Stroke Flashcards
Clinical definition of a stroke? [1]
Different types of stroke? [3]
Condition characterized by rapidly
progressive clinical symptoms and signs of
focal, and at times global, loss of cerebral
function lasting more that 24hrs or leading to death with no apparent cause other than that of vascular origin
Hemorrhagic Stroke
- Intracerebral Hemorrhage (rupture of a blood vessel within the brain parenchyma)
- Subarachnoid Haemorrhage (aused by bleeding into the subarachnoid space, typically due to the rupture of an intracranial aneurysm or arteriovenous malformation)
Ischemic Stroke (87% all strokes)
- Thrombotic Stroke ( blood clot (thrombus) forms within an artery supplying blood to the brain, usually due to atherosclerosis)
- Embolic stroke occurs when a blood clot or other debris (embolus) from another part of the body travels through the bloodstream and becomes lodged in an artery supplying blood to the brain.
What are the primary [1] and secondary [+] causes of ICH?
Primary
⚫ Hypertension (microaneurysm)
Secondary
⚫ Trauma
⚫ Cerebral Amyloid Angiopathy
⚫ AVM
⚫ Haemorrhagic transformation of infarct
⚫ Tumour
⚫ Venous thrombosis
⚫ Drugs e.g. cocaine
⚫ Vasculitis
⚫ Coagulopathy / Anticoagulation/ TPA
When assessing strokes initally based off symptoms - which three criteria should be assessed? [3]
The following criteria should be assessed:
1. unilateral hemiparesis and/or hemisensory loss of the face, arm & leg
2. homonymous hemianopia
3. higher cognitive dysfunction e.g. dysphasia
Total anterior circulation infarcts (TACI, c. 15%) involves which arteries? [2]
middle and anterior cerebral arteries
Total anterior circulation infarcts (TACI, c. 15%)
involves middle and anterior cerebral arteries.
Which criteria would determine that a patient has had a stroke in this area? [3]
- What would make it a partial anterior circulation infarct? [1]
- unilateral hemiparesis and/or hemisensory loss of the face, arm & leg
- homonymous hemianopia
- higher cognitive dysfunction e.g. dysphasia
NB: Partial anterior circulation infarcts (PACI, c. 25%)
involves smaller arteries of anterior circulation e.g. upper or lower division of middle cerebral artery
2 of the above criteria are present
What are the signs if stroke is lacunar / small vessels [4]
Which vessels areas of the brain are specifically affected? [3]
Lacunar – LACI (25%)
⚫ Pure motor (50%)
⚫ Pure sensory (5%)
⚫ Ataxic hemiparesis (10%)
⚫ Sensorimotor stroke (35%)]
Involves perforating arteries around the internal capsule, thalamus and basal ganglia
PM:
1. unilateral weakness (and/or sensory deficit) of face and arm, arm and leg or all three.
2. pure sensory stroke.
3. ataxic hemiparesis
Lecture / Oxford Bamford Classification:
What are the signs if stroke is caused by large vessel:
- Anterior circulation [3]
- Posterior circulation [4]
Anterior circulation - TACI/PACI (15/35%)
⚫ Unilateral motor deficit
⚫ Homonymous hemianopia
⚫ Higher cerebral function (e.g. dysphasia, neglect)
Posterior circulation - POCI (25%)
⚫ Pure hemianopia
⚫ Cerebellar signs
⚫ Diplopia & CN palsy
⚫ Bilateral/crossed
sensory-motor sign
Posterior circulation infarcts (POCI, c. 25%)
involves [] arteries
Posterior circulation infarcts (POCI, c. 25%)
involves vertebrobasilar arteries
Posterior circulation infarcts (POCI, c. 25%)
involves vertebrobasilar arteries
presents with 1 of which symptoms? [3]
- cerebellar or brainstem syndromes
- loss of consciousness
- isolated homonymous hemianopia
Lateral medullary syndrome (posterior inferior cerebellar artery)
aka []’s syndrome
Lateral medullary syndrome (posterior inferior cerebellar artery)
aka Wallenberg’s syndrome
Describe the features of Lateral medullary syndrome (posterior inferior cerebellar artery) aka Wallenberg’s syndrome:
- Ipsilateral [6]
- Contralateral [1]
ipsilateral: ataxia, nystagmus, dysphagia, facial numbness, cranial nerve palsy e.g. Horner’s
contralateral: limb sensory loss
Which two features would indicate Weber’s syndrome? [2]
Weber’s syndrome
* ipsilateral III palsy
* contralateral weakness
50% of strokes = embolic
– mainly from which arteries? [2]
50% = embolic – mainly from carotid arteries or aortic arch;
Also 20% cardioembolic (AF etc)
Describe the features of a stroke by the site of the lesion:
- ACA [3]
Anterior cerebral artery
- Contralateral hemiparesis and sensory loss, lower extremity > upper
Classically, an isolated infarction of the anterior cerebral artery leads to contralateral leg weakness only.
- This is because individual areas of the motor and sensory cortex that control movement and sensation, respectively, correspond to specific areas of the body.
