Neuromuscular diseases Flashcards
(105 cards)
1
Q
Define neuromuscular disorders.
A
Disorders that adversely affect muscle function either primarily or via nerve or neuromuscular junction abnormalities
2
Q
The primary roles of upper motor neurons are
A
directing, influencing, and modifying reflex arcs, lower-level control centers and motor neurons, and some sensory
3
Q
Upper motor neurons are
A
motor pathways completely contained within the CNS
begin in the cerebral cortex and end in the ventral horn of the spinal cord
4
Q
Describe the neuron pathway from upper motor neurons to lower motor neurons
A
upper motor neurons synapse with interneurons which then form synapses with lower motor neurons before projecting to the periphery
5
Q
The corticospinal tract originates in the
A
precentral gyrus
6
Q
The corticospinal tract goes through the
A
internal capsule, midbrain, and pons
7
Q
The corticospinal tract supplies
A
the voluntary muscles of the trunk & extremities
8
Q
Describe decussation in the corticospinal tract.
A
75-90% decussate in the medulla and form the lateral corticospinal tract
- at each cord level some leave and enter the ventral horn grey matter and synapse with lower body neurons
10-25% that do not decussate in the medulla make up the ventral corticospinal tract and travel to the spinal cord. they cross over before synapsing with lower motor neurons
9
Q
The corticobulbar tract supplies the
A
voluntary muscles of the head and follows the corticospinal tract until they reach the brainstem
10
Q
The corticobulbar tract is involved in
A
precise motor movements
11
Q
The corticobulbar tract innervates
A
cranial motor nuclei bilaterally except FACIAL & HYPOGLOSSAL
12
Q
The corticobulbar tract originates in the
A
precentral gyrus next to the lateral fissure of Sylvius
13
Q
Lower motor neurons are located in
A
the brain stem or the in the spinal cord
14
Q
Lower motor neurons are responsible for
A
direct influence on muscles
15
Q
Lower motor neurons that pass through cranial nerves primarily control the
A
skeletal muscles of the head & the neck
16
Q
The lower motor neurons that pass through the spinal nerves primarily control
A
muscles of the limbs & trunk
17
Q
Lower motor neurons send axons out through
A
nerves in the peripheral nervous system to synapse on and control skeletal muscle cells
18
Q
Briefly describe the AP at the NMJ.
A
- AP arrives & synaptic transmission begins
- Na+ channels open and depolarize
- Ca2+ enter cell and triggers vesicles to fuse presynaptically
- Ach diffuses across the cleft
- Ach binds to nachr and releases Na
- Ach, vesicles are recycled
19
Q
With upper motor lesions-
A
muscle groups are affected mild weakness minimal disuse muscle atrophy no fasciculations increased muscle stretch reflex hypertonia, spasticity pathological reflexes
20
Q
With lower motor lesions
A
occur in ventral horn (spinal cord) & motor nuclei (brainstem) -individual muscles may be affected mild weakness marked muscle atrophy fasciculations decreased muscle stretch reflex hypotonia, flaccidity no Babinski sign
21
Q
Upper motor neuron diseases include
A
cerebral palsy, multiple sclerosis, CVA, Parkinson’s, and Huntingto’s
22
Q
Cerebral palsy is a
A
non-progressive disorder caused by injury or abnormal development in the immature brain before, during, or after birth up to 1 year of age. it is damage or defects in the corticospinal pathway
23
Q
The cause of cerebral palsy is
A
still unknown although sources point to infection vs. anoxic brain injury
24
Q
Signs & symptoms of cerebral palsy include
A
muscle weakness, loss of fine motor control, impaired speech, drooling, exaggerated deep tendon reflexes, spasticity, rigidity of extremities, scoliosis, contractures, joint dislocation
25
Associated problems with cerebral palsy include
vision & hearing impairment, swallowing problems, seizures, intellectual disability and reflux disease
26
Treatment for cerebral palsy includes:
no cure
treat symptoms to increase ADLs- surgical (ortho, dental, general, ophthalmology, ENT)--> may see dorsal rhizotomy, antireflux operation, intrathecal baclofen pumps
Medications--> botulinum toxin
-physical & OT
27
Anesthesia considerations for the cerebral palsy patient include.
