Neuromuscular Diseases Flashcards
1
Q
What is a neuromuscular disease?
A
disorder that adversely affects muscle function, either primarily or via nerve or NMJ abnormalities
2
Q
What is an upper motor neuron?
A
motor pathway completely contained within the CNS.
Begins in the cerebral cortex and ends in the ventral horn of the spinal cord.
3
Q
Where does an upper motor neuron begin?
A
cerebral cortex
4
Q
Where does an upper motor neuron end?
A
ventral horn of the spinal cord
5
Q
What are the primary roles of upper motor neurons?
A
Directing, influencing, & modifying:
- reflex arcs
- lower-level control centers
- motor neurons
some sensory
6
Q
Where do upper motor neurons [generally] form synapses?
A
with interneurons
[which form synapses with lower motor neurons before projecting to the periphery
7
Q
What does the corticospinal tract supply?
A
the voluntary muscles of the trunk & extremities
8
Q
Where does the corticospinal tract begin?
A
precentral gyrus
9
Q
What 3 structures does the corticospinal tract go through?
A
- internal capsule
- midbrain
- pons
10
Q
What are the 2 structures formed from the beginning of the corticospinal tract?
A
- lateral corticospinal tract
2. ventral corticospinal tract
11
Q
What is the lateral corticospinal tract?
A
75-90%
tract that crosses (decussates) in the medulla;
at each level some fibers leave the tract & enter the ventral horn grey matter to form synapses with lower motor neurons
12
Q
What is the ventral corticospinal tract?
A
10-25%
tract that does NOT cross (decussate) in the medulla;
Fibers make a SMALL cross over before synapsing with lower motor neurons
13
Q
What is the corticobulbar tract?
A
follows the corticospinal tract until the brainstem, then innervates the cranial nerves (motor) [CN 3, 4, 6, 9, 10, 11 bilaterally]
[CN 7, 12 unilaterally- this is why strokes have facial droop or tongue “droop]
- CN 7 innervates the “upper” face bilaterally, the “lower” face unilaterally = mouth droop”)
supplies the voluntary muscles of the head & is involved in precise motor movements
originates in the precentral gyrus, next to the lateral fissure of Sylvius
14
Q
What CN does the corticobulbar tract innervate?
A
cranial nerves (motor) [CN 3, 4, 6, 9, 10, 11 bilaterally]
cranial nerves 7, 12 unilaterally- this is why strokes have facial droop or tongue “droop”]
- CN 7 innervates the “upper” face bilaterally, the “lower” face unilaterally = mouth droop)
15
Q
Where does the corticobulbar tract originate?
A
precentral gyrus, next to the lateral fissure of Sylvius
16
Q
Where are lower motor neurons located?
A
in the brainstem or spinal cord
17
Q
What are lower motor neurons responsible for?
A
direct influence on muscles
18
Q
Where do axons of the lower motor neurons go?
A
through nerves in the PNS to synapse on and control skeletal muscle cells
19
Q
What do lower motor neurons that PASS THROUGH THE SPINAL NERVES control [primarily]?
A
muscles of the limbs and the trunk
20
Q
What do lower motor neurons that PASS THROUGH CRANIAL NERVES control [primarily]?
A
skeletal muscles of the head & neck
21
Q
What does damage to lower motor neurons lead to?
A
paralysis [unless nerve re-generation occurs]
22
Q
What breaks down acetylcholine in the synaptic cleft?
A
the enzyme acetylcholinesterase
23
Q
What happens to the components of acetylcholine after it is broken down?
A
taken back up into the presynaptic cell for resynthesis
24
Q
What is recycled in the NMJ after an AP?
A
acetylcholine & vesicles
25
What are the effects of an upper motor neuron lesion?
