Patho Ch. 36 Disorders of Neuromuscular function
A client presents to a health clinic complaining of several vague symptoms. As the history/physical continues, the health care provider clearly thinks the client may have myasthenia gravis. Which statements by the client would correlate with this diagnosis? Select all that apply. A) "Sometimes I have double vision." B) "I have more energy in the morning but get worse as the day goes by." C) "Sometimes I have numbness/tingling on my face." D) "I had what felt like an electric shock race down the back of my leg when I bend my neck." E) "I feel like I don't have enough energy to chew my food sometimes."
A) "Sometimes I have double vision." B) "I have more energy in the morning but get worse as the day goes by." E) "I feel like I don't have enough energy to chew my food sometimes." Now recognized as an autoimmune disease, myasthenia gravis is caused by an antibody-mediated destruction of acetylcholine receptors in the neuromuscular junction. This results in both muscle weakness and fatigability with sustained effort. Most commonly affected are the eye and periorbital muscles, with ptosis (drooping of eyelids) or diplopia (double vision) due to weakness of the extraocular muscles as an initial symptom. The disease may progress from ocular muscle weakness to generalized weakness. Chewing and swallowing may be difficult. In most persons, symptoms are least evident when arising in the morning, but grow worse with effort and as the day proceeds. Multiple sclerosis clients have paresthesias exhibited as numbness, tingling, burning sensations, or pressure on the face or involved extremities. The Lhermitte sign is an electric shock-like tingling down the back and onto the legs that is produced by flexion of the neck.
A client with a spinal cord injury at T8 would likely retain normal motor and somatosensory function of her: A) Arms B) Bowels C) Bladder D) Perineal musculature
A) Arms A spinal cord injury at T8 would likely allow the client to retain normal function of the upper extremities, while innervations governing the function of the bowels, bladder, and perineum would be severed.
The family of a multiple sclerosis client asks, "What psychological manifestations may we expect to see in our mother?" The health care provider informs them to expect which of the following? Select all that apply. A) Depression B) Hallucinations C) Delirium D) Inattentiveness E) Forgetfulness
A) Depression D) Inattentiveness E) Forgetfulness Psychological manifestations, such as mood swings, may represent an emotional reaction to the nature of the disease or, more likely, involvement of the white matter of the cerebral cortex. Depression, euphoria, inattentiveness, apathy, forgetfulness, and loss of memory may occur. Hallucinations and delirium are not usually associated as a manifestation of MS.
A client works as a data entry worker for a large company. The client goes to employee health with pain in the wrist/hand. The nurse suspects that it is carpal tunnel syndrome based on which of the following assessment findings? Select all that apply. A) Describes numbness/tingling in the thumb and first digit B) States his forearm feels funny (paresthesia) C) Loss of tendon reflexes on the affected extremity D) Precision grip weakness in the affected hand E) Pain interferes with sleeping
A) Describes numbness/tingling in the thumb and first digit D) Precision grip weakness in the affected hand E) Pain interferes with sleeping Carpal tunnel syndrome is a mononeuropathy with compression of the median nerve as it travels with the flexor tendons through a canal made by the carpal bones and transverse carpal ligament. The condition can be caused by a variety of conditions that produce a reduction in the capacity of the carpal tunnel or an increase in the volume of the tunnel contents. Carpal tunnel syndrome is characterized by hand and wrist pain, hand or finger paresthesia, and numbness of the thumb and first two and one half digits of the hand; atrophy of abductor pollicis muscle; pain interferes with sleep; and weakness in precision grip. Guillain-Barré syndrome is characterized by rapidly progressive limb weakness and loss of tendon reflexes.
A client's recent diagnosis of Parkinson disease has prompted his care provider to promptly begin pharmacologic therapy. The drugs that are selected will likely influence the client's levels of: A) Dopamine B) Acetylcholine C) Serotonin D) Adenosine
A) Dopamine Although some antiparkinsonian drugs act by reducing the excessive influence of excitatory cholinergic neurons, most act by improving the function of the dopaminergic system. Serotonin and adenosine are not known to participate directly in the pathophysiology of Parkinson disease.