hold preop sedatives and cautious with opioids (give short-acting)
difficult vascular access
difficult airway- dentition, secretions, TMJ ankylosis, contractures
consider RSI
Succ does not produce increased K release
cautious administration of NDMR
decreased MAC need (20-30%)
prone to bleeding, hypothermia, & intravascular depletion
slow emergences
prone to latex allergies
careful w/ positioning & regional d/t contractures & scoliosis
28
Multiple sclerosis is an
autoimmune disease characterized by combination of demyelination, inflammation, and axonal damage of the CNS. peripheral nerves are not affected
T Cell mediated autoantiboides
29
_________ anesthesia is generally not recommended for the MS patient
spinal
30
Signs & symptoms of MS include
paresthesia, muscle fatigue/weakness, painful muscle spasms, autonomic instability, bulbar muscle dysfunction, visual problems (optic neuritis & diplopia), cognitive dysfunction (advanced MS)
31
Multiple sclerosis typically affects
women 20-40 or 45-60
| etiology is unknown
32
MS affects the
somatic motor
somatic sensory
and autonomic systems
33
Treatments for MS include
decrease spasticity, tremors, bladder spasticity
diazepam, dantrolene, or baclofen
glucocorticoids
immunosuppressants
CD20 monoclonal antibody, interferon B1a or glatiramer acetate
34
Situations that exacerbate symptoms of MS include
stress
increased body temperature
infection
& hyponatremia
35
Anesthetic considerations for MS icnlude
```
avoid succinylcholine, scopolamine, & atropine
NMDR- use cautiously
surgery avoided during flare
avoid spinal block
epidural safe to use
aspiration risk
increase risk of DVT
stress dose steroids
exaggerated hypotensive effects
```
36
CVA is characterized by
sudden neurologic deficits resulting from ischemia (88% of cases) or hemorrhage (12% of cases)
37
The presentation of CVA depends on
where it is located
38
Patients who have a CVA of the anterior cerebral artery have
contralateral leg weakness
39
Patients who have a CVA of the middle cerebral artery have
aphasia, contralateral visual field defect
| contralateral hemiparesis & hemisensory deficit
40
Patients who have a CVA of the posterior cerebral artery have
contralateral visual field defect & hemiparesis
41
Patients who have a CVA of the vertebral artery have
lower cranial nerve deficits
| and/or ataxia with crossed sensory deficits
42
Patients who have a CVA of the basilar artery have
oculomotor deficits and/or ataxia
| crossed sensory & motor deficits
43
Patients who have a CVA of the penetrating arteries have
contralateral hemiparesis
| contralateral hemisensory deficits
44
Stroke survivors represent the
highest rate of disability
45
Treatment for CVA includes
aspirin
TPA (IV administration or direct infusion)
surgery (crani/cerebellar resection)
46
Anesthesia considerations for CVA include
```
aspiration risk
DVT risk
BS maintenance
BP maintenance
avoid: hyperglycemia, dehydration, hypothermia, infections
statins
aspirin therapy
regional, MAC- reduce incidence of stroke because it decreases BP swings
```
47
Patients who have had a CVA should wait to come back for surgery for
3 months because they need the time to heal and have cerebral autoregulation restored
48
Parkinson's disease is a
neurodegenerative disorder of unknown cause marked by a characteristic loss of dopaminergic fibers in the basal ganglia, regional dopamine concentrations are also depleted
49
Depletion of dopamine in Parkinson's disease results in
