Deck 35: Infections of the Central Nervous System

Question 1

What is the volume of cerebrospinal fluid (CSF) in an average adult?

A) 90 to 150 mL
B) 15 to 45 mL
C) 40 to 80 mL
D) 200 to 300 mL

Answer 1

A

Question 2

What EV is commonly associated with neurologic illness?

A) Coxsackievirus B
B) Parvovirus
C) Herpesvirus 1
D) Calicivirus A

Answer 2

A

Question 3

Gram-positive diplococci, with a halo, are seen on a STAT CSF taken from an adult who presented to the emergency department with high fever, still neck, and confusion. You should suspect:

A) Streptococcus pneumoniae
B) Streptococcus agalactiae
C) Neisseria meningitidis
D) Klebsiella pneumoniae

Answer 3

A

Question 4

What type of meningitis is usually uncomplicated and resolves in 2 to 7 days?

A) Septic meningitis
B) Enteroviral
C) Bacterial
D) Meningococcal

Question 5

All of the following are common fungal causes of CNS infection, except

A) Cryptococcus neoformans.
B) Coccidioides immitis.
C) Candida albicans.
D) Histoplasma capsulatum.

Question 6

Common arboviruses that cause meningitis include all the following, except

A) St. Louis encephalitis virus.
B) La Crosse virus.
C) Venezuelan equine encephalitis.
D) West Nile virus (WNV).

Question 7

What condition is characterized by lymphocytic pleocytosis in the CSF but a lack of identifiable organism after routine culture and Gram stain?

A) Purulent meningitis
B) Septic meningitis
C) Aseptic meningitis
D) Malignant meningitis

Question 8

What organism is a common cause of meningitis in neonates and infants up to 3 months of age?

A) Streptococcus pneumoniae
B) Streptococcus agalactiae
C) Haemophilus influenzae
D) Neisseria meningitidis

Question 9

What is a common neurologic complication with the mumps virus?

A) Encephalitis
B) Meningoencephalitis
C) Viremia
D) Aseptic meningitis

Question 10

All the following viruses can resist inactivation by gastric acid, except

A) EVs.
B) adenoviruses.
C) parvovirus.
D) herpesvirus.

Question 11

A teenager and her friends spend the day swimming in a lake and picnicking. The next day, she starts to feel sick complaining of a headache and general malaise. The following morning, she is very ill and is rushed to the emergency department. Many neurologic changes are noted. Despite the staff's best efforts, she dies. Autopsy reveals the presence of small protozoa in her brain tissue. What is the most probable organism that caused her death?

A) Acanthamoeba spp.
B) Naegleria fowleri
C) Balamuthia mandrillaris
D) Angiostrongylus cantonensis

Question 12

Infection with what organism results in a chronic meningoencephalitis, more commonly known as sleeping sickness?

A) Gnathostoma spinigerum
B) Baylisascaris procyonis
C) Trypanosoma brucei
D) Trypanosoma cruzi

Question 13

All of the following organisms commonly cause meningitis, except

A) Streptococcus pneumoniae.
B) Pseudomonas aeruginosa.
C) Haemophilus influenzae.
D) Neisseria meningitidis.

Question 14

Syphilitic involvement in the CNS can take all of the following forms, except

A) syphilitic meningitis.
B) aseptic meningitis.
C) gummatous neurosyphilis.
D) parenchymatous neurosyphilis.

Question 15

E. coli is isolated from the spinal fluid of a 3-day-old infant. What is the most likely source of the bacterium?

A) Birth canal
B) Breast milk
C) Formula
D) Contact with humans

Question 16

All of the following are important arboviruses, except

A) Venezuelan equine encephalitis viruses.
B) St. Louis encephalitis virus.
C) La Crosse virus.
D) Lassa fever virus.

Question 17

What fungus causes chronic meningitis in patients with human immunodeficiency virus infection?

A) Cryptococcus neoformans
B) Coccidioides immitis
C) Candida albicans
D) Histoplasma capsulatum

Question 18

A college student is examined at the emergency department; he is disoriented with a fever, intense headache, stiff neck, vomiting, and sensitivity to light. His friends say that he has been sick for about 2 days and that his condition worsened over the last 3 hours. The serum electrolytes are normal, but the patient's white blood count is 12,000 cells/L. What test should the physician order next?

A) Urinalysis and urine culture
B) Stool Gram stain and culture
C) CSF Gram stain and culture
D) Blood cultures $\times$ 3

Question 19

What is the first step in developing bacterial meningitis?

A) A cold that compromises the immune system
B) Living in close quarters, like military barracks or a college dorm
C) Poor sanitary conditions
D) Nasopharyngeal colonization by a meningeal pathogen

Question 20

All of the following are common causes of viral encephalitis, except

A) herpes viruses.
B) EVs.
C) arboviruses.
D) toroviruses.

Question 21

CSF specimens should be analyzed for infectious agents as quickly as possible. How should a specimen collected in the hospital be transported to the laboratory?

A) Wet ice
B) Dry ice
C) Room temperature
D) Bacteriologic transport medium

Question 22

A farmer is bitten by a raccoon. He washes the wound with soap and water and then puts a dressing on it. A couple of days later, he begins to feel tired and the wound is painful. About 2 days later, the farmer begins to feel agitated. He has a seizure and hallucinations. What condition matches the farmer's symptoms and history?

A) WNV
B) Rabies
C) Colorado tick fever
D) Lassa fever

Question 23

What virus, spread by the mosquito, causes a typically self-limiting illness, but can be associated with a rash, aseptic meningitis, myelitis, and fatal encephalitis?

A) WNV
B) Eastern equine encephalitis
C) Colorado tick fever
D) Venezuelan equine encephalitis

Question 24

From where do most cerebral abscesses spread?

A) Middle ear infections
B) Mastoiditis
C) Paranasal sinus infections
D) All of the above

Question 25

What are the most common bacteria isolated from nontraumatic brain abscesses?

A) Staphylococcus
B) Enteric gram-negative rods
C) Streptococcus
D) Clostridium

Question 26

A CSF sample collected from a child yields the following results: turbid, very high total protein levels, and very low glucose levels. What would the probable diagnosis be?

A) Bacterial meningitis
B) Aseptic meningitis
C) Encephalitis
D) Brain abscess