Dr. Meg-angela Christi M. Amores Stroke Syndromes Dr. Meg-angela Christi M. Amores

Cerebrovascular Disease ischemic stroke hemorrhagic stroke cerebrovascular anomalies such as intracranial aneurysms and arteriovenous malformations (AVMs) Incidence increases with age

Stroke Most strokes manifest by the abrupt onset of a focal neurologic deficit Like patients were “struck by the hand of God” Definition: abrupt onset of a neurologic deficit that is attributable to a focal vascular cause

Definition of terms Thrombosis: inappropriate clotting Embolism: migration of clots Ischemia: loss of blood supply in a tissue due to impeded arterial flow or reduced venous drainage Infarction: cell death

Definition of Terms Cerebral ischemia is caused by a reduction in blood flow that lasts longer than several seconds infarction - death of brain tissue transient ischemic attack (TIA) - all neurologic signs and symptoms resolve within 24 h regardless of whether there is imaging evidence of new permanent brain injury

Hemorrhagic Stroke Bleeding into subdural and epidural spaces is principally produced by trauma SAHs are produced by trauma and rupture of intracranial aneurysms Hemorrhage are classified by location Often identified by CT scan

Ischemic Stroke Acute occlusion of an intracranial vessel causing reduction in blood flow to the brain region INFARCTION results when: Cerebral blood flow of 0 (zero) in 4 – 10 mins CBF <16-18 ml/ 100g tissue per min in 1 hour CBF <20ml/100g tissue per min = ischemia

Causes of Ischemic Stroke

Causes of Ischemic Stroke 30% of strokes remain unexplained despite extensive evaluation establishing a cause is essential in reducing the risk of recurrence Focus on: atrial fibrillation and carotid atherosclerosis 20% of all ischemic strokes is CARDIOEMBOLIC

Causes of Ischemic Stroke

Cardioembolic Stroke 20% of all ischemic strokes embolism of thrombotic material forming on the atrial or ventricular wall or the left heart valves thrombi then detach and embolize into the arterial circulation Embolic strokes tend to be sudden in onset, with maximum neurologic deficit at once

Cardioembolic Stroke causes: nonrheumatic atrial fibrillation MI prosthetic valves rheumatic heart disease ischemic cardiomyopathy

Carotid Atherosclerosis 10% of all ischemic strokes frequently within the common carotid bifurcation and proximal internal carotid artery RISK FACTORS: Male gender, older age, smoking, hypertension, diabetes, and hypercholesterolemia

Causes of Ischemic Stroke

Other causes of stroke Intracranial Atherosclerosis Dissection of Internal Carotid Artery Hypercoagulability Venous sinous thrombosis Fibromuscular dysplasia Vasculitis

Approach to patient Once the diagnosis of stroke is made, a brain imaging study is necessary to determine if the cause of stroke is ischemia or hemorrhage CT imaging of the brain is the standard imaging modality to detect the presence or absence of intracranial hemorrhage If bleeding is ruled out, do thrombolysis Medical management to reduce the risk of complications becomes the next priority

STROKE SYNDROMES

Middle Cerebral Artery

Middle Cerebral Artery entire MCA is occluded at its origin : contralateral hemiplegia, hemianesthesia, homonymous hemianopia, and a day or two of gaze preference to the ipsilateral side Dysarthria is common because of facial weakness global aphasia anosognosia, constructional apraxia, and neglect

to be continued........