Pathophysiology: The Central Nervous System

Course #38921 - $90-


Study Points

  1. Identify the key structures and functional inter-relationships in the central nervous system (CNS).
  2. Discuss structures and mechanisms in place to protect the CNS.
  3. Describe the components and functions of CNS circulation.
  4. Discuss the pathophysiologic and environmental influences and effects on the CNS.
  5. Outline the role of subjective data in completing a full nursing assessment of the CNS.
  6. Describe objective data compiled during a nursing assessment of the CNS.
  7. Identify diagnostic tests used in the identification and classification of CNS diseases.
  8. Outline the nursing diagnoses, planning, and management of conditions related to CNS dysfunction.
  9. Discuss clinical manifestations of congenital diseases of the CNS.
  10. Review signs and symptoms of CNS disorders of multifactorial origin and related nursing actions.
  11. Describe the common causes, appearances, and treatment of degenerative CNS disorders.
  12. Analyze the presentation and nursing management of immunologic CNS disorders.
  13. Evaluate pathologic causes and manifestations of infectious and inflammatory disorders of the CNS.
  14. Discuss the pathophysiology and clinical manifestations of neoplastic and obstructive CNS disorders.
  15. Outline the concepts and information the nurse should provide for the patient who has sustained a traumatic CNS injury.

    1 . Which of the following is a major type of sensory receptor?
    A) Nociceptors
    B) Chemoreceptors
    C) Thermoreceptors
    D) All of the above

    THE NERVOUS SYSTEM IN HEALTH AND ILLNESS: STRUCTURAL AND FUNCTIONAL INTER-RELATIONSHIPS

    Structurally distinct neurons are responsible for receiving and sending specific messages to the brain about the body's internal and external environment. There are five major types of sensory receptors [2,3]:

    • Mechanoreceptors: Receive impulses related to pressure, touch, and mechanical deformation of the receptor

    • Thermoreceptors: Respond to heat and cold

    • Nociceptors: Receive messages about pain caused specifically by physical or chemical damage

    • Electromagnetic receptors: Respond to light on the retina

    • Chemoreceptors: Sense flavors, odors, oxygen levels, osmolality of body fluids, and the concentration of carbon dioxide

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    2 . The principal extracellular cation is
    A) sodium.
    B) calcium.
    C) potassium.
    D) morphine.

    THE NERVOUS SYSTEM IN HEALTH AND ILLNESS: STRUCTURAL AND FUNCTIONAL INTER-RELATIONSHIPS

    The principal extracellular cation is sodium; the main intercellular cation is potassium. With stimulation of the cell, the charge is reversed, as sodium moves into the cell and potassium moves out. This reversal results in a flow of electric current. With sufficient stimulation, the reversal of polarity travels along the entire axon. This process, known as an action potential, requires only a few milliseconds. Quickly, electrical forces and ion concentration forces re-establish the resting membrane potential. If a stimulus is not sufficient to produce an action potential and another stimulus occurs before the membrane has completely stabilized, depolarization will be facilitated [43,44,45].

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    3 . Which cranial nerves are responsible for tongue movement?
    A) Cranial nerve I
    B) Cranial nerve IV
    C) Cranial nerve IX
    D) Cranial nerve XII

    THE NERVOUS SYSTEM IN HEALTH AND ILLNESS: STRUCTURAL AND FUNCTIONAL INTER-RELATIONSHIPS

    Cranial Nerve XII (Hypoglossal Nerves)

    The hypoglossal nerves exit from the medulla oblongata and pass through the hypoglossal canals located beneath the tongue. These nerves are responsible for tongue movement [47].

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    4 . The cerebellum
    A) maintains body posture and muscle tone.
    B) modulates and coordinates skeletal muscle activity.
    C) controls movement with both excitatory and inhibitor signals.
    D) All of the above

    THE NERVOUS SYSTEM IN HEALTH AND ILLNESS: STRUCTURAL AND FUNCTIONAL INTER-RELATIONSHIPS

    The cerebellum modulates and coordinates skeletal muscle activity and maintains body posture and muscle tone. It controls movement with both excitatory and inhibitor signals, which modulates fine movements in ways the cerebral cortex is incapable of carrying out. Each hemisphere influences the movement of the ipsilateral side of the body and modifies activity initiated elsewhere in the body. There is no conscious input [48].

