Module 9: Nervous System Disorders Chapter 14 Classification: General Learning Objectives Classification: General 1. Review the anatomy and physiology of the nervous system 2. Describe and compare the diagnostic tests to evaluate nervous system conditions 3. Discuss the general signs and symptoms of alterations in nervous system functioning 4. Compare and contrast the causes, signs and symptoms, treatment and usual course of: • a. transient ischemic attacks (TIA) • b. cerebrovascular accident (CVA) • c. brain injury • d. spinal cord injury • e. herniated intervertebral disc • f. seizure disorders • g. multiple sclerosis • h. amyotrophic lateral sclerosis • i. myasthenia gravis 5. Discuss the implications of neurological disorders as they relate to the Spheres of Caring Conceptual Framework Classification: General Nervous System Anatomy Review What are the components of the central nervous system? • Brain and Spinal cord What about the peripheral nervous system? • Cranial nerves, peripheral nerves, spinal nerves What does the brain do? • Communication and control center What protects the brain? • Skull, meninges, cerebrospinal fluid, blood-brain barrier Classification: General Classification: General LO1 Classification: General Diagnostics Classification: General LO2 General Effects of Neurologic Dysfunction Classification: General LO3 Alterations in Nervous System Functioning Level of Consciousness • Normally a person is totally aware of surrounding activities and incoming stimuli and oriented to time, place, and people; the person can respond quickly and appropriately to questions, commands, or events. • The cerebral cortex and the RAS in the brain stem determine the level of consciousness. • Decreased level of consciousness or responsiveness • Early changes with acute brain disorders How do we • Levels of reduced consciousness may lead to: measure LOC • Confusion and disorientation in the hospital • Memory loss setting? • Unresponsiveness to verbal stimuli • Difficulty in arousal • Loss of consciousness or coma Classification: General Classification: General Transient Ischemic Attacks Interruption of blood flow to a local portion of the brain Most TIAs last less than one hour, TIAs longer are most often associated with brain infarction LO4 Risk of permanent tissue injury (ie. Infarction), even when focal transient neurologic symptoms last less than an hour TIAs are a warning sign and patient should seek immediate medical treatment. One in 3 patients will progress to an ischemic stroke Classification: General Good and Bad CholesterolHDL | LDL Classification: General Transient Ischemic Attacks LO4 SIGNS AND SYMPTOMS • Directly related to the location of the ischemia • Patient remains conscious • Muscle weakness in an arm or leg, visual disturbances • Paresthesia, numbness in the face • Transient aphasia or confusion • Usually quite short TREATMENT if symptomatic, ASA or anticoagulant may be used and then follow up with neurology. Classification: General Classification: General Cerebrovascular Accidents (Stroke) Plaque or Embolus Cerebrovascular Accidents Infarction of brain tissue Classification: General LO4 Types of CVAs • Occlusion of an artery by an atheroma • Often develop in large arteries • Sudden obstruction caused by an embolus • Lodging in a cerebral artery • Intracerebral hemorrhage • Caused by rupture of a cerebral artery in patient with severe hypertension • Effects are evident in both hemispheres. • Complicated by secondary effects of bleeding Classification: General Cerebrovascular Accidents TREATMENT • Quick CT scan • Thrombolytic agents (tPA/tnkclot busting agent) • Vasodilating agents SIGNS AND SYMPTOMS • Sudden weakness, numbness, tingling in • Medications to decrease intracranial pressure the face, arm, leg or one side of the • Ensure not a hemorrhagic stroke body *Hemiparesis/ Hemiplegia • Loss of speech, failure to comprehend, • O2 • Surgical interventions or new confusion • Management pre-existing • Loss of vision suddenly conditions • Sudden severe headache • Unusual dizziness or unsteadiness Classification: General Cerebral Aneurysms Classification: General • An aneurysm is a localized dilation/weakness in the wall of an artery. • Cerebral aneurysms are frequently multiple and usually occur at the points of bifurcation on the circle of Willis CVA (Hemorrhagic) Classification: General (Ischemic) (District of Columbia Department of Health, n.d.) Acute Stroke Treatments Classification: General Classification: General Brain Injuries Primary injuries, Direct injuries • Lacerations, crushing of neurons, glial cells, blood vessels • Concussions, contusions, closed head injuries, open, fracture Secondary injuries • From additional effects of cerebral edema, hemorrhage, cerebral vasospasm, infection, systemic ischemia Classification: General Traumatic brain injury (TBI) Temporary loss or alteration of a part or all of the brain’s ability to function without apparent physical damage to the brain. *Disturbance of function, not structural injury* Classification: General Head Injury Signs & symptoms due to increased ICP • Decreasing level of consciousness most reliable indicator as mental status extremely sensitive to oxygen levels in cerebral blood. • Seizures, CSF/Blood from nose or ears • Pupil dilation with no response to light • Motor deficits, abnormal posturing • Increased BP (widening pulse pressure), bradycardia, and respiratory depression Classification: General TREATMENT Watched for the next day or so. Waking periodically, watching for vomiting, change in sensation, behavior. Prognosis is better now due to surgical techniques, monitoring devices and supportive rehab and drug therapies LO1 tough, fibrous double layered membrane (DURABLE) loose, web-like covering Classification: General delicate connective tissue that adheres to the brain Hematomas Epidural (extradural) hematoma • bleeding between the dura and the skull • Signs of trouble usually arise within a few hours of injury Subdural hematoma • bleeding between the dura and the arachnoid • Frequently there is a small tear in a vein, which causes blood to accumulate slowly. • A hematoma may be acute (signs present in about 24 hours) or subacute (increasing ICP develops over a week or so). • A chronic subdural hematoma may occur in an elderly person, in whom brain atrophy allows more space for a hematoma to develop. Classification: General Hematomas continued… Subarachnoid hemorrhage • Bleeding between the arachnoid and pia • associated with traumatic bleeding from the blood vessels at the base of the brain • blood mixes with circulating CSF, a localized hematoma cannot form! Intracerebral hematoma • results from contusions or shearing injuries and may develop several days after injury Classification: General Think About Differentiate an open head injury from a closed head Differentiate injury in terms of appearance and effects. Classification: General Describe Describe the location, common source, and time of development of a subdural hematoma. Describe Describe three significant signs of an injury to the right occipital lobe, including one specific focal sign and two general signs. The Spinal Cord The protection for the spinal cord is very similar to the protection for the brain. It includes: • Skin, Spine, Meninges, Cerebrospinal Fluid • Cervical: innervate the chest, head, neck, shoulders, arms, hands, and diaphragm (C1-C7) 8 nerves • Thoracic: extend to the intercostal muscles of the ribcage, the abdominal muscles, and the back muscles (T1-T12) 12 nerves • Lumbar: innervate the lower abdominal wall and parts of the thighs and legs (L1-L5) 5 nerves • Sacral: extend to the thighs, buttocks, muscles, skin of the legs and feet, and anal and genital regions (S1-S5) 5 nerves Classification: General LO1 TETRAPLEGIA Classification: General Spinal Cord Injury • Classification of vertebral fractures • Simple • Single line break • Compression • Crushed or shattered bone in multiple fragments • Wedge • Displaced angular section of bone • Dislocation • Vertebra forced out of its normal position Classification: General Spinal Cord Injury Classification: General Spinal Cord Injury Signs and symptoms at time of injury • Pain at injury site • Localized acute tenderness • Self-splinting or guarding • Deformity (not usually obvious) • Symptoms worse right after injury • Spinal shock Classification: General Spinal Cord Injury Treatment • Saving the clients life – airway management • Immobilization to prevent further damage – traction • Special beds and cushions to prevent complications of immobility • Drug therapy – high doses of methylprednisolone sodium during first 8 hours • Preserving cord function – laminectomy – removing all or part of the posterior arch of the vertebrae – to alleviate compression on the cord or spinal nerves Most frequent trigger?? • Monitor for Autonomic dysreflexia • Massive sympathetic reflex response that cannot be controlled from the brain • Often initiated by genital stimulation, infection or other stimuli • Leads to: Increased blood pressure, Vasoconstriction below the injury, Vasodilation above the injury, Tachycardia heart failure or stroke if cause/stimulus not removed and BP not lowered! Classification: General Autonomic Dysreflexia Following Spinal Cord Damage Classification: General Herniated intervertebral disc Based on your knowledge of anatomy can you predict the the sign/symptoms? What treatments would you expected? Classification: General Herniated Intervertebral Disc • Herniation involves protrusion of the nucleus pulposus, the inner gelatinous component of the intervertebral disc • Tear in capsule may occur suddenly or develop gradually with aging or obesity. • Sensory, motor, or autonomic function may be impaired. • Most common location—lumbosacral disks • Some herniations involve cervical disks. • If pressure is prolonged, severe permanent damage may occur Predisposition to herniated disks • Degenerative changes in the intervertebral disk: Age, Metabolic changes, Obesity • Herniation usually caused by trauma or poor body mechanics Signs depend on location and extent of protrusion. • Most effects are unilateral. • Large protrusions may cause bilateral effects. Classification: General Pathophysiology Seizure Disorders Classification: General • Electrical impulses in chaotic pattern abnormal activity and behavior Status epilepticus • Recurrent or continuous which can affect respiration, and potentially brain damage. • Involves large number of hyperactive neurons that use excessive oxygen and glucose stores-can lead to permanent damage • Used to be called ‘epilepsy’ • Classified by location in the brain and clinical features Seizure Disorders • Generalized (both hemispheres/brain stem and loss of consciousness. Multiple foci or origins) • Partial (focal- often cerebral cortex and may or may not lose consciousness) • Etiology • Idiopathic or primary (genetic) • Acquired • Uncontrolled, excessive discharge of neurons in the brain • Many possible causes Classification: General Pathophysiology • Sudden, spontaneous, uncontrolled depolarization of neurons • Each seizure lasts for a few seconds or minutes • EEG during seizures indicate the type of seizure • Complications may arise from generalized seizures • Status epilepticus • Continuous seizures without recovery of consciousness Classification: General Triggers • Triggers (precipitating factors) • Physical stimuli • Loud noises • Bright lights • Biochemical stimuli • Stress • Excessive premenstrual fluid retention • Hypoglycemia • Change in medication • Hyperventilation Classification: General Treatment Treatment of any primary cause Anticonvulsant drugs Once seizure begins it cannot be stopped Partial seizures Signs and Symptoms Arise from an epileptogenic focus • General seizure patterns Manifested by repeated motor • Prodromal signs hours before the seizure. • An aura precedes the loss of consciousness activity Auditory or visual experiences in many persons. may occur • Loss of consciousness Memory and consciousness • Strong tonic muscle contraction remain • A cry • The clonic stage follows Most • Contractions gradually subside • The person is confused and fatigued, with common aching muscles, and falls into a deep sleep in Tonic-Clonic this postictal period. Classification: General Generalized Seizures Tonic-Clonic (Grand mal) •Prodromal signs •Nausea, irritability, muscle twitching hours before onset •Aura: peculiar visual or auditory sensation just before •Loss of consciousness Absence (petit mal) • More common in children • Brief loss of awareness • Transient facial movements • Twitching of eye • Lip smacking Post- ictal, period of disorientation following the seizure Classification: General Emergency First Aid: Seizures • Clear space and guide person to floor • Position on side, cushion head, loosen neckwear • Move dangerous objects away • Do not restrain the person in any way • NEVER put anything in the mouth • When it is finished, offer reassurance, check breathing and orientation • If it continues or immediately repeats. Call 911 Classification: General Learning Objective • Compare and contrast the causes, signs and symptoms, treatment and usual course of: Brain and Spinal cord: Multiple Sclerosis (MS) Peripheral Nervous system: Amyotrophic Lateral Sclerosis (ALS) Myasthenia gravis (MG) Classification: General Classification: General Multiple Sclerosis (MS) “Body is attacking itself” • Progressive, demyelination of neurons in brain, spinal cord and cranial nerves • Remissions and exacerbations • Pathophysiology: • Loss of myelin interferes with conduction of impulse (motor, sensory and autonomic) • Plaques form on neurons, inflame and then subside • Etiology: • Symptoms start: 20-40 years of age, more common in women • Cause UNKNOWN Genetic? Immunologic? Environmental? Viral? Abnormal immune response? • More in Europeans, Common in temperate zones Classification: General Signs and Symptoms • Manifestations determined by areas of demyelination • Blurred vision, weakness in legs • Diplopia, scotoma • Dysarthria • Paresthesia, areas of numbness, burning, tingling • Progressive weakness and paralysis extending to the upper limbs • Loss of coordination, bladder, bowel and sexual dysfunction, chronic fatigue Classification: General Tests ● nothing definitive ● History ● Often there is a big delay between onset and diagnosis ● MRI to detect lesions Treatment ● Interferon beta 1b appears to reduce frequency and severity of exacerbations ● Supportive (rehabilitation, physio, counselling) Amyotrophic Lateral Sclerosis (ALS) • Known as Lou Gehrig’s disease • Disease of the motor neurons • degeneration of motor neurons in the anterior horn of the spinal cord, brain stem and motor cortex • Progresses rapidly, loss of ability to move virtually all of the muscles Amyotrophic: muscle wasting Lateral: indicates one of the regions of the spinal cord affected Sclerosis: hardening of lateral corticospinal tracts Affects particularly men: 40-60 years Cause: Unknown, about 10% of people live beyond 8 y ears Classification: General Classification: General Chronic degenerative disorders: Myasthenia Gravis Classification: General Myasthenia Gravis “Grave muscle weakness” • Myasthenia gravis is an autoimmune disorder that impairs the receptors for ACh at the neuromuscular junction. • Antibodies form, blocking and ultimately destroying the receptor site, thus preventing any further stimulation of the muscle. • Skeletal muscle weakness and rapid fatigue of the affected muscles • Unknown cause • Myasthenic crisis- stress, trauma, infection or alcohol can cause respiratory impairment. Classification: General Signs and symptoms • Facial and eyes weakness (1st affected) • Fatigue • Diplopia and ptosis • Speech nasal and monotone • Loss of spontaneous facial expressions Treatment • Antibody serum testing • Nerve testing • Treat symptoms and see if they improve • Antcholinesterase agents (mestinon and prostigmin) which prolong action of Ach • Plasmapheresis: removal of antibodies from blood Classification: General
0
advertisement
Download
advertisement
Add this document to collection(s)
You can add this document to your study collection(s)
Sign in Available only to authorized usersAdd this document to saved
You can add this document to your saved list
Sign in Available only to authorized users