A sudden traumatic complete transection of the spinal cord results in what type of injury below the site? A) Flaccid paralysis B) Vasoconstriction C) Deep visceral pain D) 3+ tendon reflexes
A) Flaccid paralysis Sudden complete transection of the spinal cord results in complete loss of motor, sensory, reflex, and autonomic function below the level of injury. This immediate response to spinal cord injury, spinal cord shock, is characterized by flaccid paralysis with loss of tendon reflexes below the level of injury, absence of somatic and visceral sensations below the level of injury, and loss of bowel and bladder function. Loss of systemic sympathetic vasomotor tone may result in vasodilation, increased venous capacity, and hypotension. These manifestations occur regardless of whether the level of the lesion eventually will produce spastic or flaccid paralysis. In persons in whom the loss of reflexes persists, hypotension and bradycardia may become critical but manageable problems. In general, the higher the level of injury, the greater is the effect.
A clinician is assessing the muscle tone of a client who has been diagnosed with a lower motor neuron (LMN) lesion. Which of the following assessment findings is congruent with the client's diagnosis? A) Hypotonia B) Spasticity C) Tetany D) Rigidity
A) Hypotonia Typically, UMN lesions produce increased tone (e.g., spasticity, tetany, and rigidity), whereas LMN lesions produce decreased tone (hypotonia).
Which of the following peripheral nerve injuries will likely result in cellular death with little chance of regeneration? A) Nerve fibers destroyed close to the neuronal cell body B) Crushing injury where the nerve is traumatized but not severed C) Cutting injury where slow-regeneration axonal branches are located D) Incomplete amputation where tubular implants are used to fill in the gaps of nerves
A) Nerve fibers destroyed close to the neuronal cell body The successful regeneration of a nerve fiber in the PNS depends on many factors. If a nerve fiber is destroyed relatively close to the neuronal cell body, the chances are that the nerve cell will die; if it does, it will not be replaced. If a crushing type of injury has occurred, partial or often full recovery of function occurs. Cutting-type trauma to a nerve is an entirely different matter. A number of scar-inhibiting agents have been used in an effort to reduce this hazard, but have met with only moderate success. Various types of tubular implants have been used to fill longer gaps in the endoneurial tube but again only with moderate success.
Disorders of the pyramidal tracts, such as a stroke, are characterized by: A) Paralysis B) Hypotonia C) Muscle rigidity D) Involuntary movements
A) Paralysis Disorders of the pyramidal tracts (e.g., stroke) are characterized by spasticity and paralysis, whereas those affecting the extrapyramidal tracts (e.g., Parkinson disease) by involuntary movements, muscle rigidity, and immobility without paralysis. Hypotonia is a condition of less than normal muscle tone, hypertonia or spasticity is a condition of excessive tone, and paralysis refers to a loss of muscle movement. Upper motor neuron (UMN) lesions produce spastic paralysis and lower motor neuron (LMN) lesions flaccid paralysis.
More complex patterns of movements, such as throwing a ball or picking up a fork, are controlled by which portion of the frontal lobe? A) Premotor cortex B) Primary motor cortex C) Reflexive circuitry D) Supplementary motor cortex
A) Premotor cortex Nerve signals generated by the premotor cortex produce much more complex "patterns" of movement; the movement pattern to accomplish a particular objective, such as throwing a ball or picking up a fork, is programmed by the prefrontal association cortex and associated thalamic nuclei. The primary motor cortex is concerned with the purpose and planning of the motor movement and controls specific muscle movement sequences. The lowest level of the hierarchy occurs at the spinal cord, which contains the basic reflex circuitry needed to coordinate the function of the motor units involved in the planned movement. The supplementary motor cortex, which contains representations of all parts of the body, is involved in the performance of complex, skillful movements that require coordination of both sides of the body.
Following his annual influenza vaccination, a client begins to feel achy, like he has developed the flu. An hour later, the client is rushed to the emergency department. Diagnosis of Guillain-Barré syndrome was made based on which of the following assessment findings? Select all that apply. A) Rapid deterioration of respiratory status B) Lack of any physical pain C) Flaccid paralysis of limbs D) BP 90/62 E) Pale, cool, dry skin
A) Rapid deterioration of respiratory status C) Flaccid paralysis of limbs D) BP 90/62 Guillain-Barré syndrome usually is a medical emergency. There may be a rapid development of ventilatory failure and autonomic disturbances that threaten circulatory function. The disorder is characterized by progressive ascending muscle weakness of the limbs, producing a symmetric flaccid paralysis. Paralysis may progress to involve the respiratory muscles. Autonomic nervous system involvement that causes postural hypotension, arrhythmias, facial flushing, abnormalities of sweating, and urinary retention is common. Pain is another common feature of Guillain-Barré syndrome.