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    5 . The occipital lobes
    A) are part of the limbic system.
    B) are involved in emotional functions.
    C) receive input from hearing, taste, and smell.
    D) contain the primary visual and visual association areas.

    THE NERVOUS SYSTEM IN HEALTH AND ILLNESS: STRUCTURAL AND FUNCTIONAL INTER-RELATIONSHIPS

    The occipital lobes contain the primary visual and visual association areas. The primary visual areas receive information and perceive color, while the visual association areas give visual input meaning and have a role in visual reflexes for fixing the eyes on a stationary or moving object. Injury to the medial surface on the dominate side can result in loss of the ability to recognize objects and know their function, although recognition of faces still is possible. A consequence of damage to the nondominant side may be the inability to recognize faces and differentiate various animals, such as horses and elephants [7,10].

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    6 . The middle layer of the meninges is the
    A) pia mater.
    B) arachnoid.
    C) trabeculae.
    D) dural sinus.

    PROTECTION AND MAINTENANCE OF THE CNS

    In the spinal cord, the inner layer of dura is continuous with the spinal dura mater. The spinal dura extends to the second sacral vertebrae, where it joins with the external filum terminal and attaches to the back of the first segment of the coccyx. The middle layer of the meninges, the arachnoid, is a thin, fibrous membrane that adheres closely to the inner surface of the dura, allowing only a narrow space between the two. The inner layer of the meninges, the pia mater, adheres so closely to the brain that it follows the contour of the fissures and sulci. The space between the pia mater and arachnoid is bridged with weblike strands of arachnoid called trabeculae. A rich network of pia blood vessels extends into the brain. The area between the arachnoid and pia mater is called the subarachnoid space. Located here are arteries, veins, arachnoid trabeculae, and CSF. Within the spinal cord, fibrous bridges join the pia mater with the arachnoid and dura mater. These bridges, known as denticulate ligaments, help to stabilize the cord within the spinal canal [56].

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    7 . Which of the following statements regarding central nervous system (CNS) circulation and energy needs is TRUE?
    A) The brain requires about 1,400 kcal of glucose per day.
    B) The CNS functions well with intermittent blood supply.
    C) The average cerebral blood flow is about 750 mL per minute.
    D) The brain utilizes approximately 80% of the body's oxygen supply.

    CENTRAL NERVOUS SYSTEM CIRCULATION

    The viability and functioning of the CNS depends on a rich and continuous blood supply. The brain utilizes approximately 20% of the body's oxygen supply and requires about 400 kcal of glucose per day. The average cerebral blood flow is about 750 mL per minute [56].

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    8 . All of the following have a direct and potent effect on cerebral blood flow, EXCEPT:
    A) Oxygen concentration
    B) Glucose concentration
    C) Hydrogen ion concentration
    D) Carbon dioxide concentration

    CENTRAL NERVOUS SYSTEM CIRCULATION

    Three major factors that have a direct and potent effect on cerebral blood flow are elevations in concentrations of carbon dioxide, hydrogen ions, and oxygen. The increase in hydrogen ion concentration causes vasodilation of the cerebral vessels. Vasomotor reflex response that affects the body's general vascular perfusion also affects the perfusion of blood in the CNS. Vasomotor centers in the pons and medulla maintain vascular tone through impulses transmitted via the spinal cord to all blood vessels in the body. The reticular areas of the brain stem and hypothalamus have both excitatory and inhibitory effects on vasomotor activity. The hypothalamus also influences vasoconstriction activity through excitatory or inhibitory action on the vasomotor centers. It also helps to regulate total body water (and therefore blood pressure) by increasing or decreasing the release of antidiuretic hormone [56].

