Disorders of Motor Function Flashcards
(180 cards)
1
Q
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)
A
propioception
2
Q
The condition characterized by spasms or other uncontrolled contractions of the skeletal muscles.
A
spasticity
3
Q
An abnormal condition characterized by an inability to coordinate voluntary muscular movement.
A
ataxia
4
Q
Involuntary quivering or trembling movements caused by the alternating contraction and relaxation of opposing groups of skeletal muscles.
A
tremor
5
Q
A spasm of a portion of a muscle, an entire muscle, or a group of muscles.
A
myoclonus
6
Q
Involuntary, rapid, rhythmic movements of the eyeball.
A
nystagmus
7
Q
An abnormal condition characterized by the impairment or loss of motor function due to a lesion of the neural or muscular mechanism.
A
paralysis
8
Q
Slight or partial paralysis.
A
paresis
9
Q
______ 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.
A
skeletal
10
Q
Motor function, whether it involves walking, running, or precise finger movements, requires movement and maintenance of
A
posture
11
Q
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.
A
spinal cord
12
Q
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
A
cerebral cortex
13
Q
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.
A
frontal
14
Q
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
A
spinal cord
15
Q
The simplest circuits are monosynaptic, containing only a primary motor neuron. However, most reflexes are __________, involving one or more interposed interneurons.
A
polysnaptic
16
Q
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.
A
medial
17
Q
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.
A
lateral
18
Q
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.
A
frontal
19
Q
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.
A
central sulcus
20
Q
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.
A
premotor
21
Q
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.
A
supplementary
22
Q
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 ________.
A
thalamus
23
Q
The ______ _____ provide gracefulness to the performance as well the supportive posture for highly skilled movements
A
basal ganglia
24
Q
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.
A
ataxia
25
The motor neuron and the group of muscle fibers it innervates in a muscle are called a _______ _____
motor unit
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.
single
27
The motor neurons supplying a motor unit are located in the ventral horn of the spinal cord and are called _______ _____ ________
lower motor neurons
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
CNS
29
________ are coordinated, involuntary motor responses that are initiated by a stimulus applied to peripheral receptors.
reflexes
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
tone (resistance to active and passive stretch at rest).
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.
Proprioception
32
The _______ ________, which are distributed throughout the belly of a muscle, relay information about muscle length and rate of stretch.
muscle spindles
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.
Golgi tendon organs
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
stretch
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.
true
36
Stretch reflexes tend to be _______ or _____ in cases of peripheral nerve damage or ventral horn injury involving the test area.
hypoactive or absent
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.
hyperactive
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.
intrafusal fibers
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.
CNS
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.
pyramidal
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
extrapyramidal system
42
Disorders of the ________ tracts (e.g., stroke) are characterized by spasticity and paralysis
pyramidal
43
disorders affecting the __________ tracts (e.g., Parkinson disease) result in involuntary movements, muscle rigidity, and immobility without paralysis.
extrapyramidal
44
Assessing the motor system should include assessment of (5)
* Body position
* Involuntary movements
* Muscle characteristics (strength, bulk, and tone)
* Spinal reflexes
* Coordination
45
_________ refers to loss of movement
paralysis
46
weakness or incomplete loss of strength
paresis
47
destruction of pyramidal UMN innervation of one limb
monoparesis or monoplegia
48
destruction of pyramidal UMN innervation of both limbs on one side
hemiparesis or hemiplegia
49
destruction of pyramidal UMN innervation of both upper or lower limbs
Diparesis or diplegia or paraparesis or paraplegia
50
destruction of pyramidal UMN innervation of all four limbs
Tetraparesis or tetraplegia, also called quadriparesis or quadriplegia
51
______________ as occurs with Duchenne muscular dystrophy (DMD), refers to an increase in bulk without an accompanying increase in strength.
pseudohypertrophy
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
fasciculation
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
clonus
54
failure to accurately perform rapid alternating movements
Dysdiadochokinesia
55
a wide-based, unsteady gait
ataxia
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.
