Disorders of the Central and Peripheral Nervous Systems and the Neuromuscular Junction Chapter 17 Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc.

2 Brain Trauma Traumatic brain injury Traumatic brain injury A traumatic insult to the brain possibly producing physical, intellectual, emotional, social, and vocational changes A traumatic insult to the brain possibly producing physical, intellectual, emotional, social, and vocational changes

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 3 At-Risk Individuals Infants 6 months to 2 years Infants 6 months to 2 years School-age children School-age children Adolescents and young adults 15 to 35 years of age Adolescents and young adults 15 to 35 years of age People more than 70 years of age People more than 70 years of age Men 1.5 times as likely to sustain a TBI Men 1.5 times as likely to sustain a TBI Persons living in high-crime areas Persons living in high-crime areas

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 4 Brain Trauma Blunt (closed, nonmissile) trauma Blunt (closed, nonmissile) trauma Head strikes hard surface or a rapidly moving object strikes the head Head strikes hard surface or a rapidly moving object strikes the head The dura remains intact; brain tissues not exposed to the environment The dura remains intact; brain tissues not exposed to the environment Causes focal (local) or diffuse (general) brain injuries Causes focal (local) or diffuse (general) brain injuries Open (penetrating, missile) trauma Open (penetrating, missile) trauma Injury breaks the dura and exposes the cranial contents to the environment Injury breaks the dura and exposes the cranial contents to the environment Causes primarily focal injuries Causes primarily focal injuries

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 5 Brain Trauma Compound fractures Compound fractures Basilar skull fracture Basilar skull fracture

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 6 Brain Trauma

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 7 Causes of Brain Injury Falls 28% Falls 28% Motor vehicle crashes 20% Motor vehicle crashes 20% Moving objects or moving against stationary objects 19% Moving objects or moving against stationary objects 19% Assault 11% Assault 11% Sports-related events Sports-related events Blasts (military active duty personnel) Blasts (military active duty personnel)

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 8 Severity of Brain Injury 75% to 90% of head injuries not severe 75% to 90% of head injuries not severe Focal brain injury and diffuse axonal injury (DAI) each account for half of all injuries Focal brain injury and diffuse axonal injury (DAI) each account for half of all injuries Focal brain injury accounts for more than two thirds of head injury deaths; DAI less than one third of deaths Focal brain injury accounts for more than two thirds of head injury deaths; DAI less than one third of deaths DAI accounts for the greatest number of severely disabled survivors DAI accounts for the greatest number of severely disabled survivors

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 9 Severity of Brain Injury Hallmark of severe brain injury Hallmark of severe brain injury Loss of consciousness for six or more hours Loss of consciousness for six or more hours

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 10 Focal Brain Injury Observable brain lesion Observable brain lesion Cerebral edema Cerebral edema Coup injury Coup injury Injury directly below the point of impact Injury directly below the point of impact Contrecoup Contrecoup Injury on the pole opposite the site of impact Injury on the pole opposite the site of impact

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 11 Focal Brain Injury Force of impact typically produces contusions Force of impact typically produces contusions Contusions can cause: Contusions can cause: Extradural (epidural) hemorrhage or hematoma Extradural (epidural) hemorrhage or hematoma Subdural hematoma Subdural hematoma Intracerebral hematoma Intracerebral hematoma Clinical manifestations of contusion Clinical manifestations of contusion

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 12 Extradural Hematoma 85% arterial bleeding 85% arterial bleeding 15% meningeal vein or dural sinus injury 15% meningeal vein or dural sinus injury 90% have a skull fracture 90% have a skull fracture The temporal fossa is the most common site of extradural hematoma caused by injury to the middle meningeal artery or vein The temporal fossa is the most common site of extradural hematoma caused by injury to the middle meningeal artery or vein Clinical manifestations of hematoma Clinical manifestations of hematoma

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 13 Subdural Hematoma 10% to 20% of persons with traumatic brain injury 10% to 20% of persons with traumatic brain injury MVAs are the most common cause MVAs are the most common cause 50% of subdural hematomas associated with skull fractures 50% of subdural hematomas associated with skull fractures Falls (older adults, substance abuse) Falls (older adults, substance abuse)

