NS Infection - Meningitis/Encephalitis Flashcards Preview

Yr 2 Nervous System > NS Infection - Meningitis/Encephalitis > Flashcards

Flashcards in NS Infection - Meningitis/Encephalitis Deck (16)
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1
Q

Causes of Meningitis?

A
  • Infective
  • Inflammatory e.g. Sarcoid
  • Drugs Induced e.g. NSAIDs
  • Malignant (Metastatic or Leukemia)
2
Q

How do we approach meningitis?

A
  • Blood Cultures & Gram Stain
  • LP (CSF culture & Microscopy)
  • Only image if LP is contraindicated
3
Q

How do we approach encephalitits?

A
  • Blood Culture
  • CT/MRI
  • LP (PCR of the CSF for viral DNA)
  • EEG
4
Q

When would an LP be contraindicated?

A

You don’t do it if there’s sign of a mass or swelling as the pressure could cause herniation when you repressurise by puncturing it.

  • Focal Neuro deficits
  • New Seizures
  • Papilloedema
  • GCS<10
  • Severe Immunocompromisation
5
Q

What would you find on an LP in meningititis?

A

Bacterial:

  • raised pressure
  • Raised cell count (Mainly Neutrophils)
  • Low Glucose (Bacteria consume it)
  • Very High Protein

Viral:

  • Normal/raised pressure
  • Raised Cell Count (Mainly Lymphocytes)
  • Normal glucose (~60% of blood glucose)
  • Slightly raised protein
6
Q

Causes of Encephalitis?

A
  • Infective (HSV is main cause of encephalitis, Enterovirus etc)
  • Inflammatory (i.e. autoimmune)
  • Metabolic (Hepatic, uraemic, hyperglycaemic)
  • Malignant, either a metastases or a paraneoplastic syndrome
  • Post Ictal (After Seizure)
7
Q

What microorganisms cause infective meningitis?

A
Neisseria Meningitidis (Meningococcus)
Streptococcus Pneumoniae (Pneumococcus)

Enteroviruses

8
Q

How do we treat viral encephalitis?

A

Aciclovir based on clinical suspicion of Viral encephalitis.

9
Q

How does HSV cause encephalitis?

A

It goes latent, in your trigeminal or sacral ganglion

It reactivates later and encephalitis is a rare complication, which mostly results from Type 1 HSV

10
Q

Name some enteroviruses and how you spread/test for them in encephalitis?

A

Polioviruses, coxsackie virus, echovirus

Faecal-oral spread

Do PCR of a stool sample if you suspect

11
Q

Other than HSV and Enteroviruses what else causes infectious encephalitis?

A

Arbovirus Encephalitides

Common in other parts of the world they are vector-transmitted (tick or mosquito) so a travel history is important

E.g. West Nile Virus (Location name viruses dont relate to current geographical distribution)

12
Q

How does Meningitis Present?

A

Classic Triad of Fever, neck stiffness and altered mental status
Also:
- Short history of headache
- Meningism (Stiff neck, photophobia, N&V)

Cerebral dysfunction e.g. confusion is common and many have a lowered GCS

Cranial Nerve Palsies, Seizures and focal neuro deficits can occur

13
Q

What presentation of meningitis is specific to which cause?

A

Petechial Skin Rash

A hallmark of meningococcal meningitis (But can occur in viral)

14
Q

How does Encephalitis Present?

A

Flu-like Prodrome for 4-10 days

  • Progressive Headache with Fever
  • ~Meningism
  • Progressive cerebal dysfunction (Seen as confusion, memory issues, behaviour etc)
  • Seizures
  • Focal Signs
15
Q

How is viral encephalitis different from bacterial meningitis?

A

It has a slower onset and more prominent cerebral dysfunction…generally

16
Q

Describe the types of auto-immune encephalitis?

A

Anti-VGKC (Voltage Gated K Channel) antibodies:
- Seizures, Amnesia & Altered mental state

Anti-NMDA receptor antibodies:

  • Flue like prodrome
  • Prominent Psych features
  • Altered Mental state & Seizures
  • Progresses to a movement disorder then coma