Copyright © 2015 Cengage Learning ®. Chapter 15 Nervous System Diseases and Disorders.

Copyright © 2015 Cengage Learning®.

Chapter 15

Nervous System Diseases and Disorders


Anatomy and Physiology• Nervous system

– Brain, spinal cord, and nerves

– Central nervous system (CNS)• Brain• Spinal cord

– Peripheral nervous system (PNS)• Autonomic nervous system• Cranial and spinal nerves


Common Signs and Symptoms

• Headache• Nausea and vomiting• Weakness• Mood swings• Fever



• Symptoms specific to CNS:

– Stiffness in neck, back, or extremities– Inability to move any part of body– Seizures or convulsions– Paralysis– Visual difficulties



• Symptoms specific to CNS: (continued)

– Inability to speak– Paralysis– Extreme or prolonged drowsiness– Stupor, unconsciousnes – Amnesia or extreme forgetfulness


Diagnostic Tests

• Cerebrospinal fluid• Measurement of intracranial pressure• X-rays of skull and vertebral column• Myelogram• Angiogram• Electroencephalography (EEG)• CT and MRI


Infectious Diseases• Encephalitis

– Inflammation of brain tissue caused by bacteria and viruses

– Symptoms:• Headache• Elevated temperature• Stiff neck and back• Lethargy• Mental confusion• Coma

– Treatment:• Treatment is supportive• Antiviral medication may be effective


Infectious Diseases

• Meningitis– Inflammation of meninges or coverings of brain

and spinal cord

– Causes:• Bacteria• Virus• Fungi• Toxins

– E.g., lead, arsenic


Infectious Diseases

• Meningitis

– Symptoms:• High fever• Severe headaches• Photophobia• Stiffness and resistance in neck (nuchal rigidity)• Drowsiness, stupor, seizures• Coma


Infectious Diseases

• Meningitis

– Diagnosis • Lumbar puncture to find causative agent

– Treatment• Antibiotics for bacterial infection• Antipyretics• Anticonvulsants• Quiet, dark environment

–


Infectious Diseases

• Poliomyelitis

– Viral infection affecting brain and spinal cord

– Cause:• Virus spread by oropharyngeal secretions and

infected feces

– Almost eliminated by vaccine in United States


Infectious Diseases

• Poliomyelitis– Symptoms:

• Muscle weakness• Neck stiffness• Nausea and vomiting• Muscles atrophy and become paralyzed

– Diagnosis • Virus culture from throat, feces, and/or spinal fluid


Infectious Diseases

• Poliomyelitis– Supportive treatment:

• Analgesics

• Bedrest during acute phase

• Long-term physical therapy and braces may be needed

• If respiratory system involved, mechanical ventilation may be needed


Infectious Diseases

• Tetanus

– Highly fatal infection of nerve tissue

– Cause• Bacteria Clostridium tetani

– First symptom:• Jaw stiffness • Commonly called lockjaw


Infectious Diseases

• Rabies– An often fatal encephalomyelitis

– Caused by virus

– Primarily affects animals• E.g., dogs, cats, raccoons, squirrels

– Transmitted to humans through bite of infected animal


Infectious Diseases

• Rabies– Symptoms:

• Fever• Pain• Paralysis• Convulsions• Rage• Spasms and paralysis of muscles for swallowing• Throat spasms leading to hydrophobia


Infectious Diseases

• Rabies– Symptoms:

• Inability to swallow• Drooling of frothy saliva

– Treatment:• Immediate washing of area with soap and water• Anti-rabies injections

– No cure


Infectious Diseases• Shingles

– Viral disease caused by herpes zoster (chicken pox virus)

– Symptoms• Itchy, painful, red rash and small vesicles on sensory

nerve paths• Symptoms last 10 days to several weeks

– Diagnosis• Made based on the appearance of lesions• Viral culture test


Shingles

Photo courtesy Robert A. Silverman, MD, Pediatric Dermatology, Georgetown University


Infectious Diseases

• Shingles– Treatment:

• There is no cure• Treatment is symptomatic• Antivirals• Analgesics• Antipyretics• Antipruritics

– Vaccine recommended by CDC for adults over age 60


Vascular Disorders

• Cerebrovascular accident (CVA)– Also known as stroke– Is due to a poor blood supply to the brain

– Causes• Cerebral thrombus• Cerebral embolism• Cerebral hemorrhage


Vascular Disorders

• CVA– Symptoms: numerous symptoms depending on

the area of the brain affected and the severity of the CVA

• Sudden loss of consciousness• Confusion• Poor coordination• Dysphasia• Dysphagia• Hemiparesis


