Dougherty Part 10

Question 1

Limb Girdle Muscular Dystrophy presents where

Answer 1

proximal muscles affected:
shoulder to humerus
thigh

Question 2

what is seen Limb Girdle Muscular Dystrophy

Answer 2

begin to walk with a waddling gait because of weak hip and leg muscles
trouble getting out of chair or climbing stairs
weakness in shoulder

Question 3

Limb Girdle Muscular Dystrophy is typically related to what

Answer 3

dystrophyn glycoprotein complex

Question 4

Facioscapulohumeral Muscular Dystrophy presents where

Answer 4

face
pecks
biceps

Question 5

Facioscapulohumeral MD presents how

Answer 5

facial weakness
wasting of the upper arms and shoulder muscles
the scapular bones look like wings when the arms are raised

Question 6

Emery-Dreifuss Muscular Dystrophy presents with what triad

Answer 6

early on humeropperoneal weakness (proximal in the upper limbs and distal in the lower limbs)
prominent contractures, especially elbows and ankles
cardiomyopathy

Question 7

what muscular dystrophy do you see cardiomyopathy

Answer 7

Emery Dreifuss Muscular Dystrophy

Question 8

what muscular dystrophy do you see a waddling gait

Answer 8

limb girdle muscular dystrophy

Question 9

what muscular dystrophy do you see the scapular bones popping out like wings when arms are raised

Answer 9

Facioscapulohumeral MD

Question 10

what issue can be elicited by percussion of the thenar eminence

Answer 10

myotonic dystophy

Question 11

what is seen in myotonic dystrophy

Answer 11

facial muscle atrophy and ptosis
myotonia (sustained involuntary contration)- stiffness, difficulty releasing grip
abnormal gait and weak foot dorsiflexion
weakness of intrinsic hand and wrist extension

Question 12

what is the issue in myotonic dystrophy

Answer 12

AD
Dystrophila myotonia-protien kinase (DMPK)
CTG repeat expansion on 19q

Question 13

what is anticipation and when is it seen

Answer 13

onset at a younger age in succeeding generations

myotonic dystrophy

Question 14

hypotonic channelopathies are due to what

Answer 14

potassium:
hypokalemic periodic paralysis
hyperkalemic periodic paralysis
normokalemic periodic paralysis

Question 15

malignant hyperpyrexia aka malignant hyperthermia is due to what

Answer 15

Calcium channel

Ryanodine Receptor RyR1 (RYR1 gene)

Question 16

what is seen in malignant hyperpyrexia and what triggers it

Answer 16

sudden hyper metabolic state with tachypnea and general muscle contraction
triggered by anesthesia (halogen containing gases or succinylcholine)

Question 17

how do you treat malignant hyperthermia

Answer 17

dantrolene

Question 18

what are the underlying processes occurring in malignant hyperpyresia

Answer 18

lactic acidosis (anaerobic metabolism)
rhabdomyolysis
hyperkalemia
renal failure
hyperthermia

Question 19

congenital myopathies may present as what

Answer 19

“floppy baby” (hypotonia)

arthrogryposis- congenital fixation of a join in an extended or flexed position

Question 20

a central light center (hole) in an area of type 1 fibers histologically is seen in what

Answer 20

central core disease

Question 21

central core disease is what and due to what

Answer 21

hypotonia

AD- ryanodine receptor-1 (RYR1) gene defect

Question 22

central core disease proposes a risk for what

Answer 22

malignant hyperthermia

Question 23

Nemaline Myopathy presents how

Answer 23

nonprogressive hypotonia, weakness
delayed development in kids
involves proximal limb muscles

Question 24

what is seen histologically in Nemaline Myopathy

Answer 24

subsarcolemmal spindle-shaped particles from Z-band (alpha-actin) material
look like purple deposits in blue cells (trichrome stain)

Question 25

Centronuclear (myotubular) myopathy is characterized by what

Answer 25

central nuclei usually confine to type 1 fibers

Question 26

what is seen in lipid myopathies

Answer 26

lipids accumulare in myocytes | RED DOTS in the cells on lipid stain

Question 27

lipid myopathies are due to what

Answer 27

defects in carnitine transport | defects in mitochondrial dehydrogenase enzyme system

Question 28

ragged red fibers are seen in what

Answer 28

mitochondrial myopathies

Question 29

mitochondrial myopathies are also known as what and is due to what

Answer 29

"oxidative phosphorylation diseases" | defect may be mtDNA or nuclear DNA

Question 30

what is seen histologically in mitochondrial myopathies aka oxidative phosphorylation diseases

Answer 30

ragged red fibers from aggregated mitochondria | mitochondria "parking lot" paracrystalline inclusions

Question 31

Dermatomyositis presents how

Answer 31

lilac or heliotrope discoloration of upper eyelids with periorbital edema scaling erythematous eruption or dusky red patches over knuckles, elbows, knees (Grotten lesions) muscle weakness +/- myalgias (slow and symmetrical)

Question 32

what are grotten lesions and when are they seen

Answer 32

seen in dermatomyositis | scaling erythematous eruption or dusky red patches over knuckles, elbows, knees

Question 33

dermatomyositis is associated with what

Answer 33

``` up to 25% have caner (paraneoplastic w/ breast and lung) juvenile DM (in addition GI involved causing abdominal pain) ```

Question 34

dermatomyositis is due to what

Answer 34

microvasculature being attacked by antibodies and compliment creating ischemia

Question 35

what is seen on bone X-rays of people with dermatomyositis

Answer 35

calcinosis

Question 36

what cells mediate Dermatomyositis

Answer 36

CD4 T-cells | B cells

Question 37

what is seen in dermatomyositis due to microvascular attack

Answer 37

inflammation of perimysial connective tissue NOT muscle telangiectasias in nail folds, eyelids, and gums perifasicular atrophy- atrophy prominent at periphery of fascicles

Question 38

what is polymyositis

Answer 38

systemic inflammatory myopathy | cytotoxic CD8+ T cells in endomysium destroy muscle

Question 39

what is seen in polymyositis

Answer 39

muscle weakness +/- myalgias (EARLY PROXIMAL muscles, late distal muscles) autoantibodies against tRNA synthetases +/- ANA positive

Question 40

Inclusion Body myositis is seen what patients and presents how

Answer 40

over 50 years old EARLY DISTAL muscles (loss of quads) +/- amyloid deposits inflammation centered on myocytes

Question 41

what cells mediate inclusion body myositis

Answer 41

CD8+ cytotoxic T cells

Question 42

what are the intracellular deposits seen in inclusion body myositis

Answer 42

beta-amyloid protein beta-pleated sheet fibrils hyperphosphorylated tau protein

Question 43

what myositis starts with proximal muscles and which one starts distal

Answer 43

polymyositis and dermatomyositis begin proximally | inclusion body myositis begins distally