Disorders of Motor Function

Question 1

The reception of stimuli originating from within the body regarding body position and muscular activity by proprioceptors (sensory nerve endings found in muscles, tendons, joints)

Answer 1

propioception

Question 2

The condition characterized by spasms or other uncontrolled contractions of the skeletal muscles.

Answer 2

spasticity

Question 3

An abnormal condition characterized by an inability to coordinate voluntary muscular movement.

Answer 3

ataxia

Question 4

Involuntary quivering or trembling movements caused by the alternating contraction and relaxation of opposing groups of skeletal muscles.

Answer 4

tremor

Question 5

A spasm of a portion of a muscle, an entire muscle, or a group of muscles.

Answer 5

myoclonus

Question 6

Involuntary, rapid, rhythmic movements of the eyeball.

Answer 6

nystagmus

Question 7

An abnormal condition characterized by the impairment or loss of motor function due to a lesion of the neural or muscular mechanism.

Answer 7

paralysis

Question 8

Slight or partial paralysis.

Answer 8

paresis

Question 9

______ muscles are required to carry out skilled movements that coordinate and execute these contractions in a manner that provides for smooth, purposeful, and coordinated movement.

Answer 9

skeletal

Question 10

Motor function, whether it involves walking, running, or precise finger movements, requires movement and maintenance of

Answer 10

posture

Question 11

The motor systems are organized in a functional hierarchy, each concerned with increased levels of complexity. The lowest level of the hierarchy occurs at the _______ _______, which contains the basic reflex circuitry needed to coordinate the function of the motor units involved in the planned movement.

Answer 11

spinal cord

Question 12

Above the spinal cord is the brain stem. Above the brain stem are the cerebellum and basal ganglia—structures that modify the actions of the brain stem systems. Overseeing these supraspinal structures are the motor centers in the

Answer 12

cerebral cortex

Question 13

The highest level of function, which occurs at the level of the ________ cortex, is concerned with the purpose and planning of the motor movement. The efficiency of movement depends on input from sensory systems that operate in parallel with the motor systems.

Answer 13

frontal

Question 14

The _______ _____ contains the neuronal circuits that mediate a variety of reflexes and automatic rhythmic movements. Similar circuits governing reflex movements of the face and mouth are located in the brain stem

Answer 14

spinal cord

Question 15

The simplest circuits are monosynaptic, containing only a primary motor neuron. However, most reflexes are __________, involving one or more interposed interneurons.

Answer 15

polysnaptic

Question 16

The ______ pathways of the brain stem provide for the basic postural control systems that the cortical motor areas use to organize highly differentiated movements. They consist of tracts that descend in the ipsilateral ventral columns of the spinal cord and terminate in interneurons that influence motor neurons of axial and proximal muscles. These axial and proximal muscles are responsible for postural reflexes, such as those needed for pacing of steps during walking or running and recovery of posture when balance is disrupted.

Answer 16

medial

Question 17

The _______ brain stem pathways are more concerned with goal-directed movements. They terminate on the interneurons in the dorsolateral part of the spinal gray matter and thus influence the motor neurons that control distal muscles of the limbs. These descending pathways modify the activity of extensor and flexor motor neurons to produce complex motor movements such as walking and running.

Answer 17

lateral

Question 18

The cortex represents the highest level of motor function. The primary, premotor, and supplementary motor cortices located in the posterior part of the _______ lobe initiate and control precise, skillful, and intentional movements of the distal and especially flexor muscles of the limbs and speech apparatus. These motor areas receive information from the thalamus and somatosensory cortex and, indirectly, from the cerebellum and basal ganglia.

Answer 18

frontal

Question 19

The primary motor cortex (area 4 if using Brodmann classification of the brain cortical areas), also called the motor strip, is located on the rostral surface and adjacent portions of the ________ _____. The primary motor cortex controls specific muscle movement sequences. It is also the first level of descending control for precise motor movements.

Answer 19

central sulcus

Question 20

The ________ cortex (Brodmann areas 6 and 8), which is located just anterior to the primary motor cortex, sends some fibers into the corticospinal tract but mainly innervates the primary motor strip. Nerve signals generated by the premotor cortex produce much more complex “patterns” of movement than the discrete patterns generated by the primary motor cortex. For example, 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.

Answer 20

premotor

Question 21

The __________ motor cortex, which contains representations of all parts of the body, is located on the medial surface of the hemisphere in the premotor region (Brodmann areas 6 and 8). It is intimately involved in the performance of complex, skillful movements that involve both sides of the body.

Answer 21

supplementary

Question 22

The cerebellum and basal ganglia provide feedback circuits that regulate cortical and brain stem motor areas. They receive inputs from various areas of the cortex and project to the motor cortex through the ________.

