Cerebral Vascular Diseases Lecture 8 PDF

Pathophysiology PHMU 534 Lecture 8 Cerebral Vascular Diseases Prof. Dr. Nabila Hamdi MD, PhD in Molecular Medicine and Pathology  Outlin I. Stroke statistics e II. Cerebral circulation III. Stroke Pathogenesis of cerebral infarcts (Strok...

Pathophysiology PHMU 534 Lecture 8 Cerebral Vascular Diseases Prof. Dr. Nabila Hamdi MD, PhD in Molecular Medicine and Pathology  Outlin I. Stroke statistics e II. Cerebral circulation III. Stroke Pathogenesis of cerebral infarcts (Stroke) 1. Ischemic - Thrombotic - Embolic - Lacunar/small vessel disease 2. Hemorrhagic - Primary brain parenchymal hemorrhage - Subarachnoid hemorrhage & saccular aneurysm IV. Traumatic brain vascular injury - Epidural hematoma - Subdural hematoma 2  Competenc ies Demonstrate understanding of the pathophysiological mechanisms of various cerebral vascular diseases. Utilize the proper medical terms in pharmacy practice. Integrate knowledge from fundamental sciences to relate the mechanisms of cerebral vascular diseases to their clinical manifestations and possible complications. Recognize the role of physicians as members of the health care professional team and perform responsibilities in compliance with the professional structure. Relate etiology, epidemiology, pathophysiology, laboratory diagnosis, and clinical features of cerebral vascular diseases to understand their pharmacotherapeutic approach.  Stroke About 795,000Statistics Americans each year suffer a new or recurrent stroke. That means, on average, a stroke occurs every 40 seconds. No. 3 cause of death after cardiovascular diseases and cancer About 1 of every 18 deaths. On average, every 4 minutes someone dies of stroke. More women than men die of stroke each year (life expectancy) Of all strokes, 87% are ischemic, 10% are intracerebral hemorrhages, and 3% are subarachnoid hemorrhages The estimated direct and indirect cost of stroke for 2009 is (inpatient $68.9 billion care, rehabilitation and follow-up lastin care necessary for g  Cerebral Circulation 5 http://mauryillustrates.com/anatomica Neuro4Students, Cerebrovascular  Cerebral Circulation  Major cerebral arteries: ACA, MCA, PCA Circle of Willis: major source of collateral flow Deep penetrating vessels with little if any collateral flow (thalamus, basal ganglia, and deep white matter) No backup/ may be affected with atherosclerosis 6  Types of Stroke Ischemic Hemorrhagic (Clots) (Bleeds) 87% 13% “Stroke” Hemorrhage leads to Ischemic direct tissue damage injury/infarction of as well as secondary specific regions of the ischemic injury (rupture brain, depending on of walls) 10% intracerebral the vessel involved hemorrhage 7 3% subarachnoid  Stroke versus TIA Focal neurological deficit Longer than 24 hours Less than 24 hours (minutes) Permanent tissue No permanent tissue damage damage Stroke Transient ischemic attacks (TIAs) (Cerebrovacular accident) 1/3 of patients with TIA develop clinically significant infarcts within 8 5 years Signs and Symptoms of Stroke 9  Signs and Symptoms of Stroke Hemiplegia: Sudden paralysis of a leg, arm or one side of the face Hemiparesis: Sudden numbness or weakness of arm, leg or face Consciousness: +/- loss of consciousness Aphasia: loss/impairment of the power to use or comprehend words. Dysarthria: affects the mechanics of speech. Amaurosis fugas sudden loss of vision in one or both eyes: “gray or black shade coming down over their eye” Hemianopsia: loss of half of the visual field. Ataxia: Sudden trouble walking, dizziness, loss of balance or coordination, leading to difficulty in walking normally Vertigo (spinning form of feeling dizzy) Headache: sudden severe with no known cause Memory, emotions, orientation Incontinence 1 0 Warning Symptoms of Stroke Does one side Is one Is speech slurred? Is even if the of the face arm weak the person unable symptoms go away, droop or is it or speak or to call emergency and numb? Ask numb? Ask understand? hard Ask the to get the person to the person to the person person to repeat a the hospital smile. Is the to raise both simple sentence. Is immediately. Check person's the sentence the time so you'll smile uneven? arms. Does repeated correctly? know when the first one arm symptoms drift appeared 1 downward? 