Vascular Disorders

• CVA– Diagnosis

• Physical exam, EEG, CT scan, and MRI

– Treatment:• Anticoagulant• Hypertensive medications• Rehabilitation program


Vascular Disorders

• CVA– Risk factors:

• Smoking• High-fat diet• Obesity• Lack of exercise

– Surgical prevention treatment:• Carotid endarterectomy


Vascular Disorders

• Transient ischemic attacks (TIAs)– Also known as mini-strokes

– Due to insufficient blood supply to brain

– Symptoms:• Weakness of arm and/or leg• Dizziness• Slurred speech• Mild loss of consciousness


Vascular Disorders

• TIAs– Symptoms last few minutes to 1 hour

– Diagnosis by angiogram

– Treatment:• Surgery to improve blood flow


Functional Disorders• Degenerative disk disease• Headaches• Epilepsy• Bell’s palsy• Parkinson’s disease


Functional Disorders

• Degenerative disk disease– Degeneration or wearing away of intervertebral

disk• Allows vertebrae to bump or rub against each other

– Symptoms:• Difficulty walking• Radiating pain in back and in one or both legs

– Diagnosis by X-ray, myelogram, CT scan, and MRI



• Degenerative disk disease

– Treatment:• Rest back and legs• Back brace• Analgesics• Anti-inflammatories• Exercise to ease pain• Surgery


Functional Disorders• Headaches

– One of the most common disorders in humans

– Usually a symptom of another disease rather than a disorder in and of itself

– Disorders that typically have headaches as a symptom include:

• Sinusitis Meningitis• Encephalitis Hypertension• Anemia Constipation• Premenstrual tensionTumors



– Caused by two mechanisms:• Tension on facial, neck, and scalp muscles• Vascular changes in arterial size of vessels inside

head

– Contributing factors:• Stress• Toxic fumes• Noise• Lack of sleep• Alcohol consumption



– Headaches may be acute or chronic– Pain may be mild to unbearable and

incapacitating– Pain may be constant, pressure, throbbing,

stabbing, or intermittent

– Types:• Tension• Cluster• Following lumbar puncture• Migraine



– Diagnosis:• History and physical, X-ray, EEG, MRI, and CT

– Treatment:• Lifestyle changes – improved diet, sleep, exercise• Analgesics• Bedrest• Muscle massage• Muscle relaxants• Warm baths• Biofeedback


Functional Disorders• Epilepsy

– Chronic disease of brain

– Intermittent episodes of abnormal electrical activity in brain

– Symptoms:• Seizure• Convulsions


Functional Disorders• Epilepsy

– Common types of seizures– Petit mal– Grand mal– Status epilepticus

– Diagnosis by EEG, CT scan, cerebral angiogram, and blood tests

– Treatment:• Anticonvulsive medications• Close monitoring and adjusting of medication



• Bell’s palsy– Affects facial nerve (7th cranial) leading to

unilateral (one-sided) paralysis

– Affects individuals 20 to 60 years of age

– Symptoms:• Drooping weakness of eye and mouth• Inability to close the affected eye• Drooling of saliva



• Bell’s palsy– Symptoms: (continued)

• Unable to whistle or smile• Distorted facial appearance

– Diagnosis by history and symptoms

– Treatment:• Analgesics• Anti-inflammatories


Functional Disorders• Parkinson’s disease

– Slow, progressive brain degeneration

– Cause is unknown, but may be related to a decrease of brain neurotransmitter – dopamine

– Symptoms:• Rigidity and immobility of hand• Very slow speech pattern• Pill-rolling motion of fingers• Expressionless facial appearance



• Parkinson’s disease– Symptoms: (continued)

• Abnormal bent-forward posture• Short, fast-running steps with shuffling appearance

– Symptomatic treatment:• Dopamine replacement• Physical and psychological therapy


Dementias• Loss of mental ability due to loss of

neurons or brain cells• Types of dementia

– Senile (old age)• Alzheimer’s disease – the most common type of

senile dementia• Senile and Alzheimer’s disease are often used

synonymously, but they are not the same.