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    9 . All of the following are possible causes of CNS inflammation, EXCEPT:
    A) Trauma
    B) Meningitis
    C) Lumbar puncture
    D) Amyotrophic lateral sclerosis (ALS)

    PATHOPHYSIOLOGIC INFLUENCES AND EFFECTS

    Inflammatory processes affecting nervous tissue alter the metabolism and thus the tissue's nutritional immune processes. Causes of CNS inflammation include trauma, lumbar punctures, and infectious processes, such as meningitis.

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    10 . The loss of vibratory perception in the lower extremities usually begins at about
    A) 30 years of age.
    B) 50 years of age.
    C) 70 years of age.
    D) 85 years of age.

    PSYCHOSOCIAL/LIFESTYLE INFLUENCES AND EFFECTS

    The loss of vibratory perception in the lower extremities usually begins at about 50 years of age. Touch becomes significantly diminished due to skin changes and a decrease in the number of sensory receptors. This fact may be particularly significant to nurses during neurologic assessment. Corneal sensitivity, an accurate measurement of sensory perception, shows a decrease with age. Visual, auditory, gustatory, and olfactory senses are also diminished [4,27].

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    11 . Symptoms of ataxia should raise concern about
    A) inner ear infection.
    B) cerebellar dysfunction.
    C) degeneration of the posterior tracts of the spinal cord.
    D) Both B and C

    THE NURSING PROCESS FOR PATIENTS WITH CNS DYSFUNCTION

    Bowel and bladder function is controlled by various components of the autonomic nervous system. For patients with known or suspected CNS deficits, it is important to thoroughly review symptoms such as constipation, urinary retention, and fecal and urinary incontinence. Symptoms of ataxia (i.e., lack of muscle coordination) should raise concern about degeneration of the posterior tracts of the spinal cord or cerebellar dysfunction. Spasticity of muscles occurs with CVA and multiple sclerosis. In contrast, flaccidity (i.e., decreased or absent muscle tone) can result from isolation of muscles from neuronal impulses. Fasciculations—fine, rapid, twitching movements originating in small groups of muscle fibers—are often present in patients with ALS [30,40].

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    12 . Fasciculations are defined as
    A) flopping of the ankles during walking.
    B) intense, irregular torsion and muscle spasms.
    C) slow, twisting, snakelike movements in the upper extremities.
    D) fine, rapid, twitching movements originating in small groups of muscle fibers.

    THE NURSING PROCESS FOR PATIENTS WITH CNS DYSFUNCTION

    Bowel and bladder function is controlled by various components of the autonomic nervous system. For patients with known or suspected CNS deficits, it is important to thoroughly review symptoms such as constipation, urinary retention, and fecal and urinary incontinence. Symptoms of ataxia (i.e., lack of muscle coordination) should raise concern about degeneration of the posterior tracts of the spinal cord or cerebellar dysfunction. Spasticity of muscles occurs with CVA and multiple sclerosis. In contrast, flaccidity (i.e., decreased or absent muscle tone) can result from isolation of muscles from neuronal impulses. Fasciculations—fine, rapid, twitching movements originating in small groups of muscle fibers—are often present in patients with ALS [30,40].

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    13 . Which of the following statements regarding the Glasgow Coma Scale is TRUE?
    A) It measures reflexive responses only.
    B) It is an objective measure of level of consciousness.
    C) Using this scale, coma is defined as a score of 11 or greater.
    D) With scores of 3 or 4, there is an 85% chance of full recovery.

    THE NURSING PROCESS FOR PATIENTS WITH CNS DYSFUNCTION

    The Glasgow Coma Scale is an objective measure of level of consciousness that can also be somewhat predictive of recovery. Eye, motor, and verbal responses are measured. Coma is defined as a score of 7 or less. With a score of 3 or 4, there is an 85% chance of dying or remaining vegetative. A score greater than 11 is associated with an 85% chance of moderate disability or good recovery. Response to pain is also significant in determining the prognosis [11,41].

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    14 . Which motor response is indicative of cortical damage?
    A) Appropriate response
    B) Decortication response
    C) Decerebration response
    D) Mesencephalon response

    THE NURSING PROCESS FOR PATIENTS WITH CNS DYSFUNCTION

    Observation of the patient's station (i.e., manner of standing) and gait can provide useful insight. A decortication response is indicative of cortical damage, and unusual gait, stance, or settling posture can result from motor or sensory deficits. With decorticate posturing, the patient demonstrators hyperflexion of the upper extremities and hyperextension of the lower extremities. With decerebrate posturing, both the upper and lower extremities are hyperextended. This response indicates brain-stem injury [11,41]. Postures can also be influenced by mental and physical problems.

