Download Human Diseases - Cengage Learning

Chapter 15
Nervous System Diseases
and Disorders
Copyright © 2015 Cengage Learning®.
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
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Common Signs and Symptoms
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Headache
Nausea and vomiting
Weakness
Mood swings
Fever
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Common Signs and Symptoms
• Symptoms specific to CNS:
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Stiffness in neck, back, or extremities
Inability to move any part of body
Seizures or convulsions
Paralysis
Visual difficulties
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Common Signs and Symptoms
• Symptoms specific to CNS: (continued)
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Inability to speak
Paralysis
Extreme or prolonged drowsiness
Stupor, unconsciousnes
Amnesia or extreme forgetfulness
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Diagnostic Tests
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Cerebrospinal fluid
Measurement of intracranial pressure
X-rays of skull and vertebral column
Myelogram
Angiogram
Electroencephalography (EEG)
CT and MRI
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Infectious Diseases
• Encephalitis
– Inflammation of brain tissue caused by bacteria and
viruses
– Symptoms:
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Headache
Elevated temperature
Stiff neck and back
Lethargy
Mental confusion
Coma
– Treatment:
• Treatment is supportive
• Antiviral medication may be effective
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Infectious Diseases
• Meningitis
– Inflammation of meninges or coverings of brain and
spinal cord
– Causes:
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Bacteria
Virus
Fungi
Toxins
– E.g., lead, arsenic
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Infectious Diseases
• Meningitis
– Symptoms:
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High fever
Severe headaches
Photophobia
Stiffness and resistance in neck (nuchal rigidity)
Drowsiness, stupor, seizures
Coma
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Infectious Diseases
• Meningitis
– Diagnosis
• Lumbar puncture to find causative agent
– Treatment
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Antibiotics for bacterial infection
Antipyretics
Anticonvulsants
Quiet, dark environment
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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
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Infectious Diseases
• Poliomyelitis
– Symptoms:
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Muscle weakness
Neck stiffness
Nausea and vomiting
Muscles atrophy and become paralyzed
– Diagnosis
• Virus culture from throat, feces, and/or spinal fluid
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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
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Infectious Diseases
• Tetanus
– Highly fatal infection of nerve tissue
– Cause
• Bacteria Clostridium tetani
– First symptom:
• Jaw stiffness
• Commonly called lockjaw
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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
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Infectious Diseases
• Rabies
– Symptoms:
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Fever
Pain
Paralysis
Convulsions
Rage
Spasms and paralysis of muscles for swallowing
Throat spasms leading to hydrophobia
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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
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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
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Shingles
Photo courtesy Robert A. Silverman, MD,
Pediatric Dermatology, Georgetown University
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Infectious Diseases
• Shingles
– Treatment:
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There is no cure
Treatment is symptomatic
Antivirals
Analgesics
Antipyretics
Antipruritics
– Vaccine recommended by CDC for adults over age 60
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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
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Vascular Disorders
• CVA
– Symptoms: numerous symptoms depending on the
area of the brain affected and the severity of the CVA
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Sudden loss of consciousness
Confusion
Poor coordination
Dysphasia
Dysphagia
Hemiparesis
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Vascular Disorders
• CVA
– Diagnosis
• Physical exam, EEG, CT scan, and MRI
– Treatment:
• Anticoagulant
• Hypertensive medications
• Rehabilitation program
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Vascular Disorders
• CVA
– Risk factors:
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Smoking
High-fat diet
Obesity
Lack of exercise
– Surgical prevention treatment:
• Carotid endarterectomy
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Vascular Disorders
• Transient ischemic attacks (TIAs)
– Also known as mini-strokes
– Due to insufficient blood supply to brain
– Symptoms:
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Weakness of arm and/or leg
Dizziness
Slurred speech
Mild loss of consciousness
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Vascular Disorders
• TIAs
– Symptoms last few minutes to 1 hour
– Diagnosis by angiogram
– Treatment:
• Surgery to improve blood flow
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Functional Disorders
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Degenerative disk disease
Headaches
Epilepsy
Bell’s palsy
Parkinson’s disease
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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
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Functional Disorders
• Degenerative disk disease
– Treatment:
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Rest back and legs
Back brace
Analgesics
Anti-inflammatories
Exercise to ease pain
Surgery
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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:
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Sinusitis
Encephalitis
Anemia
Premenstrual tension
Meningitis
Hypertension
Constipation
Tumors
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Functional Disorders
• Headaches
– Caused by two mechanisms:
• Tension on facial, neck, and scalp muscles
• Vascular changes in arterial size of vessels inside head
– Contributing factors:
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Stress
Toxic fumes
Noise
Lack of sleep
Alcohol consumption
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Functional Disorders
• Headaches
– Headaches may be acute or chronic
– Pain may be mild to unbearable and incapacitating
– Pain may be constant, pressure, throbbing, stabbing,
or intermittent
– Types:
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Tension
Cluster
Following lumbar puncture
Migraine
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Functional Disorders
• Headaches
– Diagnosis:
• History and physical, X-ray, EEG, MRI, and CT
– Treatment:
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Lifestyle changes – improved diet, sleep, exercise
Analgesics
Bedrest
Muscle massage
Muscle relaxants
Warm baths
Biofeedback
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Functional Disorders
• Epilepsy
– Chronic disease of brain
– Intermittent episodes of abnormal electrical activity in
brain
– Symptoms:
• Seizure
• Convulsions
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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
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Functional Disorders
• 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