– Vascular– Head trauma– Substance induced


Dementias

• Alzheimer’s disease– A form of senile dementia

– Usually affects individuals age 70 and older

– Early symptoms:• Short-term memory loss• Inability to concentrate• Slight changes in personality


Dementias

• Alzheimer’s disease

– Symptoms of disease progression:• Diminished communication skills• Meaningless words• Inability to form sentences• Increased forgetfulness• Irritability and agitation


Dementias

• Alzheimer’s disease– Diagnosis

• Positive only by autopsy• Initially, diagnosis may be made by ruling out other

brain diseases

– Treatment• Supportive, no known cure• Focused on safety, maintaining nutrition, hydration,

personal hygiene• Emotional support for family and caregivers


Dementias

• Vascular dementia

– Atrophy and death of brain cells due to decreased blood flow

– Atherosclerotic plaque can cause decreased blood flow

• Common with aging


Dementias


– Symptoms:• Changes in memory, personality, and judgment• Irritability• Depression• Sleeplessness• Lack of personal hygiene


Dementias


– Diagnosis: • History and physical, blood flow testing

– Treatment:• Increasing blood flow to brain• Carotid endarterectomy


Dementias

• Head trauma dementia

– Death of brain cells due to head trauma

– Symptoms:• Decrease in mental intellect and cognitive function• Loss of ability to reason, remember, or show

appropriate emotions• Changes in personality


Dementias

• Head trauma dementia– Diagnosis:

• History, cranial X-rays, CT scan, and MRI

– Treatment:• Correct damage, if possible• Therapy and rehabilitation

– Prevention:• Is often easy to prevent with proper use of protective

equipment


Dementias• Substance-induced dementia

– Brain cell death from drug toxicity and toxins

– Toxic substances include:• Alcohol Cocaine• Heroine Lead• Mercury Paint fumes and thinner• Insecticides

– Symptoms:• Mental impairment • Decreased cognitive ability


Sleep Disorders• Insomnia

– The most common form of sleep disorder

– Inability to fall or stay asleep

– Cause:• Stress, pain, fear, depression, caffeine, alcohol,

nicotine, and bronchodilators

– Treatment:• Identifying and removing cause


Sleep Disorders• Sleep apnea

– Characterized by periods of breathlessness

– Cause:• More common in men• Obesity• Hypertension• Airway obstruction• Alcohol ingestion• Cigarette smoking



– Symptoms:• Daytime sleepiness• Extreme snoring• Changes in personality• Depression• Impotence

– Diagnosis:• Monitoring affected individual during sleep for apnea

and low blood oxygen levels



– Treatment:• Based on cause• Weight loss• Surgery to correct nasal obstruction• Oxygen during sleep• Medications to stimulate breathing

– Prevention:• Most cases can be prevented by maintaining a

healthy weight, avoiding alcohol, not smoking, and avoiding environmental smoke


Tumors• Brain tumor

– Classified as primary and secondary– Primary tumors are called brain tumors– Secondary tumors are named after the organ

of origin– Cause:

• Unknown

– Symptoms:• Headache• Vomiting• Seizures• Changes in mood and personality• Visual disturbance• Loss of memory


Tumors

– Diagnosis:• Clinical symptoms• X-ray • CT scan • MRI• Biopsy

– Treatment:• Surgery• Radiation• Chemotherapy


Trauma• Concussions and contusions

– Concussion less serious than contusion– Contusion is a physical bruising of the brain

tissue– Cause

• Blow to head by object, fall, or other trauma– E.g., automobile accident

– Symptoms:• Disruption of normal electrical activity in brain –

unconsciousness• Unconsciousness may last a few seconds to several

hours• Headache• Blurred vision


Trauma

• Concussions and contusions– Symptoms: (continued)

• Irritability• Draw up knees and begin vomiting

– Contusions can lead to:• Hematoma• Increased intracranial pressure (ICP)• Permanent brain damage

– Coup and contrecoup contusions


Coup and Contrecoup


Trauma• Concussions and contusions

– Diagnosis:• History of injury, neurologic examination, cranial X-ray, CT

scan, and MRI

– Treatment:• Bedrest• Direct observation

– Individual should be checked every 2 to 4 hours

• Monitoring of changes in consciousness, eye pupil size, mood, and behavior

• Analgesics, stimulants, and sedatives should not be given• Medications may mask symptoms and make assessment

difficult


Trauma

• Skull fracture– A break in a cranial (skull bone)

– Greatest danger: • Brain tissue damage from bony fragments• Potential of cutting brain, severing vessels, causing

hematoma

– Brain damage may be temporary or permanent


Trauma

• Skull fracture– Symptoms:

