Viral Meningitis and Encephalitis

Question 1

What type of viruses have no lipid membranes

Answer 1

Adenoviruses

Question 2

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

Answer 2

White cell count- >5x106/L in CSF

-ve bacterial culture of the CSF

Question 3

What are the most common causes of aseptic meningitis?

Answer 3

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

Question 4

Which age group is viral meningitis common in?

Answer 4

2 peaks of hospital admissions; neonates and 5 yr olds

Question 5

How does enterovirus enter your body?

Answer 5

Via the GI tract- faecal oral transmission

Question 6

Causative organisms of viral meningitis

Answer 6

Enterovirus
HSV
VZV
Mumps
HIV

Question 7

Via what paths do viruses invade the CNS?

Answer 7

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

Question 8

What are the 3 symptoms of meningism?

Answer 8

Headache, neck stiffness, photophobia

Question 9

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

Answer 9

Fever

Question 10

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

Answer 10

No

Question 11

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

Answer 11

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

Question 12

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

Answer 12

Kernig’s sign

Question 13

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

Answer 13

Brudzinski’s sign

Question 14

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

Answer 14

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

Question 15

What is the opening pressure for bacterial meningitis?

Answer 15

Above normal (200-500)

Question 16

Is the WBC count higher in viral or bacterial meningitis?

Answer 16

Bacterial

Question 17

What is the WBC differential in viral meningitis?

Answer 17

Lymphocytic

Question 18

What is the WBC differential in bacterial meningitis?

Answer 18

High neutrophil count

Question 19

What is the protein conc. for bacterial meningitis?

Answer 19

High

Question 20

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

Answer 20

Low

Question 21

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

Answer 21

Gram stain positive

Question 22

Treatment for bacterial meningitis

Answer 22

Cefotaxime

Question 23

Treatment for viral meningitis

Answer 23

Some argument suggest aciclovir

Question 24

Is meningitis a notifiable disease?

Answer 24

Yes

Question 25

Commonest cause of viral meningitis in the UK?

Answer 25

Enterovirus

Question 26

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

Answer 26

Enterovirus

Question 27

How does HSV1 manifest?

Answer 27

cold sores and encephalitis

Question 28

How does HSV2 manifest?

Answer 28

genital herpes and meningitis

Question 29

What is mollaret's meningitis?

Answer 29

Recurrent aseptic meningitis. Recurrent cause- HSV2

Question 30

In what proportion of mumps cases do you get meningitis?

Answer 30

10-30%

Question 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.

Answer 31

Mumps

Question 32

At what point in the HIV infection does meningitis occur?

Answer 32

Occurs as part of primary infection

Question 33

What are the associated features of HIV meningitis?

Answer 33

Like glandular fever; fever, lympadenopathy, pharyngitis, rash

Question 34

What is the major viral cause of encephalitis

Answer 34

HSV1

Question 35

What are the common causes of viral encephalitis?

Answer 35

``` HSV VZV, EBV Measles Mumps Enteroviruses ```

Question 36

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

Answer 36

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

Question 37

Treatment for viral encephalitis

Answer 37

High dose IV aciclovir

Question 38

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

Answer 38

Herpes simplex encephalitis

Question 39

What age range is typical for Herpes simplex encephalitis?

Answer 39

Bimodal distribution (50yrs)

Question 40

What are the 2 stages of herpes simplex encephalitis?

Answer 40

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

Question 41

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

Answer 41

Acute focal necrotising encephalitis

Question 42

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

Answer 42

Acute disseminated encephalomyelopathay (ADEM)

Question 43

How would you treat acute disseminated encephalomyelopathy (ADEM)?

Answer 43

Steroids/other immunosuppressants.