diminished inhibition of neurons controlling the extrapyramidal motor system and unopposed stimulation by acetylcholine
50
Signs & symptoms of Parkinson's disease include
skeletal muscle tremor (pill rolling) more prominent during rest & disappear during voluntary movement
rigidity
akinesia
diaphragmatic spasms
dementia
depression
facial immobility (infrequent blinking & paucity of emotional expressions)
51
Treatment for Parkinson's disease include
levodopa, carbidopa, amantadine, selegiline & rasagiline, surgery
acetylcholinestarse inhbitiors
antiviral agents--> prolongs QT
dopamine agonist
52
For patients with Parkinson's disease who take seregine, we need to avoid
meperidine because it can lead to serotonin syndrome
53
Anesthetic considerations of the patient with Parkinson's disease include
```
levodopa therapy continued
hypotension & cardiac dysrhythmias
-droperidol/haldol
airway risk
aspiration risk
risk of HTN
prone to post-extubation laryngospasm
avoid benzos
sevo is agent of choice
NDMB is less effective if patient on anticholinergic for dementia/uses sugammedex
```
54
Huntington's disease is a
degenerative disease of the CNS characterized by marked atrophy of the caudate nucleus and to a lesser degree the putamen & globus pallidus
55
Signs & symptoms of Huntington's disease include
progressive dementia, chorea (involuntary jerking or writhing movements), tremors, rigidity/contractures, depression, aggressive outburst, mood swings, difficulty with speech & swallowing
56
Treatment of Huntington's disease includes
treat the choreiform movements/jerking
antidepressants
physical, occupational, & speech therapy
57
Anesthetic considerations for the patient with Huntington's disease includes
```
high aspiration risk
prolonged response to succinylcholine
sensitive to NDMR
consider avoiding (Reglan & anticholinergics)
-glyco>atropine
difficult IV access
autonomic dysfunction (labile BP)
```
58
Anesthetic considerations for all patients who have upper motor neuron diseases includes
thorough assessments
check meds
disease severity & systemic involvement
need to be alert before you can pull tube to ensure they can protect their airway
59
Diseases of the lower motor neuron include
myasthenia gravis, lambert-eaton, muscular dystrophy, myotonic dystrophy, mitochondrial disorder, Guillain-Barre, spinal muscular atrophy
60
Myasthenia gravis is an
autoimmune destruction (IgG antibodies against the nicotinic acetylcholine receptor) or inactivation of postsynaptic acetylcholine receptors at the neuromuscular junction leading to reduced numbers of receptors and degradation of their function and to complement-mediated damage to the postsynaptic end plate
61
Signs & symptoms of myasthenia gravis include
diplopia, ptosis, fluctuating fatigue & weakness that improves after rest, muscle weakness of mouth and throat, dyspnea with exertion, proximal muscle weakness
62
Treatment for myasthenia gravis includes
plasmapheresis, corticosteroids, immunosuppressants, immunoglobins, thymectomy, cholinesterase inhibitor
63
Situations that exacerbate symptoms of myasthenia gravis include
pregnancy, infection, electrolyte imbalance, surgical & psychological stress, aminoglycoside antibiotics
64
Anesthetic considerations for the patient with myasthenia gravis includes
aspiration risk
sensitive to NDMR
sensitive to respiratory depressants
regional preferred (amide locals not esters)
-avoid >mid thoracic or interscalene or supraclavicular blocks
resistant to succinylcholine (2mg/kg)--> DOA increased by 5-10 min.