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 14 Subdural Hematoma Acute Acute Develops within 48 hours Develops within 48 hours Often located at the top of the skull Often located at the top of the skull Chronic Chronic Develops over weeks to months Develops over weeks to months Older adults Older adults Alcohol abuse Alcohol abuse 80% complain of chronic headaches and have tenderness at site of injury 80% complain of chronic headaches and have tenderness at site of injury

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 15 Intracerebral Hemorrhage Associated with MVA and falls Associated with MVA and falls Intracerebral hemorrhage and resultant hematoma acts as an expanding mass Intracerebral hemorrhage and resultant hematoma acts as an expanding mass Increased ICP and compression of brain tissues with resultant edema Increased ICP and compression of brain tissues with resultant edema

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 16 Diffuse Brain Injury DAI DAI Shaking, inertial effect Shaking, inertial effect Acceleration/deceleration Acceleration/deceleration Axonal damage Axonal damage Shearing, tearing, or stretching of nerve fibers Shearing, tearing, or stretching of nerve fibers Severity corresponds to the amount of shearing force applied to the brain and brainstem (mild, moderate, severe) Severity corresponds to the amount of shearing force applied to the brain and brainstem (mild, moderate, severe)

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 17 Diffuse Brain Injury Concussions Concussions Mild concussion Mild concussion Classical concussion Classical concussion

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 18 Mild Concussion Temporary axonal disturbances causing attention and memory deficits but no loss of consciousness Temporary axonal disturbances causing attention and memory deficits but no loss of consciousness Iconfusion, disorientation, and momentary amnesia Iconfusion, disorientation, and momentary amnesia IImomentary confusion and retrograde amnesia IImomentary confusion and retrograde amnesia IIIconfusion with retrograde and anterograde amnesia IIIconfusion with retrograde and anterograde amnesia

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 19 Classic Cerebral Concussion Grade IV Grade IV Disconnection of cerebral systems from the brainstem and reticular activating system Disconnection of cerebral systems from the brainstem and reticular activating system Physiologic and neurologic dysfunction without substantial anatomic disruption Physiologic and neurologic dysfunction without substantial anatomic disruption Loss of consciousness (<6 hours) Loss of consciousness (<6 hours) Anterograde and retrograde amnesia Anterograde and retrograde amnesia Uncomplicated (no focal injury) Uncomplicated (no focal injury) Complicated (focal injury) Complicated (focal injury)

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 20 Postconcussive Syndrome Headache, cognitive impairments, psychologic and somatic complaints, cranial nerve signs and symptoms Headache, cognitive impairments, psychologic and somatic complaints, cranial nerve signs and symptoms Treatment Treatment Reassurance and symptomatic relief Reassurance and symptomatic relief Close observation for 24 hours by a reliable individual so immediate intervention can be obtained if delayed effects become severe Close observation for 24 hours by a reliable individual so immediate intervention can be obtained if delayed effects become severe

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 21 Spinal Cord Trauma Commonly occurs from vertebral injuries Commonly occurs from vertebral injuries Simple fracture, compressed fracture, and comminuted fracture Simple fracture, compressed fracture, and comminuted fracture Traumatic injury of vertebral and neural tissues due to compressing, pulling, or shearing forces Traumatic injury of vertebral and neural tissues due to compressing, pulling, or shearing forces Most common locations: cervical (1, 2, 4-7), and T1-L2 lumbar vertebrae Most common locations: cervical (1, 2, 4-7), and T1-L2 lumbar vertebrae Locations reflect most mobile portions of vertebral column and the locations where the spinal cord occupies most of the vertebral canal Locations reflect most mobile portions of vertebral column and the locations where the spinal cord occupies most of the vertebral canal Primary vs. secondary injury Primary vs. secondary injury

