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86 Cards in this Set
- Front
- Back
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4 components of a Motor Unit?
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1. Motor Neuron in BS or SC
2. Axons 3. NMJ 4. Skeletal Muscle Fibers |
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Common Sx's of Primary Myopathies?
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1. Weakness
2. Pain/Tender Muscles 3. Wasting/Atrophy 4. Myotonia |
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Types of age-specific weakness?
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Infant: delayed motor milestones
Child: Abnormal Gait Adult: Difficulty walking/getting out of chair |
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Types of Myotonia?
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Grip: can't let go
Percussion: muscles contract when handled/rubbed |
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Testing for Myopathic vs Neurogenic?
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CLINICAL
prox vs distal symmetrical/diffuse vs focal atrophy vs hypertrophy Tone, Reflexes |
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When will there be hypertonia and hyperreflexia?
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ALS cause it hits UMN's too
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What type of hypertrophy occurs?
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not real
Pseudohypertrophy via fat |
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Labs to watch?
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Creatinine Kinase (CK) is increased with acute damage
Autoantibodies are increased w/ certain diseases |
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Change in muscle fiber shape with myopathic or neurogenic disorders?
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Myopathic: small round fibers
Neurogenic: small angulated fibers |
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what happens to nuclei of muscle fibers when there is a disorder?
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Nuclei are internalized
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What are the special histo stains?
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Gomori Trichrome
PAS Oil Red O |
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What can you see with Gomori?
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Ragged Red fibers
Rimmed Vacuoles |
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What can you see with PAS?
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abnormal glycogen accumulations
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What can you see with Oil Red O?
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Abnormal Lipid Accumulation
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Enzymes tested with stains?
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ATPase -pH 4.3 and 9.4
Mitochondria oxidative Esterase Myophosphorylase |
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Two Types of Muscle Fibers
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Type I-slow twitch
Type II - fast twitch |
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TYPE I VS TYPE II
energy/metabolism? |
Type I = high
Type 2 = low |
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TYPE I VS TYPE II
Mitochondria? |
Type I - Many
Type 2 - Few |
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TYPE I VS TYPE II
lipid content? |
Type I - High
Type 2 - Low |
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TYPE I VS TYPE II
glycogen level: |
Type 1: low
Type 2: High |
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Who is dark with a ATPase pH 4.3 stain?
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Type I
slow twitch |
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What is up with Neurogenic Atrophy?
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Degeneration of LMN (in ant horn of SC or their axons)
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Neurogenic Atrophy
Causes? |
Adults: ALS, Some peripheral neuropathys (Diabetes), Spinal Muscle Atrophy III
Kids: SMA Types I/II |
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what is the difference between type grouping and group atrophy?
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Type Grouping means the loss of a motor neuron(e.g. type 2) leads to the reinnervation by another motor neuron (maybe Type 1) which can alter the Types of fibers
Group atrophy just means a whole group of usually the same type of fiber atrophies secondary to loss of its motor neuron |
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What's the unique progression with Neurogenic Atrophy?
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There is denervation followed by reinnervation
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SPINAL MUSCULAR ATROPHY
onset? |
childhood/adolescence
intellect normal, |
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SPINAL MUSCULAR ATROPHY
Etiology |
Auto Recessive disorder of Anterior Horn Cells causing them to die off
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SPINAL MUSCULAR ATROPHY
genetics? |
Chromosome 5: SMN1 gene del or mut in 90%
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SPINAL MUSCULAR ATROPHY
Types? |
SMA-1
SMA-2 SMA-3 |
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SPINAL MUSCULAR ATROPHY
Other name for type I |
Werdig Hoffman
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SPINAL MUSCULAR ATROPHY
other name for type III? |
Kugelberg-Welander
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SPINAL MUSCULAR ATROPHY
Comparison of onset of different types? |
I = birth to 4 months
II = <18 months III = any age |
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SPINAL MUSCULAR ATROPHY
more severe type? |
I
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SPINAL MUSCULAR ATROPHY
Clinical Fts of Werdig Hoffman? |
< in utero movements
Hypotonia Poor Feeding Poor Resp Floppy Baby |
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SPINAL MUSCULAR ATROPHY
Clinical Fts of Type II |
No Standing
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SPINAL MUSCULAR ATROPHY
Clinical fts of III? |
Stand Independently
but w/ frequent cramps |
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SPINAL MUSCULAR ATROPHY
compare lifespans? |
I: birth to 4 months
II: >4years III: adulthood |
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DDX of neurogenic atrophy?
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Myopathy (rounded fibers)
Ischemic (contiguous area) Peri-fascicular Atrophy: dermatomyositis Type II Fiber Atrophy: disuse, steroids |
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What type of steroids can cause atrophy?
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Corticosteroids
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What are the types of Type II Atrophy?
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Endogenous (cushing's)
Exogenous (Prednisone Rx) |
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Type II Atrophy vs Neurogenic Atrophy
Fibers affected? |
Type II: just type II
Neurogenic: both |
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Type II Atrophy vs Neurogenic Atrophy
Grouping? |
II: no
Neurogenic: yes |
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Type II Atrophy vs Neurogenic Atrophy
Esterase? |
II: negative
N: positive |
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Type II Atrophy vs Neurogenic Atrophy
Target Fibers? |
II: absent
N: present |
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General Types of Primary Myopathies?
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Inflammatory
Toxic Congenital Metabolic Mitochondrial Disorders Muscular Dystrophies |
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Main Pathological Findings w/ Primary Myopathies?
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Central Nuclei
Split Fibers Regenerating (blue) fibers Size variation Necrotic fibers |
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Types of Inflammatory Myopathies?
