Cerebral Inflammation

Question 1

Define

Meningitis

Answer 1

inflammation of the meninges caused by viral or bacterial infection

Question 2

Define

Encephalitis

Answer 2

inflammation of the brain caused by infection or autoimmune mechanisms

Question 3

Cerebral vasculitis

Answer 3

inflammation of blood vessel walls (sometimes called angiitis)

Question 4

How is the brain protected from content of blood?

what aids this protection - features?

Answer 4

Blood Brain Barrier - BBB

Capillary system is very densly packed

Question 5

Proof of density of capillaries?

distance of neurons from capillaries?

Answer 5

No neuron is more than 100µm from a capillary.

Question 6

What massively reduces solute and fluid leak across the capillary walls in the Brain [as opposed to systemic circulation]

Answer 6

BBB capillaries have extensive tight junctions at endothelial cell-cell contacts

Question 7

Why do solute / fluid leaks occur at peripheral capillaries?

Answer 7

Capillaries are not densely packed.

Not tight like BBB capillaries which prevent exchange and crossing over BBB into brain

Question 8

How does the BBB protect the brain and from what?

Answer 8

• reduced entry into CNS tissue

- Blood borne infectious agents

Question 9

Disruption to BBB

what follows?

Answer 9

• disruption can be trauma or inflammation
• something causes Endothelial layer opening
• fibrinogen leaks from blood into tissues / cells
• astrocytes recruited : ASTROGLIOSIS
• Astrocyte end-feet change
• In repairing the endothelial layer, collagenous disruption occurs : too much collagen = sclerosis [tissue hardening]

Question 10

Encephalitis
symptoms
initial

Answer 10

Pyrexia (high body temp)

Headache

Question 11

Subsequent Encephalitis Symptoms

6

Answer 11

confusion or disorientation
seizures or fits
changes in personality and behaviour
difficulty speaking
weakness or loss of movement
loss of consciousness

Question 12

Causes : Encephalitis

Answer 12

Viral infection :

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

Mosquito, ticks, insect bite
Bacterial, fungal
Trauma
Autoimmmune

Question 13

Treatment : Encephalitis

Answer 13

Antivirals e.g. acyclovir
Steroids
Antibiotics/antifungals
Analgesics
Anti-convulsants
Ventilation

Question 14

MS - what is it?

Answer 14

Autoimmmune demyelinating disease of the CNS
Has a intermittent period w relapses : linked to inflammatory activity
Progression is due to neurodegeneration
Axonal loss is characteristic w duration of disease time

Question 15

What has been linked to the demyelination caused in MS

Answer 15

Inflammation

Question 16

Cellular Pathology of MS

Answer 16

Inflammation

Demyelination

Axonal loss

Neurodegeneration

Question 17

What are markers of inflammation in MS

Answer 17

immune cells infiltrate BBB
Perivascular immune cell infiltration
CD3 T cells
CD20 B cells

Question 18

What distinctive findings in an MRI scan of MS

Answer 18

• Areas that should be white matter lose colouration
• Periventricular white matter changes
• Asymmetry

Question 19

Meningitis

Overview

Answer 19

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 20

Causes of Meningitis

Answer 20

Bacterial
Meningococcal – the most common cause of bacterial meningitis in UK
Pneumococcal
Haemophilus Influenzae type b (Hib)
Streptococccal – the main cause in newborn babies

Other causes
Viral - very rarely life-threatening
Fungal