Answer 22

thalamus

Question 23

The ______ _____ provide gracefulness to the performance as well the supportive posture for highly skilled movements

Answer 23

basal ganglia

Question 24

Cerebellar circuits are involved with the timing and coordination of movements that are in progress and with learning of motor skills. Damage to the cerebellum by vascular lesions of certain familial degenerative disorders produces cerebellar ______, a characteristic loss of coordination and accuracy of limb movement.

Answer 24

ataxia

Question 25

The motor neuron and the group of muscle fibers it innervates in a muscle are called a _______ _____

Answer 25

motor unit

Question 26

When the motor neuron develops an action potential, all of the muscle fibers in the motor unit it innervates develop action potentials, causing them to contract simultaneously. Thus, a motor neuron and the muscle fibers it innervates function as a _____ unit—the basic unit of motor control.

Answer 26

single

Question 27

The motor neurons supplying a motor unit are located in the ventral horn of the spinal cord and are called _______ _____ ________

Answer 27

lower motor neurons

Question 28

UMNs, which exert control over LMNs, project from the motor strip in the cerebral cortex to the ventral horn and are fully contained in the

Answer 28

CNS

Question 29

________ are coordinated, involuntary motor responses that are initiated by a stimulus applied to peripheral receptors.

Answer 29

reflexes

Question 30

For skeletal muscle to perform normally, the brain must be continually informed of the current state of the muscles, and the muscles must exhibit

Answer 30

tone (resistance to active and passive stretch at rest).

Question 31

Information from sensory afferents is relayed to the cerebellum and cerebral cortex and is experienced as _________ or the sense of body movement and position, independent of vision.

Answer 31

Proprioception

Question 32

The _______ ________, which are distributed throughout the belly of a muscle, relay information about muscle length and rate of stretch.

Answer 32

muscle spindles

Question 33

The ______ _______ ________ are found in muscle tendons and transmit information about muscle tension or force of contraction at the junction of the muscle and the tendon that attaches to bone.

Answer 33

Golgi tendon organs

Question 34

The _______ reflex, a contraction of muscle fibers that occurs when a muscle is stretched, is essential to the control of muscle tone and maintenance of posture

Answer 34

stretch

Question 35

true or false

Stretch reflexes can be evoked in many muscles throughout the body and are tested routinely (e.g., knee-jerk reflex) during clinical examination for the diagnosis of neurologic conditions.

Answer 35

true

Question 36

Stretch reflexes tend to be _______ or _____ in cases of peripheral nerve damage or ventral horn injury involving the test area.

Answer 36

hypoactive or absent

Question 37

They are _________ when lesions of the corticospinal tract (e.g., stroke or spinal cord injury [SCI]) reduce or disrupt the inhibitory effect of the brain on the spinal cord.

Answer 37

hyperactive

Question 38

The muscle spindles consist of a group of specialized miniature skeletal muscle fibers called ________ ______ that are encased in a connective tissue capsule and attached to the extrafusal fibers of a skeletal muscle.

Answer 38

intrafusal fibers

Question 39

The ____, through its coordinated control of the muscle’s alpha and the spindle’s gamma motor neurons, can suppress the stretch reflex. This occurs during centrally programmed movements, such as pitching a baseball, that require a muscle to produce a full range of unopposed motion.

Answer 39

CNS

Question 40

the ________ pathway consists of the motor pathways originating in the motor cortex and terminating in the corticobulbar fibers in the brain stem and the corticospinal fibers in the spinal cord.

Answer 40

pyramidal

Question 41

fibers from the cortex and basal ganglia project to the brain stem reticular formation and reticulospinal pathways to LMNs of proximal and extensor muscles. These fibers do not decussate in the pyramids, hence the name

Answer 41

extrapyramidal system

Question 42

Disorders of the ________ tracts (e.g., stroke) are characterized by spasticity and paralysis

Answer 42

pyramidal

Question 43

disorders affecting the __________ tracts (e.g., Parkinson disease) result in involuntary movements, muscle rigidity, and immobility without paralysis.

Answer 43

extrapyramidal

Question 44

Assessing the motor system should include assessment of (5)

Answer 44

• Body position
• Involuntary movements
• Muscle characteristics (strength, bulk, and tone)
• Spinal reflexes
• Coordination

Question 45

_________ refers to loss of movement

Answer 45

paralysis

Question 46

weakness or incomplete loss of strength

Answer 46

paresis

Question 47

destruction of pyramidal UMN innervation of one limb

Answer 47

monoparesis or monoplegia

Question 48

destruction of pyramidal UMN innervation of both limbs on one side

Answer 48

hemiparesis or hemiplegia

Question 49

destruction of pyramidal UMN innervation of both upper or lower limbs

Answer 49

Diparesis or diplegia or paraparesis or paraplegia

Question 50

destruction of pyramidal UMN innervation of all four limbs

Answer 50

Tetraparesis or tetraplegia, also called quadriparesis or quadriplegia

Question 51

______________ as occurs with Duchenne muscular dystrophy (DMD), refers to an increase in bulk without an accompanying increase in strength.