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    15 . Electroencephalography (EEG) is
    A) only used to establish brain death.
    B) able to reveal abnormal brain-wave patterns.
    C) useful in the assessment of Alzheimer disease.
    D) an invasive test assessing cerebrospinal fluid (CSF).

    THE NURSING PROCESS FOR PATIENTS WITH CNS DYSFUNCTION

    Electroencephalography (EEG) is essentially a noninvasive test that records a portion of the brain's electrical activity. The EEG is valued for its ability to reveal abnormal brain-wave patterns that help in diagnosing seizure disorders, brain tumors, abscesses, and psychiatric disorders. Diagnosis is made by evaluating patterns and characteristics of brain waves recorded, along with the patient's clinical state. An absence of brain waves generally establishes brain death; however, acute drug intoxication or severe hypothermia can also cause a flat EEG [5,6,8].

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    16 . Cerebral angiography may be used to help diagnose all of the following, EXCEPT:
    A) Aneurysm
    B) Seizure disorders
    C) Arteriovenous malformation
    D) Displacement of vessels by edema

    THE NURSING PROCESS FOR PATIENTS WITH CNS DYSFUNCTION

    Cerebral angiography (also referred to as intra-arterial digital subtraction angiography) is used to diagnose intracranial lesions. With this approach, a radiopaque contrast medium is injected into blood vessels of the head and neck to allow visualization of intracranial and extracranial vessels on x-ray. Cerebral angiography can reveal aneurysms, arteriovenous malformations, and displacement of vessels by masses, edema, or herniation. The test is also used during surgery to check the position and integrity of aneurysm clips [5,6,8].

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    17 . When a lumbar puncture is done, the needle usually enters the subarachnoid space at the level
    A) L1-to-L2 or L2-to-L3.
    B) C1-to-C2 or C2-to-C3.
    C) L3-to-L4 or L4-to-L5.
    D) T3-to-T4 or T4-to-T5.

    THE NURSING PROCESS FOR PATIENTS WITH CNS DYSFUNCTION

    Lumbar puncture can be done at the bedside or in the diagnostic lab. The procedure is done with the patient positioned to one side (typically the left) with head and knees flexed toward the abdomen. The patient is assisted in maintaining this position, which separates the vertebrae, allowing the needle to enter the subarachnoid space at the level L3-to-L4 or L4-to-L5. Aseptic technique is required [5,6,8]. In some patients, particularly those who are overweight, sitting and leaning forward may provide better access.

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    18 . CSF pressure in the supine patient ranges from
    A) 0.7–2 cm/H2O.
    B) 7–20 cm/H2O.
    C) 17–35 cm/H2O.
    D) 70–200 cm/H2O.

    THE NURSING PROCESS FOR PATIENTS WITH CNS DYSFUNCTION

    Because CSF is in contact with the components of the CNS, it can be valuable in the diagnosis and evaluation of CNS disease progression or healing process. CSF is colorless and consists of water and traces of protein, glucose, sodium, chloride, and potassium. The average volume in adults ranges from 100–150 mL. CSF pressure in the supine patient ranges from 7–20 cm/H2O. Fluid that is dark in color or even pink-tinged indicates hemorrhage or a cerebral bleed [5,6,8].

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    19 . Which of the following nursing interventions is recommended to promote airway clearance in patients with CNS dysfunction?
    A) Careful positioning
    B) Appropriate oral care
    C) Active or passive range-of-motion exercises
    D) All of the above

    NURSING DIAGNOSES, PLANNING, AND IMPLEMENTATION

    For the physically impaired or obtunded patient, careful positioning with pillows and special devices promotes drainage of secretions, maintains a patent airway, and reduces the risk of aspiration. This includes careful positioning during meals, supplemental oral intake, nasogastric feedings, and oral care. A suction machine should be at hand if choking is a risk or secretions are unmanageable. Active or passive range-of-motion exercises and frequent position changes help to promote mobilization of secretions [41].

