2(E): Raised ICP Flashcards
(94 cards)
1
Q
What is normal range ICP
A
5-15mmHg
2
Q
What ICP is considered raised
A
Above 20mmHg
3
Q
What 4 focal mass effects cause raised ICP
A
Bleed: extradural, SAH
Intracranial tumour
Abscess
Hydrocephalus
4
Q
What diffuse mass effective lead to raised ICP
A
Vasogenic oedema
Cytogenic oedema
Ischemic stroke
Meningitis
5
Q
What is cytogenic oedema
A
Accumulation fluid in brain parenchyma due to build up Na+ and H2O
6
Q
What is vasogenic oedema
A
Build-up fluid in interstitial space
7
Q
What causes oedema
A
Ischaemic Strokes
Meningitis
8
Q
Explain ‘early’ clinical-presentation of raised ICP
A
- Headache: worse in mornings, on sneezing, coughing, moving head
- Vomiting
- Lethargy
- Altered mental state
9
Q
What are late clinical symptoms of raised ICP
A
- Continuous vomiting
- CN3 Palsy
- Decrease in GCS
- Cushing’s triad (bradycardia, HTN, irregular respiration)
- Coma and death
10
Q
What may be seen on fundoscopy in raised ICP
A
Papilloedema
11
Q
What doctrine explains why raise in ICP can cause herniation
A
Monroe-Kellie doctrine
12
Q
What is uncal herniation also called
A
Trans-tentorial
13
Q
What is trans-tentorial herniation
A
Uncus of hippocampus is forced under tentorium
14
Q
What are three signs of transtentorial herniation
A
- CN3 Palsy
- Ipsilateral weakness
- Occludes PCA - causing ischaemic stroke of occipital lobe = homonymous hemianopia with macula sparing
15
Q
How does CN3 palsy present
A
- Fixed Mid-Dilated Pupil
- Eye deviated down and out
16
Q
What is central herniation
A
Diencephalon passes through tentorium
17
Q
How does central herniation present
A
Sunset eyes
- Paralysis of upward gaze meaning eyes appear downwards
- Lower eyelid may cover lower half of pupil
- Only sclera is visible between pupil and upper eyelid
18
Q
When is sunsetting of the eyes particularly common
A
Children with raised ICP
19
Q
What is cingulate herniation also known as
A
Subfalcrine
20
Q
What is sub-falcine herniation
A
Herniation of cingulate gyrus through fall cerebri
21
Q
What does sub-falcrine herniation cause
A
Compress ACA causing ischaemic stroke
22
Q
What is upward cerebellar herniation
A
Vermis is pushed upwards through transtentorium
23
Q
What is tonsillar herniation
A
Herniation cerebellar tonsils through foramen magnum
24
Q
How does tonsillar herniation present
A
- Compress brainstem causing respiratory and cardiac dysfunction
- Headache, neck stiffness
- Drop in GCS
25
What are indications for ICP monitoring
- Hydrocephalus
- TBI
- High-risk hydrocephalus (SOL, IIH, SAH, Reye's)
26
What are contraindications for ICP monitoring
Anticoagulation
| Brain abscess
27
What are the three types of ICP monitoring
EVD
Subarachnoid bolt
Extradural bolt
28
What is external ventricular drain also known as
Fluid-filled transducer ventriculostomy
29
What is gold-standard for ICP monitoring
EVD
30
What is the advantage of external ventricular drain
Able to drain CSF
31
Where is EVD placed
Kocher Point
32
What is the advantage of subarachnoid bolt
Less invasive than EVD
33
What is the problem with subarachnoid bolt
- High infection risk
| - Limited therapeutic use
34
What is advantage of epidural bolt
- Less Infection risk then subarachnoid bolt
35
What is problem with epidural bolt
- Limited use
36
If raised ICP is suspected, how should patient be approached
A-E
IV Access
O2 if required
Basic investigations to determine cause
37
If GCS less than 8, how is patient managed
- Nurse at 30'
- Anaesthetist to intubate
Treat ICP if signs herniation:
- Mannitol or Hyper-osmotic Saline
- Hyperventilation (Ambubag)
38
If GCS is more than 8 in suspected raised ICP what is ordered
CT Scan to identify lesion
39
If lesion is identified on CT what should be done
Dexamethasone and refer to neurosurgery
40
Define idiopathic intracranial HTN (Bening intracranial HTN)
Raised in ICP (above 20mmHg) with no hydrocephalus or mass present
41
What demographic is IIH more common in
Obese women 15-45 years
| Especially if gained weight quickly
42
What are 3 broad risk factors for IIH
- Pregnant
- Obese
- Medications
43
What 5 medications increase risk of IIH
- Lithium
- Steroids
- Vitamin A
- GH
- Tetracycline
44
How does IIH present clinically
- Headache: may be associated with nausea and vomiting
- Visual changes
- CN6 Palsy
45
What visual changes may occur in IIH
- Enlarged blind spot
- Blurred vision
- Papilloedema
46
How does CN6 Palsy present
Horizontal diplopia - due to inability to abduct
47
What will be seen on ophthalmoscopy in IIH
Bilateral papilloedema
48
What should be ordered in all cases of IIH and why
MRI - Identify and exclude structural lesions