Answer 51

pseudohypertrophy

Question 52

visible squirming and twitching movements of muscle fibers that can be seen as flickers under the skin. They are caused by spontaneous contractions of all the muscle fibers in a motor unit due to irritation and hyperexcitability of the cell body and its motor neuron and suggest LMN disease

Answer 52

fasciculation

Question 53

the rhythmic contraction and alternate relaxation of a limb that is caused by suddenly stretching a muscle and gently maintaining it in the stretched position. It is seen in the hypertonia of spasticity associated with UMN lesions, such as SCI

Answer 53

clonus

Question 54

failure to accurately perform rapid alternating movements

Answer 54

Dysdiadochokinesia

Question 55

a wide-based, unsteady gait

Answer 55

ataxia

Question 56

inaccuracies of movements leading to a failure to reach a specified target. It is possible to test for this by having the person touch the examiner’s finger and then alternately touch his or her finger. These movements are normally smooth and accurate. Asking the person to touch the examiner’s finger with an outstretched arm and finger, first with the eyes open and then closed, provides a test for position sense. Repetitive and consistent deviation to one side (referred to as past pointing), which is worse with the eyes closed, suggests cerebellar or vestibular disease.

Answer 56

dysmetria

Question 57

abnormal writhing movements

Answer 57

chorea

Question 58

abnormal simultaneous contractions of agonist and antagonist muscles, leading to abnormal postures

Answer 58

dystopia

Question 59

rhythmic movements of a particular body part

Answer 59

tremor

Question 60

slowness of movements

Answer 60

bradykinesea

Question 61

involuntary jerking movement

Answer 61

myoclonus

Question 62

Disorders affecting the nerve cell body are often referred to as

Answer 62

lower motor neuron disorders

Question 63

disorders affecting the nerve axon are referred to as

Answer 63

peripheral neuropathies

Question 64

disorders affecting the muscle fibers are referred to as

Answer 64

myopathies

Question 65

When a normally innervated muscle is not used for long periods, the muscle cells shrink in diameter, and although the muscle cells do not die, they lose much of their contractile proteins and become weakened. This is called

Answer 65

disuse atrophy

occurs with conditions such as immobilization and chronic illness

Question 66

The most extreme examples of muscle atrophy are found in people with disorders that deprive muscles of their innervation. This is called

Answer 66

denervation atrophy

Question 67

a number of genetic disorders that produce progressive deterioration of skeletal muscles because of mixed muscle cell hypertrophy, atrophy, and necrosis. They are primary diseases of muscle tissue and probably do not involve the nervous system.

Answer 67

muscular dystrophies

Question 68

muscular dystrophy

As the muscle undergoes necrosis, fat and connective tissue replace the muscle fibers, which increases muscle size and results in muscle weakness. The increase in muscle size resulting from connective tissue infiltration is called

Answer 68

pseudohypertrophy

Question 69

true or false

The muscle weakness seen in MD is insidious in onset but continually progressive, varying with the type of disorder

Answer 69

true

Question 70

the most common form of MD

Answer 70

DMD - 1 in 3500 live male births

Question 71

DMD is inherited as a _________ single-gene defect on the X chromosome and is transmitted from the mother to her male offspring.

Answer 71

recessive

Question 72

X-linked MD but manifests later in childhood or adolescence and has a slower course of progression.

Answer 72

becker MD

Question 73

DMD is caused by mutations in a gene located on the short arm of the X chromosome that codes for a protein called ________.

Answer 73

dystrophin

Dystrophin is a large cytoplasmic protein located on the inner surface of the sarcolemma or muscle fiber membrane. The dystrophin molecules are concentrated over the Z bands of the muscle, where they form a strong link between the actin filaments of the intracellular contractile apparatus and the extracellular connective tissue matrix. It is thought that abnormalities in the dystrophin-associated protein complex compromise sarcolemma integrity, particularly with sustained contractions. This disruption in integrity may be responsible for the observed increased fragility of dystrophic muscle, excessive influx of calcium ions, and release of soluble muscle enzymes such as creatine kinase into the serum

Question 74

The degenerative process in DMD consists of a relentless necrosis of muscle fibers, accompanied by a continuous process of repair and regeneration, and progressive fibrosis. The degenerative process eventually outpaces the regenerative capacity of the muscle, causing a gradual replacement of muscle fibers by fibrofatty

