Stroke - Basics Flashcards
Where can strokes occur? (Think baaaaaasic)
Arteries and Veins
What are the 2 types of arterial stroke?
Ischaemic and haemorrhagic
What am I getting at when I say venous stroke?
Venous sinus thrombosis
What are the venous sinuses in the brain?
Folds between the layers of dura mater that carry the veins that drain the brain
Why might an adult pt get a venous sinus thrombosis?
- Pregnancy and post-natal period (pro-coag state)
- Clotting problems - antiphospholipid syndrome, Lupus anticoagulant, protein C and S deficiency, antithrombin III deficiency…
- Cancer
- Collagen vascular diseases
- Intracranial hypotension
- Obesity
What are the causes of ischaemic strokes?
- Cardioembolic cause
- Atherothrombotisis
- Vessel dissection
- Vasculitis
- Hypercoagulability (High RBCs, thrombocthemia, sickle cell, antiphospholipid antibody syndrome)
- Other (infection, migraine, pregnancy, COCP)
What are the causes of intracerebral haemorrhagic strokes?
- Hypertension
- AVM
- Haematological disorders (idiopathic or inherited)
What are the types of haemorrhagic stroke? i.e. where does the blood go?
Extradural haemorrhage
Subdural haemorrhage
Subarachnoid haemorrhage
Intracerebral haemorrhage
What is the NIHSS?
National institue of health stroke scale - tool used to measure the severity and impact of a stroke on a pt and their ability to perform various tasks.
What is the first thing tested on the NIH stroke scale?
Level of consciousness
How is the level of consciousness measured on the NIHSS?
- AVPU
- Basic questions (current month and pt age)
- Motor commands (open and close eyes, then grip with unaffected hand)
What is a TIA?
Temporary inadequacy of the circulation in a part of the brain. It is transient and reversible, and gives a similar clinical picture to a stroke.
How long do TIAs usually last?
No more than 24 hours, but most last less than half an hour.
What % of stroke pts have had a preceeding TIA?
15%
What are the risk factors for TIA?
Same as for stroke:
- HTN
- Smoking
- DM
- Heart disease
- Peripheral arterial disease
- PCV
- Carotid disease
- COCP
- Hyperlipidaemia
- Alcohol
- Clotting disorders
Where is the most common source of an embolus in TIAs and strokes?
What does this mean?
The carotids - if embolic TIA is suspected, carotids should be scanned.
What symptoms might a pt get if their carotid territory/anterior circulation is affected by a TIA/stroke?
Usually unilateral Usually motor Dysarthria Sensory symptoms in same area (Broca's area -> expressive dysarthria) May have fleeting loss of vision
What symptoms might a pt get if their vertibrobasilar territory/posterior circulation is affected by a TIA/stroke?
Homonymous hemianopia or bilateral visual impairment
Hemiparesis, hemisensory symptoms, diplopia, vertigo, vomiting, dysphagia, ataxia
Cranial nerve and cerebellar signs and symptoms
What are the main differentials for TIA?
V - stroke if before recovery, space occupying lesion e.g. subdural haematoma, cardiac arrhythmia -> syncope, retinal/vitreous haemorrhage, postural hypotension
I - Giant cell arteritis
T - head trauma causing secondary seizures
A
M - Hypoglycaemia
I
N - intracranial mass
N - migraine, seizure, Todd’s paralysis
D - Demyelination/MS
I - drugs e.g. cocaine, vasoconstricting OTC cold remedies.
C
How quickly do strokes or TIAs come on?
Very - within a few minutes.
What examinations can we do some someone who has had a TIA?
Cardiac - check for underlying pathology e.g. cartoid bruit, arrythmia, murmur suggestive of valve disease, BP in each arm.
How can a TIA be distinguished from:
- A mass lesion
- Epilepsy
- Migraine
???
- Clinically very difficult, need imaging
- Epilepsy has limb jerking, symptoms onset takes longer than TIA, recovery period longer (post-ictal)
- Migraine has headache, confusion, and characteristic zig-zag visual disturbance
A pt in a TIA clinic scores 3 on their ABCD2 score. What invetsigations should be done if they haven’t already?
- Carotid doppler
- ECG
- Bloods inc. FBC, U&Es, cholesterol
- Consider echo and brain imaging
How should a TIA be managed immediately?
High dose aspirin for 2 weeks as long as cerebral haemorrhage has been ruled out.
Where is the most common site affected in stroke presentations?
Middle cerebral artery
What are the 2 types of infarct causing strokes?
Regional and lacunar infarcts
Where are the symptoms when a pt has an MCA stroke?
On the contralateral side to where the stroke occurs
When does aphasia occur with a stroke?
When the dominant hemisphere is affected - this usually confers a worse prognosis.
What signs might we get that a stroke is haemorrhagic?
If there is headache and/or impaired consciousness, as that implies swelling which combined with acute onset suggests haemorrhage.
Also more likely to be progressive than ischaemic stroke.
How do lacunar infarcts present?
Very localised symptoms. Often purely motor or purely sensory symptoms. Aphasia Hemiparesis Hemisensory loss Unilateral ataxia
How should an acute stroke be managed?
