CVA Path Lecture PDF

CNS Pathology Cerebro-Vascular Accident Dr. Ahmed Almobarak Oct 2024  The intended learning outcomes (ILOs) By the end of this lecture, the student is expected to be able to: 1. Define ischemic stroke. 2. Describe the epidemiology 3. Identify the most common sites 4....

CNS Pathology Cerebro-Vascular Accident Dr. Ahmed Almobarak Oct 2024  The intended learning outcomes (ILOs) By the end of this lecture, the student is expected to be able to: 1. Define ischemic stroke. 2. Describe the epidemiology 3. Identify the most common sites 4. Explain the Pathophysiology 5. Identify the etiology 6. List the most common clinical features 7. Describe the Macro& Microscopic features 8. Describe the methods of Diagnosis 9. Define the treatment principles 10. Identify the prognostic factors in stroke. 11. Describe the various types of intracranial hemorrhage.  CVA - Lecture outlines Definition Epidemiology Sites Pathophysiology Etiology Clinical features Macro& Microscopic description Diagnosis Treatment Prognosis Intracranial hemorrhage  Cerebrovascular Accident CVA also referred to Cerebrovascular Disease “CVD” / Stroke. Stroke Defined as acute neurological deficit due to vascular insult; whether: A) Thrombosis ? B) Embolism ? C) Hemorrhage ? Associated with low blood supply/hypoxia “Low 02” Definition / general CNS infarction is defined as cell death due to ischemic injury in the CNS based on 1. Imaging, 2. Neuropathology 3. or clinical assessment.  Classifications 1- Transient, then evolving and Completed. 2- Ischemic “Thrombotic/Embolic” or Hemorrhagic. 3- Focal or Global. 4- Arterial or Venous. 5- Severity: varying according to, location & types.  Epidemiology Stroke is the second most common leading cause of neurologic disability after Alzheimer’s disease worldwide. About 12 million strokes per year worldwide, with about 4 million deaths. The third most common cause of death worldwide.  Risk Factors - Non modifiable: - Modifiable: 1- HT. 1- Age. 2- DM. 2- Male sex. 3- Smoking. 3- Race. 4- Hyperlipidemia. 4- Heredity. 5- Excess Alcohol. 6- Cardiac diseases “AF”. 7- Oral contraceptives. 8- Hypercoagulability states 9- Diet/Sedentary life / Stress.  Sites Ischemic stroke can affect any site in the CNS. Middle cerebral artery (MCA) is the most affected vessel in the brain by: thromboembolism (e.g., internal carotid atherosclerotic plaque fragmentation, atrial fibrillation)  Pathophysiology 1. Decreased blood flow: Liquefactive necrosis. 2. Increased intracranial pressure (ICP) and herniation: due to edema or hemorrhage.  Etiology of CVA Most frequently associated with atherosclerosis, cardiac pathology and hypertension. Less common causes of ischemic infarcts include 1. Vasculitis 2. Coagulation disorders 3. Arterial dissection 4. Reversible vasoconstriction syndrome 5. HIV associated arteriopathy 6. Moyamoya disease (narrowing of the internal carotid arteries at the level of basal ganglia) 7. Fat embolism Ischemic insults in utero are the most common cause of cerebral injury among preterm / very low body weight infants. Clinical features Mostly dependent on the location of the ischemic brain tissue. Common symptoms include 1. Contralateral hemiparesis (unilateral weakness of the upper and lower limbs, opposite to the site of the infarct) 2. Hemianesthesia (absence of unilateral sensations) 3. Aphasia (inability to understand or to express oral language; lesion at the dominant hemisphere) Left ( Dominant) Hemisphere Stroke: Clinical 1- Aphasia. 2- Right hemiparesis. 3- Rt-sided sensory loss. 4- Rt-visual field defect. 5- Poor right conjugate gaze. 6- Dysarthria. 7- Difficulty reading, writing & calculating. Right ( Non- Dominant) Hemisphere Stroke 1- Left visual field defect. 2- Extinction of left-sided stimuli. 3- Left hemiparesis. 4- Left-sided sensory loss. 5- Left visual field defect. 6- poor left conjugate gaze. 7- Dysarthria. 