Answer 74

connective tissue

Question 75

Signs of muscle weakness seen with DMD manifested by frequent falling usually become evident beginning when the child is between

Answer 75

2 and 3

Question 76

first muscles of the body to be affected in MD

Answer 76

postural muscles of shoulders and hips

Question 77

Imbalances seen in DMD between agonist and antagonist muscles lead to abnormal postures and the development of

Answer 77

contractures and joint immobility.

scoliosis is also common

Question 78

Respiratory muscle involvement results in weak and ineffective cough, frequent respiratory infections, and decreasing respiratory reserve. ____ also affects cardiac muscle, and cardiomyopathy is a common feature of the disease. The severity of cardiac involvement, however, does not necessarily correlate with skeletal muscle weakness. Some people die at an early age from severe cardiomyopathy, whereas others maintain adequate cardiac function until the terminal stages of the disease. Death from respiratory and cardiac muscle involvement usually occurs in young adulthood.

Answer 78

DMD

Question 79

Serum levels of the enzyme __________ _______, which leaks from damaged muscle fibers, can be used to assist the diagnosis of MD

Answer 79

creatinine kinase

Question 80

_________ ________ which shows a mixture of muscle cell degeneration and regeneration and reveals fat and scar tissue replacement, is diagnostic of DMD

Answer 80

muscle biopsy

Question 81

A specific molecular genetic diagnosis is possible by demonstrating defective __________ through the use of immunohistochemical staining of sections of muscle biopsy tissue or by polymerase chain reaction (PCR) analysis of genomic deoxyribonucleic acid (DNA) derived from leukocytes in a blood sample. The same methods of DNA analysis may be used on blood samples to establish carrier status in female relatives at risk, such as sisters and cousins.

Answer 81

dystrophin

Question 82

Management of DMD is directed toward maintaining

Answer 82

ambulation and preventing deformities

Passive stretching, correct or counter posturing, and splints help to prevent deformities.

Question 83

The neuromuscular junction serves as a synapse between a motor neuron and a skeletal muscle fiber. It consists of the axon terminals of a motor neuron and a specialized region of the muscle membrane called the motor

Answer 83

end plate

Question 84

The transmission of impulses at the neuromuscular junction is mediated by the release of the neurotransmitter ___________ from the axon terminals. It binds to specific receptors in the end-plate region of the muscle fiber surface to cause muscle contraction. It is active in the neuromuscular junction only for the brief period of time that it takes to generate an action potential in the innervated muscle cell

Answer 84

acetylcholine

Question 85

Neurotoxins from the botulism organism (Clostridium botulinum) produce paralysis by blocking release of

Answer 85

acetylcholine

Question 86

Classic food-borne _______ occurs through ingestion of soil-grown foods that are not properly cooked or preserved. Spores can be dormant, are resistant to heat, and germinate in low-acidity and low-nitrate environments. Canned vegetables, items preserved in garlic oil, and soups are usually the cause of sporadic outbreaks.

Answer 86

botulism

Question 87

infant botulism, now the most commonly reported form of the disease, occurs through infant ingestion of C. botulinum spores. An infant’s immature gastrointestinal tract allows the spores to germinate and elaborate the botulinum toxins. Infants usually develop botulism by ingesting C. botulinum spores, which are found in the soil or in ______ products

Answer 87

honey

Question 88

The aminoglycoside antibiotics (e.g., gentamicin) prevent the release of acetylcholine from nerve endings and may produce a clinical disturbance similar to botulism. Once the drug is eliminated from the body, the symptoms usually subside rapidly. These drugs are particularly dangerous in people with preexisting disturbances of neuromuscular transmission, such as

Answer 88

myasthenia gravis

Question 89

a disorder of transmission at the neuromuscular junction due to antibody-mediated attack on nicotinic AChR or muscle-specific tyrosine kinase (MuSK) that affects communication between the motor neuron and the innervated muscle.9 This autoimmune disease may occur at any age, but the peak incidence occurs in young adulthood. The disease is approximately three times more common in women than men

Answer 89

myasthenia gravis

Question 90

Neonatal myasthenia gravis, caused by placental transfer of the acetylcholine receptor antibody, occurs in about __% of infants born to mothers with the disease

Answer 90

10

Spontaneous resolution of symptoms usually occurs within a few months of birth.

Question 91

As an autoimmune disease, the disorder is caused by an antibody-mediated loss of acetylcholine receptors in the neuromuscular junction. Although the exact mechanism that triggers the autoimmune response is unclear, it is thought to be caused by sensitized helper T cells and an antibody-directed attack on the acetylcholine receptor in the neuromuscular junction. The antibody attack leads to a shedding of the acetylcholine receptor–rich terminal portions of the folds in the end plate of the muscle fiber, a decreased number of receptors, and a widened synaptic space that impairs signal transmission.