1  Ischemic Definition: Stroke Ischemic stroke or cerebral infarct is a focal brain necrosis due to complete and prolonged ischemia that affects all tissue elements, neurons, glia and vessels. Modifiable Non modifiable Hypertension Age >55 Risk factors: Diabetes Male gender Atrial fibrillation Black race Smoking Family history of stroke Hyperlipidemia Personal history of stroke Carotid stenosis Sickle Cell Disease Lack of physical activity Major Causes: 1. Atherosclerosis 2. Embolisms 3. Small vessel disease 4. Vascular spasm (following hemorrhagic stroke) 5. Other: Vasculitis, hypercoagulability, dissection of a vessel wall, sickle cell  Ischemic Stroke 1. Atherosclerosis (most common cause) Kindly refer to CVS lecture  Neuro4Students Cerebrovascular attack 1 3  Left MCA Right ACA Left PCA 1 Neuroradiology Unit, S P Institute of Neurosciences,Solapur,Maharashtra, INDIA Radiology department of the Rijnland Hospital in Leiderdorp, the Netherlands Lacunar infarct 4  Ischemic Stroke 1. Atherosclerosis  Risk factors ! Atheromatous plaques can cause narrowing or occlusion of the vascular lumen by themselves or after rupture and thrombosis Bifurcation points of large arteries & major cervical and intracranial arteries (blood flow!)  Atherothrombotic infarcts evolve within hours or days The most severe atherosclerotic lesions are typically encountered within large vessels  However, Some patients have an Cerebrovascular anatomy and common sites of atherosclerosis hemorrhagic 1 asymptomatic stroke!! occlusion of a cervical 5  Ischemic Stroke 2. Lacunar Infarcts Occlusion of deep penetrating branches of major cerebral arteries (subcortical area) Deeper parts of the brain (basal ganglia, thalamus, deep white matter) and brain stem. The infarcts are generally from 2-20 mm in diameter Typically, no impairments in cognition, memory, speech, or level of  Atherosclerosis consciousness of small (cortex not affected) arteries hyaline arteriosclerosis  Small vessel hypertension Lacunar stroke in disease; and in old diabetes, but predisposing age 1 occurs conditions. w/o these 6  Ischemic 3. Embolism Stroke Most emboli are fragments of blood clot that originate in the heart or major vessels  MI, atrial fibrillation and other arythmias, endocarditis… Rarer causes are fat, air and tumor emboli  Embolic infarcts have an abrupt onset  Assumed if: - source of embolism is present - multiple infarcts in the brain - infarcts in other organs 17 UCSF Department of Surgery , The University of California,  Hemorrhagic Stroke Subarachnoid Hemorrhage (Saccular Aneurysms) Non- Traumatic Primary Brain Parenchymal Hemorrhage Epidural Subdural Traumatic Hematoma Hematoma Intracranial Hemorrhages 1 8  Hemorrhagic 1. Stroke Primary Brain Parenchymal Hemorrhage Spontaneous, nontraumatic intraparenchymal hemorrhages  Rupture of small penetrating arteries (basal ganglia & thalamus) Hypertension is the most underlying cause (poorly controlled HT!) Accounts for 15% of deaths among patients with chronic hypertension Small vessel disease: arteriolar walls affected by hyaline change are weaker than normal vessels and are therefore more vulnerable to rupture. Other risk factors: aging, smoking, oral 1 contraceptives, drug abuse, excessive alcohol 9 http://www.strokecenter. org  Hemorrhagic 1. Stroke Primary Brain Parenchymal Hemorrhage  Brain is asymmetrically (mass effect distorted + associated edema)  Hematoma may dissect into the ventricles  Onset is always abrupt with evidence increased of intracranial pressure: sever headache, vomiting, seizures, e loss rapid consciousness, papilledema of of (swelling disc) optic Risk of herniation cerebellum of stem compression and respirations, brain deep coma, dilated non- spasticity irregular responsive Massive hypertensive pupils hemorrhage rupturing into a and lateral ventricle 2 0  Hemorrhagic Stroke file:///Users/Guc/Downloads/Management%20of Radiopedia.or %20Intracerebra l%20Haemorrhage_2018%20(2).pdf g Large right sided intracerebral Large left sided intracerebral hematoma. hematoma. Mass effect with midline shift Mass effect with midline shift and and compression of 3rd ventricle