Stroke Flashcards
1
Q
What is the clinical definition of a stroke?
A
- rapidly developing clinical signs/symptoms of focal cerebral dysfunction
- lasting more than 24hrs
- with no apparent cause other than vascular
2
Q
Stroke is defined clinically as rapidly developing clinical signs/symptoms of focal cerebral dysfunction, suggest 5 other pathologies that may present similarly? (hence this definition is problematic)
A
- syncope
- seizure/epilepsy
- migraine aura
- CNS inflammation
- space occupying lesion / neurodegeneration e.g. MS
- hypoglycaemia (!) -don’t forget
3
Q
Stoke definition “rapidly developing clinical signs/symptoms of focal cerebral dysfunction” but there are many ddx, how do the symptoms of stroke often vary from stroke mimics?
A
- stroke sx usually negative e.g. loss of speech, loss of power
- mimics more likely to have + ftx e.g. tingling, visual aura…
4
Q
Hypoglycaemia (!) should not be missed, how can it present that may mean it is misdiagnosed as a stroke?
A
- acutely unwell
- drowsy
- confused
- slurred speech
- weakness down one side
5
Q
Radiological definition of a stroke
A
-episode of neuro dysfunction with evidence of acute infarction or haemorrhage
6
Q
Radiological definition of TIA:
A
- transient episode of neuro dysfunction caused by focal brain/spinal cord/retinal ischemia
- without acute infarction
- duration <24hrs (mean duration 10mins)
7
Q
How seriously should TIA be treated?
A
like a stroke, as a neurological emergency (as high risk of stroke recurrence)
8
Q
Common causes of infarction behind a stroke, suggest 2:
A
- AF
- carotid artery stenosis
- atherosclerosis of small perforators in brain
- venous infarction aka cerebral venous sinus thrombosis
9
Q
Common causes of haemorrhage behind a stroke, suggest 2:
A
- anticoagulant related ICH
- cerebral amyloid angiopathy esp in elderly -> lobar haemorrhage
- hypertensive ICH e.g. deep subcortical haemorrhages
10
Q
Stroke hx important qs?
suggest 4
A
- onset of focal neuro symptoms (acute)
- contiguous parts of body affected
- negative or positive sx
- LOC, headache, syncope? (atypical in stroke)
- RFs e.g. smoking, BP, DM, AF, high cholesterol
- Family Hx
- Ask about ETOH and recreational drugs
11
Q
What is Fabry’s disease? What is it associated with?
A
A lysosomal storage disorder, a rare genetic disease affecting e.g. kidneys heart and skin
- most common skin manifestation is angiokeratomas: tiny painless papules, can arise on any area of body
- it is a rare cause of stroke
12
Q
What imaging ix are recommended if a pt presents with a suspected stroke?
A
- CT brain (sensitive, can take hours for an acute infarct to show up so if done too soon can miss one)
- MRI - gold standard for ischaemic stroke (DWI)
- vascular imaging e.g. carotid Doppler (carotid stenosis, dissection…)
- CTA, MRA (angiography - uses contrast)
CXR: can identify pneumonia, pulmonary oedema, malignancy
13
Q
What blood ix are recommended if a pt presents with a suspected stroke?
A
- FBC, U&E, Cr, LFT. CRP, ESR-autoimmune signif, TFTs
- Cholesterol, Glucose, Hb1AC
- cardiac troponin
14
Q
What blood ix are recommended if a pt presents with a suspected stroke and is young e.g. <40yrs? (young stroke screen bloods)
A
- HIV
- ANA, ANCA, dsDNA
- thrombophilia screen
- anticardiolipin antibody
15
Q
What cardiac ix are recommended if a pt presents with a suspected stroke?
A
- ECG (AF, LVH-chronic HT, MI…)
- ECHO (e.g. bubble echo, TOE in younger pts with cryptogenic stroke-no obvious cause found, to look for patent foramen ovale or ASD)
- 7 day tape
- in hospital cardiac halter monitoring (telemetry-looks mainly for AF)
16
Q
large vessel strokes affect the cortex hence can alter:
-attention
-language
-motor control
hence what abnormalities in these categories may arise?
A
- inattention, neglect
- dysphagia, dyslexia, dysgraphia
- dyspraxia
17
Q
Why might you get a homonymous hemianopia with a stroke?
A
- when posterior circulation and occipital lobes are involved
- lost in both eyes (as behind chiasm)
- as optic radiations are in the white matter that run through the MCA and PCA territories
- only large strokea causes major disruption
18
Q
If a stroke pts pattern of weakness is x, where is the infarct territory?
