viral meningitis and encephalitis Flashcards Preview

Clinical Pathology > viral meningitis and encephalitis > Flashcards

Flashcards in viral meningitis and encephalitis Deck (62):
1

what does "itis" mean

inflammation

2

define meningitis

inflammation of the meninges

3

define encephalitis

inflammation of the brain

4

define menigo-encephalitis

inflammation of the meninges and the brain

5

define aseptic meningitis

white cell count in CSF >5x 10^6/L
negative bacterial culture

6

commonest causes of aseptic meningitis

viral- most common
partially treta bacterial meningitis (so culture is negative but WBC is high).
Malignancy
Autoimmune conditions and drugs, Listeria, TB, Syphilis.

7

most common cause of viral meningitis

unknown-37%
Enterovirus
Herpes simplex virus

8

most common enetroviruses to cause viral encephalitis

Echovirus, coxsackie virus, parencho virus, enterovirus and polio

9

most common herpes virus to cause viral encephalitis

HSV1, HSV2 , varicella zoster

10

how doe pathogens cause viral meningitis

colonise mucosal surfaces
invade epithelial cells
replicate cells
disseminate and CNS invasion

11

how do pathogens invade the CNS

cerebral microvascular endothelial cells
choroid plexus epithelium- bloodstream.
spread along the olfactory nerve.

12

clinical features of viral meningitis.

fever, meningism, viral prodrome (lethargy, myalgia’s, arthralgia’s, sore throat ), diahorrhea and vommitting and rash.

13

what is meningism (what 3 symptoms does it involve`0

headahce, neck stiffness and photophobia

14

clinal features of viral meningitis in children

nuchal rigidity (neck stiffness), bulging anterior frontelle.

15

what 3 examinations are carried out on suspected patients with viral meningitis

kernigs sign
Brudzinskis sign
nuchal rididity

16

what is Kernigs sign

hip and knee flexed at 90, knee cannot be extended due to pain and stiffness in hamstrings.

17

what is Brudzinski's sign

flexing neck causes hips and knees to flex at it reduces stretch on spinal cord and meninges

18

what blood investigations are carried out in viral meningitis

Blood test- FBC, U and E, CRP, clotting (before LP), blood culture, renal function (dehydration).

19

why might a CT be used in viral meningitis

look for raised intracranial pressure and other diagnosis of mass, lesion, subarachnoid haemorrhage.

20

why should a lumbar puncture not be carried on a patient with raised intracranial pressure.

removing the CSF can cause the brain to herniate through the foramen magnum

21

when should a lumbar puncture be carried out on a patient with suspected viral meningitis

ASAP
before antibiotics and CT
within 1 hr of admission.

22

what can the CSF obtained from a lumbar puncture be used for

– Microscopy, culture and sensitivity (MCS)
– Protein
– Glucose (CSF and blood glucose)
– Viral PCR

23

what is the WBC in bacterial meningitis

100-20,000 mm ^2

24

what is the WBC in viral meningitis

5-500 mm^2

25

what is the glucose level in bacterial meningitis

26

what is the glucose level in viral meningitis

30-70 mg/dL

27

what is the protein level in bacterial meningitis

100-500 mg/dL

28

what is the protein level in viral meningitis

30-150 mg/dL

29

what microbiological investigations other than those obtained from CSF can be undertaken for viral meningitis

throat swab, stool sample
serology- Mumups, EBV/CMV/HIV

30

what is the treatment for viral meningitis

Mainly supportive therapy (e.g. analgesia and antipyretics)
no antibiotics unless bacterial where you give IV cefotaxime.
some treat HSV/VZV with aciclovir

31

is viral meningitis a notifiable condition

Yes

32

Commoest cause of meningitis in the UK is

enterovirus

33

what is the prognosis of enetrrovirus caused viral meningitis

full recovery.

34

common symptoms of enterovirus infection

fever, vomitting, anorexia, rash, upper respiratory tract symptoms.

35

what condition does HSV1 infection cause

encephalitis (cold sores)

36

what condition does HSV2 infection cause

meningitis (genital herpes)

37

define mollaret's meningitis and what organism causes it

recurrent aseptic meningitis and wide differential but major cause= HSV2

38

what does primary infection of VSV cause

chickenpox

39

what does secondary infection of VSV cause

shingles

40

does viral meningitis occur during chickenpox and shingles to not

most commonly not, but it can occur with it.

41

aciclovir is not used in what 2 pathogen caused viral meningitis

HSV and VZV

42

when do CNS symptoms in mumps meningitis

5 days after onset of parotitis

43

clinical features of mumps meningitis excluding for CNS symptoms

abdominal pain
Orchitis- inflammation of the testes

44

prevention of Mumps meningitis

vaccine

45

when does HIV meningitis occur

part of primary infection

46

clinical features associated with HIV meningitis

glandular fever
Fever
Lymphadenopathy
Pharyngitis
Rash

47

what causes viral encephalitis

unknown-37%
herpes- HSV1
can be bacterial-
acute disseminated encephamyophaty (damages myelin)

48

what part of a history is key to encephalitis and meningitis

travel history

49

clinical presentation of encephalitis

Major features- low GCS.
Altered mental state (confusion, bizarre behaviour and even coma)
Fever, headache, meningism (may be absent)
+/- Focal neurology
Seizures, weakness, dysphasia, aphasia, cranial nerve palsy and ataxia.
Neuroexamination needed and get a collateral history from friend or relative to ask if they have noticed any confusion in the patient.

50

what investigations are carried out for viral encephalitis.

blood test- – FBC, U&E,CRP, clotting, (Blood cultures), Serology

CT – likely to be necessary before LP- due to low GCS score focal neurology will need to be checked.

MRI – may see changes typical of HSV encephalitis
Lumbar puncture:
– Microscopy
– Culture and sensitivity
– Protein/glucose
– Viral PCR

EEG: In HSV encephalitis 75% will show abnormal temporal lobe activity

51

In HSV encephalitis 75% will show abnormal activity in which lobe of the brain, what investigation is used to prove this

temporal lobe
EEG-electroencephalogram

52

What is the treatment for viral encephalitis.

• High dose IV aciclovir
o 10mg/kg tds
o 14-21 days

53

why is oral switch of acicolovir not recommended

long time period over which drugs might have to be taken.

54

what is the bimodal distribution of herpes encephalitis

50 yrs.

55

what signs are present in the neurological sequel of herpes encephalitis

– Paralysis
– Speech loss
– Personality change

56

what is the pathogenesis of herpes in causing viral encephalitis.

o Direct transmission of the virus along neural/olfactory pathways
o Reactivation in the trigeminal ganglia (HSV1)

57

Is herpes simplex encephalitis more common on primary infection or reactivation

primary

58

define Acute focal necrotising encephalitis

brain tissue dies, increased ICP and increased Inflammation.

59

what pathogenic organism infection causes Acute focal necrotising encephalitis

herpes simplex

60

define Acute disseminated encephalomyelopathy

AUTOIMMUNE

immune mediated CNS demyelination
can follow viral infection or vaccine

61

what investigation is useful in (ADEM) Acute disseminated encephalomyelopathy

MRI

62

what is the main treatment for Acute disseminated encephalomyelopathy (ADEM)

Steroids and immunosuppression.