Answer 91

myasthenia gravis

Question 92

Approximately 70% of people with myasthenia gravis also have abnormalities of the

Answer 92

thymus

thymoma (i.e., thymus tumor) or thymic hyperplasia (i.e., increased thymus weight from an increased number of thymus cells).

Question 93

In people with __________ ______ who have a reduced postsynaptic membrane area and fewer acetylcholine receptors, each release of acetylcholine from the presynaptic membrane results in a lower-amplitude end-plate potential. This results in both muscle weakness and fatigability with sustained effort. Most commonly affected are the eye and periorbital muscles, with ptosis due to eyelid weakness or diplopia due to weakness of the extraocular muscles as an initial symptom.

Answer 93

myasthenia gravis

Question 94

In most people with this disorder symptoms are least evident when arising in the morning, but grow worse with effort and as the day proceeds.

Answer 94

myasthenia gravis

Question 95

Myasthenic crisis usually occurs during a period of stress, such as infection, emotional upset, pregnancy, alcohol ingestion, cold exposure, or surgery. What is the main concern in myasthenic crisis?

Answer 95

ventilation

Question 96

_________ crisis results from inadequate or excessive doses of the anticholinesterase drugs used in treatment of myasthenia gravis.

Answer 96

cholinergic

Question 97

Research has found that ______ virus, a lymphotropic human herpes virus, is present in the thymuses of many people with myasthenia gravis.

Answer 97

Epstein-Barr

Question 98

__________ removes antibodies from the circulation and provides short-term clinical improvement. It is used primarily to stabilize the condition of people in myasthenic crisis or for short-term treatment in people undergoing thymectomy. Intravenous immunoglobulin also produces improvement in people with myasthenia gravis. Although the effect is temporary, it may last for weeks to months

Answer 98

plasmaphoresis

Question 99

Segmental demyelination occurs when there is a disorder of the Schwann cell, as seen in

Answer 99

gullian-barre

Question 100

It is caused by 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 (i.e., bony or ligamentous changes) or an increase in the volume of the tunnel contents (i.e., inflammation of the tendons, synovial swelling, or tumors).

Answer 100

carpal tunnel syndrome

Question 101

Most cases of carpal tunnel syndrome are due to repetitive use of the

Answer 101

wrist

Question 102

_______ _______ is characterized by pain, paresthesia, and numbness of the thumb and first two and one half digits of the hand; pain in the wrist and hand, which worsens at night; atrophy of the abductor pollicis muscle; and weakness in precision grip. All of these abnormalities may contribute to clumsiness of fine motor activity.

Answer 102

carpal tunnel syndrome

Question 103

The ____ sign is the development of a tingling sensation radiating into the palm of the hand that is elicited by light percussion over the median nerve at the wrist.

Answer 103

tinel

Question 104

The _____ maneuver is performed by having the person hold the wrist in complete flexion for approximately a minute. If numbness and paresthesia along the median nerve are reproduced or exaggerated, the test result is considered to be positive.

Answer 104

Phalen

Question 105

treatments of carpal tunnel syndrome (4)

Answer 105

avoidance of movements that cause nerve compression
splinting
anti inflammatory drugs
corticosteroids

Question 106

an acute immune-mediated polyneuropathy.17 The syndrome defines a clinical entity that is characterized by rapidly progressive ascending symmetrical limb weakness and loss of tendon reflexes. It has been described as the most common cause of acute, flaccid nontraumatic paralysis

Answer 106

Guillain-Barré syndrome

Question 107

motor axonal degeneration and axonal degeneration of both motor and sensory nerves. The disorder is manifested by infiltration of mononuclear cells around the capillaries of the peripheral neurons, edema of the endoneurial compartment, and demyelination of ventral spinal roots.

Answer 107

gulliain-barre syndrome

Question 108

the majority of people with guillian barre syndrome report having had this before onset of symptoms

Answer 108

flu like illness

Question 109

Paralysis seen with this disorder may progress to involve the respiratory muscles, which will mandate the use of a ventilator for these people. 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 ________ ______ ________. It may have a rapid development of ventilatory failure and autonomic disturbances that threaten circulatory function or it may present as a slow, insidious process

Answer 109

Guillain-Barré syndrome.

Question 110

Risk factors include heavy lifting, twisting, bodily vibration, obesity, and poor conditioning. However, _____ ______ _____ is common even in people without these risk factors.

Answer 110

low back pain

Question 111

The diagnostic measures used in the evaluation of back pain include history and physical examination, including a thorough neurologic examination. Other diagnostic methods include

Answer 111

MRI

Question 112

it is important that the provider also manage this common problem seen with lower back pain

Answer 112

sleep disorders

Question 113

lifting while in the flexed position, slipping, falling on the buttocks or back, or suppressing a sneeze may all cause

Answer 113

herniated intravertebral disc

Question 114

Degenerative processes such as _________ or _________ __________ predispose to malalignment of the vertebral column.

