Deck 35: Infections of the Central Nervous System

Question 1

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 physician does a complete blood count (CBC) and electrolytes.The electrolytes are normal, but the patient's white blood count (WBC) is 12,000 cells/L.What test should the physician order next?

A)Urinalysis and urine culture
B)Stool Gram stain and culture
C)Cerebrospinal fluid Gram stain and culture
D)Blood cultures ´ 3

Answer 1

C
Patients with acute meningitis usually present with fever, headache, vomiting, photophobia, and altered mental status.

Question 2

A teenager and her friends go to the lake and spend the day swimming and picnicking.Later that evening, she starts to feel sick.She complains of a headache and general malaise.The next morning, she is very ill and is rushed to the emergency department.Many neurologic changes are noted.Despite the staff's best efforts, the teenager dies.Autopsy reveals the presence of small protozoans 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

Answer 2

B
N.fowleri can cause a rapidly progressive and almost always fatal primary meningoencephalitis.It is found in warm fresh water and moist soil.Most cases of infection have been associated with swimming in warm natural bodies of water.Acanthamoeba spp.and B.mandrillaris usually cause granulomatous amebic encephalitis with a more insidious onset.

Question 3

What is the first step in developing meningitis?

A)A cold that compromises your 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

Answer 3

D
The first step in the development of a meningeal infection with bacteria involves nasopharyngeal colonization by one of the meningeal pathogens, followed by local invasion across the mucosal barrier and entry into the bloodstream.

Question 4

Common arborviruses 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.

Question 5

What organism is a common cause of meningitis in neonates and infants up to 3 months of age and can be contracted by passing through the birth canal?

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

Question 6

What organism is the most common cause of meningitis in adults?

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

Question 7

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 8

What condition is characterized by lymphocytic pleocytosis in the cerebrospinal fluid (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 9

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

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

Question 10

All of the following are important arboviruses except:

A)alphaviruses (Venezuelan equine encephalitis viruses, eastern equine encephalitis, and western equine encephalitis).
B)St.Louis encephalitis virus.
C)La Crosse virus.
D)Lassa fever virus.

Question 11

What virus is an uncommon cause of aseptic meningitis that can be acquired from dust or food contaminated with urine or feces from infected rodents and hamsters?

A)Lymphocytic choriomeningitis virus
B)Epstein-Barr virus
C)Guillain-Barré virus
D)Astrovirus

Question 12

What fungus causes chronic meningitis in HIV patients?

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

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 central nervous system (CNS) can take all of the following forms except:

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

Question 15

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

Question 16

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

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

Question 17

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

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

Question 18

All of the following are common fungal causes of central nervous system (CNS) infection except:

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

Question 19

What enterovirus is commonly associated with neurologic illness?

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

Question 20

What is a common neurologic complication with the mumps?

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

Question 21

From where do most cerebral abscesses spread?

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

Question 22

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

A)West Nile virus
B)Rabies
C)Colorado tick fever
D)Lassa fever

Question 23

A cerebrospinal fluid (CSF) sample collected from a child yields the following results: turbid and cloudy, 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

Question 24

Diagnosis of central nervous system (CNS) infections is based on:

A)neurologic symptoms.
B)physical symptoms.
C)history.
D)laboratory examination of CSF.

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

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)West Nile virus
B)Eastern equine encephalitis
C)Colorado tick fever
D)Venezuelan equine encephalitis