2.16 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

Question 4

What is the meninges?

Answer 4

Three layers of membranes that cover the brain and the spinal cord?

Question 5

What are the 3 layers of the meninges?

Answer 5

Skull
1. Dura mater
2. Arachnoid mater
3. Pia mater
Brain

Question 6

Where is the inflammatory infection of meningitis?

Answer 6

In the sub-arachnoid space, where the CSF is.

Question 7

What colour is CSF?

Answer 7

clear

Question 8

What colour is CSF in a meningitis patient?

Answer 8

milky

Question 9

What is myelitis?

Answer 9

inflammation of the spinal cord

Question 10

What is the BBB formed from?

Answer 10

capillaries

Question 11

What is special about the capillaries that form the BBB?

Answer 11

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

Question 12

How do capillaries form the bbb?

Answer 12

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 and reduce entry of blood-borne infectious agents.

Question 13

Other than endothelium, what else forms the blood brain barrier?

Answer 13

astrocytes

Question 14

How does the bbb control the exchange of substances?

Answer 14

using specific membrane transporters to transport into and out of the CNS (influx and efflux transporters, active process)

Question 15

What are the layers of the bbb?

Answer 15

capillary
endothelial layer
basement membrane
astrocytes
outer

Question 16

How could the blood brain barrier be compromised?

Answer 16

stroke,

trauma

Question 17

What happens if the bbb is disrupted?

Answer 17

blood components leak into the brain
astrocytes withdraw end feet from vessel to surround product
compromising even more

Question 18

What are the 3 initial symptoms of encephalitis?

Answer 18

pyrexia
flu like
headache

Question 19

What are the subsequent symptoms of encephalitis?

Answer 19

confusion
seizures
changes in personality/behavior (frontal lobe)
difficulty speaking
weakness, loss of movement (motor cortices)
loss of consciousness (brain stem)

Question 20

What are the causes of encephalitis? (5)

Answer 20

virus (by far most common)
mosquito, tick, other insect bites
bacterial or fungal infection
trauma
autoimmune

Question 21

What are 4 common viruses that can lead to encephalitis?

Answer 21

herpes simplex
measles
varicella (chickenpox)
rubella

Question 22

What is the treatment for encephalitis?

Answer 22

antivirals e.g. acyclovir
steroids
antibiotics/antifungals

treating symptoms:

• analgesics
• anticonvulsants
• ventilation

Question 23

What is multiple sclerosis?

Answer 23

autoimmune demyelinating disease of CNS

Question 24

What is multiple sclerosis relapse linked to?

Answer 24

inflammatory activity

Question 25

What is multiple sclerosis progression linked to?

Answer 25

neurodegeneration | --> more demyelination, more symptoms

Question 26

What is secondary progression in MS?

Answer 26

When neurological deficit starts to get worse, axons start dying and so becomes less linked to inflammation

Question 27

What are the 4 stages of MS?

Answer 27

inflammation demyelination axonal loss neurodegeneration

Question 28

What is the pattern of demyelination in MS?

Answer 28

random

Question 29

What do we see at the cellular level in MS?

Answer 29

perivascular immune cell infiltration (perivascular cuffing - inflammation around a blood vessel) CD3-T and CD20-B cells

Question 30

How do we investigate MS?

Answer 30

MRI --> look for more white spots

Question 31

Why do symptoms of MS vary?

Answer 31

because the amount and location of demyelination varies in each patient

Question 32

Why is meningitis dangerous?

Answer 32

6th most common infectious disease killer | leaves 1 in 5 of the infected people with an impairment (esp in neonates)

Question 33

What are the 3 causes of meningitis?

Answer 33

bacterial viral - very rarely life threatening fungal

Question 34

What are 4 bacterial causes of meningitis?

Answer 34

meningococcal - most common in UK pneumococcal haemophilius influenzae type b (Hib) streptococcal - main cause in neonates

Question 35

How do we confirm diagnosis of meningitis?

Answer 35

Spinal tap

Question 36

What is infection of the brain and spinal cord known as?

Answer 36

encephalomyelitis

Question 37

What are focal neurological findings?

Answer 37

weakness visual disturbances aphasia behaviour change

Question 38

What are some hallmarks of meningitis?

Answer 38

``` sudden fever severe headache nausea or vomiting double vision drowsiness photophobia stiff neck ```

Question 39

What are symptoms you might see in encephalitis that are more uncommon in meningitis?

Answer 39

seizure

Question 40

What are symptoms we see in meningitis that we don't often see in encephalitis?

Answer 40

nuchal rigidity | photophobia

Question 41

What is a hallmark symptom of encephalitis that we sometimes see in meningitis (50%)?

Answer 41

mental status alteration/focal neurological findings

Question 42

What diagnostic tests can be performed?

Answer 42

``` neurological examination CT MRI lumbar puncture blood test ```

Question 43

What might we see in a blood test of someone with bacterial meningitis?

Answer 43

low blood glucose in bacterial meningitis | raised WBC due to inflammation

Question 44

Why would corticosteroids be used in the treatment of meningitis and encephalitis?

Answer 44

reduce inflammation