ABCDE
Hx and Examination
Get urgent CT
Get neuro/stroke team/medical SpR involved asap
Thrombolysis if not haemorrhagic or otherwise contraindicated
How should haemorrhagic strokes be managed?
Supportively.
Stop anti-coags and antiplatelets/reverse wiith Vit K/FFP/Platelets
After 2 weeks of aspirin, what do pts need to be on long term following an ischaemic stroke?
Clopidogrel 75mg daily
OR if they can’t tolerate clopidogrel, Dipyridamole can be substituted.
What is assessed in the NIHSS?
Level of consciousness Gaze and visual fields Facial palsy Motor in legs and arms Ataxia Sensory Language Speech Extinction and Inattention (aka neglect)
What do we look for in the gaze section of the NIHSS?
Horizontal eye movements, both voluntary and reflexive, looking for partial gaze palsy, or total gaze paresis/forced deviation.
What visual field defects score points on the NIHSS?
Partial hemianopia
Complete hemianopia
Bilateral hemianopia inc. cortical blindness
What are the grades of facial palsy according to the NIHSS?
0 - normal
1 - minor paralysis (flattened nasolabial fold, asymmetry on smiling)
2 - partial paralysis (total/near total paralysis of lower face)
3 - complete paralysis of one or both sides
What are the motor gradings for the upper and lower limb according to the NIHSS?
0 - no drift 1 - drift 2 - some effort against gravity 3 - no effort against gravity 4 - no movement UN - amputation/joint fusion
What is limb ataxia assessment aimed at finding? How is this assessed?
If there are any unilateral cerebellar lesions.
Finger-nose-finger test and heel-shin test on both sides. Scored according to whether ataxia (out of proportion to any weakness present) in present on both/either side.
How is sensory loss assessed and scored according to the NIHSS?
Pinprick test, or withdrawal from noxious stimulus in an aphasic pt.
0 - normal
1 - mild to moderate sensory loss
2 - severe to total sensory loss
What is described as mild to moderate aphasia according to the NIHSS?
Some obvious loss of fluency or comprehension
No significant limitation of expression
Reduced speech &/or comprehension
What is described as severe aphasia according to the NIHSS?
All communication is through fragmentary expression.
Lots of guessing, inference, and questioning needs to be done by examiner.
What is described as mutism/ global aphasia according to the NIHSS?
No usable speech or auditory comprehension
How can dysarthria be assessed and what are the levels of dysarthria according to the NIHSS?
Ask pt to read or repeat words from a specific list.
0 - normal
1 - mild/moderate (slur some words -> can be understood with some difficulty)
2 - severe (slurring as to be unintelligible in absence of/out of proportion to dysphasia present)
UN - intubated, or other physical barrier
What are extinction and inattention, and how are they assessed?
Extinction is impaired ability to perceive multiple stimuli of the same type simultaneously.
Inattention is impaired ability to recognise or acknowledge one side of space.
Only fill in half the face of a clock, bilateral stimulus not recognised by pt.
What might cause a stroke in a younger patient?
- Vasculitis
- Thrombophilia
- Subarachnoid haemorrhage
- Venous sinus thrombosis
- Carotid artery dissection
- Antiphospholipid syndrome
Describe the basic blood supply to the brain?
The anterior cerebral arteries supply the anteromedial area of the cerebrum.
The middle cerebral arteries supply the majority of the lateral cerebrum.
The posterior cerebral arteries supply a mixture of the medial and lateral areas of the posterior cerebrum
According to the Bamford/Oxford Classification of stroke, what needs to be present to diagnose a total anterior circulation stroke?
All of:
- Unilateral weakness (and/or sensory deficit) of the face, arm and leg
- Homonymous hemianopia
- Higher cerebral dysfunction (dysphasia, visuospatial disorder)
According to the Bamford/Oxford Classification of stroke, what needs to be present to diagnose a partial anterior circulation stroke?
Two of the following:
- Unilateral weakness (and/or sensory deficit) of the face, arm and leg
- Homonymous hemianopia
- Higher cerebral dysfunction (dysphasia, visuospatial disorder)
According to the Bamford/Oxford Classification of stroke, what needs to be present to diagnose a posterior circulation syndrome?
One of the following:
- Cranial nerve palsy and a contralateral motor/sensory deficit
- Bilateral motor/sensory deficit
- Conjugate eye movement disorder (e.g. horizontal gaze palsy)
- Cerebellar dysfunction (e.g. vertigo, nystagmus, ataxia)
- Isolated homonymous hemianopia
According to the Bamford/Oxford Classification of stroke, what needs to be present to diagnose a lacunar syndrome?
One of the following:
- Pure sensory stroke
- Pure motor stroke
- Senori-motor stroke
- Ataxic hemiparesis
What are the consequences of a stroke in the long term?
Pts may recover almost fully depending on the pt.
Psychological effects (mood disorders, anxiety, poor concentration and cognition)
Physical effects (dysphagia, dysphasia, ataxia, reduced mobility)
Poor eyesight
Pneumonia
Falls