8- Spatial disorientation. Gross description 1. Acute infarct (1 - 4 days): Neurons are more susceptible to ischemia than glia. Necrosis with neutrophilia. 2. Subacute (5 - 14 days): more Subacu te necrosis and more macrophages. 3. Chronic (15 days - years): Cavitated lesion with vessels and macrophages surrounded by a glial scar Chronic: cavity due to liquefaction Macro& Microscopic description Infarct morphology depends on the interval between stroke onset and time of brain examination. 1. Acute changes → blurring of gray-white matter junction (gross), edema and red neurons (micro) 2. Subacute → cracking artifact (gross), dense macrophage infiltration and neovascularization (micro) 3. Chronic → cavitated lesions (gross) with macrophages and surrounding gliosis (micro) Diagnosis is made by: A) Clinical diagnosis. B) Imaging: CT, CT Angiography, MRI, PET, ECG, CX-Ray C) Laboratory: CBC, Platelet count & Coagulation tests (i.e., aPTT, PT, TT) are relevant to rule out coagulation disorders (contraindication for thrombolysis) Blood glucose, serum electrolytes, RFT &LFT. Treatment for acute ischemic stroke (if within 6 - 8 hours of onset) 1.Systemic thrombolysis 2.Thrombectomy Prognostic factors for patients with CVA 1.Age at presentation 2.Degree of neurologic impairment. 3.Infarct volume and location  Intracranial Hemorrhages Ahmed Almobarak The intended learning outcomes By the end of this session the student is expected to be able to: 1. Describe the various types of intracranial hemorrhage. 2. List the most common causes for each type of intracranial bleeding.  Types of Intracranial Hemorrhage 1. Epidural. 2. Subdural. 3. Subarachnoid. 4. Intraparenchymal (Intracerbral). 5. Diffuse axonal injury (DAI). Diffuse injury at the level of the gray-white matter junction seen in high velocity injuries.  Epidural.1 : hemorrhage Epidural hemorrhage typically results from trauma, most frequently with temporal bone fracture and rupture of the middle meningeal artery. :Epidural hematoma Subdural Hemorrhage Subdural hemorrhages may or may not follow trauma. Most common in elderly patients with some degree of cerebral atrophy, as well as in patients with systemic cancer and CNS tumors. :Subdural hematoma :Subarachnoid Hemorrhage.2 The most frequent cause of subarachnoid hemorrhage is rupture of a saccular (berry) aneurysm. Other causes include: 1. Vascular malformation. 2. Trauma. 3. Hematologic disturbances. 4. Tumors. Saccular aneurysms. A, View of the base of the brain, dissected to show the circle of Willis with an aneurysm of the anterior cerebral artery (arrow). B, Dissected circle of Willis to show large aneurysm :Subarachnoid aneurysm :Subarachnoid hemorrhage  Hemorrhage into Brain.3 :Parenchyma Massive hemorrhage displaces and compresses the surrounding brain tissue. Smaller hemorrhages may be subacute or chronic. Caused by: 1.Hypertension 2.Arteriovenous malformations (AVMs) 3.Subarachnoid aneurysms. Intracerebral hemorrhage Intracranial hemorrhage Intracranial hemorrhage (ICH), is bleeding within the skull. Subtypes are 1.Intracerebral (intraventricular bleeds and intraparenchymal bleeds), 2.Subarachnoid, 3.Epidural, 4.Subdural hemorrhage. Intracerebral hemorrhage: intraventricular and intraparenchymal Intraparenchymal hemorrhage Subarachnoid hemorrhage Epidural hemorrhage Subdural hemorrhage Traumatic intracranial hemorrhage DIA: Diffuse axonal injury Causes of intracranial hemorrhage 1.Trauma: is the most common cause. 2. Non-traumatic causes include: 1) hypertension: most common. 2) cerebral amyloid angiopathy, 3) hemorrhagic conversion of ischemic infarction, 4) cerebral aneurysms, 5) dural arteriovenous fistulae, 6) cerebral venous sinus thrombosis, 7) cerebral vasculitis 8) and mycotic aneurysm. Complications of intracranial hemorrhage 1- Coma, 2- Persistent vegetative state, 3- Cardiac arrest 4- Death Thank You