Lower Motor Neuron Disorders Flashcards
1
Q
What is the following a defintion of?
Adaptive shortening of a muscle-tendon unit
A
Contracture
2
Q
What has this cause?
Caused by prolonged immobility of muscle and connective tissue in a shortened position
A
Contracture
3
Q
Connective tissue in tendons, ligaments, and muscles lose what when immobilized in a shortened position for a prolonged period of time?
A
Loses elasticity and thickens
4
Q
What is the following involuntary muscle contraction?
- severe, painful muscle contractures lasting seconds to minutes
- high-frequency discharges of LMN overstimulated by sensory and UMN input
- can occur in a healthy neuromuscular system or may be a sign of pathology
A
Muscle Cramps
5
Q
What is the following involuntary muscle contraction?
- quick twithces of all muscle fibers in a single motor unit
- visible on surface of skin
- cause is unknown
- can occur in a healthy neuromuscular system or may be a sign of pathology
A
Fasciculations
6
Q
What is the following involuntary muscle contraction?
- brief, involuntary contraction of muscle or group of muscles
- pathologicly occurs in epilepsy, brain or spinal cord injury, stroke and chemical or drug poisoning
- cause in the awake neuromuscular system is unknown
- sleep-onset: when the wake-sleep transition elicits spinal motor neuron activity
- can occur in healthy neuromuscular system or could be a sign of pathology
A
Myoclonus
7
Q
What is the following involuntary muscle contraction?
- random, spontaneous, brief contractions of single muscle fibers not visible on surface of the skin; always pathologic
- occurs when muscle membrane is unstable owing to denervation, trauma, or electrolyte imbalance, and alterted membrane potential elicits involuntary contractions
- muscle membrane undergoes denervation hypersensitivity & entire muscle membrane surface becomes hypersensitive to ACh
- dectable only with electromyography
A
Fibrilations
8
Q
What is the following a defintion of?
involuntary, rhythmic movments of a body part
A
Tremors
8
Q
What type of tremor is this?
- action tremor
- occurs when body part is maintained against gravity
- visble when person flexes shoulders and holds arms outstretched and unsupported
- typical cause: enhanced physiologic tremor
- cerebellar disorders
A
Postural tremor
8
Q
What type of tremor is this?
- Action tremor
- occurs only when standing and affects trunk and lower limbs
- most visible when person stands without support
- typical cause: cerebellar lesion
A
Orthostatic Tremor
8
Q
What are some physiologic reasons as to why a tremor could occur? (7)
A
- Anxiety
- stress
- fatigue
- medications
- metabolic disorders
- caffeine
- alcohol withdrawal
9
Q
What type of tremor is this?
- Action tremor
- occurs with voluntary movement and increases as target is approached
- absent at rest
- most visible when person performs finger-to-nose test or heel-to-shin test
- typical cause: cerebellar lesion
A
Intention Tremor
10
Q
What type of tremor is this?
- occurs in relaxed body part that is supported
- visible when person is not intentionally moving & tend to decrease with voluntary movement, sitting or lying down with upper and lower limbs supported
- worsens during voluntary movement of another body part
- Typical cause: Parkinson’s disease and related disorders
- mainly affects hands and lower limbs
- chin, lips, and trunk may also have tremors
A
Resting tremor
11
Q
What type of tremor is this?
- most common pathologic action tremor
- both postural and intention tremors
- affecting mainly head and hands
- voice, lower limbs and trunk may also be affected
- autosomal dominant inheritance: accounts for about half of these tremor cases
A
Esstential tremor
12
Q
What type of tremor is this?
- any of the tremor types
- characterized by sudden onsent and remission
- affects one body part then changes to a different body part
- tremor diminishes or disappears when the person is distracted
- caused by abnormal brain function in the absence of a structural lesion
A
Functional Tremor
13
Q
When LMN signals to muscles are interrupted what happens?
A
Decrease or prevention of muscle contraction
14
Q
What type of damage causes interruption of LMN? (4)
A
- trauma
- demyelinating diseases
- infection
- chronic neuropathy
15
Q
What happens when there is a decrease or loss of reflexes when LMN has been interupted?
A
- interrupt the efferent limb or reflexes
- hyporeflexia or areflexia
- reflexive contraction is absent if paralysis is due to a complete LMN lesion
16
Q
What happens when paresis or paralysis occurs due to a LMN lesion?
