Ch. 36 Disorders of Neuromuscular Function Flashcards
1
Q
What is hypotonia?
A
Diminished resistance to passive movement.
Soft muscles on palpation.
Diminished deep tendon reflexes.
2
Q
What is hypertonia?
A
Hyperexcitable stretch reflex causing rigidity and spasticity.
3
Q
What is clonus?
A
Involuntary rhythmic muscular contractions and relaxations.
4
Q
What does the suffix “plegia” mean?
A
Stroke or paralysis
5
Q
What does “paralysis” mean?
A
Loss of movement.
6
Q
What does the suffix “paresis” mean?
A
Weakness
7
Q
What does the prefix “mono” mean?
A
One limb
8
Q
What does the prefix “hemi” mean?
A
Both limbs on one side
9
Q
What do the prefixes “di” and “para” mean?
A
Both upper limbs or both low limbs
10
Q
What do the prefixes “quadri” and “tetra” mean?
A
all four limbs
11
Q
What is paraparesis?
A
A defect causing weakness in both arms
12
Q
What is hemiparesis?
A
A weakness in the right arm and leg
13
Q
What is monoparalysis?
A
Inability to move one leg
14
Q
What results from upper motor neuron damage?
A
Weakness and loss of voluntary control. The spinal reflexes remain intact but cannot be modulated by the brain.
15
Q
What are the manifestations of upper motor neuron damage?
A
Increased muscle tone
Hypertonia/hyperreflexia
Spasticity
16
Q
What neurons are affected by lower motor neuron damage?
A
Neurons directly innervating muscles are affected.
17
Q
What occurs as a result of irritated neurons in lower motor neuron damage?
A
Involuntary muscle contractions: fasciculation (small/local)
18
Q
What occurs as a result of death of neurons (lower motor neuron damage)
A
Spinal reflexes are lost.
Flaccid paralysis
Denervation atrophy of muscles.
19
Q
What are the two causes of muscle atrophy?
A
Disuse and denervation
20
Q
What is the pathophysiology of muscular dystrophy?
A
Contractile proteins not properly attached to cytoskeleton of muscle cell. Protein movement does not effectively contract muscle cell.
21
Q
What is Duchenne Muscular Dystrophy?
A
Recessive X-linked
Affects 1 in 3500 male births
Females usually asymptomatic if carrier (or mild symptoms)
22
Q
What is Becker Muscular Dystrophy?
A
Slower progression and less severe than DMD.
Occurs later in childhood than DMD
23
Q
What is the clinical presentation of muscular dystrophy?
A
Boys asymptomatic at birth. Begins with hips/shoulder muscles. Calf muscles pseudohypertrophy (fat/connective tissue). by 2-3 years, abnormal posture, falls, contractures, joint immobility, scoliosis. Wheelchair needed by teen years. Incontinence. Weak cough = resp infections. CVS: cardiomyopathy.
24
Q
How is muscular dystrophy diagnosed by the physician?
A
Family history Observation of voluntary movement Elevated Creatine-kinase Muscle biopsy Echo, ECG
25
What is the treatment for muscular dystrophy?
Maintain ambulation (helps prevent deformities with bones)
Prevent deformity
Prevent respiratory infections
Death in young adulthood common
26
What is Gower's sign?
Difficulty standing up and walking
27
Why are creatine-kinase levels elevated in muscular dystrophy?
Muscle damage causes elevated CK
28
What kinds of problems can arise with the neuromuscular junction?
Decreased acetylcholine release.
Decreased acetylcholine effects on muscle cell (receptors are lost).
Decreased acetylcholinesterase activity resulting in too much acetylcholine at neuromuscular junction, also interfering with nerve impulse.
29
What is myasthenia gravis?
An autoimmune disorder caused by antibody-mediated loss of acetylcholine receptors in the neuromuscular junction. It results in decreased motor response.
30
What are the risk factors for myastehnia gravis?
Early adulthood (women)
Older than 50 years of age (men)
Placental transfer from mother (10-15% only and often spontaneous resolution within months.)
Thymus tumor or hyperplasia in 75% of cases.
31
What is the autoimmune pathophysiology of myastenia gravis?
Gradual destruction of acetylcholine receptors in neuromuscular junction
Injury to postsynaptic muscle membrane
Receptor sites degraded and blocked d/t antibodies
32
What are the initial manifestations of myesthenia gravis?
