Cerebrovascular diseases 1 Stroke Cerebrovascular diseases 1 Dr. Mohammed Aziz F.I.B.M.S Neuro . 50

Stroke is the third largest killer. Stroke is one of the major causes of disability, particularly in the elderly. 50

Approximately 800,000 people have a stroke each year about one every 4 seconds 50

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 50

CVAs neurological symptoms and signs usually focal acute localized acute sudden onset result from diseases involving blood vessels. ~ 50

50

Transient ischemic attack Transient ischemic attack TIA: an episode of neurological dysfunction due to CVD with negative neuroimaging (DWIMRI brain). 50

STROKE IN EVOLUTION An episode of neurological dysfunction due to CVD which last for more than 24hr. continues to deteriorate for more than 6hr. 50

Multi-infarct dementia dementia due to multiple ischemia & infracted areas in the brain. 50

50

50

50

50

50

50

50

50

50

50

50

Blood Supply of Brain Arises from aortic arch 2 common carotid arteries (extracranial) give rise to external & internal carotid 2 vertebral arteries ~ 50

Vertebral Artery Anterior spinal artery Posterior inferior cerebellar artery 50

Basilar Artery Anterior inferior cerebellar artery Superior cerebellar artery Posterior cerebral artery Blood supply to the thalamus, midbrain, pons, medulla, cerebellum 50

Types of stroke Occlusive(ischemic) stroke : Hemorrhagic 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. ~ 50

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. 50

Stroke types and incidence: 50

50

50

50

50

What"s underlying ANATOMY OF STROKE Is the stroke in the In the Carotid distribution anterior circulation OR Vertebrobasillar distribution posterior circulation.. 50

What is the underlying PATHOLGY OF STROKE. Atherosclarosis Hypertention Embolisation to the brain Vasculitis Intravascular coagulation 50

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 . 50

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 50

Atherosclerosis Platelets& fibrin deposit on those ulcers thus thrombus is formed . 50

Embolism formation: 50

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 50

50

Hypertensive arterial diseases Affect small arteries & arterioles. 50

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; 50

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 50

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 50

Hypertensive arterial diseases Because the vessel wall is weak at the site of aneurysm; it may rupture & leak blood [peri-aneurysmal hemorrhage]. 50

Both cases [ischemia & hemorrhage] small pin-head sized areas of infarction are found in brain tissue; this called LACUNAE 50

Embolisation to the brain Either from carotid A. Or from the heart . 50

Cardioembolic Sources High Risk Medium Risk Low / Unclear Risk Atrial fibrillation Recent anterior MI Mechanical valve Rheumatic mitral stenosis Thrombus / tumor Endocarditis LV hypokinesia / aneurysm Bioprostetic valve Congestive failure Cardiomyopathy Patent foramen ovale Atrial septal aneurysm 50

Vasculitis It's inflammation of the vessel wall as part of a systemic diseases e.g. SLE Behcet disease 50

In travascular coagulation: [thrombophilia] Causes Congenital: prot.C , S, deficiencies. Activated prot.C resistance. Acquired: polycythemia rubra vera. Essential thrombocythemia Antiphospholipid Ab syndrome 50

Pathophysiology of stroke 50

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 ~ 50

Pathophysiology Cerebral blood flow ( rCBF): changes after acute ischemia seen by PET scan Normal = 40 to 50 ml/100 g/min Necrosis <12 50

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 50

The Penumbra 50

Local infarction: Cell death ~ 6min central infarct area or umbra, surrounded by a penumbra of ischemic tissue that may recover 50

Ischemic penumbra: 50

Saving penumbra area Keep BP high Good oxygenation hypothermia Euglycemia Keeping the brain dry 50

Cerebral edema 50

Risk factors for stroke. Modifiable Non modifiable 50

Risk factors Modifiable: Hypertension: Most important modifiable risk factor DM Heart disease including Atrial fibrillation Hyperlipidemia Cigarette Smoking 50

Risk factors Modifiable Excessive alcohol consumption Cocaine and Amphetamine abuse Previous H/O stroke or TIA Estrogen –containing drugs e.g oral contraceptive pill IBD & vasculitis Sickle cell diseases Malignancy 50

Risk factors Non modifiable: age Race/ethnicity Gender : Male>Female Post menopause : Female risk equals male Family history 50

THANK YOU 50