CNS Pathology Flashcards

1
Q

What pathologies can affect the CNS?

A

Trauma, neurodegenerative disorders, cerebrovascular diseases, neoplasia, infectious disorders, demyelinating disorders

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is trauma (to CNS)?

A

Injury or damage to living CNS tissue caused by an extrinsic force or agent by either direct or indirect mechanisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What can a concussion lead to?

A

Bruising, swelling, tearing of blood vessels, injury to nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are two types of traumatic brain injury?

A

Diffuse and focal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is a diffuse brain injury?

A

Generalised injury to all areas of brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are two examples of a diffuse traumatic brain injury?

A

Diffuse traumatic axonal injury, diffuse hypoxic injury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is a focal traumatic brain injury?

A

Localised injury of the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are two examples of focal traumatic brain injury?

A

Lobar cerebral contusion, subdural haemorrhage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What causes diffuse TBI?

A

Outside mechanical force applied to head, eg. fall, car crash, struck by/against object, assault, blasts (war)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are primary brain injuries in diffuse TBI?

A

Mechanical damage, eg. laceration, cerebral contusion, diffuse axonal injury, haemorrhage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are secondary injuries in diffuse TBI?

A

Indirect result of TBI, eg., intracranial hypertension, brain shift and herniation, biochemical processes, swelling, cerebral ischemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What causes diffuse axonal injury?

A

Global disruption of axons due to severe shearing forces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does diffuse axonal injury result in?

A

Immediate primary axotomy, delayed secondary axotomy due to ischemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How does diffuse axonal injury present?

A

Immediate loss of consciousness, no lucid interval, sustained unconsciousness and vegetative state until death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe the histology of diffuse axonal injury

A

4-5 hours: focal accumulations of beta-amyloid precursor protein (APP)
12-24 hours: axonal varicosities, swelling
24 hours-2 months: axonal swellings
2 weeks-5 months: micro-gliosis
2 months-years: loss of myelinated fibres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What causes cerebral contusion in focal TBI?

A

Blunt trauma, ie. blow to the head, leading to rapid tissue displacement. Contact between brain and rough skull surfaces like orbital floor and petrous ridges

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What does a cerebral contusion result in?

A

Rupture of vessels leads to haemorrhage, tissue injury and edema

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the clinical symptoms of a cerebral contusion?

A

Drowsiness, confusion, agitation, hemiparesis, unequal pupil size

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is a brain hematoma?

A

Haemorrhaging from ruptured blood vessel caused by brain trauma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is an epidural hematoma?

A

Hematoma between skull and dura mater caused by torn artery and branches

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What does an epidural hematoma result in?

A

Increased intracranial pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the mortality rate for epidural hematomas?

A

30% when treated quickly

23
Q

What is a subdural hematoma?

A

Hematoma between dura mater and arachnoid mater caused by torn subdural veins

24
Q

What causes subdural hematoma?

A

Blunt trauma to frontal or occipital lobes

25
Q

What causes Parkinson's disease?

A

Atrophy and loss of dopaminergic neurons in substantia nigra pars compacta (SNPc) in basal ganglia

26
Q

What change can be seen in SNPc in PD?

A

Depigmentation

27
Q

What symptoms does loss of dopamine in deep structures cause?

A

Resting tremor, bradykinesia, rigidity, postural imbalance

28
Q

Describe the histology of PD.

A

Levy bodies visible. Result of accumulation of intracellular fibrillar aggregates, mutant alpha-synuclein forms fibrils together with ubiquitin and neurofilaments

29
Q

What is the median age of PD onset?

A

60 years

30
Q

What percentage of PD cases are sporadic and genetic?

A

95% sporadic, 5% genetic

31
Q

What is an example of a cerebrovascular disease?

A

Stroke

32
Q

What is a stroke?

A

Transient or permanent reduction to cerebral blood flow

33
Q

What are two types of stroke?

A

Ischemic and haemorrhagic

34
Q

What is a haemorrhagic stroke?

A

Rupture of weakened blood vessel in brain

35
Q

What causes haemorrhagic stroke?

A

Weakened blood vessels, as a result of uncontrolled hypertension (mainly) and atherosclerosis

36
Q

Where do most haemorrhagic strokes occur?

A

In cerebrum, bleed in to lateral ventricle

37
Q

What symptoms precede a haemorrhagic stroke?

A

Intense headache and vomiting

38
Q

What are the two types of haemorrhagic stroke?

A

Subarachnoid and intracerebral

39
Q

What is an ischemic stroke?

A

Stroke in which a clot blocks an artery to the brain

40
Q

What causes ischemic stroke?

A

Narrowed arteries in brain. Embolism, thrombosis of cerebral artery (thrombotic ischemic stroke), hypoperfusion

41
Q

What is the result of ischemic stroke?

A

Decreased cerebral blood flow

42
Q

What is and infarct in ischemic stroke?

A

Area of dead tissue at site of occlusion

43
Q

What is penumbra in ischemic stroke?

A

Tissue surrounding ischemic event, which is also injured. Will succumb to death

44
Q

What occurs immediately after ischemic event (stroke)?

A

Blood flow and oxygen reduced leading to hypoxia of local cells

45
Q

Describe the ischemic cascade.

A

Energy depletion -> failure of Na and K pumps -> depolarisation of neuronal membrane -> glutamate released in synaptic cleft -> excitotoxin -> glutamate acts on channel receptors (NMDA, AMPA) -> calcium influx -> activation of catabolic enzymes or activation of NO synthase -> cellular injury (free radicals, destruction of structural proteins leads to necrosis; mitochondrial injured leads to apoptosis)

46
Q

Describe the histology of ischemic stroke.

A

1 day- Injured neurons shrink and become eosinophilic (red anoxic neurons), nuclei condense, 1 week- damaged neurons disintegrate and removed by macrophages, >3 weeks- cortical atrophy and gliosis

47
Q

How is ischemic stroke treated?

A

First line therapy: intravenous alteplase initiated within 4.5 hours of symptoms
Surgical thrombectomy in large blood vessels

48
Q

What are gliomas?

A

Malignancy arising from glial cells in CNS

49
Q

What are types of gliomas?

A

Astrocytoma, ependymoma, oligodendroglioma, glioblastoma

50
Q

What are meningiomas?

A

Non-aggressive neoplasm arising from arachnoidal cells

51
Q

What can result from a meningioma?

A

Hydrocephalus caused by interference with CSF circulation

52
Q

What are two types of infectious disorders affecting the CNS?

A

Encephalitis and meningitis

53
Q

What is encephalitis?

A

Infection causing inflammation of the brain, mostly caused by viruses

54
Q

What is meningitis?

A

Inflammation of meninges of brain or spinal cord