UMN (pyramidal cells) Motor Cortex
- muscle groups are affected
- mild weakness
- minimal disuse muscle atrophy
- no fasciculations
- increased muscle stretch reflex
- hypertonia
- spasticity
- pathological reflexes
26
What type of muscles are affected in an upper motor neuron lesion?
muscle groups
27
What kind of atrophy is seen in upper motor neuron lesions?
minimal disuse atrophy
28
Is the muscle stretch reflex increased or decreased in upper motor neuron lesions?
increased
29
Are muscles spastic or flaccid in upper motor neuron lesions?
spastic
30
What are the affects of a lower motor neuron / ventral horn / motor nuclei lesion?
- individual muscles are affected
- mild weakness
- marked muscle atrophy
- fasciculations
- decreased muscle stretch reflex
- hypotonia, faccidity
- NO babinski sign
31
What are 5 upper motor neuron diseases?
1. cerebral palsy
2. multiple sclerosis
3. cerebrovascular accident
4. Parkinson's
5. Huntington's
32
What is cerebral palsy?
non-progressive disorder caused by injury or abnormal development in the immature brain;
before, during, or after birth, up to 1 year of age.
**damage to the CORTICOSPINAL PATHWAY
33
What are neurological s/s of CP?
intellectual disabilities
psychiatric conditions
seizures
vision/hearing/speaking impairment
34
What are musculoskeletal s/s of CP?
```
problems with swallowing
difficulty speaking
exaggerated reflexes/spasticity
stiff muscles
lack of coordination
slow movement
scissors like gait
muscle weakness
scoliosis/contractures/joint dislocation
```
35
What is a GI problem associated with CP?
GERD
36
In CP do patients have any up or down regulation of receptors? If so, what receptor?
yes, up-regulation of nAChR
37
What are 5 types/categories of surgery commonly seen in CP?
```
ortho
dental
general
optho
ENT
```
- dorsal rhizotomy
- Nissen
- intrathecal baclofen pumps
38
What is one medication commonly used to relieve some of the s/s of CP?
botulinum toxin
39
What are () anesthetic considerations of CP?
1. hold/caution with pre-op sedatives/opioids (use short acting & small doses)
2. decreased dose of volatile anesthetics (↓MAC by 20-30%) & NDMR [sux does not cause increased K]
- USE BIS & NM MONITORING!
3. difficult airway & risk of aspiration
- RSI
- dentition, secretions, TMJ ankylosis, contractures
4. difficult vascular access
5. high risk of latex allergy
6. prone to bleeding, hypothermia, intravascular depletion
7. SLOW EMERGENCE
8. do they take seizure medications?
- how are liver labs?
40
What effect does succinylcholine have in patients with CP?
does NOT produce elevated K!!
- but patients have an upregulation of nAChR??
41
Can succinylcholine be given in patients with CP?
YES! [will not cause an increase in K] but avoid if you can or use a ↓ dose!
42
What type of problem is multiple sclerosis?
- upper motor neuron disorder
- autoimmune disease
- conduction problem
43
What is multiple sclerosis?
autoimmune dz characterized by a combination of DEMYELINATION, INFLAMMATION, & AXONAL DAMAGE of the CNS.
**peripheral nerves are NOT affected
44
What are 7 s/s of multiple sclerosis?
1. paresthesia (face, arms, fingers, legs)
2. muscle fatigue/weakness
3. painful muscle spasms
4. visual problems (optic neuritis & diplopia)
5. autonomic instability
6. bulbar muscle dysfunction
7. cognitive dysfunction (advanced MS)
45
What are the 2 visual problems that can occur in multiple sclerosis?
optic neuritis
| diplopia
46
What are 6 drugs that can be used in the treatment of multiple sclerosis?
BONUS: 2 more drugs
```
diazepam
dantrolene
baclofen
steroids
immunosuppressants
monoclonal antibodies
```
interferon B1a [anti-inflammatory]
glatiramer acetate [immunomodulator]
47
What are 5 situations that exacerbate s/s of MS?
```
stress
increased body temp (↑1c = block APs)
infection
hyponatremia
surgery
```
48
What vital sign is specifically important in patients with MS?
temperature.
increase by 1c can block action potentials from transmitting
49
What are 3 medications to specifically AVOID in multiple sclerosis?