- Broca’s/Wernicke’s?
- weak in legs predominantly
- weak in face, hands, arm mostly
A
- MCA territory
- ACA
- MCA
19
Q
Cerebral small vessel disease can lead to lacunar stroke, process? Key RFs?
A
- tiny perforating vessels are v small diameter and vulnerable to progressive hyaline arteriosclerosis, most occlusions here due to thrombosis in situ (rather than embolisation)
- RFs: age, hypertension, rare genetic disorders, vasculitis
20
Q
Lacunar syndromes. Name 3 common?
these lesions are in the deep white matter (cortex not affected but motor/sensory pathways are affected)
A
- pure motor hemiparesis
- hemisensory loss
- sensorimotor stroke
- ataxic hemiparesis
- dysarthria clumsy hand syndrome
21
Q
Cerebral small vessel disease is the most important cause of what?
A
-Vascular dementia (frontal dysexuctive syndrome, gait apraxia, urinary incontinence)
22
Q
Signs of Vertebrobasilar strokes?
A
- weakness, sensory loss
- unsteadiness, ataxia
- cranial neve e.g. diplopia, abnormal eye movements, dysarthria, dysphagia
- impairment of conciousness
- note PCA stroke often –> hemianopia
23
Q
Primary intracerebral haemorrhage (ICH) main cause is what? main RFs?
A
- small artery (small friable perforators) rupture with intraparenchymal cerebral bleeding
- HT, age, hyaline arteriosclerosis, microaneurysm formation
24
Q
In the elderly what is a common intracerebral haemorrhage cause other than small artery rupture?
A
-Cerebral amyloid angiopathy , affects arteries on brain cortex
(amyloid deposition in the surface of small leptomeningeal vessels->vessel fragility leading to vessel rupture)
25
What imaging is important to have after a haemorrhagic stroke (e,g, 2-3months later)?
- follow up MRI scan
| - (swelling down, blood products gone down, can see clearly the underlying structures and any damage)
26
Haemorrhagic stroke outcomes are often poor, what phenomenon increases chance of death haematoma _____. What are RFs for this?
- high chance of early deterioration as the bleeding is unstable
- 'haematoma expansion' in first few hours, poor prognosis, RFs include: uncontrolled HT, anticoagulation..
- ~50% survival at 1yr, but most of these pts will be left with a severe stroke deficit
27
Venous stroke is called ___ ___ ___ ___ (CVST), represents 1% of strokes, think of it like a ___ of the brain. Reasonable recovery.
-when these cerebral veins are occludes what happens? Hence what sx do people present with?
- Cerebral venous sinus thrombosis (CVST)
- DVT in brain
- occlusion --> high pressures in veins --> high pressure headache (raised ICP),
- sx: diplopia, pulsatile tinnitus, papilledema, focal neuro deficits, seizures due to infarction and venous haemorrhage due to raised pressure.
28
Venous stroke is called Cerebral venous sinus thrombosis (CVST). (think similar to DVT risk)
Suggest 4 causes:
- bacterial/fungal infection
- inherited or acquired thrombophilia (SLE, pregnancy, birth)
- dehydration
- inflamm. (Behcet's, Wegener's, SLE
- Haematology: sickle cell, PRV, thrombocythemia, PNH
- Haematological malignancy
- Head injury, neurosurgery, LP
- Combined OCP
29
Venous stroke is called Cerebral venous sinus thrombosis (CVST). How to diagnose? What is the basis for treatment? If untreated what can happen?
- Confirm diagnosis with CT / MR Venogram to confirm filling defect in vein
- Anticoagulation for 6months or lifelong if thrombophilia tendency ongoing
- investigate for underlying cause
- untreated -> can deteriorate as thrombus can break off and go to lung (PE)
30
As well as ABC what are key aspects of stroke treatment/assessment:
- Assess swallowing - aspiration risk (swallow screen within 4hrs at bedside, if fails, place NBM until SALT assessment)
- nutrition (early NG tube for feeding and medication)
- check BM, treat hyperglycaemia and if hypo ask -is this a stroke?
- fever - treat w paracetamol and screen for infection
- DVT prophylaxis -thigh length intermittent pneumatic compression (IPCs) - benefit seen in CLOTS3 trial
31
Why is -DVT prophylaxis with LMWH or TED stoking CI in stroke pts, what is used instead?
