Cerebral Inflammation

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?

Answer 3

inflammation of blood vessel walls (sometimes called angiitis)

Question 4

No neurone is how far from a capillary?

Answer 4

100µm from a capillary, CNS densely vascularised

Question 5

What are the blood brain barrier capillaries like?

Answer 5

BBB capillaries have extensive tight junctions at the endothelial cell-cell contacts, massively reducing solute and fluid leak across the capillary wall

Question 6

What does the tightness of the BBB mean?

Answer 6

1. solutes that can exchange across peripheral capillaries cannot cross the BBB
2. 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)
3. Blood-borne infectious agents have reduced entry into CNS tissue

Question 7

What are the symptoms of encephalitis?

Answer 7

• Initially symptoms are flu-like with pyrexia (high body temperature) and headache
• Subsequently, within hours, days or weeks:
  1. confusion or disorientation
  2. seizures or fits
  3. changes in personality and behaviour
  4. difficulty speaking
  5. weakness or loss of movement
  6. loss of consciousness

Question 8

What are the viral causes of encephalitis?

Answer 8

1. Herpes Simplex
2. Measles
3. Varicella (chickenpox)
4. Rubella (German measles)

Question 9

What are the other causes of encephalitis?

Answer 9

• Mosquito, tick and other insect bites
• Bacterial and fungal infections
• Trauma
• Autoimmune

Question 10

What are the. treatments for encephalitis?

Answer 10

• Treatment depends onthe underlyingcause, but may include:
  1. Antivirals e.g. acyclovir
  2. Steroids
  3. Antibiotics/antifungals
  4. Analgesics
  5. Anti-convulsants
  6. Ventilation

Question 11

What is multiple sclerosis?

Answer 11

1. Autoimmune demylienating disease of the CNS
2. Relapses linked to inflammatory activity
3. Progression linked to neurodegeneration
   - Can affect white matter randomly in CNS (hence why symptoms change)
   - Amount and location of damage to nervous system is different in each person with. MS
   - Leptomeningeal inflammation as well

Question 12

What is the cellular pathology. of multiple sclerosis?

Answer 12

1. Inflammation
2. Demyelination
3. Axonal loss
4. Neurodegeneration

Question 13

What is the impact of meningitis?

Answer 13

• 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

Question 14

What are the bacterial causes of meningitis?

Answer 14

1. Meningococcal – the most common cause of bacterial meningitis in UK
2. Pneumococcal
3. Haemophilus Influenzae type b (Hib)
4. Streptococccal – the main cause in newborn babies

Question 15

What are the other causes of meningitis?

Answer 15

• Viral - very rarely life-threatening

* Fungal

Question 16

When can the BBB be disrupted? e.g. trauma

Answer 16

1. Endothelial layer disruption
2. Collagen disruption
3. Fibrinogen leakage
4. Astrogliosis
5. Astrocytic end feet change

Question 17

What is the inflammation like in MS?

Answer 17

• Perivascular immune cell infiltration (CD3 T cells and CD20 B cells) - perivascular cuffing
• Autoimmune breakdown of BBB and consequent demyelination