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    20 . Impairment of cardiac output can follow injury to the
    A) meninges.
    B) diaphragm.
    C) cranial nerve VIII.
    D) brain stem's vasomotor center.

    NURSING DIAGNOSES, PLANNING, AND IMPLEMENTATION

    Impairment of cardiac output can follow injury to the brain stem's vasomotor center, which influences cardiac function via the autonomic nervous system. The brain stem's vasomotor center also controls blood pressure. With sharp elevation in blood pressure initiated to perfuse a severely edematous brain, the vasomotor center initiates a reflex slowing of the heart, reduces contractility, and produces vasodilation. Cardiac output can also be compromised by anoxia stemming from alterations in respiratory function [30,40].

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    21 . Patients with CNS dysfunction often experience
    A) an inability to void.
    B) increased sensitivity to bladder fullness.
    C) a decreased ability to empty the bladder.
    D) All of the above

    NURSING DIAGNOSES, PLANNING, AND IMPLEMENTATION

    Urinary retention or incontinence can result from diseases affecting the cerebral cortex, spinal cord, and/or peripheral nervous system. Patients with CNS dysfunction often experience both a diminished awareness of bladder fullness and a decreased ability to empty the bladder. Alterations in consciousness from trauma, electrolyte imbalance, anoxia, and disease processes can produce temporary or permanent urinary incontinence [30,40].

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    22 . All of the following are types of muscular dystrophy, EXCEPT:
    A) Palsy
    B) Myotonic
    C) Duchenne
    D) Limb-girdle

    CONGENITAL DISORDERS AFFECTING THE CENTRAL NERVOUS SYSTEM

    Muscular dystrophy is a hereditary, degenerative neuromuscular disorder characterized by chronic, progressive wasting and weakness of voluntary muscles. Far more common in men than women, the disease affects both children and young adults. The nine different types of muscular dystrophy (i.e., myotonic, Duchenne, Becker, Emery-Dreifuss, limb-girdle, facioscapulohumeral, congenital, oculopharyngeal, and distal) vary in the age of onset, rate of symptom progression, and clinical manifestations. All types exhibit degenerative changes in the muscle fibers [42,46].

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    23 . What is the most striking characteristic of Huntington chorea?
    A) Labile mood swings
    B) Unintelligible speech
    C) Choreiform movements
    D) Progressive memory impairment

    CONGENITAL DISORDERS AFFECTING THE CENTRAL NERVOUS SYSTEM

    The choreiform movements are the most striking characteristic of Huntington chorea. They begin slowly, usually first in the face and upper extremities. Facial grimacing and jerking limb movements occur. Over time, movements become frequent, erratic, and violent [42].

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    24 . Plexiform neuromas associated with neurofibromatosis typically affect the
    A) trunk.
    B) face and scalp.
    C) lower extremities.
    D) fingers and hands.

    CONGENITAL DISORDERS AFFECTING THE CENTRAL NERVOUS SYSTEM

    In the peripheral form of neurofibromatosis, multiple cutaneous and subcutaneous nodules occur. Cutaneous tumors are palpated in the dermis as discrete soft or firm papules varying in size from millimeters to centimeters. If pressed, these soft nodules feel like a seedless grape, which aids in distinguishing lesions of neurofibromatosis from other tumors. Subcutaneous tumors are usually multiple, assuming two forms: discrete or plexiform neuromas. Discrete tumors are firm nodules that attach to the peripheral portion of a nerve. These nodules may cause neurologic or paresthetic pain to pressure and rarely cause weakness, atrophy, or sensory loss in the distribution of the affected nerve. The number of nodules varies from a few to thousands, and the size varies from pea-sized to orange-sized. Plexiform neuromas are an overgrowth of subcutaneous tissue and can reach enormous sizes. The face, scalp, chest, and neck are typically affected with growths that feel like a "bag of worms" when palpated. The hypertrophy is highly disfiguring and often accompanied by underlying bone abnormalities. These tumors, if large enough, can cause increased ICP and brain stem compression [19].

