Week 3 - D - Stroke - Pathophysiology, treatment, follow up

Question 1

Why does an upper motor neuron lesion lead to hyperreflexia and spasticity of the muscle?

Answer 1

Basically there is the loss of inhibitory descending inputs to the lower motor neuron supplying the muscle so there is increased muscle tone and exaggerated reflexes

Question 2

Why does a lower motor neuron lesion lead to atrophy and fasciculations?

Answer 2

The muscles twitches as there may be a small number of motor units that are firing but not enough to cause actual contraction

Atrophy will occur due to there being no nerve supply to the muscle

Question 3

• Stroke is the experience of persisting neurological complications of cardiovascular disease – NOT a diagnosis

What are the symptoms of stroke via the acronym FAST?

Answer 3

F - facial drooping usually occurs unilaterally (or unable to open an eye or even smile)
A - arms, patient may be unable to lift both arms due to weakness in one of the arms

S - Speech may be slurred or unable to speak despite appearing awake

T - tiime to call 999

Question 4

What are the main types of stroke?

Answer 4

Ichaemic stroke - most common at 85%

Haemorrhagic stroke - 10% of strokes

Subarachnoid haemorrhage - 5% of strokes

Question 5

What are the different causes of ischaemic stroke?

Answer 5

Cardioembolic, atheroembolic and small vessel disease are the main causes of ischaemic stroke - artery becomes occluded resulting in loss of blood supply to an area of the brain

Question 6

What is the main cause of haemorrhagic stroke?

What is the condition in which proteins called amyloid build up on the walls

Answer 6

Main cause of haemorrhagic stroke is hypertension

Cerebral amyloid angiopathy is the condition where amyloid deposits are found in the arteries of the brain (this is linked with alzheimer’s dementia but differers from the amyloid depositied in the

Question 7

What are the three pathological hallmarks of alzhiemers dementia?

Answer 7

Loss of cortical neurons (widening of gyri basically)
Senile plaques - these are amyloid beta protein deposition in the brain parenchyma

Neurofibrillary tangles are aggregates of Tau proteins

Question 8

Give the difference in definition between a transient ischaemic attack and a stroke?

Answer 8

Stroke is focal neurological deficit lasting longer than 24 hours due to an interruption in blood supply to the brain

The original definition of a transient ischaemic attack (TIA) was time-based: a sudden onset of a focal neurologic symptom and/or sign lasting less than 24 hours, brought on by a transient decrease in blood flow.

However, this has now changed as it is recognised that even short periods of ischaemia can result in pathological changes to the brain. Therefore, a new ‘tissue-based’ definition is now used: a transient episode of neurologic dysfunction caused by focal brain, spinal cord, or retinal ischaemia, without acute infarction.

Question 9

What type of dementia can multiple TIAs be a precursor to?

Answer 9

Due to TIAs actually causing damage to the brain, they can cause vascular dementia

Question 10

The key to diagnosis of a TIA is via history as the symptoms have usually gone by this time

What is the risk reduction in a stroke happening in a patient who has had a TIA and has been managed early?

Answer 10

80% risk reduction in stroke if a TIA is managed early

Question 11

If a patient experiences a transient ischaemic attack, what is the scoring system used to determine whether the patient is likely to have a stroke or not and therefore referral should be performed?

Answer 11

This is the ABCD2 scoring system

Question 12

The maximum score in the ABCD2 scoring system is 7

What are the different categories?

Answer 12

• Age
• Blood pressure
• Clinical features
• Unilateral weakness
• Speech disturbance w/oweakness Duration of symptoms
• Symptoms lasting =/> 1hours
• Symptoms lasting 10-59 minutes Diabetes

Question 13

Age

Blood pressure

Clinical features

• Unilateral weakness
• Speech disturbance without weakness

Duration of symptoms

Less or greater than an hour

Diabetes

How is each score categorised?

