Nervous System Disorders (Part B-1) Module 8 -Chapter 14 Overview ACUTE NEUROLOGIC DISORDERS Vascular Disorders Infections/Inflammation/Toxins Metabolic, Endocrinologic, Nutritional, Toxic Neoplastic Traumatic Injuries CHRONIC NEUROLOGIC DISORDERS Seizure Disorders Degenerative Disorders Dementia Congenital Mental Susie Turner, MD Vascular Disorders Cerebrovascular disease S/S Functional abnormality of the cerebrum Caused by disorder of blood vessels of the brain Depend on; Location of ischemia Duration of decreased blood flow. 1
Risk Factors for Cerebrovascular Disease Transient Ischemic Attack TIA Temporary, localized decreased blood flow Usually due to atherosclerosis, embolus, or vascular spasm Often warning of impending stroke (CVA) Recover within 24 hours 2
TIA S/S Sudden weakness, numbness or paralysis. Slurred or garbled speech or difficulty understanding others Sudden blindness in one or both eyes or double vision Dizziness, loss of balance or coordination Cerebrovascular Accident (CVA) Infarction of brain tissue due to lack of blood flow Perfusion Approximately 5 minutes or less of O2 causes brain tissue necrosis Death of neurons leads to atrophy of muscles Also called a stroke 3
Types of Strokes 3 Major Types 1. Ischemic Stroke 2. Intracerebral Hemorrhage 3. Subarachnoid Hemorrhage Most common type 80% of strokes Usually caused by arteriosclerosis of arteries of brain or neck (carotid artery) 2 Causes 1. Artery Occlusion Most common; Blocked by atheroma and atherosclerosis of arteries of brain or neck (carotid artery) 2. Artery Obstruction Occurs suddenly by embolus in the cerebral artery. Ischemic Stroke 4
Intracerebral Hemorrhage Sudden rupture of cerebral artery within brain Blood compresses brain structures & destroys them. Causes hemorrhagic stroke Affects large portions of the brain Subaranoid Hemorrhage Commonly occurs after a cerebral aneurysm ruptures in the subarachnoid space. Usually ruptures after sudden increase in BP due to exertion Aneurysm is a localized dilation in an artery Weakness in arterial wall Where branching occurs 5
Stroke S/S Hemiparesis Weakness on one side of body Hemiplegia Paralysis on one side of body Aphasia Inability to speak Ataxia Loss of muscle coordination LOC Loss of consciousness TIA = transient ischemic attack 1. Decrease bld flow/ O2 2. No cell death CVA cerebrovascular accident (stroke) 1. Decrease bld flow/ O2 2. Cell Death TIA vs Stroke 6
Cerebral Angiography Angiography of the blood vessels of the brain after injection of a contract medium Also called Cerebral Arteriography Infections/Inflammation Brain, spinal cord, and surrounding structures can become infected by microorganisms. Bacteria and viruses are the most common Parasites, fungi and others are rarely involved 7
Infection/Inflammation Infecting germ causes an inflammation of the area invaded. Different names are given to the diseases in different locations Meningitis Encephalitis Myelitis Abscess Brain Involvement Fever, stiff neck Severe headache & vomiting Altered consciousness Spinal Cord Involvement Limb weakness (especially legs) Radicular pain Pain in the distribution of a single spinal nerve. Signs & Symptoms 8
CNS Infection & Inflammation Meningitis Inflammation or infection of the meninges Bacterial more common & more serious than viral Encephalitis Irritation and swelling (inflammation) of the brain Most often due to viral infections. CNS Infection & Inflammation Brain Abscess Localized infection Frequently in the frontal or temporal lobe Transverse Myelitis Inflammation of the spinal cord 9
Lumbar Puncture Spinal Tap CSF removed for analysis Performed below L3 vertebrae to avoid hitting spinal cord Also called infantile paralysis Virus attacks skeletal motor neurons (gray matter) of brain & spinal cord Can cause paralysis, spinal & muscle deformity Death if attacks respiratory muscles Poliomyelitis 10
Viral Skin Infections Herpes Zoster Shingles Chronic infection in sensory nerves Caused by chicken pox virus Called varicella zoster Lesions appear in clusters Very painful Acute encephalopathy & fatty infiltration of the brain, liver Sometimes other organs. Usually seen as a complication of children younger than 15 with an acute viral infection Use of aspirin in children with chicken pox or influenza may induce Reye syndrome Mortality may be 80% Reye Syndrome 11