1. succinylcholine
2. scopolamine
3. atropine
d/t denervation
50
Can neuromuscular blocking drugs be used in patients with multiple sclerosis?
yes, but..
do NOT use succinylcholine
and use
non-depolarizing muscle relaxants sparingly
51
What is an anesthetic consideration during a flare of multiple sclerosis?
cancel surgery if it is elective!!
52
Can patients with multiple sclerosis receive a spinal block?
?questionable...
| can possibly cause LA toxicity
53
Are epidurals safe in patients with multiple sclerosis?
yes
54
What type of induction should patients with multiple sclerosis have? Why?
RSI d/t aspiration risk
55
Patients with multiple sclerosis are at higher risk of (3)
1. aspiration
2. DVT
3. exaggerated hypotensive effects (d/t impaired autonomic response)
56
Are steroids OK in patients with multiple sclerosis?
yes! they might be taking them as part of their treatment, you may need to give stress dose steroids.
57
Why might a patient with multiple sclerosis have an exaggerated hypotensive effect?
impaired autonomic response (ie. during induction)
58
Anesthetic considerations of multiple sclerosis (6):
1. avoid sux, scopolamine, atropine, spinal block
2. use NDMR cautiously
3. give stress dose steroids, epidurals are OK
4. avoid surgery during "flare-up" (if possible)
5. Increased risk of aspiration, DVT, exaggerated hypotensive effects
6. increased PACU length of stay... make sure pt is fully reversed.... could be s/s of a flare?
59
What is a cerebrovascular accident?
stroke characterized by sudden neurologic deficits d/t ischemia (88%) or hemorrhage (12%)
60
What are s/s seen in anterior cerebral artery stroke?
contralateral leg weakness
61
What are s/s seen in middle cerebral artery stroke?
contralateral hemiparesis & hemisensory deficit (face & arm > leg)
aphasia
contralateral visual field defect
62
What are s/s seen in posterior cerebral artery stroke?
contralateral visual field defect & hemiparesis
63
What are s/s seen in a penetrating artery stroke?
contralateral hemiparesis
| contralateral hemisensory deficit
64
What are s/s seen in a basilar artery stroke?
oculomotor deficits and/or ataxia (loss of coordination/balance)
crossed sensory and motor deficits
65
What are s/s of vertebral artery stroke?
lower cranial nerve deficits and/or ataxia with crossed sensory deficits
66
What is the first thing done/obtained in a patient with suspected stroke?
non-contrast CT scan
67
What is the "new" stroke mneumonic?
Balance
Eyes
Face
Arm
Speech
Time
68
In a stroke patient, what will their blood pressure be?
HYPERtensive
69
What is the goal BP in a stroke patient?
SBP 140-180 / DBP <105 before intervention
SBP 120-140 after intervention
70
What will hypotension cause in a stroke patient?
cerebral vascular vasospasm
71
What are 3 treatments for cerebrovascular accident?
1. asprin
2. TPA (IV administration or direct infusion into clot)
[only in ischemic strokes]
3. surgery (crani/cerebellar resection) - mechanical clot removal
72
In an ischemic stroke patient, when can heparin be re-dosed in the OR?
> 1 hour since administration of heparin
73
What is the goal ACT in an ischemic stroke patient?
ACT 200-300
74
What are anesthetic considerations of a cerebrovascular accident?
1. Increased risk of
- DVT
- aspiration
- hyperglycemia (keep normal)
2. BP maintenance
3. AVOID hyperglycemia, dehydration, hyperthermia, infection
4. regional/MAC can give more stable BP & reduced incidence of stroke
5. Pts may be on aspirin, -statin, anticoagulant/anti-platelet therapy
6. succinylcholine OK if <24H since insult
7. ASSESSMENT/HX for baseline before surgery
75
What is the goal SaO2 and SpO2 in cerebrovascular accident patients?
SaO2 >90%
| PaO2 >60mmHg
76
What is Parkinson's disease?
neurodegenerative disorder of unknown cause marked by a characteristic loss of dopaminergic fibers in the basal ganglia
77
In Parkinson's dz, where does the loss of dopaminergic neurons occur?
in the basal ganglia
78
What does depletion of dopamine in the basal ganglia cause?
