Meningitis

Question 1

Definition

Answer 1

A viral, bacterial, fungal infection causing inflammation of the meninges (subarachnoid space)

The arachnoid space is the space in between the Pia mater and the arachnoids it holds the cerebrospinal fluid

These 2 together are the leptomeninges

So its an inflammation of the leptomeninges

It is not an inflammation of the brain, that is called ‘encephalitis’, when they occur together, it is known as ‘meningoencephalitis’

Question 2

Viral meningitis

Answer 2

Inflammation of the leptomeninges caused by a virus

Causes:
– virus:
most common-
—- herpes simplex
—- enteroviruses
—- coxackie
—- HIV

Less common:
—- Epstein-Barr virus
—- polymyositis
—- Varicella zoster
—- Mumps

Epidemiology:
– most common form of meningitis, self limiting so it tends to go away without treatment

Clinical presentation:
– classic triad:
—- headaches
—- fever
—- nuchal rigidity (neck stiffness)

• usually benign and self limiting
• usually lasts about 4-10 days

Question 3

Bacterial meningitis

Answer 3

Medical emergency- requires immediate antibiotic treatment or else it could be fatal

Aetiology:
– neisseria meningitidis
—- causes- meningococcal disease (most common type of bacterial meningitis)

• newborns:
  – streptococcus group B
  – E. coli
  – listeria monocytogenes
• children and teens:
  – neisseria meningitidis
  – streptococcus pneumoniae

Epidemiology:
– Most serious but rarer than viral
– most common under 5 or between 15-19
– medical emergency, can be very fatal, 1 in 5 will have prolonged damaging effects from it

Pachymeningitis:
– inflammation of the dura mater
– most commonly due to direct spread following- otitis media and mastoiditis

Clinical presentation:
– triad- headaches, fever, nuchal rigidity

– photophobia (intolerance to light)
– phonophobia (discomfort with loud noises
– vomiting
– Kernig’s sign:
—- severe shooting pain when leg into full extension

– papilledema may occur
– rash
– confusion
– seizures can occur
– feeling fatigued

Question 4

Fungal meningitis

Answer 4

Aetiology:
– cryptococcus genuses
– coccidiodes genuses
– tuberculosis meningitis:
—- mycobacterium tuberculosis