Viral CNS infxn Flashcards Preview

Neurology > Viral CNS infxn > Flashcards

Flashcards in Viral CNS infxn Deck (68)
Loading flashcards...
1

Viral Meningitis

Usually mild and self-resolving

2

Bacterial Meningitis

Life threatening

3

Predictors of bacterial etiology regarding meningitis?

- Low CSF glucose
- High CSF protein
- High CSF white count
- High CSF neutrophil count

The presence of any one of these predicts bacterial etiology with 99% certainty

4

Viral meningitis appearance

- Pts don't appear extremely ill, are NOT ENCEPHALOPATHIC
- fever and malaise
- headache
- neck stiffness
- low back pain

Usually lasts 10-14 days
Recurrent viral meningitis can result from persistent or latent infections (HSV)

5

Most common cause of Viral Meningitis?

Enteroviruses....80%

6

What are some of the enteroviruses that cause viral meningitis?

echo, coxsackie, enterovirus 71

7

10% of viral meningitis caused by

Mumps

8

How are enteroviruses spread

oral/fecal route

9

HSV-2 generally causes

genital herpes

Can also be a cause of RECURRENT aseptic meningitis

10

Mollerat cells in the CSF?

HSV-2

11

HIV and VZV cause?

recurrent meningitis

12

30% of viral encephalitis caused by

Arboviruses (arthropod born viruses) such as St. Louis, West Nile, La Crosse

Transmitted by mosquitos and ticks
Predominantly affects the children or the elderly

13

25% of viral encephalitis caused by

Enteroviruses (echo, coxsackie, entero 71)

14

25% of viral encephalitis caused by

Herpes Simplex 1

15

What is important to recognize about HSV-1

It is a deadly cause of encephalitis if not treated promptly with acyclovir

16

Clinical course of viral encephalitis

fever
headache
lethargy
URI
Confusion
then.... seizures, coma, death in some cases

If you see Fever, headache, lethargy and a prodromal URTI...think encephalitis

- Looks exactly like bacterial meningitis so you MUST treat it empirically before you really even know what the diagnosis is

17

What is the prognosis associated with mosquito born viruses?

poor

18

What is the characteristic site of damage in HSV encephalitis?

Temporal lobe....MRI shows necrosis in temporal lobe

19

Diagnosis of HSV1?

PCR is definitive but false negatives occur

20

Mortality without tx for HSV1

70%

21

Flaviviruses

St. Louis and West Nile

22

Flavivirus morphology

Small, enveloped, +RNA viruses

23

Flavivirus replication cycle

1) Enters by receptor mediated endocytosis
2) + strand genome is translated into single polyprotein, that polyprotein is cleaved.
3) virions bud into intracellular organelles and are transported via the eocytotic pathway and released

24

All members of the flavivirus genus are transmitted how>

through insect vectors....They are the most important group of arboviruses

25

Flaviviruses that cause disease in the US

- St. Louis, West Nile, Dengue fever, Yellow Fever

SWDY

26

Disease course of flavivirus

Virus replicates at the site of inoculation.

Initial infection = primary viremia (mild fever, chills, aches)

Usually cleared by reticuloendothelial system (spleen, liver, etc..)

Continued replication can give rise to a secondary viremia which can invade CNS. Generally would only occur in children, elderly, or immunocompromised

27

SLE ( St. Louis Encephalitis) syndromes and symptoms slide

SLE found in north, central, and south america

- Onset characterized by flu-like symtpms, most do not progress. If secondary viremia occurs, it can lead to acute or subacute neurological signs and symptoms associated with CNS disease.

28

Primary host for west nile

birds

29

Vector for west nile

mosquitos

30

West nile disease symptoms and treatments

- Febrile, influenza like illness with abrupt onset
- moderate to high fever
- headache, sore throat, backache, myalgia, arthralgia, fatigue
- Rash, lymphadenopathy
- Acute aseptic meningitis or encephalitis
- most fatal cases occur in the elderly