65
Lambert-Eaton disease is a
presynaptic defect of the neuromuscular transmission in which antibodies to voltage-gated calcium channels on the nerve terminal markedly reduce the quantal release of acetylcholine at the motor end plate
66
Signs & symptoms of Lambert-Eaton disease includes
proximal muscles are mostly affected
weakness generally worse in the AM and improves through the day
respiratory & diaphragm muscles become weak
autonomic nervous system dysfunction- orthostatic hypotension, slowed gastric mobility, & urinary retention
67
Treatment of Lambert-Eaton includes
3,4 DAP, Guanidine hydrochloride, corticosteroids, immunosuppressants, plasmapharesis
68
Anesthetic considerations for the patient with Lambert-Eaton includes
Sensitive to succinylcholine & NDMR
inadequate reversal with anticholinesterase
high risk of postop respiratory failure
60% have small cell carcinoma
69
Duchenne's muscular dystrophy is a
X-linked recessive disorder that results from production of abnormal protein dystrophin
70
Duchenne's muscular dystrophy is more likely to affect
males>females, & presents between 3-5 years of age and rarely live past 30 years
71
S&S of Duchenne's muscular dystrophy include
```
symmetric proximal muscle weakness that is manifested as a gain disturbance-"Gower sign"
fatty infiltration typically causes enlargement of muscles, particularly the calves
kyphoscoliosis
respiratory muscle weakness
degeneration of cardiac muscles
impaired GI hypo-motility
impaired airway reflex
impaired cardiac conduction
cognitive impairment
pulmonary hypertension
```
72
Becker's disease is a
X-linked recessive disorder but less common than Duchenne's
| still have dystrophin just lower
73
Becker's disease is typically found in
males
| presents later in life (adolescence) than Duchenne's and progresses more slowly
74
S/S of Becker's disease includes
intellectual disability is less common, proximal muscle weakness, prominent calf pseudohypertrophy, degeneration of cardiac muscles
death d/t respiratory compromise
75
Diagnosis of Duchenne's & Becker's Muscular dystrophy includes
genetic testing, CK levels, muscle biopsy (rare)
76
Treatment of Duchenne's & Becker's muscular dystrophy includes
```
surgery
physical therapy
steroids
biphosphates
mystatin inhibitors
gene modification
protease inhibitors
stem cell infusions
```
77
Anesthetic considerations for includes Duchenne's & Becker's muscular dystrophy include
association with malignant hyperthermia (TIVA)- avoid succinylcholine & inhalation agents
preoperative pre-medications with opioid and benzos should be avoided
intraoperative position complications due to kyphoscoliosis
sensitive to NMDR
local & regional preferable
aspiration risk
78
Myotonic dystrophy is a
hereditary degenerative disease of the skeletal muscle that results in the dysfunctional calcium sequestration by the sarcoplasmic reticulum
sodium & chloride channel dysfunction is implicated as well
79
Myotonic dystrophy symptoms include
weakness- facial, thoracic, intercostal, diaphragm, sternocleidomastoid, & distal limb
inability to relax hand grip (myotonia)
cardiomyopathy, conduction defects (1st degree AV block)
dysphagia, slowed gastric emptying
endocrine dysfunction
central sleep apnea
Ptosis
Triad in males includes- frontal balding, cataracts, & testicular atrophy
80
Treatment for myotonic dystrophy includes
procainamide, phenytoin, mexiletine, baclofen, dantrolene, carbamazepine, & cardiac pacemaker
81
Anesthetic considerations for the patient with myotonic dystrophy include
avoid succinylcholine
aspiration risk
volatile anesthetic may produce exaggerated myocardial depression but high concentrations can abolish myotonia. still questionable d/t MH
anesthesia & surgery can aggravate cardiac conduction problems by increasing vagal tone
neostigmine & physostigmine can aggravate myotonia
sensitive to respiratory depressant
maintain normothermia & avoid shivering
pulmonary function test, ECG, and transthoracic pacing should be readily available
82
Mitochondrial disorders are a
heterogenous group of disorders of skeletal muscle energy metabolism. mitochondria produce the energy required by skeletal muscle cells through the oxidation-reduction reactions of the electron transfer chain and oxidative phosphorylation thereby generating ADP
83
Signs & symptoms of mitochondrial disorders include
abnormal fatigability with sustained exercise, skeletal muscle pain and progressive weakness, hearing loss, impaired vision, balance & coordination problems, seizures, learning deficits, organ problems for the heart, liver, kidney & brain