Answer 114

osteoarthritis or ankylosing spondylitis

Question 115

The _____ and ______ regions are the most flexible areas of the spine and are most often involved in disk herniations

Answer 115

cervical and lumbar

Question 116

_____ is the first and most common symptom of a herniated disk.

Answer 116

pain

Question 117

The most common sensory deficits seen with herniated discs from spinal nerve root compression are paresthesias and numbness, particularly of the ____ and ____

Answer 117

leg and foot

Question 118

this test is an important diagnostic maneuver for herniated disc. It is done in the supine position and is performed by passively raising the person’s leg. The test can also be done by slowly extending the knee while the person sits on a table, with both hip and knee flexed at 90 degrees. The maneuver is designed to apply traction along the nerve root, which exacerbates pain if the nerve root is acutely inflamed. Normally, it is possible to raise the leg approximately 90 degrees without causing discomfort of the hamstring muscles. The test result is positive if pain is produced when the leg is raised to 60 degrees or less.

Answer 118

straight-leg

Question 119

Damage to the part of the cerebellum associated with the ________ system leads to difficulty or inability to maintain a steady posture of the trunk, which normally requires constant readjusting movements. This is seen as an unsteadiness of the trunk, called truncal ataxia, and can be so severe that standing is not possible. The ability to fix the eyes on a target also can be affected.

Answer 119

vestibular

Question 120

Cerebellar dystaxia or, if severe, ______ is characterized by a decomposition of movement, with each succeeding component of a complex movement occurring separately instead of being blended into a smoothly proceeding action.

Answer 120

ataxia

Question 121

Reaching to touch a target breaks down into small sequential components, each going too far, followed by overcorrection. The finger moves jerkily toward the target, misses, corrects in the other direction, and misses again, until the target is finally reached. This is called over- and underreaching or ________.

Answer 121

dysmetria

Question 122

the most common cause of cerebellar ataxia

Answer 122

MS

Question 123

It is rare for children to have acute cerebellar ataxia, but the most common virus associated with this manifestation in children is

Answer 123

varicella

Question 124

It is possible to assess ________ function as it relates to tremor by asking a person to touch one heel to the opposite knee, to gently move the toes along the back of the opposite shin, or to touch the nose with a finger.

Answer 124

cerebellar

Question 125

Cerebellar ________ is characterized by slow, slurred speech of continuously varying loudness.

Answer 125

dysarthria

Question 126

difficulty swallowing or chewing

Answer 126

dysphagia

Question 127

disorder of speech

Answer 127

dysarthria

Question 128

Overactivity of the indirect pathway relative to the direct pathway would result in _________ disorders such as Parkinson disease.

Answer 128

hypokinetic

Question 129

Underactivity of the indirect pathway would result in __________ disorders such as chorea and ballismus.

Answer 129

hyperkinetic

Question 130

Involuntary, oscillating contractions of opposing muscle groups around a joint. Usually fairly uniform in frequency and amplitude

Answer 130

tremor

Question 131

Irregular wriggling and writhing movements. May be grimacing movements of the face, raising the eyebrows, rolling of the eyes, and curling, protrusion, withdrawal of the tongue. In the limbs, the movements largely are distal. There may be piano playing–type movements with alternating extension and flexion of the fingers.

Answer 131

chorea

Question 132

Continuous, wormlike, twisting and turning motions of the joints of a limb or the body

Answer 132

athetosis

Question 133

Violent, sweeping, flinging motions, especially of the limbs on one side of the body (hemiballismus)

Answer 133

ballismus

Question 134

Abnormal maintenance of a posture resulting from a twisting, turning movement of the limbs, neck, or trunk. Often the result of simultaneous contraction of agonist and antagonist muscles

Answer 134

dystonia

Question 135

Bizarre wriggling and writhing movements. Frequently involve the face, mouth, jaw, and tongue, causing grimacing, pursing of the lips, or protrusion of the tongue. Limbs affected less often

Answer 135

dyskinesia

Question 136

an untoward reaction that can develop with long-term use of some antipsychotic medications.

Answer 136

tardive dyskinesia

Question 137

a degenerative disorder of basal ganglia function that results in variable combinations of tremor, rigidity, akinesia/bradykinesia, and postural changes. The disorder is characterized by progressive destruction of the nigrostriatal pathway, with subsequent reduction in striatal concentrations of dopamine.

Answer 137

parkinson’s

Question 138

The primary brain abnormality found in all people with Parkinson disease is degeneration of the nigrostriatal ________ neurons.