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    25 . The most common clinical manifestations of arteriovenous malformations of the brain are
    A) syncope and dizziness.
    B) seizure activity and hemorrhage.
    C) intractable nausea and vomiting.
    D) headaches and memory impairment.

    CONGENITAL DISORDERS AFFECTING THE CENTRAL NERVOUS SYSTEM

    Clinical manifestations of arteriovenous malformations include seizures, hemorrhage, headaches, motor and sensory deficits, organic mental impairments, visual dysfunction, and syncopal episodes. The most common are seizure activity and hemorrhage [9,13].

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    26 . Which of the following statements regarding hemorrhagic stroke is TRUE?
    A) Chronic hypertension is not a factor in hemorrhagic stroke.
    B) Almost all hemorrhagic strokes are due to intracerebral hemorrhage.
    C) The highest mortality rate is associated with hemorrhage in the cerebellum.
    D) Most cases of intracerebral hemorrhage are the result of congenital vascular abnormalities.

    CNS DISORDERS OF MULTIFACTORIAL ORIGIN

    Hemorrhagic strokes are categorized by the location of the hemorrhage, either intracerebral or subarachnoid, with the former being more than twice as common—because of this, the term hemorrhagic stroke often refers to intracerebral hemorrhage (ICH) [76; 77; 78]. ICHs are characterized by bleeding directly into the brain parenchyma [78,79]. Intraventricular hemorrhage describes bleeding that extends into the ventricles [79,80]. Nontraumatic ICH is categorized as primary (unrelated to congenital or acquired lesions), secondary (caused by a congenital or acquired condition), or spontaneous (unrelated to trauma or surgery) [79].

    The signs and symptoms of ICH include headache, vomiting, seizures, depressed consciousness, meningeal irritation, and blood-tainted CSF. The onset of symptoms may occur within seconds to minutes after the start of an ICH. Individuals with this type of stroke often feel more ill than those with an ischemic stroke.

    ICH is the least treatable type of stroke [81]. Functional independence is regained within six months in approximately 20% of survivors [82]. The morbidity and mortality depend on the volume and location of the hematoma. The one-year mortality rate varies according to anatomic location, with the highest mortality rate (65%) associated with ICH in the brain stem; the rate is 57% for lobar hemorrhage, 51% for deep hemorrhage, and 42% for cerebellar hemorrhage [83]. Overall, 46% of patients with ICH survive one year and 29% survive five years [84].

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    27 . Which of the following is a possible sign of hydrocephalus?
    A) Flat affect
    B) Mental status changes
    C) Decrease in level of consciousness
    D) All of the above

    CNS DISORDERS OF MULTIFACTORIAL ORIGIN

    Communicating hydrocephalus, the third most common complication of subarachnoid hemorrhage, can occur with the bleed or weeks later as a result of a malabsorption or blockage of CSF. Hydrocephalus should be suspected if any of these signs appear:

    • Mental status changes

    • A decrease in level of consciousness

    • Dementias

    • Flat affect

    • Urinary incontinence

    • Disturbances in gait

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    28 . What proportion of patients who have a transient ischemic attack will experience an ischemic stroke within seven days?
    A) 5%
    B) 25%
    C) 50%
    D) 80%

    CNS DISORDERS OF MULTIFACTORIAL ORIGIN

    The risk of ischemic stroke is dangerously high in the period following a TIA. Research indicates that one-half of subsequent strokes occur within the first 48 hours, and a meta-analysis showed that approximately 5% of patients who have a TIA will have an ischemic stroke within seven days of that event [107,110].

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    29 . The phase of actual seizure activity is called the
    A) aura.
    B) prodrome.
    C) ictal phase.
    D) postictal phase.

    CNS DISORDERS OF MULTIFACTORIAL ORIGIN

    The ictal phase is the duration of the actual seizure activity. The patient experiences a paroxysmal, uncontrolled, abnormal, and excessive discharge of electrical activity in the brain. There are also corresponding EEG changes [116]. The clinical manifestations will coincide with the type of seizure activity that the patient is experiencing.

