Viral Meningitis / Encephalitis (CNS Pathology) Flashcards Preview

Clinical Pathology > Viral Meningitis / Encephalitis (CNS Pathology) > Flashcards

Flashcards in Viral Meningitis / Encephalitis (CNS Pathology) Deck (26)
Loading flashcards...
1
Q

What is Meningitis?

A

Inflammation of the meninges

2
Q

What is Encephalitis?

A

Inflammation of the brain

3
Q

What is Aseptic Meningitis?

A

Is the inflammtion of the meninges however it is not caused by bacteria. Viruses are usually the cause e.g.syphilis

4
Q

What is the stucture / components of a virus?

A

Nucleic Acid:

  • DNA or RNA
  • Single or double stranded
  • circular or linear

Viral Proteins:
-form capsid / membrane projections.

Viral Enzymes:

  • replication
  • transcription
  • protein modification
5
Q

What is the epidemiology of Viral Meningitis?

A

-common is children

6
Q

What are the causes of Viral Meningitis?

A

1) Enteroviruses
2) Herpes Viruses
3) Mumps
4) HIV
5) Measles
6) Influenza

7
Q

How do these pathogens cause meningitis?

A

1) COLONISE on mucosal surfaces
2) ENTER epithelial surface
3) REPLICATE in cells
4) spread and INVADE CNS

8
Q

What are the clinical features of Meningitis

A

1) Fever

2) Meningism
- headache
- neck stiffness
- photophobia

***3) bulging anterior fontanelle (top of skull) in infants

9
Q

What is Kernig’s Sign?

A

When the hip and knee are both flexed to 90’ the knee cannot be extended further due to pain / stiffness in hamstrings. It is a sign of meningitis.

10
Q

What is Brudzinki’s sign?

A

Flexing the neck causes the hips and knees to flex.

11
Q

What investigations should be done for meningtis?

A
  • Lumbar puncture ASAP alongside blood glucose levels.

- CT scan (raised intracranial pressure)

12
Q

What are the CSF findings in viral meningitis?

A
  • White Cell count (lymphocytic, neutrophils)
  • Protein (0.2 - 0.4 g/L)
  • Glucose ratio normal or low.
13
Q

What is the treatment of meningitis?

A

-IV antibiotics (if bacterial)

14
Q

what is the commonest cause of viral meningitis in the uk?

What are the symptoms?

A

Enteroviral

Symptoms:
-fever, vomiting, anorexia, rash, respiratory tract problems

15
Q

Which form of Herpes Simplex Virus (HSV) causes meningitis?

A

HSV2 = meningitis + genital herpes

HSV1 = Encephalitis + cold sores

16
Q

What virus causes chickenpox & shingles ?

A

Varicella Zoster Virus

17
Q

What are the symptoms of mumps meningitis?

A

CNS symptoms 5days after onset of parotitis (inflammation of parotid gland)

18
Q

Whats are the associated features of HIV meningitis?

A
  • fever
  • lymphadenopathy
  • pharyngitis
  • rash
19
Q

What are the causes of Viral Encephalitis?

A

1) Herpes Simplex Virus (HSV1)

2) Varicella Zoster Virus
3) Measles
4) Mumps
5) Enteroviruses
6) Influenza
7) Rubella
8) HIV

20
Q

What are the bacterial cause of encephalitis?

A

1) Strep pneumoniae
2) Neisseria meningitidis
3) TB

21
Q

What are the clinical features of Encephalitis?

A

1) Altered mental state (confusion, bizaare behaviour)
2) Fever, headache
3) seizures

22
Q

What are the investigations for encephalitis?

A

1) CT
2) MRI *may see changes typical of HSV encephalitis
3) Lumbar Puncture
4) EEG *HSV will show abnormal temporal lobe activity
5) bloods

23
Q

What are the CSF findings in viral encephalitis?

A

*same as in viral meningitis

1) White cell count
- Lymphocytic
2) Protein mildy elevated
3) Glucose ratio is normal or slightly low.

24
Q

What is the treatment for viral encephalitis?

A

High dose of IV Aciclovir

25
Q

How does Herpes Simplex virus cause (HSE) Encephalitis?

A

*Medical emergency
The virus directly transmitted along neural pathways.

It resides in the trigeminal ganglia.

26
Q

what is Acute disseminated encephalomyelopathy (ADEM)

A

Immune mediated CNS DeMyelination

  • can follow viral illness
  • clinical features same as encephalitis
  • CSF findings same as viral meningitis.
  • treatment = steroids /immunosuppressants

Decks in Clinical Pathology Class (59):