dysmetria
57
abnormal writhing movements
chorea
58
abnormal simultaneous contractions of agonist and antagonist muscles, leading to abnormal postures
dystopia
59
rhythmic movements of a particular body part
tremor
60
slowness of movements
bradykinesea
61
involuntary jerking movement
myoclonus
62
Disorders affecting the nerve cell body are often referred to as
lower motor neuron disorders
63
disorders affecting the nerve axon are referred to as
peripheral neuropathies
64
disorders affecting the muscle fibers are referred to as
myopathies
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
disuse atrophy
occurs with conditions such as immobilization and chronic illness
66
The most extreme examples of muscle atrophy are found in people with disorders that deprive muscles of their innervation. This is called
denervation atrophy
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.
muscular dystrophies
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
pseudohypertrophy
69
true or false
The muscle weakness seen in MD is insidious in onset but continually progressive, varying with the type of disorder
true
70
the most common form of MD
DMD - 1 in 3500 live male births
71
DMD is inherited as a _________ single-gene defect on the X chromosome and is transmitted from the mother to her male offspring.
recessive
72
X-linked MD but manifests later in childhood or adolescence and has a slower course of progression.
becker MD
73
DMD is caused by mutations in a gene located on the short arm of the X chromosome that codes for a protein called ________.
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
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
connective tissue
75
Signs of muscle weakness seen with DMD manifested by frequent falling usually become evident beginning when the child is between
2 and 3
76
first muscles of the body to be affected in MD
postural muscles of shoulders and hips
77
Imbalances seen in DMD between agonist and antagonist muscles lead to abnormal postures and the development of
contractures and joint immobility.
scoliosis is also common
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.
DMD
79
Serum levels of the enzyme __________ _______, which leaks from damaged muscle fibers, can be used to assist the diagnosis of MD
creatinine kinase
80
_________ ________ which shows a mixture of muscle cell degeneration and regeneration and reveals fat and scar tissue replacement, is diagnostic of DMD
muscle biopsy
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.
dystrophin
82
Management of DMD is directed toward maintaining
ambulation and preventing deformities
Passive stretching, correct or counter posturing, and splints help to prevent deformities.
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
end plate
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
acetylcholine
85
Neurotoxins from the botulism organism (Clostridium botulinum) produce paralysis by blocking release of
acetylcholine
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.
botulism
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
honey
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
myasthenia gravis
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
myasthenia gravis
90
Neonatal myasthenia gravis, caused by placental transfer of the acetylcholine receptor antibody, occurs in about __% of infants born to mothers with the disease
10
Spontaneous resolution of symptoms usually occurs within a few months of birth.
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.
myasthenia gravis
92
Approximately 70% of people with myasthenia gravis also have abnormalities of the
thymus
thymoma (i.e., thymus tumor) or thymic hyperplasia (i.e., increased thymus weight from an increased number of thymus cells).
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.
myasthenia gravis
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.
myasthenia gravis
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?
ventilation
96
_________ crisis results from inadequate or excessive doses of the anticholinesterase drugs used in treatment of myasthenia gravis.
cholinergic
97
Research has found that ______ virus, a lymphotropic human herpes virus, is present in the thymuses of many people with myasthenia gravis.
Epstein-Barr
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
plasmaphoresis
99
Segmental demyelination occurs when there is a disorder of the Schwann cell, as seen in
gullian-barre
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).
carpal tunnel syndrome
101
Most cases of carpal tunnel syndrome are due to repetitive use of the
wrist
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.
carpal tunnel syndrome
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.
tinel
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.
Phalen
105
treatments of carpal tunnel syndrome (4)
avoidance of movements that cause nerve compression
splinting
anti inflammatory drugs
corticosteroids
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
Guillain-Barré syndrome
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.
gulliain-barre syndrome
108
the majority of people with guillian barre syndrome report having had this before onset of symptoms
flu like illness
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
Guillain-Barré syndrome.
