Neuro Emergency- Strokes

Question 1

A cerebrovascular event can be described as a ‘TIA’. What does this stand for?

Answer 1

TIA= Transient Ischaemic Attack

Question 2

What is a Transient Ischaemic Attack (TIA)?

Answer 2

Transient Ichaemic Attack= a stroke like condition that lasts less than 24hrs (usually <1hr). It resolves on its on with no permanent deficits. Often referred to as a ‘mini stroke’

Question 3

A cerebrovascular event can be described as a ‘RIND’. What does this stand for?

Answer 3

RIND= Reversible Ischaemic Neurological Deficit

Question 4

What is a Reversible Ischaemic Neurological Deficit (RIND)?

Answer 4

Reversible Ischaemic Neurological Deficit (RIND)= similar to a TIA but it lasts for 24-72hrs. It resolves on its own with no permanent deficits

Question 5

If a person has a TIA or a RIND, what are they then at high risk of experiencing in the next few days?

Answer 5

TIAs and RINDs are likely indicators of an impending Cerebrovascular Accident (CVA)

Question 6

Deficits from:
1. TIAs last __
2. RINDs last ___
3. CVAs last __

Answer 6

1. Deficits from TIAs last <24hrs
2. Deficits from RINDs last 24-74hrs
3. Deficits from CVAs last >72hrs

Question 7

What are the two arteries that supply the brain with blood?
(Note- Each artery has a L and R branch)

Answer 7

The brain recieves blood through:
1. INTERNAL CAROTID ARTERIES
(left & right internal carotid arteries)
2. VERTEBRAL ARTERIES
(left & right vertebral arteries)

Question 8

The Internal Carotid Artery and the Vertebral Artery are the two vessels that supply cerebral blood flow. Which one supplies 80%, and which supplies 20%?

Answer 8

CEREBRAL BLOOD FLOW:
1. Internal Carotid Artery supplies 80%
2. Vertebral Artery supplies 20%

Question 9

The Internal Carotid Arteries supply the ___ portion of the brain, while the Vertebral Arteries supply the ___ portion of the brain.
[Hint- anterior/posterior]

Answer 9

Internal Carotid Arteries= supply ANTERIOR portion
Vertebral Arteries= supply POSTERIOR portion

Question 10

What is the main branch of the Internal Carotid Artery?

Answer 10

Internal Carotid Artery branches into the MIDDLE CEREBRAL ARTERY

Question 11

What is the main branch of the Vertebral Artery?

Answer 11

Vertebral Artery branches into the POSTERIOR CEREBRAL ARTERY

Question 12

What are the 2 main types of Cerebrovascular Accidents (CVA/Stroke) that can occur? Very briefly summarise the difference

Answer 12

CEREBROVASCULAR ACCIDENTS/ STROKES:
1. Ischaemic Stroke= blood clot blocks blood flow to a portion of the brain (ischaemia) and then tissue death (infarction)
2. Haemorrhagic Stroke= rupture of blood vessels cause an intra-cranial (below skull) haemorrhage in the brain

Question 13

Strokes cause neurological deficits due to reduced cerebral blood flow/perfusion. This results from an ‘infarcted umbra’ and an ‘ischaemic penumbra’. What do these 2 terms mean?

Answer 13

Acute neurological deficits occur from:
1. Infarcted Umbra (a dead area of the brain caused by the clot)
2. Ischaemic Penumbra (the area surrounding the infarcted tissue which is at imminent danger of tissue death)

Question 14

Describe the pathophysiology of an Ischaemic Stroke
[Hint- start from the build up of plaque/atherosclerosis]

Answer 14

ISCHAEMIC STROKE:
1. Atherosclerosis/plaque builds up in the arteries of the brain
2. Plaque ruptures & platelets aggregate to site of rupture
3. a Thrombus (blood clot) is formed
4. blood vessel is occluded
5. blood & oxygen can’t get through to perfuse cerebral tissue
6. Cerebral ischaemia + infarct
7. Neurological deficits result

Question 15

Ischaemic Strokes are most often caused by a THROMBUS, but they can also be caused by an EMBOLUS. What is the difference between a thrombus & embolus?

Answer 15

A thrombus= a blood clot originating in the area where it causes deficits (eg. in the brain)
An embolus= a fragment of a thrombus (blood clot) which originated in another part of the body and then travels (eg. thrombus forms in heart, fragment breaks off, it travels to brain & then causes an ischaemic stroke). Often results from atrial-fib or a myocardial infarct

Question 16

The signs & symptoms of ischaemic strokes depend on which part of the brain is affected. If the ANTERIOR circulation of the brain is impacted, this may mean an issue with the MIDDLE CEREBRAL ARTERY (MCA). What signs/symptoms is this likely to cause?

Answer 16

Middle Cerebral Artery Stroke (supplies anterior part of brain)
- Face deficits on same side as body deficits
- Motor/sensory deficits on opposite side to the side of the occlusion
- Forehead not affected
- Speech deficits (frontal lobe affected)

Question 17

The signs & symptoms of ischaemic strokes depend on which part of the brain is affected. If the POSTERIOR circulation of the brain is impacted, this may mean an issue with the POSTERIOR CEREBRAL ARTERY (PCA). What signs/symptoms is this likely to cause?