Answer 138

dopamine

Question 139

_______ _______ are produced inside degenerated neurons in many people with Parkinson disease or parkinsonism

Answer 139

lewey bodies

Question 140

Over the past several decades, several pathologic processes (e.g., oxidative stress, apoptosis, and mitochondrial disorders) that might lead to degeneration have been identified as causes of _________ ________.

Answer 140

Parkinson disease.

Question 141

The evidence suggests that welders may have an occupational hazard of developing ___________ ________ more often compared to people not exposed to manganese

Answer 141

parkinson’s disease

Question 142

Although rare, the autosomal dominant form of the disease has received considerable attention because α-synuclein is one of the major components of the Lewy bodies that are found in brain tissue of people with

Answer 142

parkinson’s disease

Question 143

Mutations in a second gene coding the protein parkin is associated with an autosomal _______, early-onset form of Parkinson disease.

Answer 143

recessive

Question 144

The cardinal manifestations of Parkinson disease are (3)

Answer 144

tremor, rigidity, and bradykinesia or slowness of movement.

Question 145

This is the most disabling of the symptoms of Parkinson disease.

Answer 145

bradykinesia

Question 146

Because the basal ganglia also influence the autonomic nervous system, people with Parkinson disease often have excessive and uncontrolled (3)

Answer 146

sweating
sebaceous glands excretion
salivation

Question 147

Cognitive dysfunction may also be an important feature associated with Parkinson disease. The most severe form of dementia is seen in about __% of people with Parkinson disease

Answer 147

20%

Question 148

Dopamine does not cross the blood–brain barrier. Administration of _________, a precursor of dopamine that does cross the blood–brain barrier, has yielded significant improvement in clinical symptoms of Parkinson disease and remains the most effective drug for treatment.

Answer 148

levodopa

Question 149

a disorder of the UMN occurring most often in middle to late adulthood, affecting people most frequently in their fifties, with men developing the disease nearly twice as often as women.

Answer 149

ALS

Question 150

______ affects motor neurons in three locations—the anterior horn cells (LMNs) of the spinal cord; the motor nuclei of the brain stem, particularly the hypoglossal nuclei; and the UMNs of the cerebral cortex.

Answer 150

ALS

Question 151

A remarkable feature of the disease is that the entire sensory system, the regulatory mechanisms of control and coordination of movement, and the intellect remain intact.

Answer 151

ALS

Question 152

The death of LMNs leads to denervation, with subsequent shrinkage of musculature and muscle fiber atrophy. It is this fiber atrophy, called amyotrophy, which appears in the name of the disease. The loss of nerve fibers in lateral columns of the white matter of the spinal cord, along with fibrillary gliosis, imparts a firmness or sclerosis to this CNS tissue.

Answer 152

ALS

Question 153

The neurofilament proteins, which function in the axonal transport of molecules, are destroyed with

Answer 153

ALS

Question 154

The most common clinical presentation is slowly progressive weakness and atrophy in distal muscles of one upper extremity. This is followed by regional spread of clinical weakness, reflecting involvement of neighboring areas of the spinal cord. Eventually, UMNs and LMNs involving multiple limbs and the head are affected. In the more advanced stages, muscles of the palate, pharynx, tongue, neck, and shoulders become involved, causing impairment of chewing, swallowing, and speech. Dysphagia with recurrent aspiration and weakness of the respiratory muscles produces the most significant acute complications of the disease. Death usually results from involvement of cranial nerves and respiratory musculature.

Answer 154

ALS

Question 155

characterized by inflammation and destruction of mostly the white matter of the CNS myelin. The peripheral nervous system is spared, and there is usually no evidence of an associated systemic disease.

Answer 155

MS

Question 156

The age of onset is typically between 20 and 30 years, with women being affected twice as frequently as men.

Answer 156

ms

Question 157

MS occurs more commonly in people of _________ ancestry and is uncommon in certain ethnic groups such as Native Americans and Africans.

Answer 157

European

Question 158

an immune-mediated disorder that occurs in genetically susceptible people. Although the target antigen has not been identified, the data suggest an immune response to a protein in the CNS.

Answer 158

MS

Question 159

The lesions of _____ consist of hard, sharp-edged, demyelinated patches that are visible throughout the white matter as well as sometimes the gray matter of the CNS. These lesions, which represent the end result of acute myelin breakdown, are called plaques. The lesions have a predilection for the optic nerves, periventricular white matter, brain stem, cerebellum, and spinal cord white matter

Answer 159

MS

Question 160

Oligodendrocytes are decreased in number and may be absent, especially in older lesions. Acute, subacute, and chronic lesions often are seen at multiple sites throughout the CNS.

what disorder

Answer 160

MS

Question 161

Areas commonly affected by ____ are the optic nerve (visual field), corticobulbar tracts (speech and swallowing), corticospinal tracts (muscle strength), cerebellar tracts (gait and coordination), spinocerebellar tracts (balance), medial longitudinal fasciculus (conjugate gaze function of the extraocular eye muscles), and posterior cell columns of the spinal cord (position and vibratory sensation). Typically, an otherwise healthy person presents with an acute or subacute episode of paresthesias, optic neuritis (i.e., visual clouding or loss of vision in part of the visual field with pain on movement of the globe), diplopia, or specific types of gaze paralysis.