A family brings their father to his primary care physician for a checkup. Since their last visit, they note their dad has developed a tremor in his hands and feet. He also rolls his fingers like he has a marble in his hand. The primary physician suspects the onset of Parkinson disease when he notes which of the following abnormalities in the client's gait? A) Slow to start walking and has difficulty when asked to "stop" suddenly B) Difficulty putting weight on soles of feet and tends to walk on tiptoes C) Hyperactive leg motions like he just can't stand still D) Takes large, exaggerated strides and swings arms/hands wildly
A) Slow to start walking and has difficulty when asked to "stop" suddenly The cardinal symptoms of Parkinson disease (PD) are tremor, rigidity (hypertonicity), and bradykinesia or slowness of movement. Bradykinesia is characterized by slowness in initiating and performing movements and difficulty in sudden, unexpected stopping of voluntary movements. Persons with the disease have difficulty initiating walking and difficulty turning. While walking, they may freeze in place and feel as if their feet are glued to the floor, especially when moving through a doorway or preparing to turn. When they walk, they lean forward to maintain their center of gravity and take small, shuffling steps without swinging their arms.
During physiology class, the instructor asks students to explain the pathology behind development of multiple sclerosis. Which student gave the most accurate description? A) The demyelination and subsequent degeneration of nerve fibers and decreased oligodendrocytes, which interfere with nerve conduction B) Muscle necrosis with resultant increase in fat/connective tissue replacing the muscle fibers C) Atherosclerotic destruction of circulation to the brain resulting in lactic acid buildup that affects nerve transmission D) Autoimmune disease where antibody loss of acetylcholine receptors at the neuromuscular junction causes decrease motor response
A) The demyelination and subsequent degeneration of nerve fibers and decreased oligodendrocytes, which interfere with nerve conduction Multiple sclerosis (MS) is an immune-mediated disorder that occurs in genetically susceptible individuals. The pathophysiology of MS involves demyelination and subsequent degeneration of nerve fibers in the central nervous system (CNS), marked by prominent lymphocytic invasion in the lesion. The infiltrate in nerve fiber (rather than vascular) sclerotic plaques contains CD8+ and CD4+ T cells as well as macrophages, which are thought to induce oligodendrocyte injury. With muscular dystrophy, the muscle undergoes necrosis, and fat and connective tissue replace the muscle fibers, which increases muscle size and results in muscle weakness. Now recognized as an autoimmune disease, myasthenia gravis is caused by an antibody-mediated loss of acetylcholine receptors in the neuromuscular junction.
Unlike disorders of the motor cortex and corticospinal (pyramidal) tract, lesions of the basal ganglia disrupt movement: A) Without causing paralysis B) Posture and muscle tone C) And cortical responses D) Of upper motor neurons
A) Without causing paralysis Disorders of the basal ganglia comprise a complex group of motor disturbances characterized by tremor and other involuntary movements, changes in posture and muscle tone, and poverty and slowness of movement. They include tremors and tics, spasticity, hypokinetic disorders, and hyperkinetic disorders. Unlike disorders of the motor cortex and corticospinal (pyramidal) tract, lesions of the basal ganglia disrupt movement but do not cause paralysis. Disorders of the upper motor neuron pyramidal tracts are characterized by spasticity and paralysis.
The nurse is caring for a spinal cord injury client. Assessment reveals shallow breath sounds with a very weak cough effort. The nurse correlates this with which level of injury on the spinal column? A) C2 B) C5 C) T1 D) T10
B) C5 Although a C3-to-C5 injury allows partial or full diaphragmatic function, ventilation is diminished because of the loss of intercostal muscle function, resulting in shallow breaths and a weak cough. Cord injuries involving C1 to C3 result in a lack of respiratory effort, and affected clients require assisted ventilation. The intercostal muscles, which function in elevating the rib cage and are needed for coughing and deep breathing, are innervated by spinal segments T1 through T7. The major muscles of expiration are the abdominal muscles, which receive their innervation from levels T6 to T12.