Muscle weakness (periorbital muscles, ptosis, diplopia)
Fatigue
These are progressive throughout the day.
33
What are the progressive manifestationos of myesthenia gravis?
Respiratory muscle weakness, difficulty speaking/chewing/swallowing, weak limbs.
34
What is a myasthenia crisis caused by?
Due to stress, infection, emotional upset, pregnancy, alcohol, cold, surgery, etc.
35
How is myesthenia gravis diagnosed?
History, physical exam
Rise in acetylcholine receptor antibodies (blood test)
Electrohysiologic studies to assess stage.
36
What is the treatment for myesthenia gravis?
Corticosteroid (immunosuppressant)
Thymectomy (if thymoma)
Plasmapheresis (remove specific antibodies from the blood and replace with immunoglobulin IgG)
37
What is carpal tunnel syndrome?
Mononeuropathy.
| Compression of median nerve passing through carpal bones and ligaments.
38
What causes carpal tunnel syndrome?
Inflammation of tendons, synovial swelling, tumor, RA, DM
| Repetitive flexion-extension movements
39
What are the manifestations of carpal tunnel syndrome?
Pain, paresthesis, numbness of thumb, 1st, 2nd, 3rd, and part of 4th digit
Wrist and hand pain, worse at night
Atrophy of abductor pollicus muscle.
40
What is Tinel sign?
Light percussion over median nerve at wrist. Tingling sensation into palm = positive carpal tunnel
41
What is Phalen maneuver?
Complete flexion x 1 minute
| Parasthesia = positive carpal tunnel
42
What is the treatment for carpal tunnel?
Anti-inflammatories, immobilization
43
What is guillain-barre syndrome?
demyelinating polyneuropathy. It has an acute onset and is life threatening. It is immune mediated
44
What bacteria is linked with guillain-barre syndrome?
Campylobacter jejuni most common. (also cytomegalovirus, epstein-barr virus, and mycoplasma pneumoniae
45
What are the manifestations of Guillain-Barre Syndrome?
```
Manifestations are progressive and variable.
Ascending muscle weakness/paralysis
Paresthesia, numbness
Loss of tendon reflexes
ANS involvement
Pain
```
46
Where is pain located in Guillain-Barre syndrome?
Shoulder, back, posterior thighs.
47
What are the signs of ANS involvement in Guillain-Barre syndrome
Postural hypotension, arrhythmias, flushing, sweating, urinary retention
48
What are the risk factors for Guillain-Barre syndrome?
Possibly autoimmune
Association with immunizations
Frequently preceeded by mild respiratory or intestinal infection.
49
What is the treatment for guillain barre syndrome?
Support ventilation
prevent complications
Plasmapheresis
IV immunoglobulin
50
Define "choreiform" hyperkinesia
jerks
51
Define "athetiod" hyperkinesia
twisting movements
52
Define "ballismus" hyperkinesia
violent flinging movements
53
Define dystonia
rigidity
54
Which areas of the brain are affected by ALS?
Anterior horn of SC
Motor nuclei of brain stem
Cerebral cortex
55
Which part of the brain is involved in Tourette's Syndrome?
Cortical and subcortical regions (thalamus, basal ganglia, frontal cortex)
56
What is Parkinson's disease and what part of the brain does it involve?
Progressive disorder of basal ganglia and substantia nigral pathway resulting in depletion of dopamine.
57
What are the risk factors for Parkinson's?
```
Post encephalitic syndrome
Antipsychotic drug s/e
Toxins
Carbon monoxide poisoning
Genetics
Brain tumours
CVA
Head trauma
Degenerative neurological diseases
```
58
How do antipsychotic drugs cause Parkinson's?
They block dopamine receptors and output, causing symptoms of Parkinson's.
59
What are the initial manifestations of Parkinson's?
Rhythmic tremor of distal limbs that ceases with purposeful movement and sleep.
Rigidity (passive joint movement causes jerks).
Bradykinesis:
- difficulty stopping voluntary movements
- Shuffling when walking, freeze, lean forward to keep moving
60
What are the late manifestations of Parkinson's?
```
Difficulty planning, starting, or carrying out tasks.
Dementia/cognitive dysfunction (20-30%)
Motor function abnormalities.
Sleep disorders
Neuropsychiatric disorders
Autonomic Nervous System changes
```
61
What are some examples of motor abnormalities that arise as a late manifestation of Parkinson's?
