cerebral inflammation Flashcards
what is the definition of meningitis?
inflammation of the the meninges caused by viral or bacterial infection (bacterial is more aggressive)
what is the definition of encephalitis?
inflammation of the brain caused by infection or autoimmune mechanisms
what is the definition of cerebral vasculitis?
inflammation of blood vessel walls
what is inflammation of the spinal cord called?
myelitis
what are some properties of the blood brain barrier?
all neurones in the brain are very close to capillaries
capillaries of the BBB have extensive tight junctions at the cell-cell contacts
this massively reduces fluid leakage across the capillary wall
transport across it is by active transport. uses specific membrane transporters (influx and efflux transporters)
so blood borne infections have reduced entry into CNS tissue
glial cells also help to define the BBB
what happens if there is a break in the blood brain barrier?
eg and endothelial cell breaks off
blood will leak into the parenchyma
over time: astrocytes (a type of glial cell) move their end feet to help block up the hole
there is also fibrinogen leakage to help seal the hole. this can lead to fibrosis
what are the symptoms of encephalitis?
initially flu like symptoms with pyrexia and headache
within days, hours or weeks: confusion/disorientation seizures/fits changes in personality or behaviour difficulty speaking weakness or loss of movement loss of consciousness (brain stem)
the symptoms depend on the location of the swelling
what are the causes of encephalitis?
most commonly viral: Herpes Simplex Measles Varicella (chickenpox) Rubella (German measles)
Other causes include: Mosquito, tick and other insect bites Bacterial and fungal infections Trauma Autoimmune
how is encephalitis treated?
Treatment depends onthe underlyingcause, but may include:
Antivirals e.g. acyclovir
Steroids
Antibiotics/antifungals
Analgesics
Anti-convulsants (may be given as prophylaxis)
Ventilation
what is multiple sclerosis?
autoimmune demylinating disease of the CNS
starts off relapsing-remitting, then smooth constant secondary progression
relapses linked to inflammatory activity
progression linked to neurodegeneration
it causes: inflammation demyelination axonal loss neurodegeneration
what does an MRI of multiple sclerosis look like?
differs between different people depending on severity and location
there will be hyperintensities of the white matter, especially around the ventricles.
this is the inflammatory demyelination
(not mri)
there is perivascular cuffing - immune cell infiltration around the vasculature
what is meningitis?
Irritation, inflammation and swelling of the meninges
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 (particularly in neonates)
what are the causes of meningitis?
Bacterial:
Meningococcal – the most common cause of bacterial meningitis in UK
Pneumococcal
Haemophilus Influenzae type b (Hib)
Streptococcal – the main cause in new-born babies
Other causes
Viral - very rarely life-threatening
Fungal
to confirm a bacterial cause:
lumbar puncture
take CSF sample
stain for bacterial cells
What are the symptoms of meningitis?
Headache Malaise Fever Neck stiffness Photophobia Confusion