Parkinson's dz;
diminished inhibition of neurons controlling the extrapyramidal motor system & unopposed stimulation by acetylcholine
79
What are the s/s of Parkinson's?
- Skeletal muscle tremor (pill-rolling) - more prominent during rest and will disappear during voluntary movement
- rigidity
- akinesia
- diaphragmatic spasms
- dementia
- depression
- facial immobility (infrequent blinking & paucity of emotional expressions)
80
During movement/walking what are some s/s of a patient with parkinson's?
(from picture in notes)
```
masked face
stooped posture
back rigidity
forward tilt of trunk
flexed elbows & wrists
reduced arm swing
hand tremor
slightly flexed hip and knees
tremors in the legs
shuffling, short stepped gait
```
81
What are 7 classes of drugs that can be used to treat Parkinson's?
1. dopamine precursor (levodopa)
2. peripheral dopa decarboxylase inhibitor (carbidopa)
3. antiviral agent (amantadine)
4. Monoamine Oxidase Inhibitors-MAOIs (selegiline & rasagiline)
5. dopamine agonists (ropinirole, bromocriptine)
6. acetylcholinesterase inhibitors (donezepil, tacrine)
7. COMT inhibitors (entacapone)
82
What lab should be checked if the patient is taking entacapone?
liver enzymes
83
What is one cardio side effect of amantadine?
prolonged QT
84
What are the anesthetic considerations of Parkinson's?
1. continue levodopa therapy
2. hypotension & cardiac dysrhythmias
- use droperidol or haldol to correct hypotension
3. aspiration/airway risk
4. risk of HTN
5. prone to POST-EXTUBATION LARYNGOSPASM
6. avoid benzos
7. sevo? is agent of choice?
8. NDMR are LESS effective if pt is on anticholinergic for dementia.... use sugammadex
85
What kind of vasopressors should be used in patients with Parkinson's?
direct acting
86
How does chronic anticholinesterase use affect succinylcholine adminstration/dose?
chronic anticholinesterase use will prolong succinylcholine, patient will tend to be resistant
87
What is Huntington's disease?
degenerative disease of the CNS characterized by marked atrophy of the caudate nucleus and to a lesser degree the putamen and globus pallidus.
88
What 3 structures/locations of the brain are affected by Huntington's disease?
1. caudate nucleus
2. putamen
3. globus pallidus
89
What are s/s of Huntington's disease?
progressive dementia
chorea (involuntary jerking or writing movements)
tremors
rigidity/contractures
depression, aggressive outbursts, mood swings
difficulty with speech and swallowing
90
What is the overall goal/treatment of Huntington's disease?
↓ dopamine; either antagonize or deplete it
91
What is usually the 1st s/s of Huntington's disease?
chorea
92
What is the treatment of Huntington's disease?
1. treat the choreiform movements
2. antidepressants
3. physical, occupational, speech therapies
93
Huntington's disease patients will have low levels of what plasma enzyme?
plasma cholinesterase
94
What will happen if Huntington's disease is "over-treated"?
too much dopamine is blocked == will look like parkinson's disease
95
What are anesthetic considerations of Huntington's disease?
- aspiration risk
- prolonged response to succinylcholine → do not give!
- sensitive to NDMR
- can get spinal; but placement might be difficult d/t uncontrolled movements
- consider avoiding reglan & anticholinergics (avoid drugs that will cross the BBB)
[give glyco instead of atropine]
- autonomic dysfunction
- difficult IV access
96
What are 7 lower motor neuron diseases?
1. myasthenia gravis
2. lambert-eaton
3. muscular dystrophy
4. myotonic dystrophy
5. mitochondrial disorder
6. Guillain-Barre
7. Spinal Muscular Atrophy
97
What is myasthenia gravis?
lower motor neuron disease;
autoimmune destruction or inactivation of postsynaptic acetylcholine receptors
[IgG antibodies against the nicotinic acetylcholine receptor]
Leading to:
* reduced number of receptors & degradation of their function
* complement-mediated damage to the postsynaptic end plate
98
What is commonly found with myasthenia gravis?