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    30 . Cluster headaches
    A) typically last 15 to 180 minutes.
    B) usually occur following vigorous exercise.
    C) are of moderate intensity and last days or weeks.
    D) are associated with bilateral pain across the skull.

    CNS DISORDERS OF MULTIFACTORIAL ORIGIN

    Cluster headaches are one of several types of trigeminal autonomic cephalalgias, primary headaches characterized by unilateral pain in the trigeminal nerve region. As defined by the International Headache Society, cluster headaches are attacks of severe unilateral pain in the orbit and/or the surrounding region of the eye that last 15 to 180 minutes [125]. The term "cluster" refers to the headache attacks occurring in daily episodes. The patient is headache-free in between the clusters.

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    31 . Which of the following statements is the most accurate description of Alzheimer disease?
    A) The disease is progressive.
    B) The disease is reversible with treatment.
    C) The disease is more common in younger adults.
    D) The disease is characterized by remissions and exacerbations.

    DEGENERATIVE CNS DISORDERS

    Alzheimer disease is characterized by insidious, severe, and progressive cognitive impairment that is irreversible and eventually fatal. Alzheimer disease accounts for roughly 60% to 80% of all dementias in the United States [128]. It proceeds relentlessly, gradually destroying all cognitive functions.

    There are two types of Alzheimer disease: familial and sporadic. Familial Alzheimer disease follows an autosomal dominant inheritance pattern, while sporadic Alzheimer disease has no known inheritance factor. Familial Alzheimer disease can be further classified as early-onset, when it occurs in individuals younger than 60 years of age, or late-onset, when it affects individuals older than 60 years of age [129].

    The onset of Alzheimer disease is slow and insidious; impaired memory is usually the initial symptom, followed later by deficits in other cognitive domains. Symptoms may be present for several months before the family realizes the severity of the problem. In some situations, a spouse may shelter and cover for the patient so even children and friends are unaware. In other cases, it is the death of the healthy spouse that causes other family members to recognize the changes that have occurred in the living partner. After the diagnosis of Alzheimer disease, most patients will survive for 4 to 6 years; however, this number can vary from 3 to 20 years [130].

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    32 . Which of the following cardinal motor features of Parkinson disease is seldom present at diagnosis?
    A) Rigidity
    B) Akinesia
    C) Tremor at rest
    D) Postural instability

    DEGENERATIVE CNS DISORDERS

    Motor symptoms can also appear long before diagnosis. In Parkinson disease, the cardinal motor features of bradykinesia, resting tremor, rigidity, and postural/gait impairment reflect parkinsonism [145]. A mnemonic for the core motor features is TRAP [146]:

    • Tremor at rest

    • Rigidity

    • Akinesia (i.e., bradykinesia and hypokinesia)

    • Postural instability

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    33 . Myasthenia gravis is characterized by an increasing weakness of certain voluntary muscles, especially during activity. Which muscles are most often affected?
    A) The muscles of the eye
    B) The muscles of the lower legs.
    C) The muscles of the fingers and hand
    D) The muscles of the chest and diaphragm

    IMMUNOLOGIC CNS DISORDERS

    The most characteristic finding in myasthenia gravis is an increasing weakness of certain voluntary muscles with activity and some improvement with rest. The muscles of the eyes are often most affected. Unilateral or bilateral ptosis and diplopia are common [24].

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    34 . Primary symptoms of multiple sclerosis are caused by
    A) overproduction of dopamine.
    B) chronic electrolyte depletion.
    C) progressive infection affecting the brain.
    D) the inflammation and demyelination that arises within focal areas of the CNS.

    IMMUNOLOGIC CNS DISORDERS

    Primary symptoms of multiple sclerosis are caused by the inflammation and demyelination that arises within focal areas of the CNS. The clinical presentation is varied but, in general, consists of some disturbance in vision, sensation, and/or motor function. The most common primary symptoms in patients with multiple sclerosis are:

    • Fatigue

    • Heat sensitivity

    • Muscle spasms

    • Dizziness

    • Pain

    • Paresthesias

    • Ataxia

    • Cognitive changes

    • Visual complaints

    • Bowel or bladder dysfunction

    • Sexual dysfunction

    • Gait problems

    • Nausea/vomiting

    • Speech problems

    • Tremor

    • Weakness

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    35 . The best measure to prevent meningitis is
    A) regular exercise.
    B) prophylactic daily aspirin.
    C) staying mentally active and engaged.
    D) pneumococcal and influenza immunization.