Answer 13

• Age >/= 60
• Blood pressure >/= 140/90
• Clinical features - if unilateral weakness then 2 points, if speech disturbance without weakness then 1 point
• Duration - If symptoms have last >/= 1 hour then 2 points, if 10-59 minutes then 1 point
• Diabetes - 1 point

Question 14

What score should be referred to a specialist within 24 hours?

When should all patients with a suspected TIA be seen within?

Answer 14

ABCD2 score of >/= 4 should be assessed by a specialist within 24 hours

All patients with a TIA should be seen within 7 days

Question 15

1/3rd of all stroke presentations are stroke mimics

What are the common causes of stroke mimics?

Answer 15

Seizures, presyncope (light headedness tends to be a global brain dysfunction), space occupying lesion

Question 16

What is presyncope a common presenting factor of? what is different between presyncope and syncope?

Answer 16

Presyncope is a common presenting factor of orthostatic (postural) hypotension
Presyncope is feeling light headedness and feeling faint whereas syncope is actually fainting

Question 17

The rosier score is a stroke assessment scale for the likelihood of a stroke

What does the scale score range from and what score is indicative of a stroke?

Answer 17

ROSIER - stands recognition of stroke in emergency room
The scale ranges from -2 to +5

A score of greater than 0 is likely to be a stroke

Less than or equal to 0 decreases likelihood but does not exclude the possibility of stoke

Question 18

The rosier score asks questions on 7 different points of stroke

Try and name all seven points

Answer 18

Has there been loss of consciousness or syncope
Has there been seizure activity

Is there new acute

• Asymmetrical facial weakness
• Asymmetrical arm weakness
• Asymmetrical leg weakness
• Speech distrubance
• Visual field defects

Question 19

State what the different scoring is for all 7 points of the rosier scale?

The rosier scale detemrines the likelihood of stroke

Answer 19

Has there been loss of consciousness or syncope = -1
Has there been seizure activty = -1

New acute onset = all are on point

• Unilateral facial weakness
• Unilateral arm weakness
• Unilateral leg weakness
• Speech disturbance - Visual field defect
  A score of greater than 0 is likely to be a stroke

Less than or equal to 0 decreases likelihood but does not exclude the possibility of stoke

Question 20

What is the tool used by healthcare providers to objectively quantify the impairment caused by a stroke?

Answer 20

This is the NIHSS scoring system - national institue health stroke scale - this scale helps with prognosis

Question 21

State the different categories of the NIHSS system?

Answer 21

0 - no stroke symptoms
1-4 - minor stroke

5-15 - moderate stroke

16-20 - moderate to severe stroke

21-42 - severe stroke

Question 22

What is the first line investigation if a stroke occurs?

What is the most sensitive investigation for acute infarct and why is this not first line?

Answer 22

First line investigation is CT scan

Diffusion-weighted MRI is most sensitive for acute infarct but CT scan helps to rule out a primary heamorrhage and is therefore first line investigation (in hyperacute, plain CT setting may be normal)

Question 23

When will a CT show an infarct?

What does this mean for thrombolysis if you see an infarct on CT?

Answer 23

A CT usually takes more than 4/5 hours to show an infarct from the onset of symptoms

Therefore it used to rule out a primary haemorrhage and normally a CT in the acute phase ( 4.5 hrs and thrombolysis shouldnt be carried out

Question 24

What is the scoring system that allows the size of the stroke to be classified known as?

Answer 24

This is the oxford stroke classification

Question 25

What are the four different parameters in the Oxford stroke classification?

Answer 25

PACS - Partial Anterior circulation stroke
TACS - Total Anterior Circulation Stroke

POCS - Posterior Circulation Stroke

LACS - Lacunar stroke

Question 26

What is needed for the diagnosis of PACS?

Answer 26

PACS - Partial Anterior circulation stroke
Any 2 of the following 3:
Unilateral weakness (and/or) sensory defecit in arms/legs/face

Homonmymous hemianopia

Higher cerebral dysfunction - eg dysphasia or visuospatial disorder

Question 27

What is dysphasia and what is visuospatial disorder?