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 22 Spinal Cord Trauma

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 23 Spinal Cord Trauma

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 24 Spinal Cord Trauma Spinal shock Spinal shock Normal activity of the spinal cord ceases at and below the level of injury; sites lack continuous nervous discharges from the brain Normal activity of the spinal cord ceases at and below the level of injury; sites lack continuous nervous discharges from the brain Complete loss of reflex function (skeletal, bladder, bowel, sexual; thermal control; autonomic control) Complete loss of reflex function (skeletal, bladder, bowel, sexual; thermal control; autonomic control)

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 25 Spinal Cord Trauma Neurogenic shock Neurogenic shock Loss of sympathetic outflow Loss of sympathetic outflow Vasodilation Vasodilation Hypotension Hypotension Bradycardia Bradycardia Hypothermia Hypothermia

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 26 Spinal Cord Trauma Paraplegia Paraplegia Quadriplegia Quadriplegia Autonomic hyperreflexia (dysreflexia) Autonomic hyperreflexia (dysreflexia) Massive, uncompensated cardiovascular response to stimulation of the sympathetic nervous system Massive, uncompensated cardiovascular response to stimulation of the sympathetic nervous system Stimulation of the sensory receptors below the level of the cord lesion Stimulation of the sensory receptors below the level of the cord lesion

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 27 Spinal Cord Trauma Chemical and metabolic changes in tissues Chemical and metabolic changes in tissues Release of toxic excitatory amino acids, accumulation of endogenous opiates, lipid hydrolysis with production of active metabolites, and local free radical release Release of toxic excitatory amino acids, accumulation of endogenous opiates, lipid hydrolysis with production of active metabolites, and local free radical release Produce further ischemia, vascular damage, and necrosis of tissues Produce further ischemia, vascular damage, and necrosis of tissues Necrosis consumes 40% of cross-sectional cord within 4 hours of trauma and 70% within 24 hours Necrosis consumes 40% of cross-sectional cord within 4 hours of trauma and 70% within 24 hours Cord swelling increases degree of dysfunction Cord swelling increases degree of dysfunction Distinguishing functions to be lost permanently from those that are impaired temporarily becomes difficult Distinguishing functions to be lost permanently from those that are impaired temporarily becomes difficult In the cervical region, cord swelling may be life threatening In the cervical region, cord swelling may be life threatening

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 28 Autonomic Hyperreflexia

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 29 Degenerative Disorders of the Spine Degenerative disk disease (DDD) Degenerative disk disease (DDD) Spondylolysis Spondylolysis Spondylolisthesis Spondylolisthesis Spinal stenosis Spinal stenosis Low back pain Low back pain Herniated intervertebral disk Herniated intervertebral disk

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 30 Cerebrovascular Disorders Cerebrovascular accidents (CVAs) Cerebrovascular accidents (CVAs) Thrombotic stroke Thrombotic stroke Arterial occlusions caused by thrombi formed in arteries supplying the brain or in intracranial vessels Arterial occlusions caused by thrombi formed in arteries supplying the brain or in intracranial vessels Transient ischemic attacks Transient ischemic attacks Embolic stroke Embolic stroke Fragments that break from a thrombus formed outside the brain Fragments that break from a thrombus formed outside the brain

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 31 Cerebrovascular Disorders Hemorrhagic stroke (ICH) Hemorrhagic stroke (ICH) Lacunar stroke Lacunar stroke Cerebral infarction Cerebral infarction Cerebral hemorrhage Cerebral hemorrhage

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 32 Cerebrovascular Disorders Intracranial aneurysm Intracranial aneurysm Saccular (berry) aneurysms Saccular (berry) aneurysms Fusiform (giant) aneurysms Fusiform (giant) aneurysms Mycotic aneurysms Mycotic aneurysms Traumatic aneurysms Traumatic aneurysms Dissecting aneurysms Dissecting aneurysms

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 33 Intracranial Aneurysm

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 34 Cerebrovascular Disorders Vascular malformations Vascular malformations Cavernous angiomas Cavernous angiomas Capillary telangiectasis Capillary telangiectasis Venous angioma Venous angioma Arteriovenous malformation Arteriovenous malformation

