Meningitis/Encephalitis Flashcards
Causes of Meningitis? [4]
- Infective
- Inflammatory e.g. Sarcoid
- Drugs Induced e.g. NSAIDs
- Malignant (Metastatic or Leukemia)
How do we approach meningitis? [3]
- Blood Cultures & Gram Stain
- LP (CSF culture & Microscopy)
- Only image if LP is contraindicated
How do we approach encephalitits? [4]
- Blood Culture
- CT/MRI
- LP (PCR of the CSF for viral DNA)
- EEG
When would an LP be contraindicated? [6]
You don’t do it if there’s sign of a mass or swelling as the pressure [1] could cause herniation and death.
- Focal Neuro deficits
- New Seizures
- Papilloedema
- GCS<10
- Severe Immunocompromisation
Causes of Encephalitis? [5]
- 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)
What microorganisms cause infective meningitis? [2]
Neisseria Meningitidis (Meningococcus) Streptococcus Pneumoniae (Pneumococcus) Enteroviruses
How do we treat viral encephalitis?
Aciclovir based on clinical suspicion of Viral encephalitis.
Generally speaking, viral meningitis is self-limiting, with symptoms improving over the course of 7 - 14 days and complications are rare in immunocompetent patients.
How does HSV cause encephalitis? [2]
Initial infection resolves and becomes latent eg residing in trigeminal ganglion [1]
It reactivates later and can cause encephalitis - Type 1 HSV [1]
Name some enteroviruses [3] and how you spread and test for them in encephalitis? [2]
Polioviruses, coxsackie virus, echovirus
Faecal-oral spread
Do PCR of a stool sample if you suspect
Other than HSV and Enteroviruses what else causes infectious encephalitis? [1]
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)
How does Meningitis Present? [5]
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
What presentation of meningitis is specific to which cause? [1]
Petechial Skin Rash
A hallmark of meningococcal meningitis (But can occur in viral)
How does Encephalitis Present? [6]
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
How is viral encephalitis different from bacterial meningitis? [2]
It has a slower onset and more prominent cerebral dysfunction…generally
Describe the types of auto-immune encephalitis? [2]
Anti-VGKC (Voltage Gated K Channel) antibodies:
- Seizures, Amnesia & Altered mental state
Anti-NMDA receptor antibodies:
- Flu like prodrome
- Prominent Psych features
- Altered Mental state & Seizures
- Progresses to a movement disorder then coma
Indications for an LP? [6]
To Diagnose:
- Meningitis/Meningoencephalitis
- Subarachnoid Haemorrhage
- Malignancy (diagnose & Treat)
- Idiopathic Intracranial Hypertension
- Detect Oligoclonal bands to indicate CNS inflammation e.g. MS
To infuse drugs or contrast