Cerebral Inflammation And 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/angiitis?
Inflammation of blood vessel walls
What does this image show?
Meningitis
Infiltration of T cells into subarachnoid space
What does this image show?
Viral encephalitis
Proliferation of immune cells around blood vessel into brain tissue
What finding suggests that there is very dense vascularisation of the CNS?
No neuron is more than 100 micrometers from a capillary
How do capillaries form the blood brain barrier?
Have extensive tight junctions between endothelial cells reducing passive movement of solute and fluid leak across capillary wall
Which type of peri-vascular glial is most important with regards to the BBB?
Astrocytes
What structures allow the BBB to control the exchange of substances across the capillary wall?
Influx and efflux membrane transporters
Why do blood-borne infectious agents have reduced entry into the brain?
Because of the BBB - tight junctions prevent entry
What happens when the blood brain barrier gets ruptured?
Damage to endothelial cells
Leakage of blood contents into brain parenchyma (e.g. fibrinogen)
Astrocytes retract their endfeet in response (opening up blood brain barrier further)
Immune cells and inflammatory cytokines make their way to brain tissue causing inflammation, e.g. encephalitis
What are the initial symptoms of encephalitis?
Flu-like
Pyrexia
Headache
What are the subsequent symptoms of Pyrexia (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
In most cases, what is encephalitis caused by?
Viral infection
Give some examples of the most common viruses causing encephalitis
Herpes Simplex
Measles
Varicella (chickenpox)
Rubella (German measles)
What are some non-viral causes of encephalitis?
Mosquito, tick and other insect bites
Bacterial and fungal infections
Trauma
Autoimmune (channel receptors usually affected)
How is encephalitis treated?
Treatment is dependent on underlying cause, includes
- Antivirals, e.g. acylclovir
- Steroids
- Antibiotics/antifungals
- Analgesics
- Anti-convulsants (typically prophylactic)
- Ventilation
What is multiple sclerosis?
Autoimmune demyelinating disease of the CNS
What is probably the most common course of MS?
Relapsing-remitting with secondary progression
What are the hallmarks of MS?
Inflammation
Demyelination
Axonal loss
Neurodegeneration
If an individual’s MS mainly affected their spinal cord, what type of symptoms would they present with?
Motor problems
What do these images show?
Inflammation in MS
Accumulation of T And B cells around blood vessel (mainly T cells)
Classic picture of active MS lesion
What is meningitis?
Irritation, inflammation and swelling of meninges
6th most common infectious disease killer
Do people tend to fully recover from meningitis?
Not always, leaves 1 in 5 infected people with an impairment
What are the causes of meningitis?
Bacterial:
Meningococcal - most common for bact. meningitis in UK
Pneumococcal
Haemophilia Influenzae type b (Hib)
Streptococcal - main cause for new-born babies
Other causes:
Viral - rarely life-threatening
Fungal