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 35 Cerebrovascular Disorders Subarachnoid hemorrhage Subarachnoid hemorrhage Blood escapes from defective or injured vasculature into the subarachnoid space Blood escapes from defective or injured vasculature into the subarachnoid space Manifestations Manifestations Kernig sign Kernig sign Brudzinski sign Brudzinski sign Risk factors Risk factors

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 36 Headache Migraine headache Migraine headache Trigger factors Trigger factors Aura Aura Cluster headache Cluster headache Several attacks can occur during the day for days followed by a long period of spontaneous remission Several attacks can occur during the day for days followed by a long period of spontaneous remission

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 37 Headache Chronic paroxysmal hemicrania Chronic paroxysmal hemicrania Cluster-type headache that occurs with more daily frequency but with shorter duration Cluster-type headache that occurs with more daily frequency but with shorter duration Tension-type headache Tension-type headache Mild to moderate bilateral headache with a sensation of a tight band or pressure around the head Mild to moderate bilateral headache with a sensation of a tight band or pressure around the head

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 38 Central Nervous System Tumors Cranial tumors Cranial tumors Primary intracerebral tumors (gliomas) Primary intracerebral tumors (gliomas) Astrocytoma Astrocytoma Oligodendroglioma Oligodendroglioma Ependymoma Ependymoma Primary extracerebral tumors Primary extracerebral tumors Meningioma Meningioma Nerve sheath tumors Nerve sheath tumors Metastatic carcinoma Metastatic carcinoma

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 39 Central Nervous System Tumors Spinal cord tumors Spinal cord tumors Intramedullary tumors Intramedullary tumors Extramedullary tumors Extramedullary tumors Intradural Intradural Extradural Extradural Manifestations Manifestations Compressive syndrome Compressive syndrome Irritative syndrome Irritative syndrome Syringomyelic syndrome Syringomyelic syndrome

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 40 Spinal Cord Tumors

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 41 Infection and Inflammation of the CNS Meningitis Meningitis Bacterial meningitis Bacterial meningitis Aseptic (viral, nonpurulent, lymphocytic) meningitis Aseptic (viral, nonpurulent, lymphocytic) meningitis Fungal meningitis Fungal meningitis Tubercular (TB) meningitis Tubercular (TB) meningitis

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 42 Infection and Inflammation of the CNS Suppurative cerebral masses Suppurative cerebral masses Cerebral abscess Cerebral abscess Spinal cord abscess Spinal cord abscess Intramedullary spinal cord abscess Intramedullary spinal cord abscess

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 43 Infection and Inflammation of the CNS Encephalitis Encephalitis Acute febrile illness, usually of viral origin with nervous system involvement Acute febrile illness, usually of viral origin with nervous system involvement Most common forms of encephalitis are caused by arthropod-borne viruses and herpes simplex virus Most common forms of encephalitis are caused by arthropod-borne viruses and herpes simplex virus

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 44 Neurologic Complications of AIDS HIV-associated cognitive dysfunction HIV-associated cognitive dysfunction HIV myelopathy HIV myelopathy HIV neuropathy HIV neuropathy Aseptic viral meningitis Aseptic viral meningitis Opportunistic infections Opportunistic infections Cytomegalovirus infections Cytomegalovirus infections Parasitic infection Parasitic infection CNS neoplasms CNS neoplasms

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 45 HIV Dementia Affects adults and children Affects adults and children Insidious and unpredictable course Insidious and unpredictable course Impaired concentration, short-term memory, retrieval Impaired concentration, short-term memory, retrieval Generalized cognitive system deficits Generalized cognitive system deficits Occur later Occur later Psychomotor slowing Psychomotor slowing Decreased speech spontaneity and fluency Decreased speech spontaneity and fluency Progressive loss of balance, ataxia, spastic paraparesis or paralysis, and generalized hyperreflexia Progressive loss of balance, ataxia, spastic paraparesis or paralysis, and generalized hyperreflexia

