Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

NEURO > 10.2 Raised Intracranial Pressure > Flashcards

10.2 Raised Intracranial Pressure Flashcards

1
Q

Normal intracranial pressure in :

Adults, children, term infant

A

Adults : 5 - 15 mmHg
Children : 5 - 7mmHg
Term infant : 1.5 - 6mmHg

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

What value is raised ICP?

A

> 20mmHg

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

What does the Monro-Kellie doctrine say

A

Any increase in the volume of one of the cranial constituents must be compensated by decrease in volume of another

Constituents include
- venous volume, arterial volume, brain, CSF

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

What can cause raised ICP

A

Too much blood

  • raised arterial pressure - malignant hypertension
  • raised venous pressure - SVC obstruction
  • intracranial haemorrhage (pics on slide of diff hamemorhages )

Too much CSF
- hydrocephalus

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

When does raised arterial pressure become a problem for ICP

A

Only in ‘malignant hypertension’ (typically above 180/210)

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

Types of hydrocephalus

A

Congenital

Acquired:

  • meningitis
  • trauma
  • tumour
  • haemorrhage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is seen on CT of hydrocephalus

A

Enlarged ventricles

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

Causes of congenital hydrocephalus

A

Congenital obstruction to CSF flow which can be due to :

  • neural tube defect
  • aqueductal stenosis

Or COMMUNICATING hydrocephalus (not to do with obstruction)
Due to either
- increased CSF production
- decreased CSF absorption

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

How does congenital hydrocephalus present

A
  • Sunsetting eyes (downward gaze)

- enlarged head

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

How is congenital hydrocephalus treated initially ?

A

Tapping the fontanelle

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

How is short to medium term drainage of congenital hydrocephalus done?

A

External ventricular drain (EVD)

  • Allows short to medium term drainage
  • continuous pressure monitoring

(Pic)

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

3 Disadvantages of EVD

A
  • Direct pathway for bacteria from skin to brain
  • Chamber must be kept at same height as ventricles (hard to move around)
  • Not a good long term solution
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is a long term solution for congenital hydrocephalus?

A

Ventricular shunts

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

What are the 2 types of ventricular shunts ?

A
  • Ventriculo-peritoneal shunt (more common)
  • Ventriculo-atrial shunt ( less common)

Pics

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

Pros and cons of ventricular-peritoneal shunt

A
  • easier to place, can leave a loop which is good for growing children unlike ventriculo-atrial shunt
  • prone to infection
  • can kink, block, or displace
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is near the top of both types of shunts and what does it do ?

A

Omayya reservoir

  • has one way valve so CSF doesn’t flow back
  • measures pressure (set pressure so CSF drains when above certain pressure)
  • attach drain (for CSF to flow when above set pressure )
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Cerebral oedemas can lead to raised ICP.

What are the 4 types

A
  • vasogenic
  • cytotoxic
  • osmotic
  • interstitial

(Pic)

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

What are 3 other things that can cause raised ICP?

A
  • tumour
  • abscess
  • idiopathic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is cerebral perfusion pressure ?

Equation for cerebral perfusion pressure ?

A

CPP is the net pressure gradient causing cerebral blood flow to the brain

CPP = MAP - ICP

20
Q

Normal values for

  • MAP
  • ICP
  • CPP
A

MAP - 65-110 mmHg

ICP - 5-15mmHg

CPP - >70mmHg

21
Q

What does changes in CPP trigger

A

Cerebral autoregulation

22
Q

What is the risk in decreased CPP

A

hypoperfusion

Can lead to stroke etc

23
Q

What can happen to cerebral autoregulation following injury

A

The capacity for autoregulation may be completely lost
Or
Threshold for autoregulation may be rest.

24
Q

How does the CVS system try to compensate for raised ICP?

A

Cushing’s triad

25
What are the 3 stages of Cushing’s triad?
1. Increased MAP 2. Bradycardia 3. Irregular breathing
26
How is MAP increased
Raised ICP leads to lower CPP | Low CPP is detected by baroreceptors in the brain which stimulates sympathetic system - increases BP
27
How is bradycardia triggered
Aortic arch senses increase in MAP so reduces HR to reduce BP Also squashing of vagus nerve with increased MAP causes reduced HR
28
How is irregular breathing triggered
Raised ICP leads to cerebellar tonsil herniation which compresses the brainstem which contains Resp centres
29
Different types of herniation | PIC ON SLIDES
- Tonsillar herniation (aka cerebellar herniation ) - Sub-falcine herniation - Uncal herniation - Central downward herniation - external herniation through an open skull fracture
30
7 Early symptoms of raised ICP
- headache - Nausea + Vomiting - difficulty concentrating or drowsiness (May be subtle, difficulty with daily activities) - focal neurological signs - confusion - double vision - seizures (May be experienced as blackouts )
31
Features of the headache
- present on waking - worse on bending, coughing - constant
32
Features of double vision
- difficulty accommodating - worsening eyesight - visual field defects - papilloedema
33
What is Papilloedema?
Optic disc swelling
34
What is IIH?
Idiopathic intracranial hypertension AKA benign intracranial hypertension Aetiology not well understood
35
Who does IIH usually occur in and how can it be improved ?
- usually obese middle aged females | - Improves with weight loss and BP control
36
What is key to diagnosing IIH?
Lumbar puncture with high opening pressure | >25cmH20
37
How is ICP monitored
- Using ICP bolt - drill hole in skull, out transfused through, can measure pressure as continuous waveform Allows to see changes in ICP before Cushing’s reflex escalates - can also do Brain oximetry - to check brain perfusion, not as common.
38
How is Cushing’s reflex prevented from escalating/ brain protection measures 7 ways ?
- airway control and ventilation - circulatory support - sedation, analgesia, paralysis - head up (15 -30°) position - temperature - anticonvulsants - nutrition and PPI
39
Why is airway control and ventilation needed
To ensure optimal oxygenation and ventilation | Removal of CO2
40
Why is circulatory support needed
Maintain MAP to allow adequate CPPP
41
Why is sedation, analgesia and paralysis required
Decreases cerebral metabolic demand | Prevents cough, shivering, posturing
42
Whyat angle is the head up position needed And why
Angle : 15-30° To improve cerebral venous drainage Also take off C-spine collar
43
What needs to be done about temperature and why
Avoid Hugh temperature As Hugh temperature would increase metabolic demand Some units advocate cooling
44
2 reasons Why anticonvulsants needed
- To prevent seizure | - Reduce metabolic demand
45
Why is nutrition and PPIs important | 2 reasons
- Improved healing of injuries | - prevention of Cushing’s ulcer
46
How is raised ICP treated
- Mannitol - 3% hypertonic saline Both these have osmotic effect, draw out fluid Mannitol also has diuretic effect - external ventricular drain
47
If all else fails how is raised ICO treated
Decompressive craniectomy

NEURO (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions