meningitis Flashcards
what symptoms are associated with meningitis
deafness, paralysis ,
speech problems
neuropsychiatric problems
what three layers cover the skull?
dura mater, arachnoid mater, subarachnoid space and pia mater
what does the subarachnoid space contain?
csf and blood vessels
define meningitis?
inflammation of the leptomeningeal covering 4 branches: 1. infection 2. inflammation 3. parameningeal foci 4. neoplastic and paraneoplastic
viral infectious agents?
Enterovirus and mumps
bacterial infectious agents?
meningicocci and pneumococci
fungal infectious agents?
cryptococcus neoformans
parasitic
Naegleria fowleri
bbb?
prevents infection reach the brain
how do organisms reach the brain?
- bacteriamia/viraemia/ parasitaemia : reach blood stream then go into choroid plexus=> cross bbb => reach csf
- direct spread: chronic infection in cranial bones, ears and sinuses and oral cavity and upper respiratory tract
- Neuronal spread: infection of the peripheral nerves and cell to cell spread of infection. e.g. dog bit leading to spread of infection
Pathogenesis of meningitis?
mucosal colonisation => intravascular survival => meningeal invasion => increased bbb permeability, ceralbral vasculitis and inflammation => oedema and csf flow disturbances=> increase in ICP and decreased cbf and finally result with loss of cerebro-vascular autoregulation
factors influencing bacterial mengitis?
- age
- geography
- immune system
- trauma/ post neurosurgical
Bacterial meningitis
neonates specie?
GBS or e coli
bacterial meningitis species upto 50 yrs?
s. pneumoniae and N. meningitidis
bacterial meningitis more than 50 yrs?
s. pneumoniae and N. meningitidis
immunocompromised state bacterial specie?
s. pneumoniae and N. meningitidis
clinical manifestations?
head ache, neck stiffness, fever and altered mental state
clinical signs?
neck rigidity
kernig’s sign
brudzinski’s sign
what test is used to diagnose meningitis?
lumbar puncture
what are normal csf values in lumbar puncture?
normally clear, less than 5 lymphocytes and 0.5g protein a
completely sterile in culture
bacterial meningitis csf findings?
neutrophilic, 100-500 protein mg/dL, cell count 1000-10000
viral meningitis csf comp?
50-1000, lymphocytic, protein <200 mg/dL
csf extra tests?
PCR: completed for meningicocci and pneumococci
india ink: pneumococci
when to use CT or MRI for LP?
unconsciousness seizures focal neurology post trauma papilloedema
complications of bacterial meningitis?
- seizures
- transentorial herniation: uncontrolled infection so it herniates and inflames
- hydrocephalus- csf becomes sticky so accumulation of fluids in the ventricles and ballooning occurs
- infarcts
Management of meningitis?
supportive care antimicrobial therapy steroids surgical intervention prophylaxis
what is key to meningitis diagnosis?
early recognition via checking ABCDE
antibiotic therapy and referral to hospital
supportive care for meningitis?
airway, breathing, circulation, nutrition, physiotherapy and rehabilitation
what needs checking for specific antimicrobial therapy?
pathogen sensitivities CSF penetration allergy renal function route (I.V. or I.T or I.M or orally) duration of therapy
good antibiotics for csf penetration?
penicillin, ceftrianxone and chloramphenicol
poor antibiotics in csf penetration?
vancomycin and gentamicin
neurosurgery in menigitis?
drain pus to relieve pressure in the brain abcess
prophylaxis?
antibiotics and vaccines