What is needed for the diagnosis of a TACS (state what it stands for)?

Answer 27

Dysphasia is a language disorder marked by impairment in speech production or comprehension
Visuospatial disorder is where the person would have a loss of awareness

TACS - total anterior circulation sydnrome.,

All three of the following-

Unilateral weakness (and/or) sensory defecit, arms, leg, face

Homonmyous hemianopia

Higher cerebral dysfunction - dysphasia, visuospatial disorder

Question 28

WHich arteries are affected in a TACS and in a PACS?

Answer 28

In total anterior circulation stroke, it would both the middle and anterior cerebral arteries that are affected

Partial anterior circulation involves the small arteries coming from, usually the middle cerebral artery

Question 29

Which arteries are affected in posterior circulation stroke?

What is the diagnosing criteria for a POCS?

Answer 29

The vertebrobasilar arteries are affected here (this includes their branches ie the cerebellar arteries)

One of
1. Cerebellar or brainstem syndrome

2. Loss of consciousness
3. Isolated homonymous hemianopia

Question 30

LACS - lacunar strokes involves perforating arteries around the internal capsule, thalamus and basal ganglia

WHat are these arteries collectively known as?

Answer 30

These are the lenticulostriate arteries - branches of the middle cerebral artery

Question 31

What are the diagnostic oxford criteria of a LACS?

Answer 31

Patient presents with 1 of the follwing
Unilateral weakness (and/or sensory deficit) of leg, arm or face

Pure sensory loss

Ataxic hemiparases (paresis means weakness) - weakness in the limbs with ataxia also (extension in upper limb, flexion in lower)

Question 32

Patient presents with isolated homonymous hemianopia, what type of stroke would this be?
Which arteries?

Patient presents with homonymous hemianopia, unilateral weakness of arm and inability to produce speech, what type of stroke would this be?

Which arteries?

Answer 32

Isolated homonymous haemianopia - this would come under the posterior circulation stroke
Vertebrobasilar arteries affected

Homonymous hemianopia, unilateral weakness of arm, inability to produce speech - total anterior circulation stroke - middle and anterior cerebral arteries affected

Question 33

Patient presents with pure sensory stroke, what type of stroke and which arteries?

Patient presents with homonymous haemianopia and a loss of there awareness in space, what type of stroke and which arteies?

PAtient presents with lcoked in syndorme, what type of stroke could cause this and which arteries?

Answer 33

Pure sensory stroke - lacunar stroke (LACS) - lenticulostriate arteries (small vessel penetrating arteries from middle cerebral artery)
Homonymous haemianopia and loss of awareness in space (visuo-spatial defect) - partial anterior circulation stroke (PACS) - branches of the middle cerebral artery
Locked in syndrome - also known as ventral potine syndrome - brainstem affected meaning - POCS (posterior circulation stroke) - Vertebrobasilar arteries affected

Question 34

In most people left side of the brain is the dominant side of the brain , therefore left side strokes tend to have a greater functional impact as it is the more dominant hemisphere
Important know the laterality of stroke

What is the least common type of oxford classification of stroke?

Answer 34

Total anterior circulation stroke is the least common type

PACS, POCS, LACS are all equally common

Question 35

What is the most common cause of ischaemic stroke accounting for 40% of the overall stroke cases?

Answer 35

This would be atheroembolic stroke

Question 36

In atheroembolic stroke, diseased carotids causes a thrombus to break off and travel to a cerebral artery causing a stroke

Is atheroembolic stroke firbin or platelet dependent?

Answer 36

Atheroembolic infarct is platelet dependent and is generally described as a white thrombus

Question 37

Most common reason people get cots forming in the heart for cardioembolic origin of stroke is due to what?

How much does this cause of cardioembolic strokes increase the overall risk of stroke occurence by?

