Cerebral inflammation and disorders Flashcards
What is meningitis?
Inflammation of meninges caused by viral or bacterial infection
generally at the arachnoid
What is encephalitis?
Inflammation of brain from infection or autoimmune
What is cerebral vasculitis?
(angiitis)
Inflammation of blood vessel walls
What was the evidence for the existence of the BBB?
Dyes injected into mice were present in most organs (as everything receives blood supply) but not in the brain
What is the structural formation of the blood brain barrier?
BBB capillaries have tight junctions between cells - limit solute and fluid leak from capillaries. Outside capillaries are perivascular cells (astrocytes) which are involved in filtration
What is the function of the blood brain barrier?
Controls exchange of substances using influx and efflux transporters
Explain how endothelial layer disruption causes disruption to the blood brain barrier
Endothelial layer disruption leads to leakage of blood components (including fibrinogen). This triggers astrogliosis (proliferation of astrocytes) and astrocytic end feet change (where astrocytes wrap around blood vessels)
thickening of collagen
- to try and repair the damage
Why is the brain described as being immunologically different?
Resistant to blood borne diseases due to the presence of the BBB
What are initial symptoms of encephalitis?
Flu-like symptoms: pyrexia (high body temp), headache
What are some consequent symptoms of encephalitis?
hours,days,week
confusion, seizures, personality changes, difficulty speaking, weakness, loss of consciousness
What is the most common causes of encephalitis?
Viral - Her Majesty’s ViRus aka HMVR:
Herpes simplex,
Measles,
Varicella (chicken pox),
Rubella
What are other causes of encephalitis?
Bacterial/fungal infections, insect bites, trauma, autoimmune
What are the treatments for encephalitis?
Antiviral (acylovir)/
Antibacterial/Antifungal,
Steroids (anti-inflammatory), swelling can caused raised intracranial pressure
Anticonvulsants (prophylactic measure),
Analgesia
What is MS?
Autoimmune, inflammatory, degenerative disease due to demyelination of CNS
Describe the progression of MS with regards to neurological deficit
Initially relapsing-remitting, peaks of deficit which return to normal, however due to axon loss will eventually lead to secondary progression which is linear degeneration
Describe the progression of MS with regards to inflammation
Initially relapsing-remitting, however in secondary progression inflammation decreases gradually (this is due to degeneration becoming independent of inflammation)
How are relapses of MS associated with inflammation
Inflammatory spikes match up with relapses, which indicates increased inflammatory activity is their cause.
What are the 4 key cellular pathology features of MS?
Inflammation, demyelination, axonal loss, neurodegeneration
Features of MS seen on an MRI scan
White areas around the ventricles, usually due to demyelination
(increasing large perivascular lesions)
What will demyelination of the spinal cord usually lead to?
Motor issues particularly with mobility
What inflammatory cells are involved in MS?
CD3 T cells, CD8 T cells, CD20 B cells
What is perivascular cuffing
Immune cell infiltration (CD3,CD8,CD20)
originated in the bloodstream, broken through BBB and are surrounding the blood vessels
Why is meningitis a large issue?
High mortality rate, leaves 1 in 5 with impairment
What are the main causes of meningitis?
Bacterial infections: HMPS: Her Majesty’s ProkaryoteS: Haemophilus Influenza type b (Hib),
Meningococcal (most common in UK),
Pneumococcal,
Streptococcal (most common in newborns)
What are the other causes of meningitis?
Viral (rarely life threatening) and Fungal Infections
Why are MS symptoms difficult to predict
Random nature of demyelination
What is myelitis?
Inflammation of spinal cord
What are the main symptoms of meningitis?
sudden fever, headache, nausea, double vision, photophobia, rash, stiff neck
What diagnostic tests do you do for meningitis and encephalitis?
CT, MRI, Lumbar Puncture (low glucose in meningitis), Blood, Urine Analysis
What treatments are used for meningitis and encephalitis?
Antibiotics, Antivirals, Corticosteroids, Immunosuppressants
What are long term effects of meningitis?
Learning disabilities, memory loss, dizziness, hearing loss, spasms
