cerebral inflammation 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 (angitis)
why do dyes and ohher traces injected IV accumulate in most tissues but not in CNS?
due to blood brain barrier
describe broadly the vascularisation of CNS and state a fact that illustrates this
dense, no neuron is more than 100μm from a capillary
what makes the bbb?
most importantly the vascular morphology! Also glial cells
what is the difference between other cappilaries and CNS cap that leads to bbb?
extensive tight junctions at the endothelial cell-cell contacts,
massively reducing solute and fluid leak across the capillary wall
what is the purpose of the BBB
TO HAVE GREATER CONTROL over what enters the cns circulation
blood borne infecitons have reduced entry to cns tissue
what vessels do brain capillaries stem from?
Pial vessels
how to the necessary substances go into CNS if the junctions are so tight in bbb?
though influx and efflux transporters: membrane transporters specific to each relevant substance
what are astrocytes and what is their role in BBB
a specialized type of glial cell that is vital in the maintnance of the bbb integrity (astrocyte “endfeet” sitting tight to the vasculature)
what are the 4 main mechanisms of pathophysiology in BBB disruption
1) fibrinogen leakage (from cappilaries to astrocytes)
2) astrogliosis (astrocytes become activated and undergo structural changes )
3) astrocytic end-feet change
4) collagenous disruption
initial symptoms of encephalitis
flu-like with pyrexia (high body temperature) and headache
sympotms of encephalitis as time goes by (within hours days or weeks )
-confusion or disorientation
-seizures or fits
-changes in personality and behaviour
-difficulty speaking
-weakness or loss of movement
-loss of consciousness
most common cause of encephalitis and most common specific examples
viral infection,
Herpes Simplex
Measles
Varicella (chickenpox)
Rubella (German measles)
other rarer causes of encephalitis
-Mosquito, tick and other insect bites
-Bacterial and fungal infections
-Trauma
-Autoimmune
treatments of encephalitis?
depends onthe underlyingcause, but may include:
Antivirals e.g. acyclovir
Steroids. (swelling
Antibiotics/antifungals
Analgesics
Anti-convulsants
Ventilation
what other new health crisis is associated with long term neurological deficits?
covid 19
what is multiple sclerosis
autoimmune demyelinating disease of CNS
what is the progression of MS in terms of the neurological deficits? (2 phases)
first phase usually “relapsing- remitting” nature
second progression: linear increase in neuro deficits
what are the neuro deficit relapses caused by/ linked to?
inflammation
what is the seconf phase neuro def progression linked to?
axonal loss and neurodegeneration
4 terms that describe the cellular pathology of ms
Inflammation
Demyelination
Axonal loss
Neurodegeneration
where is the brain damage mostly seen in MS brain scan
atound ventricles
why do sympotms cary in ms?
because the amount and location of damage to the nervous system is different in each person with MS
what happens during inflammaiton in ms
perivascular immune cell infiltration (CD3 T-cells and CD20 B-cells)
how dangerous is meningitis death wise? how many people affected per year? how many with permanent impariment?
6th most common infectious disease killer
Affects more than 5 million people per annum worldwide
Leaves 1 in 5 of the infected people with an impairment
bacterial causes of meningitis
Meningococcal
Pneumococcal
Haemophilus Influenzae type b (Hib)
Streptococcal –
– the most common cause of bacterial meningitis in UK
meningococcal
the main cause of meningtitis in new-born babies
streptococcal
