Stroke Flashcards
How many people a year have a stroke?
~152000 a year
What percentage of stroke sufferers have good recovery?
1/3
What is the oxygen consumption of the brain?
20% of the whole body
How long before brain shuts down after blood supply has been cut off?
3-6 minutes neurons start dying
After 15 minutes pts brain dead
How is blood supplied to the brain
arch of aorta
common carotid artery
internal carotid artery
vertebral artery
circle of Willis formed through these arteries
what are the key arteries in the brain?
Anterior cerebral artery (ACA)
Middle cerebral artery (MCA)
Posterior cerebral artery (PCA)
what is a stroke
syndrome characterised by rapidly developing clinical symptoms and/or signs of focal loss of cerebral function lasting for more than 24 hours/death and due to a vascular origin
What is a TIA
Transient ischemic attack
symptoms and signs last less than 24hrs
Acts as a warning for stroke
Sign that a clot may be forming
how many stroke deaths a year vs survivors
5.45 million strok deaths/year and 9 million stroke survivors world wide
What are the classifications of stroke
Ischaemic or haemorrhagic
What are the classifications of ischaemic stroke
Cardio-embolic
atherothrombo-embolic
small vessel disease
venous thrombosis
what is an ischaemic stroke
A stroke where blood supply to an area is prevented due to a clot or other blockage
What are characteristics of a cardio-embolic stroke
AF
Mural thrombus
paradoxical embolism through patent foramen ovale
Inefective endocarditis
What is the cause of atherothrombotic-embolic strokes
Forms in arteries
Carotid, vertebral, cerebral artery occlusion and carotid dissection
How does small vessel disease lead to stroke
easier to clot in small vessels
hypertensive arterial disease, diabetic vasculopathy and vasculitis
What is associated with venous thrombosis
Lying in bed for long time, need to check pt has not been clotting
What are types of haemorrhagic strokes
sub-arachnoid
parenchymal
What is sub-arachnoid stroke associated with?
Arterio venous malformation
Aneurysm
What is parenchymal stroke associated with?
Hypertensive arterial disease
amyloid angiopathy
What occurs to form an atherosclerotic artery
Fatty streaks form on the intimal layer of the wall
massive extracellular lipids
fibrous plaques with deposits of platelets and fibrin
This stiffens leading to kinking of artery, occlusion or narrowing, decreased perfusion pressure
In combination with HTN a major risk of injury due to stretch of the walls and burst blood vessels
What is a thromboembolism
A thrombus is build up such as a clot that forms in vessels
Part breaks off and travels to the brain
What is a berry aneurysm
Referred as “tiny bomb inside head”
if part weak when extra pressure can break and bleed in brain
‘berries’ form off of vessels such as internal carotid complex, anterior communicating, trifurcations
What is an avm
Means anteriovenous malformation
Artery continous across instead of separating into capilleries
Can lead to hypoxia causing brain cell death
What are moderate effects of ischaemia?
Inadequate O2 and glucose
Leads to Inadequate energy supply
Failure of neuronal activity and regional brain dysfunction
What are severe effects of ischaemia
Inadequate energy supply feeds
Influx of H2O, Na+. Cl- with influx of Ca+
Anaerobic metabolism results
Leads to irreversible cellular injury and accumulating lactic acid
H+, compromise neuronal integrity
What occurs in advanced ischaemia
Effects of mild-to-moderate and severe
lead to loss of function and accumulation of chemicals
further influx of H2O, Na+ and Ca+ occurs
This causes destruction of cell components
What occurs in penumbra
The thrombus creates an infarction by blocking an artery however neighbouring arteries can continue collateral flow meaning some areas are restored
What are risk factors for stroke
increased age
male
race e.g. african-americans
diabetes mellitus
prior stroke / TIAs
Family history
asymptomatic carotid bruit
geography / climate
socio-economic factors
what are major risk factors for stroke
Hypertension
heart disease esp. AF
cigarette smoking
TIA
what are secondary risk factors for stroke
increased serum cholesterol / lipids
physical activity
obesity
excessive alcohol intake/drug use
acute infection
What are different clinical classifications of stroke
Total anterior circulation syndrome (TACS)
Partial anterior circulation syndrome (PACS)
Lacunar syndrome (LACS)
Posterior circulation syndrome (POCS)
How is TACS diagnosed?
Higher dysfunction interruptions
- dysphasia
-visuospatial disturbances
-decreased level of consciousness
homonymous hemianopia
- only see sides or only middle
motor and sensory defects (>2/3 of face arm leg)
How is PACS identified
2/3 of features of higher dysfunction including:
Dysphasia
Visuo-spatial disturbances
- homonymous hemianopia
- motor and sensory defects
- higher dysfunction alone
- partial motor or sensory defect
How is lacunar syndrome diagnosed?
Any combination of symptoms of
- pure motor stroke
- pure sensory stroke
- sensorimotor stroke
- ataxic hemiparesis (wobbliness, lack of control)
How is POCS identified?
Normally largely visual + coordination problems
Any combination of
- cranial nerve palsy and contralateral motor and sensory deficit
- B/L motor or sensory deficits
- conjugate eye problems
- cerebellar dysfunction
- isolated homonymous hemianopia
How is stroke diagnosed
CT scan
MRI
what factors effect prognosis
Type
extent of lesion
Access to emergency care
- thrombolysis for ischaemic stroke
MDT input
20-50% death
1/3 left with severe deficits
What is the difference between stroke and TIA?
Stroke symptoms last longer than 24 hours and TIA less than 24hrs
What are symptoms of stroke?