70% of patients have thymus hyperplasia
99
What are the s/s of myasthenia gravis?
*unevenly distributed muscle weakness & fatigue of extremities and face
```
diplopia, ptosis
fluctuating fatigue & weakness that improves after rest
muscle weakness of mouth and throat
dyspnea with exertion
proximal muscle weakness
```
100
What is the key anesthetic implication of myasthenia gravis?
*do a good pre-op exam
→ know what meds they are taking
→ keep pt in PACU longer? possibly an overnight stay
101
What is the treatment of myasthenia gravis?
*we want to ↑ the ACh @ the NMJ
```
cholinesterase inhibitor (pyridostigmine)
corticosteroids
immunosuppressants / IVIG
plasmapheresis (remove antibodies)
thymectomy
```
102
What are situations that exacerbate symptoms of myasthenia gravis?
```
pregnancy
infection
electrolyte imbalance
surgical & psychological stress
aminoglycoside antibiotics
magnesium
verapamil
lithium
steroids
phenytoin
```
103
What are 2 ways to optimize a patient with myasthenia gravis?
1. PFTs
| 2. plasmapheresis
104
What are the anesthetic implications of myasthenia gravis?
- aspiration risk
- SENSITIVE to NDMR, respiratory depressants
- RESISTANT to succinylcholine (give 2mg/kg); duration of action lasts 5-10m longer
* cholinesterase inhibitors will ↓ plasma cholinesterase
- regional anesthesia preferred (AVOID higher than mid-thoracic, interscalene, or supraclavicular blocks); do not make diaphragm weak!
* give amide LA NOT esters
105
What diagnosis is Lambert-Eaton often seen with?
small cell carcinoma
106
What is Lambert-Eaton?
antibodies to presynaptic voltage-gated calcium channels markedly reduce the release of acetylcholine at the motor end plate
107
What are the s/s of Lambert-Eaton?
proximal limb weakness, worse in the morning & improves throughout the day.
respiratory & diaphragm muscles become weak
autonomic nervous system dysfunction
- orthostatic hypotension [pts are very sensitive]
- slowed gastric motility
- urinary retention
- dry mouth
- impotenance
108
What is the treatment for Lambert-Eaton?
```
DAP
guanidine hydrochloride
corticosteroids
immunosuppressants
plasmapheresis
*want to get more Ca into the presynaptic axon
```
109
What are anesthetic considerations of Lambert-Eaton?
- sensitive to succinylcholine AND NDMR
* *inadequate reversal with anticholinesterase
- high risk of postop respiratory failure [keep pts in PACU]
110
Treatment with ___ drugs is NOT effective in Lambert-Eaton.
anticholinesterase
111
What is Duchenne's muscular dystrophy?
absence of the protein dystrophin;
membrane stays "open" → Ca+ floods into cell → muscle fiber maintains contraction & becomes necrotic → muscle fiber develops into "shell" and fills with fat [fatty infiltration & enlargement of muscles]
112
What is the function of dystrophin?
maintenance of cell membrane
113
What type of genetic disorder is Duchenne's muscular dystrophy? (dominant/recessive, X-linked or Y-linked)
X-linked recessive
114
When does Duchenne's muscular dystrophy usually present?
between 2y-5y of age; rarely live past 30y
115
What are s/s of Duchenne's muscular dystrophy?
"Gower sign"- symmetric, proximal muscle weakness that is manifested as a gait disturbance
- kyphoscoliosis
- respiratory muscle weakness
- degeneration of cardiac muscles & impaired cardiac conduction
- impaired GI hypo-motility
- impaired airway reflex
- cognitive impairment
- pulmonary HTN
116
What is Becker muscular dystrophy?