110
Risk factors include heavy lifting, twisting, bodily vibration, obesity, and poor conditioning. However, _____ ______ _____ is common even in people without these risk factors.
low back pain
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
MRI
112
it is important that the provider also manage this common problem seen with lower back pain
sleep disorders
113
lifting while in the flexed position, slipping, falling on the buttocks or back, or suppressing a sneeze may all cause
herniated intravertebral disc
114
Degenerative processes such as _________ or _________ __________ predispose to malalignment of the vertebral column.
osteoarthritis or ankylosing spondylitis
115
The _____ and ______ regions are the most flexible areas of the spine and are most often involved in disk herniations
cervical and lumbar
116
_____ is the first and most common symptom of a herniated disk.
pain
117
The most common sensory deficits seen with herniated discs from spinal nerve root compression are paresthesias and numbness, particularly of the ____ and ____
leg and foot
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.
straight-leg
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.
vestibular
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.
ataxia
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 ________.
dysmetria
122
the most common cause of cerebellar ataxia
MS
123
It is rare for children to have acute cerebellar ataxia, but the most common virus associated with this manifestation in children is
varicella
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.
cerebellar
125
Cerebellar ________ is characterized by slow, slurred speech of continuously varying loudness.
dysarthria
126
difficulty swallowing or chewing
dysphagia
127
disorder of speech
dysarthria
128
Overactivity of the indirect pathway relative to the direct pathway would result in _________ disorders such as Parkinson disease.
hypokinetic
129
Underactivity of the indirect pathway would result in __________ disorders such as chorea and ballismus.
hyperkinetic
130
Involuntary, oscillating contractions of opposing muscle groups around a joint. Usually fairly uniform in frequency and amplitude
tremor
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.
chorea
132
Continuous, wormlike, twisting and turning motions of the joints of a limb or the body
athetosis
133
Violent, sweeping, flinging motions, especially of the limbs on one side of the body (hemiballismus)
ballismus
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
dystonia
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
dyskinesia
136
an untoward reaction that can develop with long-term use of some antipsychotic medications.
tardive dyskinesia
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.
parkinson's
138
The primary brain abnormality found in all people with Parkinson disease is degeneration of the nigrostriatal ________ neurons.
dopamine
139
_______ _______ are produced inside degenerated neurons in many people with Parkinson disease or parkinsonism
lewey bodies
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 _________ ________.
Parkinson disease.
141
The evidence suggests that welders may have an occupational hazard of developing ___________ ________ more often compared to people not exposed to manganese
parkinson's disease
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
parkinson's disease
143
Mutations in a second gene coding the protein parkin is associated with an autosomal _______, early-onset form of Parkinson disease.
recessive
144
The cardinal manifestations of Parkinson disease are (3)
tremor, rigidity, and bradykinesia or slowness of movement.
145
This is the most disabling of the symptoms of Parkinson disease.
bradykinesia
146
Because the basal ganglia also influence the autonomic nervous system, people with Parkinson disease often have excessive and uncontrolled (3)
sweating
sebaceous glands excretion
salivation
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
20%
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.
levodopa
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.
ALS
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.
ALS
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.
ALS
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.
ALS
153
The neurofilament proteins, which function in the axonal transport of molecules, are destroyed with
ALS
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.
ALS
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.
MS
156
The age of onset is typically between 20 and 30 years, with women being affected twice as frequently as men.
ms
157
MS occurs more commonly in people of _________ ancestry and is uncommon in certain ethnic groups such as Native Americans and Africans.
European
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.
MS
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
MS
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
MS
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.
MS
162
_________ is one of the most common problems for people with MS.
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.
163
__________ are the mainstay of treatment for acute attacks of MS.
corticosteroids
These agents are thought to reduce the inflammation, improve nerve conduction, and have important immunologic effects
164
The most common cause of SCI is _____, followed by violence (primarily gunshot wounds), falls, and recreational sporting activities.
MVAs
165
true or false
Mortality rates are significantly higher during the first year after SCI than during subsequent years, particularly for severely injured people.
true
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.
flexion
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.
extension
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
compression
169
_______ _______ spinal cord injuries can produce highly unstable injuries
axial rotation
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.
spinal shock
171
The goal of management of acute SCI is to (2)
reduce the neurologic deficit and prevent any additional loss of neurologic function
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.
complete
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.
incomplete
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.
Central cord
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.
brown sequard
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.
anterior cord
177
true or false
Due to the possible permanent neurological damage, emergent surgery is indicated for cauda equina syndrome.
true
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.
C5
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.
C6
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.
C6