A
- loss or decreased ability to generate muscle force
17
Q
What is the following a defintion of; when would the condition occur?
weakness; decreased ability to generate amount of force required for a task
A
- Paresis
- Would occur in LMN lesion
18
Q
What is the following a defintion of; where would the condition occur?
inability to voluntary contract muscle(s)
A
- Paralysis
- Would occur in LMN lesion
19
Q
What is the following a defintion of; when would the condition occur?
interrupts all axons in a nerve producing parlysis
A
- Complete lesion of peripheral nerve
- occurs during LMN lesion
20
Q
What is the following a defintion of; when would the condition occur?
loss of muscle bulk
A
- Muscle Atrophy
- Occurs during LMN Lesion
21
Q
What is the following a defintion of; when would the condition occur?
loss of muscle bulk due to lack of muscle use
A
- disuse atrophy
- Occurs during LMN lesion
22
# What is the following a defintion of; when would the condition occur?
Loss of muscle bulk due to damage to nervous system
- Neurgenic atrophy
- occurs during LMN lesion
23
# What is the following a defintion of; when would the condition occur?
- severe muscle atrophy
- complete denervation of skeletal muscle
- occurs during LMN lesion
24
# What is the following a defintion of; when would the condition occur?
abnormally low muscular resistance to passive stretch
- hypotonia
- occurs in LMN lesion
25
# What is the following a defintion of; when would the condition occur?
lack of skeletal muscle resistance to passive stretch; complete absence of muscle tone
- Flaccidity
- Occurs during LMN lesion
26
Depolorization of a muscle is recorded as what?
Muscle action potential
27
What is a normal response to needle insertion when performing an EMG?
Brief interval of depolorization due to mechanical irritation of muscle fibers
28
What does minimal voluntary contraction elicit?
Single motor unit action potentials
29
What does maximal voluntary contraction elicit?
Full recruitment pattern created by asyncrhonous discharge of many muscle fibers
30
# Is the following fibrilation or fasciculation?
Always abnormal and occurs when demyelinated neurons develop ectopic foci, causing abnormal action potentials to be generated in the axon
Fibrilation
31
# Is the following fibrilation or fasciculation?
May occur in a normal neuromuscular system or may be pathologic
Fasciculation
32
What are some causes or normal fasiculation?
- dehydration
- electrolyte imbalance
- advanced age
33
What indicated denervated muscle during maximal voluntary contraction?
- fibrillations
- reduced firing rate
34
# What is the following a defintion of?
Short-duration, low-amplitude potentials during voluntary contraction, lack of spontaneous muscle activity, sparing of somatosensation
Myopathy
35
What structures are involved with LMN lesions?
- Cranial lower motor neurons (nuclei)
- spinal lower motor neurons
36
What pathology can cause LMN lesions? (5)
- trauma
- infection
- degnerative
- vascular disorders
- tumors
37
Damage to LMN lesions is limited to what?
Limited to muscles innervated by affected LMN
38
What are the voluntary movement impairments with LMN lesions?
weak or absent
39
What are the strength impairments with LMN lesions?
ipsilaterial paresis and paralysis; peripheral nerve or myotome pattern
40
What are the muscle bulk impairments with LMN lesions?
neurogenic atrophy with rapid, severe wasting in a peripheral nerve or myotome pattern
41
What are the reflex impairments with LMN lesions?
decreased or absent
42
What are the muscle tone impairments with LMN lesions?
decreased or absent presenting as hypotonia or flaccidity
43
# What is the following condition?
Affects people how have had polio, followed by a period of neurological stability then develop new or exacerbated symptoms several years later after acute poliomyelitis infection
Postpolio syndrome
44
What are the signs of muscle weakness in postpolio syndrome
- new muscle involvement
- asymmetic pattern of weakness (proximal, distal, patch)
- onset or aggravation of muscle atrophy
45
What are the pain symptoms of postpolio syndrome
- in parts of the body that were previously affected by polio
- associated with mechanical stress on muscles, tendons, and joint from alterted biomechanics
- overuse and substitution causing microtrauma and over exhaustion of motor units
46
What are the fatigue symptoms of postpolio syndrome?
- overwhelming exhaustion causing attention and cognitive problems
47
What are some other symptoms of postpolio syndrome?
- Respiratory defiency
- sleep disorders
- dysphonia or dysphagia
- cold intolerance
- onset or aggravation of preexting difficulites in performing activities of daily living
48
# What is the following condition?
Disease that destroys both upper and lower MN; bilateral destruction
Amyotrophic lateral sclerosis
49
# What is the following pathology for?
- bilateral degeneration of LMN and UMN
- some degeneration in frontal cerebral cortex
Amytrophic lateral scelorsis
50
# What is the following etilogy for?
Accumlation of abnormal proteins that may be toxic to motor neurons
Amytrophic lateral sclerosis
51
What is the cognitive function signs of amytrophic lateral sclerosis?
Decesion-making impaired
52
What are the communication and memory signs of amytrophic lateral sclerosis?
- normal memory
- language and verbal fluency impaired
53
What are the emotional affects of amytrophic lateral sclerosis?
- emotinal lability (abnormal uncontrolled emotions)
54
What are the signs of UMN in amytrophic lateral sclerosis? (5)
- paresis
- hyperflexia
- Babinski's sign
- Atrophy
- fasciculations
55
What are the LMN signs in amytrophic lateral sclerosis? (6)
- paresis
- hypoflexia
- myoplastic changes
- hypotonia
- atrophy
- fibrillations
56
What are the loss of LMN in CN cause difficulites in?
- eating/swallowing (CN 5,7,9,10, & 12)
- Speaking (CN 5,7,10 & 12)
- head movement (CN 11)