Answer 17

Posterior Cerebral Artery Stroke (supplies posterior part of brain)
- Face deficits on opposite side as body deficits
- Face deficits reflect side of occlusion, body deficits on opposite side of occlusion
- Forehead affected (asymmetry in forehead wrinkles)
- Visual deficits (as occipital lobe often affected)
- Vertigo, severe dizzines/imbalance, double vision [not just blurry] (if brain stem is affected)

Question 18

Describe the pathophysiology of a Hemorrhagic Stroke
[Hint- start with Hypertension]

Answer 18

HEMORRHAGIC STROKE:
1. Hypertension
2. Rupture of vessel in brain
3. Reduction of tissue perfusion [as a) blood/oxygen is no longer flowing through vessel…AND… b) brain is being compressed due to increased volume causing increased ICP]
4. Neurological deficits result

Question 19

What are some red flag signs which may point towards a hemorrhagic stroke?

Answer 19

Red Flags for HEMORRHAGIC STROKES:
1. Thunderclap headache, or headache with an acute onset & reaches 10/10 intensity in minutes
2. Significantly reduced GCS/ collapse
3. Vomiting
4. Seizures
5. No facial deficits
6. Cushing’s Triad Signs from increased ICP [Widening pulse pressure + Bradycardia + Irregular respirations]

Question 20

Hemorrhagic Strokes cause Intra-cranial haemorrhage. What are the 2 most common areas of the brain that this occurs in? Which area often causes the classic ‘thunderclap’ hemorrhagic stroke headache

Answer 20

Hemorrhagic Strokes cause Intra-cranial Haemorrhage. This includes:
1. Subarachnoid Haemorrhage (SAH) [below arachnoid, above cerebral cortext] - typically causes the classic thunderclap headache
2. Intracerebral Haemorrhage (ICH)
[within the cerebral cortex]

Question 21

A patients medical history can also provide some CLUES (not 100% accurate) as to if their stroke is ischaemic or haemorrhagic. What would you suspect if they have a history of:
a) Atrial Fibrillation
b) Anti-coagulant Meds
c) Hypertension

Answer 21

a) Atrial Fibrillation is often associated with ischaemic strokes
b) Anti-cogulants are often associated with haemorrhagic strokes
c) Hypertension is often associated with haemorrhagic strokes

Question 22

Why do patients with a history of Atrial Fibrillation have a increased risk of having an ischaemic stroke

Answer 22

Atrial Fibrillation impairs atrial contraction. This results in stasis of blood and increases risk of developing a thrombus. A fragment of this thrombus can break off and form an embolus which can then travel to the brain & cause an ischaemic stroke

Question 23

Strokes can result in a range of neurological deficits/signs & symptoms. What do the following terms mean:
1. Diplopia [Hint- eyes]
2. Ataxia [Hint- movement]
3. Hemiparesis [Hint- paralysis]
4. a. Dysarthria, b. Dysphasia [Hint- speech]
5. Dysphagia [Hint- throat]

Answer 23

Neurological/ Stroke Deficit Terminology:
1. Diplopia= double vision
2. Ataxia= trouble coordinating movement
3. Hemiparesis= paralysis on 1 side
4a. Dysarthria= trouble actually speaking
4b. Dysphasia= trouble with language/words
5. Dysphagia= trouble swallowing
[ :P Memory Hack- ‘G’ in dysphaGia is for GAG. but ‘S’ in dysphaSia is for SPEAK]

Question 24

If a stroke patient has asymmetrical ‘Palpebral Fissure’, what does this mean?

Answer 24

Palpebral Fissue= space between upper & lower eyelid
Asymmetrical Palpebral Fissue= on one side of the face, the space is larger than the other side- indicating an eye droop

Question 25

What is the prehospital management of strokes? Think about:
1. General management [eg. airway, pain, maintaining ICP]
2. Stroke specific management [eg. FAST, ‘Hyperacute Stroke Mandatory Critria’, type of cannula, destination]

Answer 25

Pre-hospital management of STROKES:
1. GENERAL- airway patency w/position & adjunct (if reduced GCS), paracetamol for pain, manage ICP by 30 degree stretcher head & antiemetics to prevent gagging/vomiting
2. STROKE SPECIFIC- FAST assessment, assess against hyperacute stroke mandatory criteria (HAMC), if pts meets it- 18G in ACF, pre-notify, transport to highest level stroke facility within 90min drive time (#1- acute thrombolytic centre, #2- acute stroke unit, #3- ED)
[Note- HAMC= FAST+, arrival to ED is <4.5hrs from symptom onset, >18yo, BGL >4mmol]

Question 26

What are some differential diagnoses for a stroke?

Answer 26

Stroke Differential Diagnoses (conditions that mimic a stroke)
a) Hypoglycaemia
b) Post-ictal (can cause todds paresis, decreased GCS)
c) Bells Palsy (temporary unilateral facial paralysis from trauma/infection)
d) Peripheral nerve damage (eg. from T2DM)