*partial loss of dystrophin; progresses more slowly
X-linked recessive
117
What are the s/s of Becker muscular dystrophy?
same as Duchenne MD but usually present later in life and progress more slowly
- proximal muscle weakness
- intellectual disability is less common
118
Death of Becker muscular dystrophy is usually caused by:
respiratory complications
119
Diagnosis of muscular dystrophy is by:
1. genetic testing
2. CPK levels
3. muscle biopsy (rare)
120
What is the treatment of muscular dystrophy?
- steroids (helps delay progression by 2-3yrs)
- biphosphates (↑ Ca level & bone mass)
- mystatin inhibitors (promote muscle growth d/t dying muscle groups)
- gene modification
- surgery (for scoliosis)
- physical therapy
- protease inhibitors
- stem cell infusions
121
Anesthetic considerations for muscular dystrophy:
"MH"-like reactions; FULL cardiac workup needs to be done
- AVOID pre-med with benzos & opioids, succinylcholine, inhalation agents
- intraoperative positioning d/t kyphoscoliosis
- sensitive to NDMR
- local & regional anesthesia preferrable
- aspiration risk
122
Muscular dystrophy patients are at increased risk of:
1. respiratory infections
2. masseter spasms
3. prolonged post-op ventilation
123
What is myotonic dystrophy?
autosomal dominant; r/t thymoma
hereditary, degenerative dz of the skeletal muscle that results in dysfunctional calcium sequestration by the sarcoplasmic reticulum
- Na and Cl channel dysfunction is implicated as well
* prolonged contractions
124
What are s/s of myotonic dystrophy? (8)
- weakness of facial, thoracic, intercostal, diaphragm, sternocleidomastoid & distal limb muscles
- inability to relax hand grip (myotonia)
- cardiomyopathy, conduction defects (1st degree block)
- dysphagia, slowed gastric emptying
- endocrine dysfunction (insulin)
- central sleep apnea
- ptosis
- TRIAD IN MALES:
1. frontal balding
2. cataracts
3. testicular atrophy
125
What kind of workup do patients with myotonic dystrophy need?
cardiac work up
126
What do you need for pts with myotonic dystrophy?
*pacer pads in room
GOAL: we do not want to start a muscle contraction b/c it will not stop
127
What is the treatment of myotonic dystrophy?
- procainamide
- phenytoin
- mexiletine
- baclofen
- dantrolene
- carbamazepine
- cardiac pacemaker
128
What can exacerbate myotonic dystrophy?
muscle contraction
- shivering
- pregnancy & retained placenta
129
What are the anesthetic considerations of myotonic dystrophy?
- AVOID succinylcholine,
- aspiration risk
- Volatile anesthetics can cause exaggerated myocardial depression, but high concentrations of VA can abolish myotonia
- anesthesia & surgery can aggravate cardiac conduction by increasing vagal tone
- Drugs that can AGGREVATE myotonia: propofol, neostigmine, physostigmine, methohexital, etomidate
- maintain normothermia & avoid shivering (causes muscle contractions)
- PFT, EKG, transthoracic pacing should be available
130
What drugs should be avoided in myotonic dystrophy?
propofol, methohexital, etomidate, neostigmine, physostigmine
*do not want to ↑ ACh at receptors
131
What are mitochondrial disorders?
disorders of skeletal muscle energy metabolism;
132
What are the s/s of mitochondrial disorders?
- abnormal fatigability with sustained exercise
- skeletal muscle pain and weeakness
- hearing loss/impaired vision
- balance & coordination problems
- seizures
- learning deficits
- organ problems (heart. liver, kidney, brain- organs that require high energy)
133
What type of work-up do pts with mitochondrial disorders need?
COMPREHENSIVE
134
What is the treatment for mitochondrial disorders?
- treat symptoms
- administer metabolites & cofactors
- sodium bicarb/dichloroacetate
- ketogenic diet
135
Can regional anesthesia be used in patients with mitochondrial disorders?
yes, as long as there are no spine, or PNS injuries/issues
* do not prolong tourniquet use d/t metabolic by-products
136
What benzodiazepine can cause mitochondrial depression?
midazolam
137
What monitor should be used on patients with a mitochondrial disorder?
