Charbagh { ℂall Girls Serviℂe Lucknow ₹7.5k Pick Up & Drop With Cash Payment ...
3. Stroke.pptx diseases of cadipvascular dsy
1.
2. Stroke – definitions
• Interruption of blood flow
(ischaemic stroke)
or
• Bleeding into or around the brain
(haemorrhagic stroke)
An injury to the brain caused by:
3. • Stroke is the generally preferred term for a group of
cerebrovascular diseases that are of abrupt onset
and cause neurological damage. An injury to the
brain can be caused by
• Sudden onset of inadequacies of blood flow to
some or all of the brain (ischaemic stroke), or
•
4. Transient ischaemic attack (TIA)
• Brief episode in which neurological deficits
suddenly occur, then disappear; can
persist up to 24 hours
• Temporary arterial blockage, with no
resultant brain damage
5. • If an ischaemic attack is brief with duration of less
than 24 hours it is known as a transient ischaemic
attack (TIA) rather than a stroke.
6. Stroke - definitions
Focal stroke: “Neurological deficit lasting more than 24 hours caused by reduced
blood flow… that ultimately results in infarction”
Transient ischaemic attack (TIA) <24 hours
Clot /
occlusion
Ischaemia
Carotid
artery
Ischaemic
Occlusion of a vessel
Haemorrhagic
Rupture of a vessel
Stroke
7. There are two different types of stroke.
One is called ischemic stroke, and is caused by
insufficient blood flow into part of the brain.
Focal stroke conventionally is defined as a
neurological deficit, lasting more than 24 hours
caused by reduced blood flow in an artery
supplying a part of the brain, and which ultimately
results in infarction.
8. During an ischaemic stroke, blockage of
an artery deprives part of the brain of
blood flow and therefore oxygen and
nutrients, leading to oxygen starvation
(ischaemia) and tissue death.
If an ischaemic attack is brief with
duration of less than 24 hours it is known
as a transient ischaemic attack (TIA)
rather than a stroke.
9. Ischaemic strokes
• Areas of brain affected
–Forebrain (frontal lobe and thalamus) > Brainstem > Cerebellum > Spinal cord
• Lacunar stroke
–Area of infarction has form of lacune or cavity (<15 mm). These are smaller
strokes
Forebrain
Thalamus
10. Stroke – definitions
Clot /
occlusion
Ischaemia
Carotid
artery
Rupture produces
injury by distorting,
compressing and
tearing the
surrounding brain
tissue or by
increasing
intracranial
pressure
Ischaemic
Occlusion of a vessel
Haemorrhagic
Rupture of a vessel
Stroke
11. Causes of haemorrhagic strokes
• Aneurysm rupture (often a subarachnoid haemorrhage
occurs first)
• AV malformation
Intracerebral haemorrhage
– Rupture of small penetrating arteries with direct bleeding
into brain or ventricles
Lobar haemorrhage (small vessels)
– Amyloid angiopathy
Approximately 50% due to
Other causes
12. Stroke – definitions
Ischaemic
Occlusion of a vessel
Haemorrhagic
Rupture of a vessel
Stroke
Clot /
occlusion
Ischaemia
Carotid
artery
Rupture produces
injury by distorting,
compressing and
tearing the
surrounding brain
tissue or by
increasing
intracranial
pressure
Stroke leads to the death of brain cells. This can result in:
Paralysis
Speech and sensory problems
Memory and reasoning deficits
Coma
Possibly death
13. Stroke – incidence and prevalence
531.000 new cases of stroke
and 200.000 recurrences of
stroke each year in the US
In 22 European countries with a
combined population of
approximately 500 million,
almost one million strokes are
estimated to occur each year
1. Cardiovascular disease
2. Cancer
3. Stroke
Cause of death
Sorelle R. Circulation 2000;102:E9047-9
Brainin M et al. Eur J Neurol 1999;7:5-10
14. Stroke – high rate of morbidity
Leading cause of morbidity and long-term disability in
most industrialised nations
When examined an average of 7 years after occurrence of stroke
Percent of stroke patients
Walking
assistance
required
Daily care
required
Impaired
ability
to work
20%
31%
71%
21. Cerebral ischaemia
Severity of the insult determines:
Transient ischaemic attack (TIA)
Selective necrosis
Cerebral infarction (pan-necrosis)
22. Cerebral ischaemia
Duration of ischaemia
Cerebral ischaemia can produce irreversible injury
to highly vulnerable neurons in 5 minutes
23. Cerebral ischaemia
Cerebral ischaemia can produce irreversible
injury to highly vulnerable neurons in 5
minutes
If cerebral ischaemia persists for
>6 hours, infarction of part or all of the