An elderly client has been brought to his primary care provider by his wife, who is concerned about his recent decrease in coordination. Upon assessment, his primary care provider notes that the client's gait is wide-based, unsteady, and lacking in fluidity, although his muscle tone appears normal. This client requires further assessment for which of the following health problems? A) Muscle atrophy B) Cerebellar disorders C) Impaired spinal reflexes D) Lower motor neuron lesions
B) Cerebellar disorders An ataxic gait is characteristic of cerebellar and/or vestibular disorders. An LMN lesion typically results in decreased muscle tone. Impaired spinal reflexes would not normally manifest as ataxia, and muscle atrophy would cause weakness and decreased muscle tone.
A client with laryngeal dystonia has gotten to the point that people on the telephone cannot understand her. She has heard about getting Botox injections into her vocal cords. The nurse will teach about the actions of Botox. Which is the most accurate description? This drug: A) Will slow the decline in muscle strength and function B) Produces paralysis of the larynx muscles by blocking acetylcholine release C) Prevents the depolarizing effect of the neurotransmitters D) Inhibits the peripheral metabolism of dopamine
B) Produces paralysis of the larynx muscles by blocking acetylcholine release Pharmacologic preparations of the botulinum toxin (botulinum type A toxin [Botox] and botulinum type B toxin [Myobloc]) produce paralysis by blocking acetylcholine release. Glucocorticoids are the only medication currently available to slow the decline in muscle strength and function in DMD. Curare acts on the postjunctional membrane of the motor endplate to prevent the depolarizing effect of the neurotransmitter. Neuromuscular transmission is blocked by curare-type drugs during many types of surgical procedures to facilitate relaxation of involved musculature. Levodopa, a dopamine agonist used in Parkinson disease, is administered with carbidopa, which inhibits its peripheral metabolism, allowing therapeutic concentrations of the drug to enter the brain without disabling adverse effects.
The client has a traumatic complete spinal cord transection at the C5 level. Based on this injury, the health care worker can expect the client to have control of which body function/part? A) Bladder B) Finger flexion C) Diaphragm D) Trunk muscle
C) Diaphragm The functional levels of cervical injury are related to C5, C6, C7, or C8 innervation. All motor and sensory function is absent below the level of cord transection. At the C5 level, deltoid and biceps function is spared, allowing full head, neck, and diaphragm control with good shoulder strength and full elbow flexion. At the C8 level, finger flexion is added. Thoracic cord injuries (T1 to T12) allow full upper extremity control with limited to full control of intercostal and trunk muscles and balance. Sacral (S1 to S5) innervation allows for full leg, foot, and ankle control and innervation of perineal musculature for bowel, bladder, and sexual function.
Among the treatments for multiple sclerosis (MS), which medication will reduce the exacerbation of relapsing-remitting MS? A) Long-term corticosteroid administration B) Mitoxantrone, an antineoplastic agent C) Interferon-β, a cytokine injection D) Baclofen, a muscle relaxer
C) Interferon-β, a cytokine injection Disease-modifying agents include interferon-b and glatiramer acetate. These agents have shown some benefit in reducing exacerbations in persons with relapsing-remitting MS. Interferon-β is a cytokine that acts as an immune enhancer. Corticosteroids are the mainstay of treatment for acute attacks of MS. These agents are thought to reduce the inflammation, improve nerve conduction, and have important immunologic effects. Long-term administration does not, however, appear to alter the course of the disease and can have harmful side effects. Mitoxantrone, an anticancer drug, is recommended for persons with worsening forms of the disease. Baclofen is a muscle relaxer for helping with symptom relief.
A client with a diagnosis of myasthenia gravis has required a mastectomy for the treatment of breast cancer. The surgery has been deemed a success, but the client has gone into a myasthenic crisis on postoperative day 1. Which of the following measures should the care team prioritize in this client's immediate care? A) Positioning the client to minimize hypertonia and muscle rigidity B) Seizure precautions with padded side rails and bed in lowest height C) Respiratory support and protection of the client's airway D) Monitoring the client for painful dyskinesias
C) Respiratory support and protection of the client's airway Myasthenic crisis occurs when muscle weakness becomes severe enough to compromise ventilation to the extent that ventilatory support and airway protection are needed. Seizures, dyskinesias, hypertonia, and muscle rigidity are not associated with myasthenia gravis in general or myasthenic crisis in particular.
