Cerebral inflammation & disorders Flashcards
what is meningitis?
inflammation of the meninges caused by viral or bacterial infection
what is encephalitis?
inflammation of the brain caused by infection or autoimmune mechanisms
what is cerebral vasculitis?
inflammation of blood vessel walls
what does the histology of meningitis look like?
infiltration of subarachnoid space by WBCs, pussy exudate
what does the histology of viral encephalitis look like?
perivascular cuffing
how vascularised is the brain?
no neuron is more than 100micrometers from a capillary
how does the BBB form?
BBB capillaries have extensive tight junctions at endothelial cell-cell contacts, nothing can freely diffuse
what happens if the BBB is broken?
blood leaks into brain, astrocytes attempt to clear blood borne products by retracting end feet (leaving BBB undefended)
what may happen long term if the BBB is chronically disrupted?
fibrosis in brain vessels, small vessel disease
what are the initial symptoms of encephalitis?
flu like with pyrexia and headache
what are the overall symptoms of encephalitis?
confusion/disorientation seizures depending on lobe affected: changes in personality/behaviour difficulty speaking weakness or loss of movement loss of consciousness catatonicity
what are the viral causes of encephalitis?
herpex simplex
measles
varicella
rubella
what are the non-viral causes of encephalitis?
mosquito/insect bites
bacterial or fungal infections - untreated meningitis
trauma
autoimmune
how is encephalitis treated?
depends on underlying cause antivirals/antibiotics/antifungals steroids analgesics anti-convulsants (often prophylactically) ventilation
what is multiple sclerosis?
demyelinating autoimmune disease of the CNS
relapsing and remitting - 1st resolves spontaneously
what is the cellular pathology of multiple sclerosis?
inflammation
demyelination & axonal loss (larger grey areas)
neurodegeneration
what are the bacterial causes of meningitis?
meningococcal (most common)
pneumococcal
haemophilus influenzae type B
streptococcal (main cause in newborns)
what are the causes of meningitis?
bacteria
viruses (rarely life threatening)
fungi
how is meningitis diagnosed?
lumbar puncture for CSF sample
what are the hallmarks of meningitis?
sudden onset of fever, headache, nausea, double vision, photophobia, stiff neck, rash
what are some long term effects of meningitis?
disabilities memory loss coordination loss behaviour changes paralysis/weakness speech coord issues visual defects
what diagnostic tests are useful for suspected encephalitis or meningitis?
lumbar puncture - raised WCC, pink colour
low csf glucose in bacterial men
CT/MRI
neurological assessment