• Variety of symptoms depending on location of fracture• Fracture near base of skull may cause impaired

breathing• Hemiparesis• Seizures• Infection

– Treatment:• Dependent on type and position of fracture• Craniotomy may be necessary to relieve ICP• Protective headgear may be necessary until fracture

healed


Trauma

• Epidural and subdural hematomas

– Epidural hematoma is a collection of blood between the bony skull and dura mater (outer meninges)

– Subdural hematoma is a collection of blood between the dura mater (outer layer) and the arachnoid (middle layer)

– Subdural hematoma occurs twice as often as epidural


Trauma

• Epidural hematoma– Cause:

• Usually the result of a fight or accident• Blood vessels rupture and hemorrhage or seep blood

usually rapidly over a period of hours

– Symptoms:• Usually occur within a few hours• Headache• Dilated pupils• Nausea• Vomiting


Trauma

• Epidural hematoma– Symptoms: (continued)

• Dizziness• As the hematoma grows:

– Loss of consciousness– Increase in ICP

• Subdural hematoma– Cause:

• Usually result of head hitting stationary object– As is seen with falls when the head hits the floor


Trauma

• Subdural hematoma– Cause: (continued)

• Blood vessels rupture and seep blood slowly, usually over a period of days

– Symptoms:• Hemiparesis• Nausea and vomiting• Dizziness• Convulsions• Loss of consciousness


Trauma

• Epidural and subdural hematoma– Diagnosis:

• Cerebral hematoma is made by– Clinical history– Cranial X-ray– CT or MRI

– Treatment:• Goal is to decrease ICP• Pressure can be relieved by

– Special craniotomy called burr holes– Electrical cauterization


Trauma• Spinal cord injury

– Usually results when bony spinal column is injured or fractured

– The cord can be injured at any level• Neck area is most vulnerable

– Cause:• Automobile accidents – leading cause• Gunshot and knife wounds• Falls and sports injuries



– Symptoms:• Varying degrees of injury

• Injury to C1-C3 is usually fatal

• Quadriplegia– Loss of movement and feeling in trunk and all four

extremities– Loss of bowel, bladder, and sexual function– If severe, respiratory ventilation

• Paraplegia– Loss of movement and feeling in trunk and both legs– Loss of bowel, bladder, and sexual function



– Diagnosis:• History of injury, neurologic exam, spinal X-rays, CT

scan, and MRI

– Emergency treatment:• Immediate treatment necessary• Do not move individual unless surroundings unsafe• Maintain position of spine with special collars and

backboards

– Treatment:• Realignment and stabilization of bony spinal column• Decompression or release of pressure on spinal cord• Prevent further injury


Rare Diseases• Amyotrophic lateral sclerosis (ALS)

– Also known as Lou Gehrig’s disease

– Destructive disease of motor or movement neurons

– Atrophy of muscles leading to progressive loss of movement of hands, arms, and legs

– Supportive treatment

– No cure


Rare Diseases

• Guillain-Barré syndrome– Acute, progressive disease affecting spinal

nerves

– Begins 10 to 21 days after febrile illness

– Early symptoms:• Nausea• Fever• Malaise


Rare Diseases• Guillain-Barré syndrome

– Within 24 to 72 hours, paresthesia, muscle weakness, and paralysis usually begin

– Symptoms may progress for several days to weeks

– Once progression ceases, recovery begins


– Recovery usually complete


Rare Diseases

• Huntington’s chorea

– Inherited disease

– Appears during middle age

– Progressive degenerative disease of brain

– Leads to mental deterioration


Rare Diseases

• Huntington’s chorea– Symptoms:

• Loss of muscle control and chorea• Changes in personality mood, and behavior• Loss of memory and dementia


– No cure


Rare Diseases• Multiple sclerosis (MS)

– Causes:• Demyelination of CNS nerves• Allows information to leak from nerve pathway• Leads to poor or absent nerve transmission

– Symptoms:• Muscle weakness and lack of coordination• Paresthesia• Speech difficulty• Loss of bladder function• Visual disturbance, especially diplopia


Rare Diseases

• Multiple sclerosis– Affects adults between ages 20 and 40

– Periods of remission and exacerbation

– Treatment:• Physical therapy• Muscle relaxants to maintain muscle tone and reduce

spastic movement


Effects of Aging• Decreased nervous system activity in

brain and spinal cord

• Loss of short-term memory

• Loss of visual acuity and peripheral vision

• Altered sleep patterns

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Copyright © 2015 Cengage Learning ®. Chapter 15 Nervous System Diseases and Disorders.

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