Falls
Voluntary facial movements become limited and slow = stiff, masklike expression
Tongue, palate, throat muscles become rigid
Slow speech, poor articulation
62
What are some examples of autonomic nervous system changes that arise as a late manifestation of Parkinson's?
```
Lacrimation (flow of tears)
Sweating
Dysphagia
Orthostatic hypotension
Thermal regulation problems
Constipation
Impotence
Incontinence
```
63
What are the nonpharmacologic treatments for Parkinson's?
Group support, education, exercise, nutrition guidance.
64
What are the pharmacologic treatments for Parkinson's?
Levodopa (increases dopamine)
Bromocriptine, pramipexole, amantadine (stimulate dopamine receptors)
Selegiline, rasagiline (slows the breakdown of dopamine)
65
What is the lifespan/prognosis of someone diagnosed with ALS?
80% die within 2-5 years of diagnosis
66
Define "amyotrophy" as it pertains to ALS
Denervation/shrinkage of muscle fibres
67
Define "lateral sclerosis" as it pertains to ALS
gliosis (scarring) of lateral columns of white matter
68
What is the pathophysiology of ALS?
Genetic mutation that causes glutamate (neurotransmitter) accumulation. This causes calcium channels to open more than normal. This damages both upper and lower neurons controlling voluntary movement. Distal neurons are affected first in lower spinal cord, then the disease moves toward parent nerve.
69
Which motor neurons are affected by ALS? (what part of the brain)
Anterior horn of SC
Motor nuclei of brain stem
Cerebral cortex
70
In ALS, damage to which part of the brain causes weakness, lack of motor control, and spasticity?
Cerebral cortex
71
What does ALS not affect in most cases?
Entire sensory system
Ocular motility
Intellect
72
What are the early manifestations of ALS?
```
Muscle cramps
One extremity progressively weakens and atrophies
Generalized weakness
Hyporeflexia
Fasciculations
Impaired fine motor control
```
73
What does ALS stand for?
Amyotrophic Lateral Sclerosis
74
What are the late manifestations of ALS?
Weakness of limbs and head.
Weakness of palate, pharynx, tongue (speech disorders, dysphagia)
Weakness of neck, shoulders, respiratory muscles
Aspiration
Death due to cerebral and respiratory complications
These manifestations are progressive.
75
What are the treatments for ALS?
Riluzole (antiglutamate) decreases glutamate accumulation and slows progression.
Support of ADLs
Nutrition
Psychological assistance
76
What is multiple sclerosis?
Inflammation and destruction of CNS myelin. It is immune mediated.
77
Which demographic is the highest risk for multiple sclerosis?
Women ages 20-40
| If immediate relative affected, 15 times more likely to develop.
78
What occurs during the first stage of multiple sclerosis?
Sequential development of small inflammatory lesions.
79
What occurs during the second stage of multiple sclerosis?
Lesions extend and consolidate, demyelination and gliosis occurs
80
What parts of the nervous system are affected by multiple sclerosis?
Nerve fibres of white matter in brain, spinal cord, and optic nerve
81
What are the characteristics of plaques in multiple sclerosis?
Hard, sharp-edged, sclerotic, patchy
82
What are the manifestations of multiple sclerosis?
```
Paresthesia
Sexual and bladder dysfunction
Fatigue, speech disturbances, mood swings
Optic nerve and muscle abnormalities
Lhermitte Sign
Muscle spasticity
```
83
What are some examples of the optic nerve and muscle abnormalities that can occur as a manifestation of multiple sclerosis?
Neuritis, diplopia, gaze paralysis, nystagmus, vertigo
84
What is the Lhermitte sign?
A shock-like response down the back and legs when the neck is flexed.
85
What physical functions are affected when the corticobulbar tracts are affected by multiple sclerosis?
Speech/swallowing
86
What physical functions are affected when the corticospinal tracts are affected by multiple sclerosis?
Muscle strength
87
What physical functions are affected when the cerebellar tracts are affected by multiple sclerosis?
Gait, coordination
88
What physical functions are affected when the spinocerebrellar tracts are affected by multiple sclerosis?
Balance
89
What physical functions are affected when posterior cell columns of the spinal cord are affected by multiple sclerosis?
Position, vibratory sensation
90
What are the four different types of multiple sclerosis?
Relapsing-remitting
Secondary progressive
Primary progressive
Progressive relapsing
