Meningitis Flashcards
Define meninigitis?
Inflammation of the leptomeningeal (pia and arachnoid mater) coverings of the brain, most commonly due to infection
The immune response to the infection causes cerebral oedema raising ICP which can have 2 effects:
- Herniation
- Raised ICP + systemic hypotension reduces cerebral perfusion
what are the 2 affects of raised ICP?
herniation
raised ICP + systemic hypotension reduces cerebral perfusion
what are the risk factors for meningitis?
Close communities (e.g. college halls)
For bacterial: being under 5 or over 60 yrs
Male
Immunosuppressed
Basal skull fractures
Mastoiditis
Sinusitis
Inner ear infections
Alcoholism
Immunodeficiency
Splenectomy
Sickle cell anaemia
Intracranial surgery
what are the bacterial causes of meningitis?
what are the viral causes of raised ICP?
VIRAL – MORE GRADUAL (OVER DAYS) THAN BACTERIAL MENINGITIS(which has rapid onset and this is also life-threatening if not attented to quickly)
Enteroviruses
Mumps
HSV
VZV
HIV
what are the fungal causes of raised ICP?
Cryptococcus(common cause of meningitis in HIV patients)
describe the epidemiology of meninigitis?
UK: 2500 notifications/yr
Tends to occur in elderly and in 15-30 yr old age group
what are the early features of meningitis?
Severe headache
Leg pain
Cold hands and feet
Abnormal skin
what are the later symptoms of meningitis?
Meningism: neck stiffness, photophobia, Kernig’s sign(see signs)
HIGH fever
Irritability/altered mental state
Reduced consciousness
Vomiting
Children: High pitched crying/fits, hypothermia, irritability, poor feeding
Petechial rash – non-blanching (Glass test) (may only be ½ spots) - rash doesn’t fade when you apply pressure
NONBLANCHING RASH => BACTERIAL (Nissiera meningitis)
what are the signs of meningism?
Photophobia
Neck stiffness
Kernig’s Sign- with the hips flexed, there is pain/resistance on passive knee extension
Brudzinski’s Sign- flexion of the hips when the neck is flexed
what are the signs of infection?
pyrexia
tachycardia
hypotension
skin rash- only with meningococcal septicaemia
altered mental state
what are the possible complications of meningitis?
Hearing loss (most common)
Sepsis
Impaired mental status
summarise the prognosis of patients with meningitis?
Mortality rate from bacterial meningitis: 10-40% with meningococcal sepsis
Viral meningitis is self-limiting
describe the management of meninigitis?
GP: benzylpenicillin IM &URGENT REFERAL TO THE HOSPITAL
atA & E: Broad spectrum antibiotics (ceftriaxone IV, benzylpenicillin IM, acyclovir if viral)
Targeted antibiotic Tx depending on sensitivities.
Consider IV dexamethasone
what are the investigations for meningitis?
CSF analysis is the most important investigation in meningitis
IMPORTANT:↑ ICP is a CONTRAINDICATION for LP
CT-headbefore LP if: neurological deficit or ↓ Consciousness
