Viral Meningitis and Encephalitis Flashcards Preview

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Flashcards in Viral Meningitis and Encephalitis Deck (43):
1

What type of viruses have no lipid membranes

Adenoviruses

2

What is the classification of aseptic meningitis, with regards to the white cell count and the bacterial culture?

White cell count- >5x106/L in CSF
-ve bacterial culture of the CSF

3

What are the most common causes of aseptic meningitis?

Viruses, listeria, TB, syphilis, malignancy, autoimmune conditions, drugs

4

Which age group is viral meningitis common in?

2 peaks of hospital admissions; neonates and 5 yr olds

5

How does enterovirus enter your body?

Via the GI tract- faecal oral transmission

6

Causative organisms of viral meningitis

Enterovirus
HSV
VZV
Mumps
HIV

7

Via what paths do viruses invade the CNS?

Via cerebral microvascular endothelial cells
via choroid plexus epithelium
spread along olfactory nerve

8

What are the 3 symptoms of meningism?

Headache, neck stiffness, photophobia

9

Apart from meningism, what other symptoms do you get in meningitis?

Fever

10

Is it easy to distinguish cliniclaly between viral and bacterial meningitis?

No

11

In infants, meningeal signs may be absent. What should you look for instead?

nuchal rigidity (neck stiffness)
bulging anterior frontalle (only if severe intracranial pressure)

12

Examination sign for meningitis; flex hip and knee to 90, the knee cannot be extended due to hamstring stiffness

Kernig's sign

13

Examination for meningitis- flexing the neck causes the hips and knees to flex

Brudzinski's sign

14

What should you look for in a CSF specimen, with suspected meningitis?

Microscopy, culture and sensitivity (MCS)
Protein
Glucose (check blood glucose at the same time)
Viral PCR; enteroviruses, HSV, VZV

15

What is the opening pressure for bacterial meningitis?

Above normal (200-500)

16

Is the WBC count higher in viral or bacterial meningitis?

Bacterial

17

What is the WBC differential in viral meningitis?

Lymphocytic

18

What is the WBC differential in bacterial meningitis?

High neutrophil count

19

What is the protein conc. for bacterial meningitis?

High

20

What is the glucose ratio (CSF:blood) for bacterial meningitis?

Low

21

What other specific bacterial test in the CSF is positive for bacterial meningitis?

Gram stain positive

22

Treatment for bacterial meningitis

Cefotaxime

23

Treatment for viral meningitis

Some argument suggest aciclovir

24

Is meningitis a notifiable disease?

Yes

25

Commonest cause of viral meningitis in the UK?

Enterovirus

26

Cause of meningitis; late summer/autumn epidemics. Fever, vomiting, anorexia, rash, upper respiratory tract symptoms. No specific treatment and full recovery normal.

Enterovirus

27

How does HSV1 manifest?

cold sores and encephalitis

28

How does HSV2 manifest?

genital herpes and meningitis

29

What is mollaret's meningitis?

Recurrent aseptic meningitis. Recurrent cause- HSV2

30

In what proportion of mumps cases do you get meningitis?

10-30%

31

What is the cause of meningitis, 5 days after onset of parotiditis, abdo pain and orchitis (inflammation of 1 or more testicles) Preventable with vaccine.

Mumps

32

At what point in the HIV infection does meningitis occur?

Occurs as part of primary infection

33

What are the associated features of HIV meningitis?

Like glandular fever; fever, lympadenopathy, pharyngitis, rash

34

What is the major viral cause of encephalitis

HSV1

35

What are the common causes of viral encephalitis?

HSV
VZV, EBV
Measles
Mumps
Enteroviruses

36

What additional features do you find in viral encephalitis, compared with viral meningitis?

Altered mental state (confusion, bizarre behaviour)
Focal neurology, seizures, weakness, cranial nerve palsy, ataxia

37

Treatment for viral encephalitis

High dose IV aciclovir

38

What form of viral encephalitis is a medical emergecy- rare but high morbidity associated with it?

Herpes simplex encephalitis

39

What age range is typical for Herpes simplex encephalitis?

Bimodal distribution (50yrs)

40

What are the 2 stages of herpes simplex encephalitis?

Primary infection: direct transmission of virus along the neural/olfactory pathways
Reactivation: in the trigeminal ganglia

41

What is a complication of herpes simplex encephalitis, that causes inflammation/swelling of the brain tissue?

Acute focal necrotising encephalitis

42

Auto-immune mediated CNS demyelination, can follow viral illness or vaccination. Clinical features are the same as encephalitis.

Acute disseminated encephalomyelopathay (ADEM)

43

How would you treat acute disseminated encephalomyelopathy (ADEM)?

Steroids/other immunosuppressants.