Anterior Horn and NMJ Flashcards
1
Q
Anterior horn cell disorders (4)
A
ALS
SMA - spinal muscular atrophy
Polio
West nile virus
2
Q
Radiculopathies and plexopathies (4)
A
cervical spine
lumbar spine
brachial plexus
lumbosacral plexus
3
Q
Mononeuropathies (3)
A
carpal tunnel
ulnar palsy
peroneal palsy
4
Q
Polyneuropathies (5 causes)
A
genetic (CMT) Diabetes systemic illness vitamin deficiency toxic
5
Q
NMJ disorders (4)
A
myasthenia
LEMS
Botulism
Organophosphate poisoning
6
Q
Myopathies (4)
A
dystrophies
myositis
metabolic
toxic and endocrine
7
Q
signs and symptoms characterizing UMN disorders
A
spastic tone
increased reflexes
emotional lability
8
Q
signs and symptoms characterizing LMN disorders
A
decreased tone
decreased reflexes
atrophy
9
Q
ALS
Average onset
A
54
10
Q
ALS
males vs females
A
males 60%
11
Q
what percent of ALS is inherited
A
5
12
Q
Onset presentation of ALS
A
Leg>arm/bulbar; multiple sites
13
Q
ALS may spread how?
A
along neuraxis
14
Q
mortality in ALS
A
median 3.5 years
worse with bulbar / respiratory onset and elderly
15
Q
Treatment ALS
A
Riluzole - slows progression / extends life 3-6 months
Comp/Alt medicine
Symptom - improve QOL / assistive devices
16
Q
ALS treatment of cramps/spasticity
consideration?
A
hydration/avoid overexertion
benzos
phenytoin
quinine
lioresal
dantrolene
gabapentin
consideration: helps jaw quivering/clenching but can increase weakness and decrease FVC
17
Q
Treatment of pseudobulbar affect in ALS
A
Ask about it - they don’t volunteer information
Tricyclic and SSRI
Dextromethorphan + quinidine
18
Q
Treatment of drooling/laryngospasm in ALS
A
To decrease saliva: glycopyrrolate, amitriptyline, diphenhydramine, oxybutinin, scopalamine, artane, salvary gland irradiation
for thick saliva: metoprolol, propanolol
nasal congestion: decongestants, antihistamines
19
Q
ALS treatment of dysphagia and dysarthria
A
Tips to reduce choking: chin tuck, multiple swallows, celaring cough
PEG indications =
>1hr to eat meal
weight loss
silent aspiration
20
Q
Treatment of sleep disturbance in ALS
A
avoid short acting sedatives
test for desaturation and consider nocturnal NIPPV
21
Q
Causes of sleep disturbance in ALS?
A
Could be multiple depression anxiety apnea periodic movements GERD pain
22
Q
Charcot Marie Tooth Disease
Characterization -
A
hereditary neuropathies
hands and feet are weak
demyelination (few myelin profiles; digestion chambers)
23
Q
CMT1A/HNPP
What causes cmt1a
A
A 1.4 Mb duplication on chr 17 (PMP gene) causes CMT1A
24
Q
What characterizes CMT1A
A
Distal weakness, sensory loss, and deformities
25
What percent of CMT1A mutations are de novo?
10
26
Genetic cause of CMT1A
Repeats on either side of gene (CMT1A) are hot spot for recombination
27
What results from deletion of CMT1A gene?
HNPP
28
What characterizes HNPP?
Focal weakness and sensory loss
29
Multidisciplinary treatment approach to CMT
Physical therapy - exercise and range of motion
Occupational therapy - orthotics and assistive devices - cane, walker, easy to use utensils
Orthopedic surgery - correct deformities - ankle fusion, tendon transplants
30
What characterizes sensory or sensorimotor distal polyneuropathies?
Stocking glove numbness and burning pain
foot drop and weak hand muscles
31
What characterizes autonomic diabetic neuropathy
hypotension, diarrhea, impotence, urinary retention
32
What nerves can be impacted by diabetic mononeuropathy?
cranial nerve (3,6,7) or peripheral (median, ulnar, peroneal)
33
What characterizes lumbosacral plexopathy?
pelvic girdle pain,
| asymmetric hip flexor weakness
34
What nerve causes carpal tunnel?
median nerve
35
Treatment of diabetic polyneuropathy
Good metabolic control of diabetes
foot hygiene to avoid ulceration / infection
pain management - anticonvulsants, antidepressants, analgesics
autonomic symptoms
diarrhea - codeine, diphenoxylate
hypotension - fluorocortisone, midodrine
urinary retention - regular voiding, suprapubic pressure
36
Myasthenia gravis
| Ocular finding?
ptosis
| ophthalmoparesis - weakness of one or more of the external ocular muscles
37
Are jaw and neck weakness characteristic of MG?