compression of lateral ventricle 2 1  Hemorrhagic 1. Stroke Primary Brain Parenchymal Hemorrhage Mass effect Normal cerebellar tonsils Cerebellar tonsils are pushed through the foramen magnum into the spinal canal Cerebellar Herniation 22 Mayfield Clinic, University of Cincinnati Department of Neurosurgery  Hemorrhagic Stroke 2. Subarachnoid Hemorrhage 2 3  Hemorrhagic Stroke 2. Subarachnoid Hemorrhage Rupture of saccular aneurysms is the most common cause of nontraumatic SAH Saccular (berry) aneurysms are present in 1% of the general population  Arise most commonly at arterial bifurcations in the territories of ICA To a less extent in posterior (vertebrobasilar) circulation  Enlarge with time and are at greatest risk for rupture once they reach 6-10 mm in Relative frequency of common sites of saccular (berry) diameter aneurysms in the circle of 2 Willis 4  Hemorrhagic Stroke Philips and Mitchell. Review Article - Imaging in Medicine (2010) Volume 2, Issue 6 Diffuse blood throughout the subarachnoid space. Blood released Subarachnoid Hemorrhage from ruptured aneurysm shows up white in a ‘star’ pattern 2 5  Hemorrhagic Stroke 2. Subarachnoid Hemorrhage  SAH resulting from rupture of saccular aneurysm is less common than primary cerebral hemorrhage, with women being more affected than males with most cases before age of 50  Abrupt onset with severe headache, often described as the "worst headache of my life”, vomiting and loss of consciousness (increased ICP)  Meningeal signs are usually present (neck rigidity and pain, back pain, and bilateral leg pain).  Seizures during the acute phase of SAH occur in 10-25% of patients. They result from the sudden rise in ICP or direct cortical irritation by blood.  Blood in CSF (lumbar puncture)  50% dye within several days of onset of symptoms  Might be acutely complicated by cerebral infarcts (arterial spasm), acute hydrocephalus (increased accumulation of CSF in ventricles) and herniation. 2 6  Traumatic Vascular Injury Epidur al space Subdur al space 2 7  Traumatic Vascular Injury Epidural Subdural Hemato Hemato ma ma C. Large organizing subdural hematoma attached to the dura B. Epidural hematoma 2 covering a portion of the 8  Traumatic Vascular Injury 1. Epidural Hematoma  Rupture of middle meningeal artery after fracture of temporal bone (severe head trauma!)  Compression of subjacent dura ( ICP) http://www.thedailybeast.com  Risks: herniation, brain stem Rescuers say that he maintained compression and death consciousness when they first reached him, but his health “Lucid interval” is typical: time in quickly deteriorated which the conditions of the patients improve after a head trauma before deteriorating (loss of consciousness)  Neurosurgical emergency requiring prompt drainage 29 https://fpnotebook.com/neuro/cv/ Traumatic Vascular Injury https:// www.grepmed.com/images/81 1 https:// www.pinterest.com/pin/346847608783840289/ Epidural Intracranial Hemorrhage 3 0 Traumatic Vascular Injury 2. Subdural Hematoma  Tearing of bridging veins that extend from brain surface to dural sinuses  Rapid change in head velocity: head blows, violent shaking in infants (Shaken baby syndrome/abusive head trauma)  In elderly, even after minor trauma: brain atrophy, veins are stretched out (more space for movement)  Size vary from small to massive hemorrhage with mass effect (increased ICP: papilledema, bulging of fontanelles in infants)  Normal acute phase with gradual decline (weeks) and progressive worsening of symptoms (No “lucid  Prevention! interval”!!) (safe home environment for elderly and MedicTests.co m Buldging 3 prevent fontanelles 1  Traumatic Vascular Injury 2. Subdural Hematoma Risk of brain damage! Bilateral retinal hemorrhage in SBS (diagnostic value!) Non-Contrast Head CT Scan https:// https:// 3 www.stepwards.com/?page_id=11332 www.memorangapp.com/flashcards/30708/Shaken+Baby+Syndrom e/ 2  Reference s Robbins Basic Pathology, 10th edition, by Vinay Kumar, Abul K. Abbas and Jon C. Aster. Elsevier, ISBN: 9780323353175, 2018 Cerebrovascular diseases, Clinical aspects. Dr. Michael P. Merchut FERNE: Foundation for Education and Research in Neurological Emergencies, Stroke Pathophysiology, Sid Shah, MD 3 3 3 4