- Best = thigh length intermittent pneumatic compression (IPCs) - benefit seen in CLOTS3 trial :)
- higher rate of pressure damage and poor protection from TED stockings
- LMWH: higher rate of haemorrhagic transformation (!)
32
Thrombolytic agents in ischaemic stroke:
- licensed is A____ (type of drug =__)
- give within ___hrs
- dose is
- given IV
- initially as a ____ over __mins then given as an ____ over ___hr
- Alteplase (recombinant tissue plasminogen activator, IV fibrinolytic drug)
- given within 4.5hrs
- dose is weight based (kg) (0.9mg/kg)
- initially as bolus (10%) given over 5-mins then 90% given as an infusion over 1hr
33
Thrombolytic agents in ischaemic stroke:
-Alteplase is lisecensed but what is a newer drug, not yet liscensed that has a better SE profile and is poss better efficacy?
-Tenecteplase (IV 0.25mg/kg) given as single bolus
34
Thrombolytic agents in ischaemic stroke:
- can only be given if stroke onset was <4.5hrs ago
- for any age presenting with __hrs can give
- if presenting __-__hrs and over ___yrs excercise caution (more risks, SEs and less likely benefit)
- what must be done before treatment
- <3hrs can give any age
- 3-4.5hrs and >80yrs , caution
- CT head to rule out haemorrhage
35
What has the wake up trial shown may be more important than time (hrs) since stroke in terms of deciding if alteplase can be given?
-MRI imaging proving diffusion-FLAIR mismatch and can guide amenability for treatment effectiveness
36
For those e.g. with large clots, for which thrombolysis is alone ineffective, what can be done?
-mechanical thrombectomy to remove the clot occluding the vessel (unlikely to achieve re-cannulisation with tPA alone but with this can do so and reduce the size of the infarct)
37
MT (mechanical thrombectomy) can be considered in stroke pts with a confirmed large vessel occlusion in which areas, name 2
within __hrs or with severe/signif ____ ____
-and CT must show what?
- proximal MCA
- carotid T
- distal MCA and basilar
- pts presenting within 6hrs
- pts with signif neuro deficit
- CT shows no established ischemia of a large area
38
What are the 2 indications for surgery in pts with ischaemic stroke?
- Malignant MCA Syndrome
| - Large cerebellar infarction (pressure on brainstem results in dropped GCS)
39
What is malignant MCA Syndrome features?
| - a large vessel occlusion of MCA affecting large area of this terriorty
- young pts more at risk (less cerebral atrophy so higher risk of malignant oedema)
- 10% of ischaemic strokes
- distal carotid and M1 occlusion
- presents w: gaze deviation, hemiplegia, visual field defect, aphasia or neglect
- early neuro deterioration, headache, vomiting, drop in GCS
- poor prognosis (80% mortality)
40
For what reasons is the mortality associated with malignant MCA Syndrome so poor (80% die)?
- subfalcine herniation
- transtentorial herniation
- brainstem herniation
41
Why are young pts more at risk of malignant MCA Syndrome?
As they have less cerebral atrophy so much higher risk of malignant oedema
42
Treatment for malignant MCA Syndrome?
-Depressive hemicraniectomy (removal of a large bone flab on the side of the stroke and dura opened to relieve the pressure)
-life saving operation (survival wise) it doesn't negate the effect of the stroke through
(refer to neurosurgery within 24hrs of stroke onset, treat within 48hrs)
43
Ischaemic cerebellum at risk of coning from direct pressure from builiding up oedema around brainstem is treated how?
- posterior fossa decompression to allow the brain to herniate through the flap
- life saving but doesn't negate effect of stroke
44
In primary intra cerebral haemorrhage, what are the 2 indications to call neurosurgeons?
- posterior fossa bleed (linked to risk of raised ICP --> herniation of brain stem)
- intraventricular bleeding as can -> hydrocephalus (risk of this can --> raised ICP and coning)
45
After an ischamic stroke what would pt start after? (4) and target levles?
- antiplatelets 75mg clopidogrel 1st line
- warfarin (INR: 2-3 target) or DOAC (1st line in non-valvular AF)
- aggressive BP control (<130/80)
- 40mg statin to keep cholesterol <4 LDL <2
- tight diabetic control if applicable
46
Urgent TIA assessment should include looking for what in the carotids with what imaging?
- look for carotid stenosis,
- use Carotid Doppler US
- MRI and CT techniques also good