Yes
38
MG treatment?
Tensilon (acetylcholinesterase inhibitor)
39
Thymus in MG?
Abnormal hyperplasia
40
What is MG associated with?
```
other autoimmune disorders:
Thyroid disease
RA
SLE
Pernicioius anemia
nephrotic syndrome
thrombotic thrombocytopenic purpura
```
41
Treatment of MG in addition to tensilon?
```
pyridostigmine
steroids
azathioprine
plasmapheresis targeting the ab
thymectomy
```
42
complications of MG steroid use
```
cataracts
infection
hypertension
obesity
osteoporosis
```
43
DMD - muscle biopsy findings
fibrosis
degeneration
opaque fibers
44
DMD - mutant?
dystrophin gene and protein
45
Genetic therapeutic strategies for DMD
Viral gene introduction
Exon skipping
Read through
upregulate utrophin
46
Symptoms of DMD
Progressive contractures
progressive scoliosis
restrictive breathing
47
____ diseases produce spastic tone, hyperactive tendon reflexes, and pathologic reflexes, emotional lability
UMN
48
____ disease produce muscle atrophy, fasciculations, diminished tone
LMN
49
_____ all motor neuron, neuromuscular junction, and muscle diseases have no sensory changes accompanying the weakness. Coexisting sensory complaines suggests ____
a nerve root, plexus, or peripheral nerve disorder
50
rapidly developing weakiness is characteristic of
NMJ disorders such as MG, botulism, and organophosphhate poisoning
51
organophosphate poisoning -
inhibition of acetylcholinesterase leads to buildup of acetylcholine - like in nerve gas
52
acute demyelination (GB), electrolyte disturbance, and toxic myopathies can all produce_
acute weakness
53
Neuromuscular disorders are characterized by
insidious, slow progressive weakness
54
proximal weakness is most characterisitc of
muscle disorders
55
distal weakness is most characteristic of
neuropathies
56
____ weakness affects extraocular, facial, and oropharyngeal muscles and are often seen in MG
Cranial weakness
57
limb disuse can yield atrophy but with neuromuscular disorders, msucle atrophy is accompanied by...
striking weakness
58
in addition to muscle weakness what other signs and symptoms are there of neuromuscular disorders
```
pain (myalgia)
tenderness
cramps
siffness
scoliosis
contractures
decreased tone
```
59
contracture
loss of range of motion at a join
60
Enzyme studies
muscle necrosis results in elevated levels of CK... muscular dystrophies and inflammatory myopathies have moderate elevations
61
Electrodiagnostic studies
NCS
EMG
repetitive nerve stimulation
62
NCS distinguish between
primary demyelinating (Very slow NCS) and axonal neuropathies
follow course of disease
63
Needle EMG differentiates
myopathic from neuropathic
64
How does the pattern of motor units at rest and with exertion allow for distinction between neuropathic disorders and myopathic?
neuropathic (anterior horn cell and peripheral nerve) results in loss of whole motor units while
myopathic disorders produce drop out fibers within a motor unit
65
classification by anatomical localization
| anterior horn
ALS
Spinal muscular atrophy
Poliomyelitis and WN virus
66
classifiation by anatomical localization
| radiculopathies and plexopathies
cervical and lumbosacral nerve root compression
brachial and lumbosacral plexopathies
67
classification by anatomical localization
| peripheral neuropathies
mononeuropathies
mononeuropathy multiplex
polyneuropathy
68
mononeuropathies (3)
carpal tunnel - entrapment of median nerve
ulnar nerve palsy - entrapment at elbow
peroneal palsy - entrapment at the head of the fibula
69
```
polyneuropathies
hereditary
systemic
vitamin deficient
exogenous toxins
```
hereditary - CMT
Systemic - diabetes / immune
Vitamin - B12 deficiency
exogenous - alcohol / chemo
70
```
myasthenia gravis
lambert eaton
botulism
organophosphate poisoning
all are examples of ???