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Autoimmune
Infectious |
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Types of Autoimmune Inflammatory Myopathies?
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Polymyositis
Dermatomyositis Inclusion Body Myositis |
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Types of Infectious Inflammatory Myopathies?
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Viral- including HIV
Parasitic (trichinella spiralis) |
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POLYMYOSITIS
Kickers |
Associated with other autoimmune disorders (e.g. SLE)
Mech: Cytotoxic T's |
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DERMATOMYOSITIS
KICKERS |
Heliotrope Rash
Associated with malignancies (ovarian in 15%) AB mediated Vasculitis and Perifascicular Atrophy CD4 T's, B's, and C' on cells |
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Inclusion Body Myositis
Kickers |
Distal Weakness
Neurogenic Component CD8 T's Rimmed Vacuoles Amyloid and Tau deposits Only one that doesn't respond to steroids |
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General Autoimmune Myositis Characteristics?
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Proximal, Symmetric Weakness
Subacute (wks to months) Increased CPK Myoglobinuria |
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Histopath of Polymyositis?
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Endomysial Inflammation (lymphocytes)
Necrotic Fibers End Stage changes (fat and necrosis) |
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Histopath of Dermatomyositis
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Perivascular, endomysial infl
Perifascicular atrophy CD4-T's C' on vessels |
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Histopath of Inclusion Body Myositis?
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Rimmed Vacuole
Beta-Amyloid in rimmed Vacuole=no regeneration |
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Types of Muscular Dystrophy?
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Duchenne's**
Becker's** Limb Girdle MD Fascio-scapulo-humeral MD Congenital Myopathy Myotonic Dystrophy |
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What is messed up in Duchenne's and becker's?
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Dystrophin
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What is messed up in Limb-Girdle?
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Sarcoglycan
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What is messed up in Congenital MD?
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Merosin (laminin2)
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Inheritance of Duchenne's and Becker's?
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X-linked recessive
1/3 have new onset mutations |
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Difference between duchenne's and becker's?
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duchenne's=no dystrophin
becker's = decreased dystrophin |
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General Sx's for D and B?
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Proximal Muscle Weakness
Often Symmetric Later on Cardiac Dysfxn Intial High CPK |
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Sx's of Duchenne's?
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Delayed Motor Milestones
Gower's sign Pseudohypertrophy of calves (due to fatty replacement) Wheelchair by teens Death in late teens due to cardiac/resp dysfxn or infections |
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Sx's of Becker's?
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Onset later in childhood
Slow progression Some normal lifespan, some cardiac dysfxn |
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Appearance of fibers in X-linked MD?
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Lots of variable size due to hypertrophy of healthier fibers
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Mitochondrial Myopathy
etiology? |
Mutations in mito DNA (maternal inheritance)
Mutations in Nuclear DNA (Auto dom/rec) Deletion/Duplication of Mito DNA |
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Mitochondrial Myopathy
Specific diseases caused by Mutations of Mito DNA |
MELAS = mitochondrial encephalo-myopathy w/ lactic acidosis and stroke-like syndrome
MERRF = Myoclonic Epilepsy w/ Ragged Red Fibers |
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Mitochondrial Myopathy
Specific diseases caused by Mutations of Nuclear DNA? |
Leigh Syndrome
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Pathogenesis of Leigh?
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Subacute Necrotizing Encephalopathy
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Who is caused by a deletion/duplication of mito DNA?
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Opthalmoplegia (Kearns-Sayre syndrome)
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METABOLIC MYOPATHY
types? |
GLYCOGEN METABOLISM
Lysosomal Cytoplasmic LIPIDS |
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METABOLIC MYOPATHY
Lysosomal Example? |
Pompe's glycogenosis Type II:
acid maltase deficiency |
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METABOLIC MYOPATHY
Pompe's Sx's? |
Infants: floppy babies, cardiac and liver failure, hypotonia, death<1yr
Teens/adults: Limb Girdle-->looks ok, but tires easily |
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METABOLIC MYOPATHY
Cytoplasmic example? |
McArdle's glycogenosis Type V:
Phosphorylase issue? |
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METABOLIC MYOPATHY
McArdle's Sx's? |
Mild Disease: suck at sports, cramps, rhabdomyolysis
Glycogen bumps beneath sarcolemma |
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METABOLIC MYOPATHY
McArdle's Rx? |
Oral Sucrose before exercise
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METABOLIC MYOPATHY
Lipid Myopathy pathology? |
Defect/Deficiency of component of Beta-Oxidation Pathway
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CONGENITAL MYOPATHY
kickers? |
Floppy Baby
TYPE I ATROPHY |
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Who are the NMJ disorders?
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Myasthenia Gravis
Lambert-Eaton Myasthenic Syndrome |
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MYASTHENIA GRAVIS
Etiology? |
Autoimmune
AB's to acetylcholine receptors |
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MYASTHENIA GRAVIS
histopath? |
minimal
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MYASTHENIA GRAVIS
gender and age |
any age
more females |
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MYASTHENIA GRAVIS
early involvement? |
Eye muscles-->ptosis, diplopia
Face and Neck muscles-->difficultly chewing, head holding, nasal speech |
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MYASTHENIA GRAVIS
Dx? |
Repetitive Nerve Stimulation: decremental response
Edrophonium (ACE inhibitor) Testing |
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Lambert-Eaton Myasthenic Syndrome differences from MG?
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AB's to presynaptic side of NMJ
Associated with neoplasm (Small cell carcinoma of lung) Ptosis Rare Repetitie Nerve Stimulation: incremental response |