Answer 161

MS

Question 162

_________ is one of the most common problems for people with MS.

Answer 162

fatigue

Fatigue often is described as a generalized low-energy feeling not related to depression and different from weakness. Fatigue has a harmful impact on activities of daily living and sustained physical activity. Interventions such as spacing activities and setting priorities often are helpful.

Question 163

__________ are the mainstay of treatment for acute attacks of MS.

Answer 163

corticosteroids

These agents are thought to reduce the inflammation, improve nerve conduction, and have important immunologic effects

Question 164

The most common cause of SCI is _____, followed by violence (primarily gunshot wounds), falls, and recreational sporting activities.

Answer 164

MVAs

Question 165

true or false

Mortality rates are significantly higher during the first year after SCI than during subsequent years, particularly for severely injured people.

Answer 165

true

Question 166

________ injuries occur when forward bending of the spinal column exceeds the limits of normal movement. Typical injuries of this kind result, for example, when the head is struck from behind, as in a fall with the back of the head as the point of impact.

Answer 166

flexion

Question 167

_______ injuries occur with excessive forced bending of the spine backward. A typical injury involves a fall in which the chin or face is the point of impact, causing hyperextension of the neck.

Answer 167

extension

Question 168

A __________ injury, causing the vertebral bones to shatter, squash, or even burst, occurs when there is spinal loading (i.e., axial load) from a high-velocity blow to the top of the head, such as a diving injury

Answer 168

compression

Question 169

_______ _______ spinal cord injuries can produce highly unstable injuries

Answer 169

axial rotation

Question 170

Sudden, complete transection of the spinal cord results in complete loss of motor, sensory, reflex, and autonomic function below the level of injury. The immediate response to SCI is often referred to as _______ _______. It 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 (UMN) or flaccid (LMN) paralysis.

Answer 170

spinal shock

Question 171

The goal of management of acute SCI is to (2)

Answer 171

reduce the neurologic deficit and prevent any additional loss of neurologic function

Question 172

________ cord injuries can result from severance of the cord, disruption of nerve fibers although they remain intact, or interruption of blood supply to that segment, resulting in complete destruction of neural tissue and UMN or LMN paralysis.

Answer 172

complete

Question 173

_________ SCI implies there is some residual motor or sensory function below the level of injury. The prognosis for return of function is better because of preservation of axonal function.

Answer 173

incomplete

Question 174

This syndrome occurs almost exclusively in the cervical cord, rendering the lesion a UMN lesion with spastic paralysis. This type damage is more frequent in older adults with narrowing or stenotic changes in the spinal canal that are related to arthritis. Damage also may occur in people with congenital stenosis.

Answer 174

Central cord

Question 175

damage to a hemisection of the anterior and posterior cord. The effect is an ipsilateral loss of voluntary motor function from the corticospinal tract and proprioception loss with a contralateral loss of pain and temperature sensation from the lateral spinothalamic tracts for all levels below the lesion.

Answer 175

brown sequard

Question 176

__________ ______ syndrome usually is caused by damage from infarction of the anterior spinal artery, resulting in damage to the anterior two thirds of the cord. The deficits include loss of motor function provided by the corticospinal tracts and loss of pain and temperature sensation from damage to the lateral spinothalamic tracts.

Answer 176

anterior cord

Question 177

true or false

Due to the possible permanent neurological damage, emergent surgery is indicated for cauda equina syndrome.

Answer 177

true

Question 178

At the ___ level, deltoid and biceps function is spared, allowing full head, neck, and diaphragm control with good shoulder strength and full elbow flexion.

Answer 178

C5

Question 179

At the ___ level, wrist dorsiflexion by the wrist extensors is functional, allowing tenodesis, which is the natural bending inward and flexion of the fingers when the wrist is extended and bent backward. Tenodesis is a key movement because it can be used to pick up objects when finger movement is absent.

Answer 179

C6

Question 180

At the ___ level, wrist dorsiflexion by the wrist extensors is functional, allowing tenodesis, which is the natural bending inward and flexion of the fingers when the wrist is extended and bent backward. Tenodesis is a key movement because it can be used to pick up objects when finger movement is absent.

Answer 180

C6