Cerebral Inflammation And Disorders

Question 1

What is meningitis?

Answer 1

Inflammation of the meninges caused by viral or bacterial infection

Question 2

What is encephalitis?

Answer 2

Inflammation of the brain caused by infection or autoimmune mechanisms

Question 3

What is cerebral vasculitis/angiitis?

Answer 3

Inflammation of blood vessel walls

Question 4

What does this image show?

Answer 4

Meningitis
Infiltration of T cells into subarachnoid space

Question 5

What does this image show?

Answer 5

Viral encephalitis
Proliferation of immune cells around blood vessel into brain tissue

Question 6

What finding suggests that there is very dense vascularisation of the CNS?

Answer 6

No neuron is more than 100 micrometers from a capillary

Question 7

How do capillaries form the blood brain barrier?

Answer 7

Have extensive tight junctions between endothelial cells reducing passive movement of solute and fluid leak across capillary wall

Question 8

Which type of peri-vascular glial is most important with regards to the BBB?

Answer 8

Astrocytes

Question 9

What structures allow the BBB to control the exchange of substances across the capillary wall?

Answer 9

Influx and efflux membrane transporters

Question 10

Why do blood-borne infectious agents have reduced entry into the brain?

Answer 10

Because of the BBB - tight junctions prevent entry

Question 11

What happens when the blood brain barrier gets ruptured?

Answer 11

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

Question 12

What are the initial symptoms of encephalitis?

Answer 12

Flu-like
Pyrexia
Headache

Question 13

What are the subsequent symptoms of Pyrexia (within hours, days or weeks)?

Answer 13

Confusion or disorientation
Seizures or fits
Changes in personality and behaviour
Difficulty speaking
Weakness or loss of movement
Loss of consciousness

Question 14

In most cases, what is encephalitis caused by?

Answer 14

Viral infection

Question 15

Give some examples of the most common viruses causing encephalitis

Answer 15

Herpes Simplex
Measles
Varicella (chickenpox)
Rubella (German measles)

Question 16

What are some non-viral causes of encephalitis?

Answer 16

Mosquito, tick and other insect bites
Bacterial and fungal infections
Trauma
Autoimmune (channel receptors usually affected)

Question 17

How is encephalitis treated?

Answer 17

Treatment is dependent on underlying cause, includes
- Antivirals, e.g. acylclovir
- Steroids
- Antibiotics/antifungals
- Analgesics
- Anti-convulsants (typically prophylactic)
- Ventilation

Question 18

What is multiple sclerosis?

Answer 18

Autoimmune demyelinating disease of the CNS

Question 19

What is probably the most common course of MS?

Answer 19

Relapsing-remitting with secondary progression

Question 20

What are the hallmarks of MS?

Answer 20

Inflammation
Demyelination
Axonal loss
Neurodegeneration

Question 21

If an individual’s MS mainly affected their spinal cord, what type of symptoms would they present with?

Answer 21

Motor problems

Question 22

What do these images show?

Answer 22

Inflammation in MS
Accumulation of T And B cells around blood vessel (mainly T cells)
Classic picture of active MS lesion

Question 23

What is meningitis?

Answer 23

Irritation, inflammation and swelling of meninges
6th most common infectious disease killer

Question 24

Do people tend to fully recover from meningitis?

Answer 24

Not always, leaves 1 in 5 infected people with an impairment

Question 25

What are the causes of meningitis?

Answer 25

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