    INFECTIOUS AND INFLAMMATORY CNS DISORDERS

    Sensory perceptual deficits can occur because of photophobia, hyperalgesia, and hyperirritability. A quiet, dark, non-stimulating environment and limited visiting hours can help reduce photophobia. The potential impact of hypoxia or bladder distention on irritability should be ruled out before considering it a neurologic problem. For headache management, keep the head of the bed elevated, unless contraindicated, with good body alignment and repositioning every two hours [33,64]. Pneumococcal and influenza immunizations are the best preventive measures [33].

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    36 . In patients with encephalitis, dexamethasone (Decadron) may be used to combat
    A) infection.
    B) headache.
    C) rapid diuresis.
    D) cerebral edema.

    INFECTIOUS AND INFLAMMATORY CNS DISORDERS

    Clinical management of encephalitis is mainly symptomatic and supportive. There is no curative drug therapy, but steroids such as dexamethasone (Decadron) may be used to combat cerebral edema. Herpes encephalitis is treated with the antiviral agents acyclovir and valacyclovir; however, antivirals are ineffective for other viral causes [159,160]. Not all patients recover completely. Those surviving an acute episode can have residual neurologic deficits, including seizures, dysphasia, memory loss, and/or personality changes [24].

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    37 . Which of the following statements regarding herpes zoster infection is TRUE?
    A) It affects the anterior root ganglia.
    B) It develops from reactivation of varicella virus.
    C) Outbreaks are more common among men than women.
    D) It is characterized by red spots (the enanthem) on the tongue and soft palate.

    INFECTIOUS AND INFLAMMATORY CNS DISORDERS

    Herpes zoster (also known as shingles) is a viral disorder that affects the posterior root ganglia. It is characterized by cutaneous eruptions of vesicles along the distribution of involved spinal or cranial nerve roots. The highest percentage of cases involve spinal ganglia. Outbreaks occur mainly in adults and are more common in women than men and during the spring and fall [8,32,34].

    Herpes zoster develops from reactivation of varicella virus, which is responsible for chickenpox. Children without immunization can develop chickenpox if exposed to an adult with shingles [8,32,34].

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    38 . Metastatic tumors of the CNS are found predominantly in
    A) neurons.
    B) the brain stem.
    C) the spinal cord.
    D) the substance of the brain.

    NEOPLASTIC AND OBSTRUCTIVE CNS DISORDERS

    Tumors within the cranium can be either primary or metastatic. Metastatic tumors are found predominantly within the substance of the brain, which they reach through the systemic circulation.

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    39 . In patients with decreased levels of consciousness, it is most important to assess which reflex?
    A) Pupil response
    B) Pupillary reflex
    C) Bilateral corneal reflex
    D) Consensual light reflex

    TRAUMATIC DISORDERS

    The neurologic status of the patient with acute head trauma should be assessed immediately after respiratory airway patency is established. Level of consciousness is the single most important aspect of the clinical nursing observation. Consciousness is assessed on a continuum from full reaction to no reaction to various kinds of stimuli. The bilateral corneal reflex should also be assessed on schedule [39].

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    40 . In the first 7 to 10 days after trauma, patients with spinal cord injury are at increased risk for
    A) shock.
    B) infection.
    C) paralytic ileus.
    D) All of the above

    TRAUMATIC DISORDERS

    Patients with spinal cord injury are at greatest risk in the first 7 to 10 days after trauma. During this time, shock, pulmonary dysfunction, infection, and paralytic ileus can be major problems. Patients who sustain quadriplegic injuries require intensive total medical and nursing management. The posttraumatic care of these patients mainly involves management of bladder and bowel dysfunction, skin care, nutrition maintenance, and physical therapy [70].

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