```
NMJ disorders
71
myopathies
| muscular dystrophies
Duchenne / Becker
limb girdle
FSH
72
Myotonic disorders -
myotonia congenital
| myotonic dystrophy
73
polymyositis
dermatomyositis
inclusio body myositis
all are?
inflammatory myopathies
74
glycogen storage
lipid myopathy
mitochondrial myopathy
all are?
metabolic myopathies
75
what is a channelopathy myopathy example?
periodic paralysis
76
ALS
characterized by progressive weakness and wasting resulting from degeneration of brainstem and spinal cord LMNs
Coexisting spasticity and hyperreflexia caused by degeneration of UMNs
77
ALS
| etiology?
most sporadic
| 5-10% familal
78
ALS initial symptoms
asymmetric limb weakness
| fasiculuations
79
ALS sensory exam?
normal
80
degeneration of brainstem and spinal cord LMNs?
ALS
81
ALS rate of spread
| what is often spared?
unpredictable
| extraocular and facial muscles are often spared
82
CMT with slow nerve conduction velocity and pathological evidence of a hypertrophic demyelinating neuropathy
CMT type 1
83
CMT with relatively normal nerve conduction velocity and axonal degeneration
CMT type 2
84
genetics of CMT 1 and 2
Autosomal dominant
85
are CMT disorders motor or sensory
motor and sensory neuropathies
86
What causes CMT1A
Duplication of the DNA containing the peripheral myelin protein gene PMP22
87
What is caused by a deletion of PMP22
Hereditary neuropathy with liability to pressure palsy HNPP
88
Most common CMT phenotype
onset of walking is normal
| distal hand and feet weakness and sensory loss develops slowly in the first two decades of life
89
Second most common CMT phenotype
Impaired as infants and experience delayed walking - confined to WC later in life
90
Third CMT phenotype
adult onset may not appear until age 40
91
Treatment of CMT
Currently no meds reverse
| Treat symptoms and improve QOL
92
What % of diabetics have DN?
50-60
93
What is the most common cause of neuropathy in the western world
diabetes
94
what kind of neuropathy is found in diabetes
all types
95
what is the most common DN
Sensorimotor polyneuropathy
96
Sensorimotor polyneuropathy presenting symptoms in DN
Patients intially complain of numbess and buring dysesthsias in tehir feet which over time spreads up the legs and eventually into the hands
Weakness of dorsiflexor and slapping foot drop gait
Pin sensation loss in a stocking glvoe disbtribution / loss of position, vibration, and light touch as well as decreased reflexes is prominent in large fiber patterns
97
NCV in SMPN in DN
often near normal if only small fibers involved
98
does autonomic dysfunction occur in DN
It can with or without evidence for a neuropathy - postural hypotension, diarrhea, impotence, urinary retention and increased sweating are typical
99
DN
| what characterizes lumbosacral plexopathy
acute onset of asymmetrical proximal weakness and pain of the legs
100
DN mononeuropathies
| which nerves?
can affect almost any
101
Examples given of disorder of the NMJ
MG
102
What is MG?
autoimmune disorder with a post-junctional defect of the ACHR
103
Thymic involvement of MG
85% of patients of thymic enlargemnet and 10% have a thymoma
104
MG
| Sex?
more common in women in earlier decades and men later in life
105
Characteristic presentation of MG
Fluctuating weakness and fatigue in cranial, limb, or trunk musculature
ocular symptoms of ptosis / diplopia / and blurred vision are present in 50% initially and eventually 90%
106
MG
| cabeza?
facial muscles are weak and speech may become slurred, nasal and hoarse as the patient continues to speak - progressive trouble chewing and swallowing can lead to choking
107
MG
| breathing
weakness of respiratory muscles can cause SOB
108
MG repetitive nerve stimulation
may produce characteristic decremental response in the train of muscle twitches
109
MG intravenous injection of edrophonium
temproraily impoves strength bc it is a ACHterase inhibito
110
MG treatmetn
pyridostimine - oral cholinesterase inhibitor
prednisone
plasma IV exchange
Thymectomy
111
DMD and BMD
| Genetics
X linked dystrophin gene
112
```
clumbsy waddling gait from the time they first walk
protuberant abdomen
lumbar lordosis
pseudohypertrophy of calves
toe walking
Gower's maneuver
common subnormal intelligence
```
DMD
113
What is unaffected in DMD
Swallowing and eye movemnets and sensations
114
DMD COD
The combination fo weak respiratory muscles and kyphoscoliosis drastically reduces pulmonary reserve so that they succumb from respiratory and hear failure by their late teens or 20s
115
what aids in dx of DMD
markedly elevated serum CK
116
DMD
| muscle biopsy and EMG
Characteristic myopathic features