84
Treatment for mitochondrial diseases include
treat the symptoms
administration of metabolites and cofactors
sodium bicarbonate/dichloroacetate
ketogenic diet
85
Anesthetic considerations for the mitochondrial disorders include
prone to acidosis & dehydration, lactate level, avoid propofol for continuous infusion, avoid succinylcholine & LR, maintain normothermia, use with caution- NDMR & local anesthetics, avoid prolonged tourniquets, avoid bupivacaine
86
Guillain-Barre is an
immunologic assault on myelin in the peripheral nerves particularly lower motor neurons
APs cannot be conducted so the motor endplate does not receive the incoming signal
persists for 2 weeks and ends with full recovery in 4 weeks with some permanent paralysis remaining
87
Guillain-Barre signs & symptoms include
flaccid paralysis that begins in the distal extremities and ascends bilaterally, intercostal muscle weakness, facial and pharyngeal weakness, sensory deficits, autonomic dysfunction is common
88
One of the most likely causes of Guillain-Barre is
the flu
89
Treatment for Guillain-Barre includes
plasmapheresis, IVIG, steroid not useful therapy
90
Anesthetic considerations for the patient with Guillain-Barre includes
avoid succinylcholine, sensitivity to NDMR, increase risk of DVT, risk of aspiration, exaggerated response to indirect sympathomimetics (A-line)
avoid respiratory depression
risk for postop mechanical ventilation
assess Na+ d/t risk for SIADH
91
Spinal muscular atrophy is due to
deletions or mutations in the survival motor neuron gene on chromosome 5q13
92
The SMN gene product is involved in the
formation of RNA complexes and their trafficking out of the nucleus
loss of SMN function promotes apoptosis of lower motor neurons
93
Spinal muscular atrophy affects the
anterior horn of spinal cord
94
SMA III is a
juvenile form that develops after age 2. patients develop weakness of proximal limb muscles with relative sparing of bulbar muscles
95
SMA II has an
autosomal recessive mode of inheritance and begins in the latter half o the first year of life
it progresses more slowly than the infantile form and patients may survive into adulthood
96
SMA I is an
infantile spinal muscular atrophy, an autosomal recessive disorder that manifests usually within the first 3 months of life
infants with this condition have difficulty sucking, swallowing, and breathing
atrophy & fasciculation are found in the tongue & limb muscles
rapidly progressive, most usually die by age 3
97
Treatment for spinal muscular atrophy includes
PT, surgery, low threshold for antibiotics, spinraza, zolgensma, evrysdi
98
Anesthetic considerations for the patient with spinal muscular atrophy include
pulmonary consultation
difficult intubation d/t increased secretions
avoid succinylcholine
varying sensitivity to NDMR (longer DOA)
regional (controversial)
cautious with opioids
postop respiratory support is a high likelihood
99
Mixed motor neuron disease include
amyotrophic lateral sclerosis
100
Amyotrophic lateral sclerosis is a
rapidly progressive degeneration of motor neurons to the corticospinal tract (primary descending upper motor neurons) and the lower motor neurons in the anterior horn gray matter of the spinal cord. Astrocytic gliosis replaces the affected motor neurons
101
S/S of ALS include
spasticity, hyperreflexia, loss of coordination, muscle weakness, fasciculations, atrophy often begins in hands, orthostatic hypotension, resting tachycardia, sensation remains intact
cognitive, bladder, & bowel function not usually affected
102
Treatment for ALS includes
No known tx
analgesics, spasmolytics, edaravone-decrease decline in ADLs
riluzole (NMDA receptor antagonist)- is the only drug that reduces mortality
103
Anesthetic considerations for the patient with ALS include
avoid succinylcholine
increase sensitivity to NDMR
aspiration risk
Consider postoperative mechanical ventilation
increase sensitivity to respiratory depressants
autonomic dysfunction with risk for hemodynamic instability
spinal anesthesia avoided
104
```
Patients with myasthenia gravis will be:
A. sensitive to rocuronium
B. Sensitive to succinylcholine
C. Resistant to rocuronium
D. Resistant to succinylcholine
```
A & D
105
```
Characteristics of lower motor neuron lesion
A. pathological reflexes
B. fasciculations
C. spasticity
D. flaccidity
E. disuse muscle atrophy
```
B & D
