CNS Viruses

Question 1

What viruses can enter the CNS via neurons of the olfactory bulb?

Answer 1

Herpesviruses

Question 2

How can rabies enter the CNS?

Answer 2

Enter via replication in the muscles and then infection of the neurons and enter the CNS via retrograde spread

Question 3

How does Herpesvirus enter the CNS?

Answer 3

Infection of the olfactory neurons and anterograde movement into the CNS

Question 4

What is unique about Herpesvirus travel on neurons?

Answer 4

Herpes viruses are set apart by their ability to transport bi-directionally in neurons

Question 5

A 24 year old man is brought to the physician by his wife after he had two days of progressive confusion. His temperature is 101F but has no other abnormalities. When he speaks, he enunciates clearly and his phrasing is of average length. However he uses words and word‐ like utterances in a manner that makes litttle sense. He doesn’t follow any commands. What is the likeliest diagnosis?

1. cerebral toxoplasmosis
2. herpes simplex encephalities
3. hiv enencephalopathy
4. meningococcal meningitis
5. subdural empyema

Answer 5

2. herpes simplex encephalities

Question 6

An 18‐year‐old female had an episode of mild intestinal infection. Approximately 6 days later, she developed severe headaches, vomiting and fever. She was alert and oriented but had mild nuchal rigidity. A spinal tap revealed CSF high in cell count and protein level. Bacteriological culture of the CSF resulted in no growth. The physician’s report indicated aseptic meningitis. Electron microscopic analysis of CSF particles would MOST likely reveal which of the following?

A. Enveloped viruses with globular projections
B. Naked icosahedral viruses with projections at each vertex
C. Minute naked viruses
D. Bullet shaped viruses with surrounding envelopes
E. Double‐shelled icosahedral viruses

Answer 6

C. Minute naked viruses - likely a Picornavirus

B - Adenovirus
D - Rhabdovirus
E - Rotavirus

Question 7

How do Flavivirus infections lead to CNS infection?

Answer 7

Viremia

Question 8

What is the typical CNS manifestation of Flavivirus infection?

Answer 8

Meningitis

Question 9

What is the typical CNS manifestation of Herpesvirus infection?

Answer 9

Encephalitis

Question 10

What population is most susceptible to West Nile Virus?

Answer 10

Elderly

Question 11

What family does Zikavirus belong to?

Answer 11

Flaviviridae

Question 12

What is Zikavirus associated with in fetuses?

Answer 12

Microcephaly

Question 13

How is Zikavirus transmitted?

Answer 13

Mosquitoes

Question 14

What is subacute sclerosing pan encephalitis?

Answer 14

Develops many years after acute measles; presence of viral inclusion bodies in brain cells; inflammation; general destruction of brain tissue. Progressive dissemination of a defective virus infection in the presence of a normal immune response that is uniformly fatal.

Question 15

Several conventional viruses and unconventional agents cause slow degenerative diseases of the central nervous system. Which virus best matches the following clinical vignette or disease description? A 17‐year‐old girl is diagnosed with subacute sclerosing panencephalitis. Her CSF has a high titer against a paramyxovirus, which can be rescued by fusion with permissive cells. Viral particles are absent from a brain biopsy specimen.

A. Measles
B. Rubella
C. HIV
D. Polyoma
E. Prions

Answer 15

A. Measles

Question 16

What virus is “bullet” shaped?

Answer 16

Rabies Virus

Question 17

How does rabies move to the CNS?

Answer 17

Uni‐directional (retrograde) transport from peripheral sites to CNS

Question 18

What is post-exposure prophylaxis of Rabies?

Answer 18

• Wash wound

- IgG prophylaxis into the wound

Question 19

What CNS manifestation do prions cause?

Answer 19

Infectious encephalopathy - neurodegenereation without inflammation

Question 20

What will be seen on histology of Kuru disease?

Answer 20

Plaques in the cerebellum

Question 21

Fifteen unrelated men, all in their late twenties, developed progressive neurological disorders. Symptoms included presenile dementia and ataxia. Serum and CSF antibody were negative in ELISA tests against a battery of known neurotropic viruses. Each of the men had received, 10‐15 years earlier, a series of growth‐stimulating treatments with pituitary growth hormone. A preliminary diagnosis of Creutzfeldt‐Jakob disease was made. The MOST likely cause of the illness is which of the following agents?

A. Slow virus
B. Unconventional agent
C. Classical virus
D. Latent virus
E. Virus

Answer 21

B. Unconventional agent