Muscle weakness normally on one side
Confusion
Speech difficulties - dysarthria
Blurred vision
Loss of balance
Difficulty walking
Ataxia - impaired coordination
Sensory loss
What are possible assessments for stroke?
Cognitive
Balance
Gait
ROM - spasticity and tone
Muscle strength
What are cognitive tests for stroke
Clock drawing test - assesses for hemineglect and cognition
Attention during functional tasks
What are balance tests for stroke?
Functional reach test
Timed unipedal stance test
4 square step test
Timed up and go
How can gait be assessed for stroke?
Timed up and go
2 minute walk test
How can strength be assessed
Oxford scale - e.g. in plinth or sitting in chair
5 time sit to stand - functional mobility, strength
How is ROM assessed in stroke
Assess range of movement and measure if increased tone on passive movements
Explore if movement reduced
Faster movements for spasticity
How is the clock drawing test performed?
Ask to drawer clock face
Place numbers on clock
Draw hand to given time
Can be given pre-drawn circle
No one scoring test main aspects are
- correct spacing with even spaces between numbers
- correct placement of 3,6,9,12
- correct in between numbers
- placement of clock hands correct
How is the functional reach test performed?
- In standing stand close but not touching wall, and arm closer to wall at 90 degrees flexion. Record initial point of 3rd digit, measure difference between start and end.
- Modified version for those that can’t stand
- Yard stick taped to wall, and make final position.
stop if feet lift up from floor/fall
What does the result of a functional reach test mean?
25cm/greater = low fall risk
15-25cm = 2x greater fall risk
15cm or less = risk of falling is 4x greater than normal
Unwilling to reach: risk of falling is 8x greater than normal
How is the unipedal stance test performed?
- Need stopwatch
- Time how long can stand on one leg
- One foot eyes open and closed
- Time how long can maintain
- Good test-retest reliability and interrater reliability found by Franchignoni et al 1998
What are average times for ages open and eyes closed?
- 20-49 28.8s open eyes, 20.7 closed
- 50-59 24.2 open, 6.1 closed
- 60-69 27.1 open, 2.0 closed
- 70-79 18.2 open, 1.0 closed
How is the 4 square step test performed?
- May have demonstration and practice trial
- Meant to perform twice
- Patient steps over 4 canes that are placed in plus sign
- Told to complete as quickly as possible
- Square 1 facing square 2, square four to the right of the patient
- Time from when foot touches square 2 and last foot reaches square 1
- Go clockwise then anitclockwise
- pt unable to side step can turn
- Fail if lose balance or touch cane
What are the cut off score for 4 step test?
> 15s or failure for stroke
How is the Timed up and go performed?
- Pt in chair with back on back of chair
- Command go
- Walk 3 meters at comfortable pace, turns and walks back to chair and sits down
- Should have a practice trial
- Can use assistive device
For 65+
Has excellent test-retest reliability in stroke according to Flasnbjer et al 2005)
What are the cut-off scores for populations in the timed up and go test?
Community adults: >13.5s
Older stroke patients: >14s
Older adults at falls clinic: >15s
Frail elderly: >32.6s
LE amputees: >19s
PD: >11.5 /7.95
Hip OA: >10
Vestibular disorder: >11.1
How is the 2 minute walk test performed
- Walk as far as possible in 2 minutes
- Can use walking aids
- Should be independently mobile
~ 15m course
What are predicted distances for populations in the 2-minute walk test?
Women 260 - (0.7 x age) - (1.7 x BMI)
Men 280 - (0.9 x age) - (1.426 x BMI)
How is the 5-minute sit to stand test performed?
- Pt in chair with arms folded across chest and back against chair (with stroke can have affected arm supported or hanging to side)
- Chair should be free from wall
- Say go and measure how long to do 5 stands
- If concern for fatigue can demonstrate to patient what plan is
What are the norms for the 5 sit to stand test?
Minimal detectable time for test is 3.6-4.2 s
60-69 normal 11.4 s
70-79 normal 12.6 s
80-89 normal 14.8 s
What mobility exercises can be given to stroke patients?
ROM
- Shoulder flexion/ extension
- Knee flexion/ extension
- Ankle circles
Likely to have circumductory gait
- Step ups for hip flexion
- Marches for hip and knee flexion
- Calf raises / heel raises
What are possible strength exersises for stroke?
Sit to stand from sitting - start with hands - remove hands / squats
Seated shoulder abduction with theraband / lat raise - heavier weight / more reps
Seated knee extension with theraband - progress to more / stronger band
Bicep curls
Marching
Toe taps with leg to side and holding chair
What are possible aspects for self-management exercises for stroke?
Frunctional exercises e.g. sit to stands with reach
dressing practice
Gait training practice walking with or without aid
Recommendation of group exercises
What education should stroke patients be provided?
Local resources e.g. voluntary organisations in the community.
Stroke centres that can help support.
Pacing activity
Performing exercise program
Progressively building up exercise
Remember aims of session
Goal - e.g. diary, can do weekly calls to check
Safety instructions
What are key aspects for group exercises to remember?
Can do mobility and strengthening exs
Warm up stretches
Cool down stretches
Exercises
Recommend to do exs x times a day
Before start check patients well
What are contraindicatiosn to exercise for stroke?
- MI within 2 days and unstable angina
- Uncontrolled cardiac arrhythmias
- Symptomatic severe aortic stenosis
- Uncontrolled symptomatic heart failure
- Acute pulmonary embolus or pulmonary infaction
