Week 7 - meningitis Flashcards
What is the name of the membrane that contains the brain and the spinal cord?
the meninges
What is fluid within the meninges called?
cerebrospinal fluid (CSF)
What happens when the meninges becomes inflamed?
Increased inter cranial pressure due to increased CSF protein levels, white cells, immunoglobulins, brain water etc
Decreased cerebral perfusion (blood flow to the brain) due to increased pressure
What are the infectious causes of meningitis?
Bacteria
Viruses - mumps, measles
Protozoa - naegleria fowleri
Fungi - cryptococcus neoformans
What are the leading causes of bacterial meningitis?
Neisseria meningitidis
Streptococcus pneumonia
Haemophilus influenza
Neonatal infections - E coli, group B strep
Immunocompromised patients - Listeria monocytogenes, Mycobacterium tuberculosis
What are the sources of material meningitis infections?
Aerosol transmission
Extensions of other infections like sinus infections
Amoeba travelling through the Nasal epithelium
Trauma
What are the symptoms of meningitis in adults/older children
High temperature
Photophobia
Neck stiffness
Vomiting
Severe headache
Muscle pains
Kernig sign
What are the symptoms of meningitis in young infants?
Fever, cold feet and hands
\No feeding
High pitched crying
Doesn’t want to be handled
Difficult to wake, lethargic
pale, complexion
Blank, staring expresssion
What tests can you carry out to try and diagnose meningitis?”
CT, MRI SCAN
Blood cultures
PCR
Antigen detection
CSF examination (collect several samples)
What steps does the CSF examination contain?
Opening pressure - check pressure
Appearnace
White cell count
Biochemistry
Gram stain
Bacterial culture
What do the results of a white cell count show?
Normal = 5 for children and adults, 20 for babies
Bacterial infection = 1000+ per mm3
What should CSF be cultured on?
chocolate and blood agar in co2 enriched air
Or anaerobic blood agar, SAB agar
Describe neisseria meningitides
Aerobic gram negative diplococci