49
Aside from MRI, what other investigation may be performed in IIH
LP
50
What will be seen on LP in IIH
Opening pressure of more than 26
51
What indicates a very raised opening pressure
>30mmHg
52
What conservative management is indicated for IIH
Weight Loss
| Medication review
53
What medical management is indicated for IIH
Acetazolamide
| Topiramate
54
Why may topiramate be beneficial
Also helps with weight loss
55
What surgical management may be indicated for iIH
- Optic nerve sheath decompression
| - VP Shunt
56
Define hydrocephalus
Dilation of ventricles, due to accumulation of CSF
57
What are the two types of hydrocephalus
1. Obstructive (Non-communicating)
| 2. Non-Obstructive (Communicating)
58
What is communicating hydrocephalus also know as
Non-obstructive
59
What causes communicating hydrocephalus
Increase CSF production
| Decrease CSF reabsorption
60
What is obstructive hydrocephalus also known as
Non-Communicating
61
What is obstructive (non-communicating hydrocephalus)
Obstruction to CSF Flow
62
What is hydrocephalus ex vacuo stand for
Compensatory enlargement of ventricles secondary to brain atrophy
63
In communicating hydrocephalus, what can increase CSF production
Chorioid carcinoma
| Chorioid papilloma
64
In communicating hydrocephalus, what are 3 causes of decrease CSF absorption
- Inflammation: eg. meningitis
- Haemorrhage: SAH or IV
- Congenital absece arachnoid villi
65
Why does SAH and IV Haemorrhage cause decreased absorption of CSF
Leads to fibrosis which can occlude arachnoid villi
66
In obstructive hydrocephalus, how may causes be divided
Congenital
| Acquired
67
What are two congenital causes of obstructive hydrocephalus
- Dandy-Walker Malformation
| - Arnold-Chiari Malformation
68
What is a dandy walker malformation
Congenital malformation due to failure fourth-ventricle to close
69
What are 3 acquired causes of obstructive hydrocephalus
- Brain tumour
- SAH or IV Haemorrhage
- Inflammaiton: post-meningitis
70
Overall, how does hydrocephalus present clinically
Symptoms raised ICP
- Morning Headache
- N+V
- Drop in GCS
- Cushing's Reflex When Severe
71
When does the anterior fontanelle close in infants
1-3 years
72
Explain symptoms raised ICP in children
- As anterior fontanelle has not closed head has room to expand causing MACROCEPHALY
- The open anterior fontanelle may feel tense and BULDGE
- Compression of superior colliculus due to raised ICP causes upward gaze palsy presenting as sun-setting eyes
73
What are sunsetting eyes
Individual has upward gaze palsy meaning pupils appear as if facing downwards. The lower eyelid may cover half of the pupil. Only sclera can be seen between pupil and upper eyelid
74
In infants under 6-months, what is used to identify hydrocephalus
US
75
What is used for children with suspected hydrocephalus
CT or MRI
76
What will be seen on CT/MRI in obstructive hydrocephalus
Dilation of ventricles superior to the obstruction
77
What will be seen on CT/MRI in non-obstructive hydrocephalus
Dilation of all ventricles
78
When should an LP only be performed in hydrocephalus
If communicating (Non-obstructive) hydrocephalus
79
What is first-line for acute hydrocephalus
External ventricular drain
| Drains into bag beside the bed-side
80
Where is external ventricular drain inserted
Right lateral ventricle
81
What is long-term management for hydrocephalus
VP Shunt
82
What is normal pressure hydrocephalus
Communicating hydrocephalus with normal opening pressure
83
In which age-group does normal pressure hydrocephalus occur
Over 60's
84
What is the mnemonic to remember symptoms in normal pressure hydrocephalus
Wet, Wacky, Wobbly
85
What triad of symptoms occurs in normal pressure hydrocephalus
- Urinary Incontinence
- Ataxia
- Dementia
86
Why does wet occur
- Dilation of ventricles disrupts the cona radiata causing urinary incontinence
87
What is wacky section of normal pressure hydrocpephalus
- Dementia
88
What is wobbly section of normal pressure hydrocephalus
- Ataxia
| - Wide based gait with small steps
89
How will gait appear in normal-pressure hydrocephalus
Wide base, small-steps
90
How will normal pressure hydrocephalus present on CT or MRI
Enlarged fourth ventricle
91
What is a arnold-chiari malformation
Herniation cerebellar tonsils, vermis and medulla through foramen magnum
92
When will arnold-chiari symptoms manifest
Infancy
93
What does Arnold chair malformation cause
- Obstructive hydrocephalus (due to stenosis cerebral aqueduct)
- Feeding difficulties
- Breathing difficulties
94
What are Arnold chiari malformations associated with
Myelomeningocele
| Syringomyelia
