🧠Neurology🧠 - Cerebral Inflammation Flashcards
What are the different types of cerebral inflammation?
Meningitis
Encephalitis
Cerebral vasculitis
What is meningitis?
Inflammation of the meninges caused by viral or bacterial (or fungal) infection
What is encephalitis?
Inflammation of the brain caused by infection or autoimmune mechanisms
What is cerebral vasculitis?
Inflammation of cerebral blood vessel walls (sometimes called angiitis)
How was the blood brain barrier discovered?
What is significant about the vascularisation of the CNS?
It is extremely dense
No neuron is more than 100µm from a capillary
What aspect of the cerebral capillaries is central to the formation of the BBB?
Extensive use of tight junctions at cell-cell contacts
Massively reducing solute and fluid leak across the capillary wall
What is the advantage of solutes being unable to cross the BBB?
BBB can control the exchange of substances using specific membrane transporters to transport into and out of the CNS (influx and efflux transporters)
Blood-borne infectious agents have reduced entry into CNS tissue
How is the BBB disrupted?
Endothelial layer disruption
Leads to leakage of fibrinogen
Astrogliosis occurs around leaked fibrinogen, moving away from the vessel
Results in a compromised blood brain barrier and collagenous disruption
What are the symptoms of encephalitis?
Initial symptoms are flu-like with pyrexia and headache
Subsequently (can be 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
In essence, classic symptoms of cerebral dysfunction
What are the causes of encephalitis?
Majority of cases are viral, most common of which is Herpes Simplex
Other viral causes include measles, varicella, rubella
Other causes: mosquito/tick/insect bites
Bacterial/fungal infections
Trauma
Autoimmune
What are the treatment options for encephalitis?
Depends on underlying cause:
Antivirals (e.g. acyclovir)
Steroids (anti-inflammatory effect, can reduce intracranial pressure)
Antibiotics/antifungals
Analgesics
Anti-convulsants
Ventilation (last resort if not enough oxygen is reaching the brain)
Outline multiple sclerosis
Briefly describe the cellular pathology of multiple sclerosis?
Inflammation
Demyelination
Axonal loss
Neurodegeneration
Why are symptoms so variable in MS?
Great variety in amount and location of damage
person with 35 years of disease so much less damage than person of <20 years of disease