Answer 37

Atrial fibrillation

5 fold increase in risk of stroke

Question 38

What is the scoring system used to calculate the risk of stroke in people with atrial fibrillation? (state what the individual sections are)

Answer 38

CHA2DS2VASc score (Chadsvasc)
CHF
Hypertension
Age >/- 75 = 2points

Diabetes

Stroke/TIA previous = 2 points

Vascular disease

Age 65 - 74

Sex category (female) - max score is 9

Question 39

What are two causes of haemorrhagic stroke again?

Answer 39

Hypertension - main cause
Cerebral amyloid angiopathy - amyloid deposits in blood vessels make bleeds more likley (also increase risk of Alzhiemer’s disease)

Question 40

What are some pointers to haemorrhagic stroke? (ie symptoms)

If an ECG is negative for atrial fibrillation, what is carried out for next investgation?

Answer 40

Meningism - stiff neck, headache, photophobia
Headache leading to coma

If ECG negative for Afib, carry out a 72 hour ECG tape

Question 41

Need to CT scan first to rule out haemorrhage because if they have a haemorrhage then not going to thrombolyse or give aspirin

If CT is potivie for infarct, thrombolysis is given if within what time limit?
What is given if over this time limit?

Answer 41

If within 4.5 hours then thrombolyse the patient

If over 4.5 hours give patient IV aspirin and supportive care

Question 42

If thrombolysis is given, how long must be waited before giving aspirin to the patient?
What investigation must be carried out before giving the aspirin?

Answer 42

24 hour post thrombolysis CT scan must be carried out to show an absence of intracranial haemorrhage before giving aspirin (need to wait at least 24 hours post thrombolysis)

Question 43

If the cause of the stroke is found to be atheroembolic (due to a carotid scan), what is given?

If the cause of the stroke is found to be cardioembolic (ECG) , what is given?

Answer 43

Atheroembolic
Aspirin (300mg) for 14days post stroke and then

1st line - clopidogrel 75mg indefinitely , 2nd line - Aspirin + dipyridamole

Cardioembolic

Aspirin for 14 days then life long anticoagulant therapy (warfarin usually drug of choice or NOACs)

Question 44

Anticoagulants are not routinely recommended in the long-term prevention of recurrent stroke, except in patients with atrial fibrillation.

Irrespective of the patients cholesterol level, how quicly should a statin be started?

Answer 44

if the cholesterol is > 3.5 mmol/l patients should be commenced on a statin. Many physicians will delay treatment until after at least 48 hours due to the risk of haemorrhagic transformation

Question 45

What treatment is given to reduce the risk of DVT post stroke in patients?

Answer 45

Intermittent pneumatic compression

Question 46

So for full diagnosis – need laterality, type and size of stroke (eg left cerebral, cardioembolic POCI)
WHat is the diagnosis of POCI? WHich arteries are affected?

55 year old male presents with sudden onset of weakness in left side of his arms and face, with dysphasia. he is known to have carotid steonsos

Give the full diagnosis of the stroke?

Answer 46

POCI - the vertebrobasilar arteries are affected - ONE OF

• Loss of consciousness
• Cranial nerve or brainstem features
• Isolated homonymous hemianopia55 year old male answer -
• Right cerebral, atheroembolic PACI
• Most likely to be a PACI - two of the following
• Unilateral weakness (and/or) sensory deficit in face, arms legs - Homonymous hemianopia, higher cerebral dysfuncton

Question 47

What symptoms may arise if a patient has a stroke affecting the
Anterior cerebral artery
Middle cerebral artery
Posterior cerebral artery

Answer 47

Anterior cerebral - Contralateral hemiparesis and sensory loss, lower extremity > upper

Middle cerebral - Contralateral hemiparesis and sensory loss, upper extremity > lower
Contralateral homonymous hemianopia
Aphasia

Posterior cerebral artery - Contralateral homonymous hemianopia with macular sparing
Visual agnosia