neuropathology

Question 1

What are primary and secondary events that can occur with head injury?

Answer 1

Primary changes are neural and vascular

Secondary changes are ischaemia, oedema and infection

Question 2

What is the mechanism by which diffuse axonal injury occurs in acceleration/decclleration injuries?

Answer 2

This is mechanoporation in which stretched axon membranes are no longer able to conduct properly

Question 3

How soon will axonal bulbs be visible after brain injury?

Answer 3

After 24 hours

Question 4

What type of bleeding will cause an extradural haemorrhage?

Answer 4

Usually middle meningeal artery?

Question 5

What type of bleeding will cause a subdural haemorrhage?

Answer 5

Usually a venous bleed from the bridging veins

Question 6

What type of bleeding will cause a subarachnoid haemorrhage?

Answer 6

usually from damage to the vertebral or intracerebral arteries

Question 7

What are the two factors that raised ICP is due to in head injury?

Answer 7

Can be due to cerebral oedema as a reaction to injury

Can be due to the mass effect of a haematoma

Question 8

What are the two most common forms of infection in the brain?

Answer 8

Meningitis

Cerebral abscess

Question 9

What typically happens to proteins in neurodegenerative disease?

Answer 9

They become misfolded and this leads to accumulation. Protein disulphide isomerase helps protein maturation, this can be damaged by free radicals and then it cannot rearrange these misfolded proteins

Question 10

What are the four most common types of dementia in order?

Answer 10

Alzheimer’s
Vascular
Lewy Body
Frontotemporal

Question 11

What is the pathogenesis in alzheimers disease?

Answer 11

There is amyloid plaque formation. This causes frontal and temporal lobe atrophy due to reduced dendritic branching and basal nuclear damage resulting in reduced cholinergic input

Question 12

What is a genetic risk factor for alzheimer’s?

Answer 12

The beta amyloid precursor protein (BAPP)

Question 13

What is the pathogenesis for lewy body disorders such as lewy body dementia and parkinsons?

Answer 13

There is loss of pigmented cells in the substantia nigra, this reduces dopaminergic input to the basal ganglia

Question 14

What is the pathogenesis behind vascular dementia?

Answer 14

This is grey matter lesions due to bilateral infarcts. This is due to small vessel disease.

Question 15

What is the mechanism behind motor neurone disease?

Answer 15

Primary lateral sclerosis of the upper motor neurones. It also causes progressive uscluar atrophy due to lower motor neurone disease. This is due to uiquitination of motor neurones resulting in axonal loss.

Question 16

What are prions and how do they lead to neurodegenerative disease?

Answer 16

They are infective protein particles that may form amyloid and prevent proper protein folding. This results in synaptic failure and cell death.

Question 17

What is the pathogenesis behind multiple sclerosis?

Answer 17

It is inflammatory demyelination of the myelin sheaths surrounding the neurones

Question 18

What is the definition of a stroke?

Answer 18

A rapid onset signs of focal disturbance of cerebral function, lasting more than 24 hours, of vascular origin

Question 19

What are the three main types of strokes?

Answer 19

Ischaemia from thrombus or emboli
Haemorrhagic
Inflammatory - due to vasculitis

Question 20

What are the degenerative changes that can follow a cerebral infarct?

Answer 20

There will be clear demarkation of the affected area at 3 weeks. Cysts can form from 3 - 8 weeks

Question 21

What are the three main types of aneurysms?

Answer 21

congenital (berry), infectious (mycotic) or atherosclerosis (fusiform)

Question 22

How does infection tend to get to the CNS?

Answer 22

Through the nasopharynx then spreads through the blood to the sinuses or middle ear to CNS.

Question 23

What pathological changes occur in bacterial meningitis?

Answer 23

there will be purulent exudate over the brain surface, cerebral abcesses can also form

Question 24

how can chronic meningitis present?

Answer 24

Isidious onset where pus can collect at the base of the brain and cause cranial nerve defects

Question 25

What viruses cause encaphalomyelitis and what symptoms does this have?

Answer 25

Caused by polioviruses and has CNS involvement, there is loss of LMNs which causes paralysis

Question 26

What is the most important prion infection?

Answer 26

Creutzfeldt-Jakob disease (CJD) which infects through the oral route and presents later in life with rapid progressive dementia

Question 27

Who are CNS tumours most common in?

Answer 27

Rare in adults but second most common type of tumour in children. Most common CNS tumour is meningioma

Question 28

What are the main types of nerve sheath tumours?

Answer 28

Schwaanoma and neurofibroma