A client is devastated to receive a diagnosis of amyotrophic lateral sclerosis (ALS). The symptomatology of this disease is a result of its effects on upper and lower motor neurons. The health care provider caring for this client will focus on which priority intervention for this client? A) Ability to turn from side to side, thereby preventing skin breakdown B) Ability to empty bladder completely, thereby preventing autonomic dysreflexia C) Respiratory ventilation assessment and prevention of aspiration pneumonia D) Assessment of lower extremities to prevent deep vein thrombosis
C) Respiratory ventilation assessment and prevention of aspiration pneumonia Amyotrophic lateral sclerosis is a mixed upper motor neuron (UMN) and lower motor neuron (LMN) disorder. In the more advanced stages of ALS, muscles of the palate, pharynx, tongue, neck, and shoulders become involved, causing impairment of chewing, swallowing (dysphagia), and speech. Dysphagia with recurrent aspiration and weakness of the respiratory muscles produces the most significant acute complications of the disease. Airway/breathing is always the priority over bladder emptying; skin breakdown, and assessing for DVT.
A client who experienced a traumatic head injury from a severe blow to the back of his head now lives with numerous function deficits, including an inability to maintain steady posture while he is in a standing position, although he is steadier when walking. Which of the following disorders most likely resulted from his injury? A) Cerebellar dystaxia B) Cerebellar tremor C) A lower motor neuron lesion D) A vestibulocerebellar disorder
D) A vestibulocerebellar disorder Damage to the part of the cerebellum associated with the vestibular system leads to difficulty in maintaining or to inability to maintain a steady posture of the trunk, which normally requires constant readjusting movements. Tremors are repetitive movements, while dystaxia is a characterized by uneven movement. An LMN lesion typically manifests as hypotonia.
Knowing that she is a carrier for Duchene muscular dystrophy (DMD), a pregnant woman arranged for prenatal genetic testing, during which her child was diagnosed with DMD. As her son develops, the woman should watch for which of the following early signs that the disease is progressing? A) Impaired sensory perception and frequent wounds B) Spasticity and hypertonic reflexes C) Muscle atrophy with decreased coordination D) Frequent falls and increased muscle size
D) Frequent falls and increased muscle size Pseudohypertrophy, falls, and muscle weakness are characteristic signs during the early course of DMD. Spasticity and muscle atrophy do not occur and sensory function is not affected.
While teaching a class of nursing students about spinal cord injury, the instructor mentions that male SCI clients will be able to have a sexual response if their injury is at which level on the spinal column? A) T12 B) S1 C) L2 D) S4
D) S4 Sexual function, like bladder and bowel control, is mediated by the S2 to S4 segments of the spinal cord. The S2 to S4 cord segments have been identified as the sexual touch reflex center. The T11 to L2 cord segments have been identified as the mental-stimulus, or psychogenic, sexual response area, where autonomic nerve pathways in communication with the forebrain leave the cord and innervate the genitalia. In T10 or higher injuries, reflex sexual response to genital touch may occur freely. However, a sexual response to mental stimuli (T11 to L2) does not occur because of the spinal lesion blocking the communication pathway. In an injury at T12 or below, the sexual reflex center may be damaged, and there may be no response to touch.
A recently injured (3 months ago) client with a spinal cord injury at T4 to T5 is experiencing a complication. He looks extremely ill. The nurse recognizes this as autonomic dysreflexia (autonomic hyperreflexia). His BP is 210/108; skin very pale; gooseflesh noted on arms. The priority nursing intervention would be to: A) Check the mouth/throat for pustules and redness B) Check the jugular vein for distention C) Assess calves of legs for redness, warmth, or edema D) Scan his bladder to make sure it is empty
D) Scan his bladder to make sure it is empty Autonomic hyperreflexia, an acute episode of exaggerated sympathetic reflex responses that occur in persons with injuries at T6 and above, in which central nervous system (CNS) control of spinal reflexes is lost, does not occur until spinal shock has resolved and autonomic reflexes return. Autonomic dysreflexia is characterized by vasospasm, hypertension ranging from mild to severe, skin pallor, and gooseflesh associated with the piloerector response. In many cases, the dysreflexic response results from a full bladder. There is no indication the client has right-sided heart failure (jugular vein distention); has a DVT (calf redness, warmth, or edema); or has strep throat (pustules and red throat/tonsils).