BIS
138
Patients with mitochondrial disorders are prone to development of....
acidosis & dehydration
*make them first case of the day
139
What kind of fluid should be used for patients with mitochondrial disorders?
normal saline. LR has lactate
140
What medications should be avoided in patients with mitochondrial disorders?
- midazolam
- succinylcholine
- LR
- continuous infusion of propofol (bolus OK)
- bupivacaine (higher cardiotoxicity)
141
What medications should be used with caution in patients with mitochondrial disorders?
NDMR
| local anesthetics
142
What is Guillain-Barre?
immunologic assualt on myelin in the PNS, particularly the lower motor neurons.
AP cannot be conducted so motor end plant does not receive signal.
143
What are the s/s of guillian-barre?
flaccid paralysis that beings in the distal extremities and ascends
sensory deficits
autonomic dysfunction is present
- resting tachycardia
- spontaneous diaphoresis
- vasodilation
144
What is the treatment of Guillain-Barre?
plasmapheresis
IVIG
*steroids are NOT useful; they inhibit the scavengers that HELP increase nerve regeneration
145
What are anesthetic considerations of Guillain-Barre?
- AVOID succinylcholine d/t denervation
- RISK of aspiration, DVT,
- increased sensitivity to NDMR
- exaggerated response to indirect sympathomimetics (place a-line for monitoring)
*regional anesthesia is controversial
146
What is spinal muscular atrophy?
gene mutation of 5q13; loss of SMN gene promotes apoptosis of lower motor neurons (anterior horn of the spinal cord)
147
What gene is implicated in spinal muscular atrophy?
survival motor neuron gene on chromosome 5q13
148
What is SMA type I
autosomal recessive
diagnosis within 3months of life
difficulty swallowing, sucking, breathing
atrophy/fasciculation of tongue & limbs
rapidly progressive with death by age 3
149
What is SMA type 2
autosomal recessive
diagnosed 3mo-2y
progresses more slowly, can survive until adulthood
150
What is SMA type 3
juvenile form that develops after age 2.
weakness of proximal limb muscles with relative sparing of bulbar muscles (head & neck)
151
What is the treatment of SMA?
```
Spinraza
Zolgensma
Evrysdi
Physical therapy
surgery
antibioticss
```
152
What are anesthetic considerations of SMA?
- pulmonary consult
- difficult intubation
- avoid succinylcholine
- NDMR have longer DOA; varying sensitivity
- regional is controversial; neuraxial difficult/unreliable
- caution with opioids
- anticipate post-op respiratory support
153
What is a mixed motor neuron disease?
| both upper motor neuron and lower motor neuron
Amyotrophic lateral sclerosis
154
What is amyotrophic lateral sclerosis?
rapid, progressive degeneration in the corticospinal tract (primarily the descending upper motor neurons) and the lower motor neurons in the anterior grey matter of the spinal cord.
*astrocytic gliosis replaces the affected motor neurons
155
What are s/s of amyotrophic lateral sclerosis?
- spasticity, hyper-reflexia, loss of coordination, weakness, fasciculations
- atrophy begins in hands
- orthostatic hypotension
- resting tachycardia
-**SENSATION REMAINS INTACT
156
What is the treatment of amyotrophic lateral sclerosis?
Riluzole (NMDA receptor antagonist)
Edaravone (decreases the decline of ADLs)
spasmolytics
analgesics
157
What are anesthetic considerations of amyotrophic lateral sclerosis?
AVOID succinylcholine
- increased sensitivity to NDMR & respiratory depressants
- aspiration risk
- consider post-op ventilation
- AUTONOMIC DYSFUNCTION with risk of hemodynamic instability
*** AVOID SPINAL ANESTHESIA
158
In what neuromuscular diseases should spinal/epidural be AVOIDED?
AML
Multiple sclerosis (avoid spinal; epidural OK)
Mitochondrial disorders (ensure no existing injuries/issues)
Guillain-Barre
SMA (controversial)