Describe the features of a stroke by the site of the lesion:
- MCA [4]
- Contralateral hemiparesis and sensory loss, upper extremity > lower
- Contralateral homonymous hemianopia
- Aphasia
Describe the features of a stroke by the site of the lesion:
- PCA [2]
Contralateral homonymous hemianopia with macular sparing
Visual agnosia
Describe the features of a stroke by the site of the lesion:
- Anterior inferior cerebellar artery (lateral pontine syndrome) [3]
- Posterior inferior cerebellar artery (lateral medullary syndrome, Wallenberg syndrome)
Posterior inferior cerebellar artery (lateral medullary syndrome, Wallenberg syndrome:
* Ipsilateral: facial pain and temperature loss
* Contralateral: limb/torso pain and temperature loss
* Ataxia, nystagmus
Anterior inferior cerebellar artery (lateral pontine syndrome):
- Symptoms are similar to Wallenberg’s (see above), but:
- Ipsilateral: facial paralysis and deafness
Whilst symptoms alone cannot be used to differentiate haemorrhagic from ischaemic strokes, patients who’ve suffered haemorrhages are more likely to have: [4]
decrease in the level of consciousness: seen in up to 50% of patients with a haemorrhagic stroke
headache is also much more common in haemorrhagic stroke
nausea and vomiting is also common
seizures occur in up to 25% of patients
Cerebral hemisphere infarcts may have the following symptoms: [4]
contralateral hemiplegia: initially flaccid then spastic
contralateral sensory loss
homonymous hemianopia
dysphasia
Complications of ICH? 5]
Local damage
Local mass effect / Herniation
Raised ICP
Hydrocephalus
Describe the imaging investigations used for ?stroke [3]
Non contrast CT head is the key investigation in patients presenting with a suspected stroke.
- very sensitive for detecting cerebral haemorrhage
- In an ischaemic stroke, CT imaging is often normal in the first few hours. Therefore, a normal CT head in the presence of neurological symptoms is presumed secondary to ischaemia.
CT Angiography.
MRI with diffusion weighted imaging (DWI) sequence is more sensitive for acute ischaemia
How do you determine if a stroke is ischaemic / haemorrhagic? [2]
The first step in acute management is to determine whether the stroke is haemorrhagic or ischaemic on the initial CT.
- If the CT head does not reveal any signs of intracerebral bleeding then the patient is managed as an ischaemic stroke
- If signs of intracerebral bleeding: haemorrhagic stroke
Describe the acute management of an ischaemic stroke [+]
One: Non-contrast CT:
- reveals no signs on intracranial bleeding
Two: Thrombolysis OR Thrombectomy
- Thrombolysis with Alteplase if NIH stroke scale >5 and < 26 and within 4.5hrs of onset. Blood pressure should be lowered to 185/110 mmHg before thrombolysis.
- If thrombolysis was given, aspirin is usually started 24-48 hours following treatment.
Thrombectomy
- pre-stroke functional status of less than 3 on the modified Rankin scale and a score of more than 5 on the National Institutes of Health Stroke Scale (NIHSS)
- Offer thrombectomy as soon as possible and within 6 hours of symptom onset, together with intravenous thrombolysis (if within 4.5 hours), to people who have:
acute ischaemic stroke and
confirmed occlusion of the proximal anterior circulation demonstrated by computed tomographic angiography (CTA) or magnetic resonance angiography (MRA)
- Offer thrombectomy as soon as possible to people who were last known to be well between 6 hours and 24 hours previously (including wake-up strokes): confirmed occlusion of the proximal anterior circulation demonstrated by CTA or MRA AND
if there is the potential to salvage brain tissue, as shown by imaging such as CT perfusion or diffusion-weighted MRI sequences showing limited infarct core volume
- Consider thrombectomy together with intravenous thrombolysis (if within 4.5 hours) as soon as possible for people last known to be well up to 24 hours previously (including wake-up strokes):
who have acute ischaemic stroke and confirmed occlusion of the proximal posterior circulation (that is, basilar or posterior cerebral artery) demonstrated by CTA or MRA and
if there is the potential to salvage brain tissue, as shown by imaging such as CT perfusion or diffusion-weighted MRI sequences showing limited infarct core volume
Acute stroke management:
with regards to atrial fibrillation, what advice is given about starting anticoagulants? [1]
with regards to atrial fibrillation, the RCP state: ‘anticoagulants should not be started until brain imaging has excluded haemorrhage, and usually not until 14 days have passed from the onset of an ischaemic stroke’
Acute ischaemic stroke management:
How do you manage a patient if thrombolysis is not appropriate? [2]
If thrombolysis is not appropriate, patients should be started immediately on 300 mg of aspirin for two weeks.
After two weeks, conversion to secondary prophylaxis with 75 mg clopidogrel is indicated unless anti-coagulation (e.g. NOAC) is appropriate because of aetiology (e.g. AF).