involved vascular territory is completed
Clinical evidence depends on the location of
stroke
Duration of ischaemia
26. Intracranial haemorrhage
Intraparenchymal haemorrhage may be relatively benign
Bleeding into the region of previous infarction causes no additional functional loss
At the site of rupture, bleeding into the brain may cause traumatic injury to the exposed tissue, and blood
or its breakdown products in the parenchyma damages brain tissues
Anterior
cerebral artery
(ACA)
Middle
cerebral
artery
(MCA)
Basilar
artery
Vertebral arteries Posterior cerebral artery
Circle of Willis
Blood in subarachnoid space
29. Permanent neurological deficits
of stroke
• Weakness or paralysis
• Loss of sensation
• Problems with vision
• Difficulty in speech comprehension / talking
• Difficulty with organization or perception
• Clumsiness or lack of balance
30. What stroke can mean for patients
• Sudden numbness or weakness of the face, arm or
leg, especially on one side of the body
• Sudden confusion, trouble speaking or
understanding speech
• Sudden trouble seeing, on one or both eyes
• Sudden trouble walking, dizziness, loss of balance or
co-ordination
• Sudden severe headache with no known cause
31. What stroke can mean for family and
carers
• Recovery from stroke is seldom complete
and it is estimated that 40% of patients
living at home after stroke need help in
daily living.
• Four out of five patients survive a stroke,
ten years later the patient has only a 50%
chance of still being alive.
32. Stroke – diagnosis
Common symptoms
Weakness and sensory loss
down one side of the body
Disturbances of consciousness
and confusion
Impariment of speech, vision
and co-ordination of movement
35. Computed tomography (CT)
CT scan
Principle: differential absorption of x-ray
beams by different tissues
Less time
Less expensive
More available in emergency rooms
Not reliable if done too early
CT
Blood
Brain tissue
Easily detects
Blood products (haemorrhages larger
than 1 cm diameter)
Hydrocephalus
Brain oedema
Herniation
36. Diffusion-weighted imaging (DWI) MRI
MRI scan
Best way to image acute stroke
Principle: rapid-pulse sequence with average total
time <2 minutes
Ischaemia can be visualised as early as within 30
minutes of stroke
Relies on reduction of random diffusion (Brownian
motion) of water after acute stroke
37. Diffusion-weighted imaging (DWI) MRI
MRI scan
Ischaemic region
Features of ischaemic region
Swollen cells
Reduced extracellular space
Decrease in diffusion of water
molecules
Best way to image acute stroke
Principle: rapid-pulse sequence with average total
time <2 minutes
Ischaemia can be visualised as early as within 30
minutes of stroke
Relies on reduction of random diffusion (Brownian
motion) of water after acute stroke
42. Ischaemic stroke – prevention and
treatment
• The first goal is to restore blood flow
(thrombolysis)
• Prophylaxis of subsequent ischaemic strokes
with antiplatelets such as acetylsalicylic acid
43. Thrombolytics (t-PA)
Some exclusion criteria for thrombolytics
Should preferably be given within 3 hours of symptom onset
No other likely explanation for the neurologic symptoms
No significant risk of bleeding
No evidence of bleeding on head CT scans
No evidence of early infarct sign on head CT scan
Benefit
30% likely to have minimal or no disabilities after 3 or 12 months
Adverse effects (5%)
Significant brain haemorrhage
44. Antiplatelets
Acetylsalicylic acid (ASA)
Small benefit within 48 hours of stroke onset
Delay for 24 hours if receiving thrombolytics
After recurrent stroke with taking ASA
Consider clopidogrel or dipyramidole/aspirin
After first stroke
45. Neuroprotective therapy
Neuroprotection targets
Calcium channels
Glutamate receptors
Free radicals
Nitric oxide
Proteases
Cell membrane components
Apoptotic pathway molecules
(e.g. Bcl-2 promoters)
Neuroprotective therapy is designed to save the penumbra, or the
area surrounding the core of the primary ischaemia, from the
damage caused by reduced blood flow to this region
47. Hospital Treatment for Stroke
• Medical Management
– Dietary
– Physical & Occupational Therapy
– Speech Therapy if indicated
– Nursing
48. Hospital Treatment for Stroke
• Rehabilitation
– Physical Medicine Consult
– Determine what type of
therapy best for patient
• Rehab Unit
• Subacute Rehab
• Extended Care Facility
• Home Care with PT/OT