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Functional Disorders
• Bell’s palsy
– Symptoms:
(continued)
• Unable to whistle or smile
• Distorted facial appearance
– Diagnosis by history and symptoms
– Treatment:
• Analgesics
• Anti-inflammatories
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Functional Disorders
• Parkinson’s disease
– Slow, progressive brain degeneration
– Cause is unknown, but may be related to a decrease
of brain neurotransmitter – dopamine
– Symptoms:
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Rigidity and immobility of hand
Very slow speech pattern
Pill-rolling motion of fingers
Expressionless facial appearance
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Functional Disorders
• Parkinson’s disease
– Symptoms:
(continued)
• Abnormal bent-forward posture
• Short, fast-running steps with shuffling appearance
– Symptomatic treatment:
• Dopamine replacement
• Physical and psychological therapy
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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
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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
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Dementias
• Alzheimer’s disease
– Symptoms of disease progression:
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Diminished communication skills
Meaningless words
Inability to form sentences
Increased forgetfulness
Irritability and agitation
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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
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Dementias
• Vascular dementia
– Atrophy and death of brain cells due to decreased
blood flow
– Atherosclerotic plaque can cause decreased blood
flow
• Common with aging
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Dementias
• Vascular dementia
– Symptoms:
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Changes in memory, personality, and judgment
Irritability
Depression
Sleeplessness
Lack of personal hygiene
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Dementias
• Vascular dementia
– Diagnosis:
• History and physical, blood flow testing
– Treatment:
• Increasing blood flow to brain
• Carotid endarterectomy
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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
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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
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Dementias
• Substance-induced dementia
– Brain cell death from drug toxicity and toxins
– Toxic substances include:
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Alcohol
Heroine
Mercury
Insecticides
Cocaine
Lead
Paint fumes and thinner
– Symptoms:
• Mental impairment
• Decreased cognitive ability
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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
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Sleep Disorders
• Sleep apnea
– Characterized by periods of breathlessness
– Cause:
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More common in men
Obesity
Hypertension
Airway obstruction
Alcohol ingestion
Cigarette smoking
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Sleep Disorders
• Sleep apnea
– Symptoms:
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Daytime sleepiness
Extreme snoring
Changes in personality
Depression
Impotence
– Diagnosis:
• Monitoring affected individual during sleep for apnea and low
blood oxygen levels
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Sleep Disorders
• Sleep apnea
– Treatment:
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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
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Tumors
• Brain tumor
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Classified as primary and secondary
Primary tumors are called brain tumors
Secondary tumors are named after the organ of origin
Cause:
• Unknown
– Symptoms:
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Headache
Vomiting
Seizures
Changes in mood and personality
Visual disturbance
Loss of memory
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Tumors
– Diagnosis:
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Clinical symptoms
X-ray
CT scan
MRI
Biopsy
– Treatment:
• Surgery
• Radiation
• Chemotherapy
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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
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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
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Coup and Contrecoup
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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
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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
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Trauma
• Skull fracture
– Symptoms:
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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
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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
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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:
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Usually occur within a few hours
Headache
Dilated pupils
Nausea
Vomiting
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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
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Trauma
• Subdural hematoma
– Cause:
(continued)
• Blood vessels rupture and seep blood slowly, usually over a
period of days
– Symptoms:
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Hemiparesis
Nausea and vomiting
Dizziness
Convulsions
Loss of consciousness
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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
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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
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Trauma
• Spinal cord injury
– 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
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Trauma
• Spinal cord injury
– 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
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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
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Rare Diseases
• Guillain-Barré syndrome
– Acute, progressive disease affecting spinal nerves
– Begins 10 to 21 days after febrile illness
– Early symptoms:
• Nausea
• Fever
• Malaise
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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
– Supportive treatment
– Recovery usually complete
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Rare Diseases
• Huntington’s chorea
– Inherited disease
– Appears during middle age
– Progressive degenerative disease of brain
– Leads to mental deterioration
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Rare Diseases
• Huntington’s chorea
– Symptoms:
• Loss of muscle control and chorea
• Changes in personality mood, and behavior
• Loss of memory and dementia
– Supportive treatment
– No cure
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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:
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•
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•
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Muscle weakness and lack of coordination
Paresthesia
Speech difficulty
Loss of bladder function
Visual disturbance, especially diplopia
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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
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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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