Describe the secondary prevention that would give for someone who has had a stroke [+]
Recommendations from NICE include:
* clopidogrel is now recommended by NICE ahead of combination use of aspirin plus modified-release (MR) dipyridamole in people who have had an ischaemic stroke
* aspirin is recommended after an ischaemic stroke only if clopidogrel is contraindicated or not tolerated
Carotid endarterectomy is recommend if the patient has suffered a stroke or TIA in the carotid territory and is not severely disabled:
* should only be considered if the stenosis > 50% according to North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria
- it should be performed as soon as possible within 7 days
Blood pressure control
Blood glucose control:
- maintain glucose between 4-11 mmol/L. Optimise diabetic control
What are the absolute contraindications to thrombolysis? [+]
- Previous intracranial haemorrhage
- Seizure at onset of stroke
- Intracranial neoplasm
- Suspected subarachnoid haemorrhage
- Stroke or traumatic brain injury in preceding 3 months
- Lumbar puncture in preceding 7 days
- Gastrointestinal haemorrhage in preceding 3 weeks
- Active bleeding
- Oesophageal varices
- Uncontrolled hypertension >200/120mmHg
Which non-imaging investigations would you perform for someone with ?stroke [4+]
Bedside: observations, blood glucose, ECG (AF)
Bloods: FBC, U&Es, Bone profile, LFT, ESR, coagulation, lipid profile, HbA1c
- These help rule out mimics like hypoglycaemia or metabolic disturbances, assess risk factors such as dyslipidaemia or diabetes mellitus
Special:
- Echocardiography: PFO; AF; valvular disease
- 24 hour tape: AF, young stroke screen - useful for AF
Carotid imaging:
- Carotid Doppler ultrasound or CT/MR angiography of the neck vessels can identify significant carotid stenosis or occlusion that may be amenable to carotid endarterectomy or stenting in patients with anterior circulation stroke.
How would you distinguish Bell’s palsy from a stroke?
Bell’s palsy is another condition that can be mistaken for stroke due to its presentation with facial weakness. However, Bell’s palsy typically affects only the lower motor neurones of the facial nerve leading to unilateral facial weakness including the forehead - this differentiates it from stroke where forehead sparing is more common due to bilateral upper motor neuron innervation.
Moreover, patients with Bell’s palsy may also experience hyperacusis or altered taste on the anterior two-thirds of their tongue
What are the causes of ischaemic stroke? [5]
50% is large and medial atherosclerosis
Carotid dissection
AF - clot forms in the left atrial appendage and then moves into cerebral.
Arteriolarsclerosis (25%)
State what is meant by the Roiser Scale [1]
The ROSIER tool (Recognition Of Stroke In the Emergency Room) gives a score based on the clinical features and duration. Stroke is possible in patients scoring one or more.
Which symptoms are most likely not associated with stroke? [3]
Confusion
LOC
Convulsive fits
The FAST tool is used as a simple way to identify stroke in the community. What does this stand for? [4]
F – Face
A – Arm
S – Speech
T – Time (act fast and call 999)
What are the demographic, lifestyle, medical risk factors for stroke? [+]
Demographic
- Age, male (x1.25), race (x2), socioeconomic status
Lifestyle
- Smoking (x2), weight (x1.64), inactivity (x1.5), alcohol (x3)
Medical
* Hypertension (50% of all stroke)
* Hypercholesterolaemia
* Diabetes (x2)
* Vascular disease (PVD, IHD & CVD)
* Cardiac (Atrial fibrillation (x5); ASD/PFO)
Describe what the modified Rankin score (MRS) classifies [6]
Thrombectomy cut off is mRS 2 (i think)
Describe what is meant by an ASPECT score [1]
Measure of how much infarction there is in MCA territory
- for this score is divided to save by the score
- e.g. 10 score: 10 areas possible to save
May be suitable for thrombolytic therapy
Offer (rather than consider) anticoagulation with warfarin or new oral anticoagulants (NOACs)
Decrease in GCS, headache and nausea/vomiting are often seen
give aspirin 300mg + arrange specialist review in TIA clinic within 24 hours
Give aspirin 300mg + supportive therapy
aspirin (lifelong) & dipyridamole (lifelong), no other antiplatelets
Consider (rather than offer) anticoagulation with warfarin or new oral anticoagulants (NOACs)
Ischaemic stroke (no drug allergies) - antiplatelets: clopidogrel (lifelong), no other antiplatelets
Posterior cerebral artery
An example is a patient who presents with isolated unilateral hemiplegia without vision or speech defects
Posterior inferior cerebellar artery
Cannot drive for 4 weeks
Total anterior circulation infarcts - involves middle and anterior cerebral arteries
Neuroimaging confirms occlusion of the proximal anterior circulation - offer thrombectomy +/- thrombolytic therapy
involves vertebrobasilar arteries
middle cerebral artery
No anticoagulation
For:
-CHA2DS2-VASc of 1 (female)
- CHA2DS2-VASc of 0
Ophthalmic artery
Anterior inferior cerebellar artery
Branches of the posterior cerebral artery that supply the midbrain
presents with ataxia and is found to have widespread cerebellar signs
Anterior cerebral artery
