T1 L19: Neuropathology

Question 1

What are the 3 layers of meninges?

Answer 1

Dura mater - Firmly attached to the skull
Arachnoid - Net-like connective tissue containing vessels
Pia mater - Covers the whole brain

Question 2

What are the causes hydrocephalus?

Answer 2

Obstruction
Impaired resorption at arachnoid granulations
Shrinking of brain tissue
Over production

Question 3

What is hydrocephalus ex vacuo?

Answer 3

Shrinking of brain Eg. Dementias

Question 4

What are the 3 areas where brain herniations occur?

Answer 4

Subfalcial (cingulate)
Central (transtentoral)
Tonsillar (cerebellar)

Question 5

Which type of brain herniation is the worst and why?

Answer 5

Tonsillar (cerebellar) herniation because it causes compression of the medulla with impairment to vital respiratory and cardiac functions

Question 6

What is a Duret haemorrhage?

Answer 6

A haemorrhage caused by herniation of the brain

It’s deadly

Question 7

Why should a lumbar puncture not be performed when someone has suspected raised intracranial pressure?

Answer 7

Because it can cause a tonsillar herniation when the pressure is relieved so quickly

(The brain is squished into the magnus)

Question 8

What are some cases of space occupying lesions?

Answer 8

Extradural/ epidural haemorrhage
Subdural haemorrhage
Subarachnoid haemorrhage
Intracranial haemorrhage 
Ischaemic infarct with subsequent oedema or haemorrhage
Neoplasm
Abscess

Question 9

What is a diffuse axonal injury?

Answer 9

A very high impact injury causing all electrical energy to be knocked out

Question 10

Why is there no countercoup when the head is stationary?

Answer 10

Because the moving object wont produce enough inertia if the head is stationary

Question 11

What is the extradural space and what type of haemorrhage occurs here?

Answer 11

The space between the skull and the dura. This space is small so only arterial pressure can cause the bleed meaning it has to be a severe injury

Question 12

Who is most likely to get a subdural bleed?

Answer 12

Old people because it’s caused by a broken vein. In older people they veins loose their elasticity so they are more likely to break with a fall

Question 13

Which artery causes a extradural bleed?

Answer 13

The Middle meningeal artery

Question 14

If someone has an injury but feels fine and then collapses later, which artery has burst in this injury?

Answer 14

The MMM. This person would die because of the build up of pressure

Question 15

What shape does a extradural bleed cause?

Answer 15

A ‘C’ shape along the border of the brain

Question 16

What shape does a subdural bleed cause?

Answer 16

A lemon shaped because the brain is deformed due to the pressure build up. Its an old bleed

Question 17

Which type of haemorrhage is associated with berry aneurysms?

Answer 17

A subarachnoid (subdural) haemorrhage

Question 18

What is a vasogenic cerebral oedema?

Answer 18

Increased vascular permeability caused by a disruption to the blood-brain barrier

Question 19

What is a cytotoxic oedema?

Answer 19

A neuronal, glial, or endothelial cell damage. Cells expand instead of expanding the extracellular space

Question 20

Why is ischaemia worse than hypoxia?

Answer 20

Because there is a build up of toxic metabolites that destroys cells. People tend not to die of hypoxia

Question 21

Which type of necrosis does an ischaemic infarct cause>

Answer 21

Liquefactive necrosis - the brain matter is destroyed and becomes jelly

Question 22

What are some histological features of ischaemic infarcts in the brain?

Answer 22

'red neurones'
Pyknosis of nucleus
Shrinkage of the cell body 
Intense eosinophilia of cytoplasm 
Liquefactive necrosis

Question 23

What is Pynosis?

Answer 23

The irreversible condensation of chromatin in the nucleus of a cell undergoing necrosis or apoptosis

Question 24

Give examples of some peripheral nerve sheath tumous

Answer 24

Schwannoma
Neurofibroma
MPNST

Question 25

Give an example of a poorly differentiated neoplasm in the brain

Answer 25

Medulloblastoma

Question 26

What are the causes of meningitis?

Answer 26

Bacterial (acute or chronic)
Viral
Fungal
RMSV
Neurosyphilis
Lyme disease
Malaria

Question 27

What is MPNST?

Answer 27

A Malignant Peripheral Nerve Sheath Tumour

Question 28

What is RMSV?

Answer 28

Rhabdomyosarcoma (RMS) is a type of sarcoma made up of cells

Question 29

What is Neurosyphilis?

Answer 29

A bacterial infection of the brain or spinal cord. that develops after many years of untreated syphilis

Question 30

What is Lyme disease?

Answer 30

A bacterial infection that can be spread to humans by infected ticks

Question 31

What is Malaria?

Answer 31

A serious and sometimes fatal disease caused by a parasite spread by mosquitos. People who get malaria are typically very sick with high fevers, shaking chills, and flu-like illness

Question 32

What causes abscesses?

Answer 32

Usually bacteria

Question 33

What are the causes of encephalitis?

Answer 33

Viral

Eg. HSV, CMV, HIV, JC polyoma virus

Question 34

What is HSV?

Answer 34

Herpes simplex virus

Question 35

What is CMV?

Answer 35

Cytomegalovirus

Question 36

What is JC polyoma virus?

Answer 36

John Cunningham Polyoma virus

Question 37

What are some symptoms of JC polyoma virus?

Answer 37

Weakness.
Clumsiness.
Having a hard time thinking.
Trouble talking or being unable to speak.
New problems with eyesight or loss of vision.
Loss of feeling in or difficulty moving your limbs.
Dementia-like symptoms and personality changes.
Seizures, and headaches (more common in people who have HIV/AIDS)

Question 38

What is Toxoplasmosis?

Answer 38

An infection caused by a single-celled parasite called Toxoplasma gondii

Question 39

What is Cysticercosis?

Answer 39

A parasitic tissue infection caused by larval cysts of the tapeworm Taenia solium