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* Cerebrovascular diseases 1
Stroke
Dr. Mohammed Aziz F.I.B.M.S Neuro .
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* Stroke
Stroke is the third largest killer. Stroke is one of the major causes of disability, particularly in the elderly.
Approximately 800,000 people have a stroke each year about one every 4 seconds
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* STROKE
Def: an episode of neurological dysfunction due to a cerebrovasculare diseases which last for more than 24hr. & reach it's peak of defecit in less than 6hr
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* CVAs
neurological symptoms and signs usually focal localized acute sudden onset result from diseases involving blood vessels. ~
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* Transient ischemic attack
Transient ischemic attack TIA: an episode of neurological dysfunction due to CVD with negative neuroimaging (DWIMRI brain).
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* STROKE IN EVOLUTION
An episode of neurological dysfunction due to CVD which last for more than 24hr. continues to deteriorate for more than 6hr.
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* Multi-infarct dementia
dementia due to multiple ischemia & infracted areas in the brain.
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* Blood Supply of Brain
Arises from aortic arch 2 common carotid arteries (extracranial) give rise to external & internal carotid 2 vertebral arteries ~
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* Vertebral Artery
Anterior spinal artery Posterior inferior cerebellar artery
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* Basilar Artery
Anterior inferior cerebellar artery Superior cerebellar artery Posterior cerebral artery Blood supply to the thalamus, midbrain, pons, medulla, cerebellum
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* Types of stroke
Occlusive(ischemic) stroke : due to the closure of a blood vessel - usually due to atherosclerosis & thrombosis. Hemorrhagic stroke : due to bleeding from a blood vessel usually due to either hypertension or an aneurysm. ~
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* Common Types and Incidence:
Ischemic: Incidence 80% - mortality 40% 50% - Thrombotic – atherosclerosis Large-vessel 30% (carotid, middle cerebral)Small vessel 20% (lacunar stroke)30% Embolic (heart dis / atherosclerosis) Young, rapid, extensive.Hemorrhage: Incidence 20% - mortality 80% Intracerebral subarachnoid.
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* Stroke types and incidence:
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* What"s underlying ANATOMY OF STROKE
Is the stroke in the In the Carotid distribution anterior circulation OR Vertebrobasillar distribution posterior circulation..
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* What is the underlying PATHOLGY OF STROKE.
Atherosclarosis Hypertention Embolisation to the brain Vasculitis Intravascular coagulation
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* Atherosclerosis
Is a diseases of large& medium sized A. Atheroseclarosis starts as deposition of lipids in the subintimal layer which is a F.B for the arterial wall; therefore; fibrosis& Ca++ deposition take place .
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* Atherosclerosis
The intima which is move with arterial pulses now lies on stiff layer that can no more withstand the pulse pressure & thus the intimal [atheroseclarotic] ulceration results
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* Atherosclerosis
Platelets& fibrin deposit on those ulcers thus thrombus is formed .
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* Embolism formation:
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* Atherosclerosis
Part of which may detach forming small emboli that lodge in an A. occluding it’s lumen& then dissolve after sec. or min. that precipitating a TIA or thrombus gets larger& expands occluding the A. leading to a stroke
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* Hypertensive arterial diseases
Affect small arteries & arterioles.
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* Hypertensive arterial diseases
This affects small arteries & arterioles which under pressure higher than normal; undergoes muscle wall hypertrophy' this make the A. withstand the pressure to a certain extend;
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* Hypertensive arterial diseases
if pressure is still higher; then the arteriolar wall undergoes fibrosis & necrosis; thus it no more tolerate the pressure; therefore; a microaneurysm developeds
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* Hypertensive arterial diseases
If the microaneurysm near area of branching; then the branch will occluded leading to infarction of the brain tissue supplied by that branch [peri-aneurysmal infarction
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* Hypertensive arterial diseases
Because the vessel wall is weak at the site of aneurysm; it may rupture & leak blood [peri-aneurysmal hemorrhage].
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* Both cases [ischemia & hemorrhage] small pin-head sized areas of infarction are found in brain tissue; this called LACUNAE
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* Embolisation to the brain
Either from carotid A. Or from the heart .
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* High Risk
Medium Risk
Low / Unclear Risk
LV hypokinesia / aneurysm Bioprostetic valve Congestive failure Cardiomyopathy
Patent foramen ovale Atrial septal aneurysm
Cardioembolic Sources
Atrial fibrillation Recent anterior MI Mechanical valve Rheumatic mitral stenosis Thrombus / tumor Endocarditis
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* Vasculitis
It's inflammation of the vessel wall as part of a systemic diseases e.g. SLE Behcet disease
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* In travascular coagulation: [thrombophilia]
Causes Congenital: prot.C , S, deficiencies. Activated prot.C resistance. Acquired: polycythemia rubra vera. Essential thrombocythemia Antiphospholipid Ab syndrome
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* Pathophysiology of stroke
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* Stroke: Ischemia
Insufficiency of blood supply Glucose & O2 deprivation, build-up of wastes NOT synonymous Anoxia: O2 deprivation only Few seconds: little or no damage 6-8 minutes ---> Infarction neurons & other cells die ~
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* Pathophysiology
Cerebral blood flow ( rCBF): changes after acute ischemia seen by PET scan Normal = 40 to 50 ml/100 g/min Necrosis <12
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* Pathophysiology
Ischemic Penumbra : area of stunned parenchyma surrounding the ischemic core Area of rCBF between 12 and 22 ml/100gm/min Has the potential for recovery ONLY if reperfusion is rapidly established
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* The Penumbra
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* Local infarction:
Cell death ~ 6min central infarct area or umbra, surrounded by a penumbra of ischemic tissue that may recover
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* Ischemic penumbra:
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* Saving penumbra area
Keep BP high Good oxygenation hypothermia Euglycemia Keeping the brain dry
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* Cerebral edema
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* Risk factors for stroke.
Modifiable Non modifiable
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* Risk factors
Modifiable: Hypertension: Most important modifiable risk factor DM Heart disease including Atrial fibrillation Hyperlipidemia Cigarette Smoking
Risk factors
Modifiable Excessive alcohol consumptionCocaine and Amphetamine abuse Previous H/O stroke or TIAEstrogen –containing drugs e.g oral contraceptive pillIBD & vasculitisSickle cell diseases Malignancy 50*
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* Risk factors
Non modifiable: age Race/ethnicity Gender : Male>Female Post menopause : Female risk equals male Family history
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THANK YOU