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 46 Lyme Disease Tick-borne spirochete bacterial infection Tick-borne spirochete bacterial infection Borrelia burgdorferi Borrelia burgdorferi Progression Progression Introduced by tick bite Introduced by tick bite Incubates 3 to 32 days Incubates 3 to 32 days Migrates to skin, lymph nodes, and other body systems Migrates to skin, lymph nodes, and other body systems

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 47 Lyme Disease Stages Stages 1 Bull's eye rash 1 Bull's eye rash 2 Cardiac and neurological manifestations 2 Cardiac and neurological manifestations 3 MS, enhanced neurological manifestations 3 MS, enhanced neurological manifestations

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 48 Demyelinating Disorders Multiple sclerosis (MS) Multiple sclerosis (MS) Progressive, inflammatory, demyelinating, autoimmune disorder of the CNS Progressive, inflammatory, demyelinating, autoimmune disorder of the CNS Degeneration of the myelin sheath in CNS neurons Degeneration of the myelin sheath in CNS neurons Types Types Mixed (general) Mixed (general) Spinal Spinal Cerebellar Cerebellar

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 49 Neurodegenerative Disorders Amyotrophic lateral sclerosis (ALS) Amyotrophic lateral sclerosis (ALS) Classic ALSLou Gehrigs disease Classic ALSLou Gehrigs disease Diffusely affects upper and lower motor neurons of the cerebral cortex, brainstem, and spinal cord (corticospinal tracts and anterior roots) Diffusely affects upper and lower motor neurons of the cerebral cortex, brainstem, and spinal cord (corticospinal tracts and anterior roots) Progressive weakness leading to respiratory failure and death Progressive weakness leading to respiratory failure and death Person has normal intellectual and sensory function until death Person has normal intellectual and sensory function until death

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 50 Peripheral Nervous System Disorders Neuropathies Neuropathies Generalized symmetric polyneuropathies Generalized symmetric polyneuropathies Distal axonal polyneuropathy Distal axonal polyneuropathy Demyelinating polyneuropathy Demyelinating polyneuropathy Generalized neuropathies Generalized neuropathies Sensory neuropathies Sensory neuropathies Focal or multifocal neuropathies Focal or multifocal neuropathies

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 51 Peripheral Nervous System Disorders Guillain-Barré syndrome Guillain-Barré syndrome Acquired inflammatory disease causing demyelination of the peripheral nerves with relative sparing of axons Acquired inflammatory disease causing demyelination of the peripheral nerves with relative sparing of axons Acute onset, ascending motor paralysis Acute onset, ascending motor paralysis Humoral and cellular immunologic reaction Humoral and cellular immunologic reaction

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 52 Peripheral Nervous System Disorders Radiculopathies Radiculopathies Radiculitis Radiculitis Inflammation of the spinal nerve roots Inflammation of the spinal nerve roots Radicular pain Radicular pain Plexus injures Plexus injures Involves the nerve plexus distal to the spinal roots but proximal to the formation of the peripheral nerves Involves the nerve plexus distal to the spinal roots but proximal to the formation of the peripheral nerves

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 53 Neuromuscular Junction Disorders Myasthenia gravis Myasthenia gravis Chronic autoimmune disease Chronic autoimmune disease IgG antibody produced against acetylcholine receptors (antiacetylcholine receptor antibodies) IgG antibody produced against acetylcholine receptors (antiacetylcholine receptor antibodies) Weakness and fatigue of muscles of the eyes and the throat, causing diplopia, difficulty chewing, talking, swallowing Weakness and fatigue of muscles of the eyes and the throat, causing diplopia, difficulty chewing, talking, swallowing

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 54 Neuromuscular Junction Disorders Myasthenia gravis Myasthenia gravis Classification Classification Neonatal myasthenia Neonatal myasthenia Congenital myasthenia Congenital myasthenia Juvenile myasthenia Juvenile myasthenia Ocular myasthenia Ocular myasthenia Generalized autoimmune myasthenia Generalized autoimmune myasthenia Myasthenia crisis Myasthenia crisis Cholinergic crisis Cholinergic crisis