Cerebral inflammation Flashcards
What is meningitis?
Inflammation of the meninges caused by viral or bacterial infection
Encephalitis
Inflammation of the brain caused by infection or autoimmune mechanisms
Cerebral vasculitis
Inflammation of blood vessel walls (sometimes called angiitis)
Explain the dense vascularisation of the CNS
No neuron is more than 100um from a capillary
How does the blood brain barrier work and how are substances stopped from getting from tissues into the brain?
At the level of capillaries
BBB capillaries have extensive tight junctions at the endothelial cell-cell contacts, massively reducing solute and fluid leak across the capillary wall
Because of the “tightness” of the BBB capillaries, solutes that can exchange across peripheral capillaries cannot cross the BBB.
This allows the BBB to control the exchange of these 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.
What are the symptoms of encephalitis
Initially symptoms are flu-like with pyrexia (high body temperature) and headache
Subsequently, 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
How does disruption in the blood brain barrier occur
Gap in endothelial cells
Fibrinogen leakage
Astrocytes move away
What are the causes of encephalitis
In most cases, encephalitis is caused by viral infection, the commonest of which are:
Herpes Simplex
Measles
Varicella (chickenpox)
Rubella (German measles)
Other causes include:
Mosquito, tick and other insect bites
Bacterial and fungal infections
Trauma
Autoimmune, mainly channel receptors attacking themselves
What is the treatment of encephalitis
Treatment depends onthe underlyingcause, but may include:
Antivirals e.g. acyclovir
Steroids
Antibiotics/antifungals
Analgesics
Anti-convulsants
Ventilation
What is multiple sclerosis
Autoimmune demyelinating disease of the CNS
Relapses linked to inflammatory activity
People come in with specific neurological deficit, most common is optic neuritis
Progression linked to neurodegeneration
Ultimate axonal loss
What is the cellular pathology of multiple sclerosis
Inflammation
Demyelination
Axonal loss
Neurodegeneration
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
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
