Chapter 15 Nervous System and Behavioral Health Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. Objectives Identify organs and structures of the nervous system. Define and spell the word parts related to the nervous system Define, pronounce and spell disease and disorder terms related to the nervous system. Define, pronounce and spell surgical terms related to the nervous system. Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-2 Function of the Nervous System Cooperates with the endocrine system in regulating and controlling the activities of the other body systems The nervous system may be divided into two parts: central nervous system (CNS): made up of the brain and spinal cord peripheral nervous system (PNS): made up of cranial and spinal nerves Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-3 Nervous System Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-4 Cranial Nerves Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-5 Central Nervous System brain: major portion of the central nervous system cerebrum: largest portion of the brain, divided into right and left hemispheres; controls the skeletal muscles, interprets general senses (temperature, pain, and touch), and contains centers for sight and hearing. Intellect, memory, and emotional reactions also take place in the cerebrum. Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-6 Central Nervous System (cont’d.) brain (cont’d) ventricles: spaces within the cerebrum that contain a fluid called cerebrospinal fluid (CSF), which flows through the subarachnoid space around the brain and spinal cord cerebral spinal fluid (CSF): clear, colorless fluid to cushion the brain and spinal column from shock; transports nutrients, and clears metabolic waste Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-7 Central Nervous System (cont’d.) brain (cont’d) cerebellum: often called the hindbrain, located under the posterior portion of the cerebrum. Its function is to assist in the coordination of skeletal muscles and to maintain balance. brainstem: stemlike portion of the brain; connects with the spinal cord. Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-8 Central Nervous System (cont’d.) brain (cont’d) pons: literally means “bridge.” It connects the cerebrum with the cerebellum and brainstem. medulla oblongata: located between pons and spinal cord; contains centers that control respiration, heart rate, and the muscles in the blood vessel walls, which assist in determining blood pressure. Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-9 Central Nervous System (cont’d.) spinal cord passes through the vertebral canal extending from the medulla oblongata to the level of the 2nd lumbar vertebra; conducts nerve impulses to and from the brain and initiates reflex action to sensory information without input from the brain. Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-10 Central Nervous System (cont’d.) spinal cord meninges: 3 layers of membrane that cover the brain and spinal cord • dura mater: tough outer layer • arachnoid: delicate middle layer; the arachnoid membrane is loosely attached to the pia mater by weblike fibers, which allow for the subarachnoid space • pia mater: thin inner layer of the meanings Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-11 Brain and Spinal Cord Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-12 Spinal Cord Showing Layers of Meninges Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-13 Peripheral Nervous System nerve: cordlike structure that carries impulses from one part of the body to another 12 pair of cranial nerves 31 pair of spinal nerves ganglion: group of nerve cells located outside the central nervous system glia: cells that support and nourish nervous tissue neuron: conduct nerve empulses Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-14 Combining Forms of the Nervous System cerebell/o - cerebellum cerebr/o – cerebrum, brain dur/o – hard, dura mater encephal/o - brain gangli/o, ganglion/o ganglion gli/o – glia, gluey substance (neuroglia) mening/i, meningi/o meninges myel/o – spinal cord neur/o - nerve radic/o, radicul/o, rhiz/o – nerve root, proximal end closest to the spinal cord Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-15 Combining Forms Commonly Used with the Nervous System esthesi/o – sensation, sensitivity, feeling ment/o, psych/o - mind mon/o – one, single phas/o - speech poli/o – gray matter quadr/I - four Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-16 Suffixes • -iatrist – specialist, physician (also –logist) • -iatry – treatment, speciality • -ictal – seizure, attack • -paresis – slight paralysis (-plegia, meaning paralysis) Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-17 Helpful Information The combining form myel/o is defined as spinal cord in Chapter 15, although it also means bone marrow, as presented in Chapter 14. The suffix “-paresis” means slight paralysis while the suffix “-plegia” means paralysis. Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-18 Clicker Question Which of the following means slight paralysis -paresis b) -plegia a) Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-19 Disease and Disorder Terms Built from Word Parts Cerebellitis – inflammation of the cerebellum cerebral thrombosis – pertaining to the cerebrum, abnormal condition of a clot (blood clot in the vessel of the brain) Onset of symptoms may appear min. to days after clot occurs ischemic stoke) Duritis – inflammation of the dura matter Encephalitis – inflammation of the brain Encephalomalacia – softening of the brain Encephalomyeloradiculitis – inflammation of the brain, spinal cord and nerve roots. Ganglitis – inflammation of a ganglion Glioblastoma – tumor composed of developing glial tissue (the most malignant and most common brain tumor) Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-20 Disease and Disorder Terms Built from Word Parts glioma – tumor composed of the glial tissue (glioma is the term now used to describe all primary neoplasms of the brain) meningitis – inflammation of the meninges meningioma – tumor of the meninges (benign and slow growing) meningocele – protrusion of the meninges (through a defect in the skull or vertebrae meningomyelocele – protrusion of the meninges and spinal cord through the vertebral column (myelomeningocele) mononeuropathy – disease affecting a single nerve such as carpal tunnel neuralgia – pain in the nerve Neurasthenia – nerve weakness Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-21 meningomyelocele Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-22 Disease and Disorder Terms Built from Word Parts (cont’d.) Neuritis – inflammation of a nerve Neuroarthropathy – disease of nerves and joints Neuroma – tumor made up of nerve cells Neuropathy – disease of the nerves (peripheral) Poliomyelitis – inflammation of the gray matter of the spinal cord (polio; 3 polio viruses) Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-23 Disease and Disorder Terms Built from Word Parts (cont’d.) polyneuritis – inflammation of many nerves polyneuropathy – disease of many nerves (most often occurs as a side effect of diabetes mellitus, but may also occur as a result of drug therapy, critical illness such as sepsis, or carcinoma; exhibiting symptoms of weakness, distal sensory loss, and burning.) radiculitis – inflammation of the nerve roots radiculopathy – disease of the nerve roots rhizomeningomyelitis – inflammation of the nerve root, meninges, and spinal cord subdural hematoma – pertaining to below the dura mater, tumor of blood (hematoma, translated literally, means blood tumor; however, a hematoma is a collection of blood resulting from a broken blood vessel) Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-24 Disease and Disorder Terms Not Built from Word Parts Alzheimer disease (AD) – disease characterized by early senility, confusion, loss of recognition of persons or familiar surroundings, restlessness, and impaired memory. amyotrophic lateral sclerosis (ALS) – Progressive muscle atrophy caused by hardening of nerve tissue on the lateral columns of the spinal cord. (also called Lou Gehrig disease) Bell palsy – paralysis of muscles on one side of the face, usually a temporary condition. Symptoms include a sagging mouth on the affected side and nonclosure of the eyelid. cerebral aneurysm – aneurysm in the cerebrum Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-25 Disease and Disorder Terms Not Built from Word Parts cerebral embolism – an embolus (usually a blood clot or a piece of atherosclerotic plaque arising from a distant site cerebral palsy (CP) – condition characterized by lack of muscle control and partial paralysis, caused by a brain defect or lesion present at birth or shortly after Dementia – cognitive impairment characterized by a loss of intellectual brain function. Patients have difficulty in various ways, including difficulty in performing complex tasks, reasoning, learning, and retaining new information, orientation, word finding, and behavior. Dementia has several causes and is not considered part of normal aging. Epilepsy – disorder in which the main symptom is recurring seizures. Hydrocephalus – increased amount of cerebrospinal fluid in the ventricles of the brain, which can cause enlargement of the cranium in infants. Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-26 Clicker Question A blood clot or a piece of atherosclerotic plaque that lodges on a cerebral artery is called? cerebral embolism b) cerebral thrombosis a) Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-27 Bell Palsy Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-28 Causes of Stroke Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-29 Disease and Disorder Terms Not Built from Word Parts (cont’d.) Intracerebral hemorrhage - bleeding into the brain as a result of a ruptured blood vessel within the brain. Symptoms vary depending on the location of the hemorrhage; acute symptoms include dyspnea, dysphagia, aphasia, diminished level of consciousness and hemiparesis. The symptoms often develop suddenly. This is a form of ischemic stroke and is frequently associated with high blood pressure. multiple sclerosis (MS) - degenerative disease characterized by sclerotic patches along the brain and spinal cord. Parkinson disease (PD) - chronic degenerative disease of the central nervous system. Symptoms include resting tremors or the hands and feet, rigidity, expressionless face, and shuffling gait. It usually occurs after the age of 50 years. Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-30 Disease and Disorder Terms Not Built from Word Parts (cont’d.) Sciatica - inflammation of the sciatic nerve, causing pain that travels from the thigh through the leg to the foot and toes; can be caused by injury, infection, arthritis, herniated disk, or from prolonged pressure on the nerve from sitting for long periods Shingles - viral disease that affects the peripheral nerves and causes blisters on the skin that follow the course of the affected nerves (also called herpes zoster) Stroke - occurs when there is an interruption of blood supply to a region of the brain, depriving nerve cells in the affected area of oxygen and nutrients. The cells cannot perform and may be damaged or die within minutes. The parts of the body controlled by the involved cells will experience dysfunction. Speech, movement, memory, and other CNS functions may be affected in varying degrees. Ischemic stroke is a result of blocked blood vessels. Hemorrhagic stroke is a result of bleeding (also called cerebrovascular accident [CVA], or brain attack. Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-31 Disease and Disorder Terms Not Built from Word Parts (cont’d.) Subarachnold hemorrhage - bleeding caused by a ruptured blood vessel just outside the brain (usually a ruptured cerebral aneurysm) that rapidly fills the space between the brain and skull (subarachnoid space) with blood. The patient may experience an intense, sudden headache accompanied by nausea, vomiting, and neck pain (a type of hemorrhagic stroke). transient ischemic attack (TIA) - sudden deficient supply of blood to the brain lasting a short time. The symptoms may be similar to hose of stroke, but with TIA the symptoms are temporary and the usual outcome is complete recovery. TIA’s are often warning signs for eventual occurrence of a stroke. Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-32 Shingles Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-33 Surgical Terms Built from Word Parts Ganglionectomy – excision of a ganglion (also called a gangliectomy) Neurectomy – excision of a nerve Neurolysis – separating a nerve (from adhesions) Neuroplasty – surgical repair of a nerve Neurorrhaphy – suture of a nerve Neurotomy – incision into a nerve radicotomy, rhizotomy – incision into a nerve root Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-34 rhizotomy or radicotomy Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-35 Diagnostic Terms Built from Word Parts Diagnostic imaging cerebral angiography – radiographic imaging of the blood vessels in the brain(after an injection of contrast medium) CT myelography – process of recording (scan) the spinal cord (after an injection of a contrast agent into the subarachnoid space by lumbar puncture. Size, shape, and position of the spinal cord and nerve roots are demonstrated. Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-36 Diagnostic Terms Built from Word Parts Neurodiagnostic procedures electroencephalogram (EEG) - record of the electrical impulses of the brain Electroencephalograph – instrument used to record the electrical impulses of the brain Electroencephalography – process of recording the electrical impulses of the brain Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-37 Diagnostic Terms Not Built from Word Parts Diagnostic imaging computed tomography of the brain (CT scan) – process that includes the use of a computer to produce a series of brain tissue images at any desired depth. The procedure is noninvasive, painless, and particularly useful in diagnosing brain tumors. magnetic resonance imaging of the brain or spine (MRI scan) - a noninvasive technique that produces sectional images of soft tissues of the brain or spine through a strong magnetic field. Unlike a CT scan, MRI produces images without use of radiation. It is used to visualize tumors, edema, multiple sclerosis, and herniated disks. positron emission tomography of the brain (PET scan) Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-38 Diagnostic Terms Not Built from Word Parts Diagnostic imaging positron emission tomography of the brain (PET scan) - an imaging technique with a radioactive substance that produces sectional imaging of the brain to examine blood flow and metabolic activity. Images are projected on a viewing screen. Neurodiagnostic procedures evoked potential studies (EP studies) - a group of diagnostic tests that measure changes and response in brain waves elicited by visual, auditory, or somatosensory stimuli. Visual evoked response (VER) is a response to visual stimuli. Auditory evoked response (AER) is a response to auditory stimuli. Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-39 Clicker Question Correct labeling of the diagram is: a) CT myelography b) CT mylography Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-40 Diagnostic Terms Not Built from Word Parts (cont’d.) Other lumbar puncture (LP) – insertion of a needle into the subarachnoid space usually between the third and fourth lumbar vertebrae. It is performed for many reasons, including the removal of cerebrospinal fluid for diagnostic purposes (also called a spinal tap). Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-41 Lumbar Puncture with Needle in Place Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-42 Complementary Terms Built from Word Parts Anesthesia – without (or loss of) feeling or sensation Aphasia – condition of without speaking (loss or impairment of the ability to speak Cephalalgia – pain in the head (headache) also called cephalgia Cerebral – pertaining to the cerebrum Craniocerebral – pertaining to the cranium and cerebrum Dysphasia – condition of difficulty speaking Encephalosclerosis – hardening of the brain Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-43 Complementary Terms Built from Word Parts gliocyte – glial cell hemiparesis – slight paralysis of half (right or left side of the body) hemiplegia - paralysis of half (right or left side of the body); stroke is the most common cause hyperesthesia – excessive sensitivity to stimuli interictal – (occurring) between seizures or attacks. intracerebral – pertaining to within the cerebrum Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-44 Complementary Terms Built from Word Parts (con’t) Monoparesis – slight paralysis of one limb Monoplegia – paralysis of one limb Myelomalacia – softening of the spinal cord Neuroid – resembling an nerve Neurologist – physician who studies and treats diseases of the nerves Neurology – study of nerves (branch of medicine dealing with diseases of the nervous system) Paresthesia – abnormal sensation (such as burning, pricking, or tingling sensation, often in the extremities; may be caused by nerve damage or peripheral neuropathy) Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-45 Complementary Terms Built from Word Parts (con’t) Panplegia – total paralysis (also spelled pamplegia) Postictal – (occurring) after a seizure or attack Quadriplegia – paralysis of four (limbs) Subdural – pertaining to below the dura mater Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-46 Complementary Terms Not Built from Word Parts Afferent – conveying toward a center (nerves carrying impulses to the central nervous system Ataxia – lack of muscle coordination Cognitive – pertaining to the mental process of comprehension, judgment, memory, and reason Coma – state of profound unconsciousness Concussion – jarring or shaking that results in an injury. Caused by slight or severe head injury. Symptoms include vertigo, headache, and loss of consciousness. Conscious – awake, alert, aware of one’s surroundings Convulsion – sudden, involuntary contraction of a group of muscles. (synonymous with seizure) Disorientation – a state of mental confusion as to time, place or identity Dysarthria – the inability to use speech that is distinct and connected because of a loss of muscle control after damage to the peripheral or central nervous system. Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-47 Complementary Terms Not Built from Word Parts efferent – conveying away from the center (carrying information away from the central nervous system) gait – a manner or style of walking incoherent – unable to express one’s thoughts or ideas in an orderly, intelligible manner paraplegia – paralysis from the waist down caused by damage to the lower level of the spinal cord seizure – sudden attack with an involuntary series of contractions (synonymous with convulsion) shunt – tube implanted in the body to redirect the flow of a fluid syncope – fainting or sudden loss of consciousness caused by lack of blood supply to the cerebrum unconsciousness – state of being unaware of surrounding and incapable of responding to stimuli as a result of injury, shock or illness Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-48 1. Hemiplegia. 2. Paraplegia. 3. Quadriplegia. Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-49 Behavioral Health Terms Built from Word Parts Psychiatrist – physician who studies and treats disease of the mind Psychiatry – specialty of the mind (treatment of mental disorders Psychogenic – originating in the mind Psychologist – specialist of the mind Psychology – study of the mind (deals with the mind and mental processes in relation to human behavior Psychopathy – any disease of the mind Psychosis – abnormal condition of the mind (major mental disorder characterized by extreme derangement, often with delusions and hallucinations Psychosomatic – pertaining to the mind and body (interrelations of) Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-50 Behavioral Health Terms Not Built from Word Parts anorexia nervosa – an eating disorder characterized by a disturbed perception of body image resulting in failure to maintain body weight, intensive fear of gaining weight, pronounced desire for thinness, and, in females, amenorrhea anxiety disorder – an emotional disorder characterized by feelings of apprehension, tension, or uneasiness arising typically from the anticipation of unreal or imagined danger attention deficit hyperactivity disorder (ADHD) – a disorder of learning and behavioral problems characterized by marked inattention, distractibility, impulsiveness, and hyperactivity. Autism – a mental disorder, the features of which include onset during infancy or childhood, preoccupation with subjective mental activity, inability to interact socially, impaired communication, and repetitive body movements. Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-51 Behavioral Health Terms Not Built from Word Parts bipolar disorder – a major psychological disorder typified by a disturbance in mood. The disorder is manifested by manic and depressive episodes that may alternate or elements of both may occur simultaneously. bulimia nervosa – an eating disorder characterized by uncontrolled binge eating followed by purging (induced vomiting). major depression – a mood disturbance characterized by feelings of sadness, despair, discouragement, hopelessness, lack of joy, altered sleep patterns, and difficulty with decision making and daily function. Depression range from normal feelings of sadness (resulting from and proportional to personal loss or tragedy), through dysthymia (chronic depressive neurosis), to major depression (clinical depression, mood disorder.) obsessive-compulsive disorder (OCD) – a disorder characterized by intrusive, unwanted thoughts that result in the tendency to perform repetitive acts or rituals(compulsions), usually as a means of releasing tension or anxiety. Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-52 Behavioral Health Terms Not Built from Word Parts panic attack – an episode of sudden onset of acute anxiety, occurring unpredictably, with feelings of acute apprehension, dyspnea, dizziness, sweating, and/or chest pain, depersonalization, paresthesia and fear of dying, loss of mind or control. phobia – a marked and persistent fear that is excessive or unreasonable cued by the presence or anticipation of a specific situation or object. pica – compulsive eating of nonnutritive substance such as clay or ice. This condition is often the result of an iron deficiency. When iron deficiency is the cause if pica the condition will disappear in 1 or 2 weeks when treated with iron therapy. Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-53 Behavioral Health Terms Not Built from Word Parts posttraumatic stress disorder – a disorder characterized by an acute emotional response to a traumatic event perceived as life threatening or severe emotional stress such as an airplane crash, repeated physical or emotional trauma, or military combat. Symptoms include anxiety, sleep disturbance, nightmares, difficulty concentrating, and depression. schizophrenia – any one of a large group of psychotic disorders characterized by gross distortions of reality, disturbance of language and communication, withdrawal from social interaction, and the disorganization and fragmentation of thought, perception, and emotional reaction. somatoform disorders – disorders characterized by physical symptoms for which no known physical cause exists. Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-54 Abbreviations AD – Alzheimer disease ADHD – attention deficit hyperactivity disorder ALS – amyotrophic lateral sclerosis CP – cerebral palsy CSF – cerebrospinal fluid CVA – cerebrovascular accident EEG - electroencephalogram EP studies – evoked potential studies LP – lumbar puncture MRI scan – magnetic resonance imaging scan OCD – obsessive-compulsive disorder PD – Parkinson disease PET scan – positron emission tomography scan PNS – peripheral nervous system PTSD – posttraumatic stress disorder TIA – transient ischemic attack Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-55 Clicker Question PTSD is the abbreviation for posttraumatic schizophrenia disease b) posttraumatic stress disorder a) Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-56 Read Medical Terms in Use A 78-year-old right-handed man presented to the Emergency Department with a right hemiparesis, expressive aphasia, and no apparent cognitive decline. He has a history of hypertension and 2 years ago had a transient ischemic attack. A computed tomography scan of the brain was negative for an intracerebral hemorrhage. A neurologist was consulted. She confirmed the diagnosis of a ischemic stroke after magnetic resonance imaging of the brain demonstrated an ischemic area of the left cerebral cortex caused by a cerebral embolism. Copyright © 2009, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved. 15-57