Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Neuroscience > 10.2 Pathophysiology and management of raised intracranial pressure. > Flashcards

10.2 Pathophysiology and management of raised intracranial pressure. Flashcards

1
Q

What are the normal ranges of ICP for adults, children and infants?

A

Adults: 5-15 mmHg
Young Children: 3-7 mmHg
Term Infants: 1.5-6 mmHg

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

Describe the components that contribute to normal intracranial pressure

A 
Brain parenchyma (80%)
CSF volume (10%)
Blood volume (10%)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the normal volume of blood and CSF in the cranium?

A

150 ml of blood

150ml of CSF

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

How are the usual components of the cranium affected in a space occupying lesion?

A

CSF and blood volumes are depleated first, before the brain has to start reducing in volume. Done by herniating out between the different foramen of the skull

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

What is shown by the intracranial elastance curve?

A

Initially there is steady / stable pressure in the cranium as the volume increases. This is because of compensatory mechanisms. After compensatory mechanisms overcome/ exhausted then the pressure gradually increases

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

How much of the CO does the brain usually receive?

A

15-20%

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

What blood vessels supply the brain

A

Internal carotid arteries

Vertebral arteries

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

What is the equation for cerebral perfusion pressure?

A

CPP = mean arterial pressure - intracranial pressure.

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

What is the normal cerebral perfusion pressure?

A

Greater than 70mmHg

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

What is the normal mean arterial pressure?

A

90mmHg

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

What is the normal intracranial pressure?

A

10mmHg

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

How do we calculate mean arterial pressure?

A

DBP + 1/3 (SBP-DBP) = MAP

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

What systemic changes occur to maintain cerebral perfusion pressure when intracranial pressure increases?

A

Increase in blood pressure to increase the mean arterial pressure. This overcomes the increase in intracranial pressure.

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

Where is CSF produced?

A

choroid plexus

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

How much CSF is produced a day?

A

500ml

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

Name some of the main functions of CSF

A

Homeostasis, protection, buoyancy and waste clearance

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

What are the 3 types of brain herniation that occur during increased intracranial pressure?

A

Subfalcine herniation (most common)
Tonsillar herniation
Uncial herniation

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

What is subfalcine herniation?

A

Cingulate gyrus from one of the cerebral hemispheres shifting across the midline under the falx cerebri

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

What is a tonsillar herniation?

A

Cerebellar tonsils herniate through the foramen magnum, which can compress the medulla and the cardirespiratory centres so patients may present with problems with their breathing if this happens

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

What is uncal herniation?

A

Herniation of the uncus of the medial temporal lobe herniating through the tentorial notch which can compress important structures in the midbrain

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

What are the clinical features of raised intracranial pressure?

A 
Headaches - severe, wake at night, constant, worse on bending over
Nausea + vomiting 
Visual disturbances e.g. double vision/ diplopia
Confusion / changes in GCS 
Seizures 
Amnesia
Papilloedema 
Focal neurological signs E.g. CN3 palsy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What changes are seen on fundoscopy during papilloedema?

A

The optic disc appears larger, with a less well demarcated edge. Appears swollen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is Cushing’s triad?

A

three primary signs that indicate raised intracranial pressure

  • hypertension
  • bradycardia
  • irregular breathing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Why are cushings triad not used to primarily indicate raised intracranial pressure

