose
- produces IgA proteases
Neisseria meningiditis
What is a good rule of thumb for what the normal level of CSF glucose should be?
2/3s that of serum glucose (approx. 66)
Why does meningitis cause HA?
bc the meninges wrap around the brain
In which pts. would fungi cause meningitis?
immunocompromised
What is the gram stain and morphology of E. coli?
- gram negative rod
- fimbriae
- K-capsule
What is the most common viral cause of meningitis? How is it transmitted?
- coxsackivirus
- fecal-oral
What does meningitis mean?
- inflammation of the leptomeninges
- leptomeninges = the light meninges: the Pia and arachnoid together
What viral family does Coxsackievirus belong to?
- Is it enveloped?
- What kind of genome does it have?
- What is its capsid symmetry?
Coxsackievirus
- family = picornavirus
- envelope = no
- genome = ss positive sense linear
- capsid = icosahedral
How does Neisseria meningiditis get to the meninges?
nasopharynx –> blood –> meninges
Dx?
- CSF findings = high neutrophils, low glucose
bacterial meningitis
Strep. pneumo: IgA protease positive or negative?
positive
From where are you trying to obtain a CSF sample when you perform an LP?
the subarachnoid space
What is the classic triad of symptoms for meningitis? What are some others?
- triad =
- HA
- stiff neck
- fever
- others =
- photophobia
- vomiting
- altered mental status
The spinal cord ends at _____.
L2
Organism?
- Spherule (much larger than RBC) filled with endospores
Coccidioidomycosis
Starting at the skin, what are the order of the layers penetrated to perform an LP?
- Skin
- Superficial fascia
- Supraspinous ligament
- Interspinous ligament
- Ligamentum flavum
- Epidural space containing the internal vertebral venous plexus
- Dura mater
- Arachnoid
- Subarachnoid space containing CSF
- *** “Some Super Supra Interesting LEDs Are Sexy”
The spinal cord ends at L2, but the subarachnoid space and the cauda equina continue to ____.
S2
What are the complications of meningitis? Which causative agent makes these most likely?
- herniation –> death
- fibrosis and scarring –>
- hydrocephalus
- hearing loss
- seizures
What is the gram stain and morphology of Neisseria meningiditis?
- gram negative diplococci
- polysaccharide capsule
