Neuromuscular Jxn and Myopathy Flashcards

1
Q

Baclofen

A

GABA 8 Receptor agonist

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Anterior horn cells

A

Stimulated by Glutamate

Inhibited by GABA and Glycine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Glutamate is broken into GABA

A

By enzyme:
Glutamate Decorboxylase (GAD)
GAD65 Ab blocks this enzyme in stiff person syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Tetanus

A

Blocks the release of presynaptic GABA and Glycine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

NeuroMyotonia

A

Voltage gated K+ channel antibodies
Myokymia is charachteristic
(another pathognomonic Myokymia was XRT induced Plexopathy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Pre-Synaptic Toxins

A

Magnesium/Mg: Blocks Ca++ Channels
Botulinum: Blocks Ach release
Lathrotoxin (Black Widow): Excessive release of Ach
Tick Paralysis: Blocks Ach realease
Scorpion Venoum: Causes Ach release
B-Bungarotoxin (Snake Venoum): Inhibits Ach release

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Post Synaptic Toxins

A

Curare: Binds nicotinic Ach receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Organophosphatase Poisoning

inhibts acetylchilnestrase so there is too much Ach

A

Leading cause of death:
Bronchospasm and Bronchorrhea
DUMBELLSS:
Diarrhea, Urination, Miosis, Bradycardia, Bronchospasm, Emesis, Lacrimation, Lethargy, Salivation, Seizure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

AntiCholinergic symptoms
Usually Drug side effect
(Reduced Ach)

A

Antihistamines, antipsychotics, antidepressants, antiparkinsonian drugs, Atropin, Benztropin, Scopolamine

Blurry vision, Hallucination/Delirum, Mydriasis, Ileus, Urinary retention, Flushing, Hyperthermia
Blind as a Bat, Mad as a Hatter, Red as a Beet, Hot as a Hade, Dry as a bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Meds Absolutely Contraindicated in MG

A

D-Penicillamine
Curare
Botulinum Toxin
Interferon-alpha

Neomycine and Quinine are contraindicated.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Myopathies with Normal CK

A

Steroid Myopathy
Hyperthyroid Myopathy
Mitochondrial Myopathy
Chanelopathies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Myopathies with Markedly elevated CK

A

Dystrophionopathies
Myoshi distal myopathy
Rhabdo, malignant hyperthermia and NMS
Polymyositis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

X-Linked Myopathies
Men only
Gower’s Maneuver when standing (may show video or pic)

A

Duchenne’s: Dystrophin is completely absent. Very severe disease. Death by late teens to 20 y.o

Becker’s: Dystrophin very reduced. Death by 30-60’s

Emery-Dreifuss: Emerin Deficiency. Joint contractures; mostly arms and shoulder. Elbow contracture is pathognomonic for ABPN.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Autosomal Dominant Muscular Dystrophies.

A

FSHD: face and winged scapula. Popeye appearance (Deltoid and Bicep spared). Big wide eyes, pouting mouth.

Oculopharyngeal muscular Dystrophy: French Canadian descent. Ptosis and Dysphagia. No other eye symptoms. If Ptosis and Diplopia think MG

Limb Girdle Muscular Dystrophy (LGMD):
LGMD type 1 is AD
LGMD type 2 is AR

Myotonic Dystrophy (DM1) Type 1: CTG repeat. Long face, Temporal wasting, frontal balding, Myotonia (grabs door handles and can’t let go. CARDIAC COMPLCATIONS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Autosomal Recessive MD’s

A

LGMD type 2: accounts for 60% of Distal Myopathies

MD2: much less common than MD1. Milder and no cardiac complications

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Distal Myopathies

A

LGMD type 2
Myotonic muscular Dystrophy
Inclusion Body Myositis

17
Q

Myotonia congenita

A
Chloride Channel disorder.  
Get stiff with sitting for a while (Rusted Tin man)
Onset age 4-12 yo
AD form is milder
AR form is more severe
18
Q

Pompe’s

A

Acid Maltase Deficiency
Glycogen storage disease

Mostly a child disoder but:

in Adult: SOB, Proximal Weakness, and Myotonic discharges in Paraspinal muscles (this is the giveaway)
It leads to respiratory failure in adults. It’s a Neurologic emergency.

TX: IV alpha-Glucosidase

19
Q

Myotonia

A

Improves with Repetition/exercise

20
Q

Para Myotonia Congenita

A

Face muscles; usually eyes
Myotonia worsens with repetition.
Video of patient closing her eyes and can not open anymore; it’s stuck
Worsens with Cold and Hyperkalemia

21
Q

Imitermittent Myopathies

A

Familial Hyperkalemic Periodic Paralysis. AD. Na+ Channel
Familial Hypokalemic Periodic Paralysis. AD. Ca++ Channel
Myophosphorylase Deficiency (McArdle’s dz)
Carnitine Palmityl Transferase Deficiency

22
Q

HyperK PP
AD
Ca++ channel

A
Children, 
paralysis minute to hours, 
Progression variable, 
Insulin Helps
Treated  HIGH Carb diet
EMG=Myotonia
23
Q

HypoK PP
AD
Na+ Channel

A
Adolescent, 
Paralysis hours to days
Progressive weakness in adulthood
Insuline Aggrevates
Treated with LOW Carb diet
EMG NO myotonia
24
Q

MyoPhosphorylase Deficiency

McArdle’s disease

A

Weakness and pain with exercise (hits a wall/Barrier)
improve with rest
Gets a second wind

25
Carnitine Palmityl Transferase deficiency
Myoglobulinuria post exercise in fasting state Young guy, may be army, forced march without breakfast has severe weakness and very high CK May be also triggered with Cold and Meds (Advil, Diazepam, general anesthetics)
26
Ophthalmoplegic Myopathies
Kearns-Sayre Syndrome: Mitochondrial Ophthalmoplegia; Hearing Loss Characteristic feature: Retinits Pigmentosa and Heart Blocks ``` Progressive External Ophthalmoplegia: Mitochondrial Ophthalmoplegia Ptosis Hearing loss Similar to MG BUT NO Diplopia ```
27
Dermatomyositis
Painful, Rash, and Muscle weakness (Rash on face, chest, hands, but Elbow knockles, knees are typical because not seen in Lupus) EMG: small motor units Can be a/w Breast Ca Anti Jo-1 Ab: Indication of Interstitial lung dz
28
Dermatomyositis Histology
PeriFascicular atrophy/inflammation | CD4 predominant
29
Polymyositis Histology
Endomysial inflammation | CD8 predominant
30
Polymyositis
Painless muscle weakness the more severe the pain, the less likely it is Polymyositis Woman 40-60 may be a/w viral prodrome
31
Inclusion Body Myositis
Most common Myopathy in >50 yo Distal muscle weakness and atrophy (Hands/feet) NO FASICULATION, NO HYPERREFLEXIA (DDX with ALS due to the hand atrophy) Rimmed Vacuoles and inclusion bodies on biopsy