A

As they are late signs

25
Describe the development of cushings triad
* A rise in ICP will initially lead to hypertension as the body increases MAP to maintain CPP * The increase in MAP is detected by baroreceptors which stimulate a reflex bradycardia via increased vagal activity (which can cause stomach ulcers as a dangerous side effect) * Continuing compression of the brainstem leads to damage to respiratory centres causing irregular breathing
26
What are the 2 main causes of too much blood within the cerebral vessels
Raised arterial pressure - malignant hypertension Raised venous pressure - SVC obstruction
27
What are the causes of too much blood outside of the cerebral vessels?
Extra dural, sub dural, subarachnoid haemorrhage
28
What is malignant hypertension?
Systolic >180mmHg or Diastolic >120mmHg
29
What are the systemic complications of malignant hypertension?
``` Retinal haemorrhages Encephalopathy Left ventricular hypertrophy Reduced renal function Increased cardiovascular and cerebrovascular events risk due to hypertension being associated with a prothrombotic state. ```
30
What is the treatment of malignant accelerated hypertension?
Urgent referral to hospital due to high mortality rate | Decrease BP gradually to avoid ischaemic events and hypoperfusion of organs.
31
What are the common causes of superior vena cava obstruction
2 causes. Extrinsic compression of the SVC. Most commonly caused by malignancy e.g lung cancers compressing the SVC or other cancers affecting the surronding lymph nodes e.g. lymphoma Intraluminal obstruction of the SVC - clot formation around intraluminal devices.
32
How is a superior vena cave obstruction treated?
Oncological emergency | Often receive dexomethosone if not contraindicated
33
Briefly describe an extra dural haematoma
``` Blood accumulation between skull and dura Most common cause = trauma Unconscious Patient vs Patient with a ‘Lucid Interval’ CT-Biconvex shape ```
34
Briefly describe a subdural haematoma
Blood accumulation b etween Dura and Arachnoid mater CT-Concave/Crescent Can be Acute or Chronic. Acute: occurs suddenly, progresses quickly. Chronic: Slow progression Usually caused by rupture of bridging veins
35
Briefly describe a subarachnoid haemorrhage
Between arachnoid and pia mater ‘Thunderclap’ headache 85% rupture of intracranial aneurysm
36
Give an example of congenital CSF accumulation
Congenital hydrocephalus
37
What is congenital hydrocephalus?
``` Present at birth Genetic and non-genetic factors Eg. mutation in L1CAM gene linked to aqueductal stenosis Present with: Enlargement of head circumference - sutures not fused Downward gaze Delay in neurological development Irritable Difficulty feeding Seizures ```
38
How does hydrocephalus appear on CT head?
Enlarged ventricles Oedema in surrounding parenchyma- loss of markings Small soul I
39
What are the causes of obstructive hydrocephalus?
Blockage of flow of CSF 1. Aqueduct stenosis (most common) 2. Neural tube defects 3. Dandy-walker syndrome
40
What is aqueduct stenosis
Blockage or narrowing of the aqueduct of sylvius (between the third and fourth ventricles) Can be congenital or acquired
41
What is dandy-walker syndrome?
Congenital condition Enlargement of fourth ventricle Outlets of ventricle partially blocked Cerebellum not fully developed
42
What is communicating hydrocephalus?
When there is no obstruction of the flow of CSF. Caused by: 1. Overproduction of CSF e.g. choroid plexus papilloma 2. Reduced absorption of CSF e.g. Infection and inflammation leading to scarring at subarachnoid space
43
What are some causes of acquired CSF?
Intraventricular haematoma Tumour Infection (meningitis) Trauma
44
What are the 4 causes of cerebral oedema swelling of the brain
Vasogenic Osmotic Interstitial Cytotoxic
45
What is vasogenic cerebral oedema?
Disruption of blood brain barrier | Breakdown of tight junctions = increased permeability
46
What is osmotic cerebral oedema?
Usually osmolarity of extracellular fluids is equal on both sides of BBB If there is a change-osmotic gradient
47
What is cytotoxic cerebral oedema?
Injury to cells of the brain (neurones, glial cells, axons) Derangements in ATP-dependent transmembrane pumps - intracellular accumulation of fluid
48
What is interstitial cerebral oedema?
Increased pressure within the ventricles, eventual damage to their linings CSF can now be found in brain parenchyma
49
In hypoxic brain injury, how does a CT head scan appear?
Generalised cerebral oedema Loss of differentiation of the grey and white matter Sulci effaced Small ventricles
50
Why can a brain tumour and a cerebral abscess be hard to differentiate on a CT head?
Both appear as a small enhanced ring structure in the brain parenchyma
51
Where do metastasis to the brain often come from?
Lung Breast Renal Colon
52
What is the difference between an intra axial and an extra axial brain tumour ?
Intra axial is within the brain tissue itself | Extra axial is when it is outside of the brain tissue such as derived from meninges
53
What is a cerebral abscess?
Localised pus formation with capsulation within brain parenchyma. Causes: Spread of infection (direct e.g. otomastoiditis vs distance), trauma, or unknown
54
How does idiopathic intracranial hypertension present?
Present with headache and visual disturbances | Headaches are worse in the morning and at night and are relieved by standing.
55
How is idiopathic intracranial hypertension treated?
``` Weight loss (risk factor is increased BMI) Blood pressure control ```
56
How is raised intracranial pressure diagnosed?
1. History and examination - look out for signs of raised intracranial pressure 2. Investigations - bedside ( vital signs, ECG, fundoscopy) - Bloods ( FBC, U+E’s, CRP, Clotting, Group & Save, Cross- match, Blood culture) - Imaging (CT scan, MRI)
57
How is raised intracranial pressure managed?
Primary survey and using ABCDE approach Stabilise patient Simple measures - Elevate head of bed, Avoid pyrexia, Analgesia Specific medical measures Anticonvulsants, Sedation or neuromuscular blockade, Mannitol or hypertonic saline Surgical: Ventriculostomy, Decompressive craniectomy
58
What is the management of hydrocephalus?
Ventriculoperitoneum shunt | Ventriculoatrial shunt
59
What is the monro-Kellie doctrine?
Any increase in the volume of one of the intracranial constituents (brain, blood or CSF) must be compensated by a decrease in the volume of one of the others

Neuroscience (20 decks)

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