Myopathies Flashcards Preview

Neuro > Myopathies > Flashcards

Flashcards in Myopathies Deck (86):
1

Neurologic Ddx of weakness

-UMN
-LMN
-NMJ
-muscle

2

Three major groups of myopathies

1) muscular dystrophies
2) inflammatory myopathies
3) metabolic myopathies

3

What are "dystrophic" features of muscles?

1) fiber splitting
2) increased CT

4

Five major muscular dystrophies

1) Duchenne
2) Becker
3) FSH
4) Myotonic
5) Limb Girdle

5

Two minor muscular dystrophies

1) Emery Dreifuss
2) Oculo-pharyngeal muscular dystrophy

6

What are the inheritance patterns of the major muscular dystrophies?

Duchenne and Becker- XR
FSH and myotonic- AD
Limb Girdle- Can be AD vs AR on multiple chromosomes

7

Duchenne/ Becker chromosome

21 deletion

8

FSH assc chromosome?
Myotonic assc chromosome?

FSH- 4
Myotonic- 19

9

When do the major muscular dystrophies onset?

Duchenne and Becker: early (5-10 years old)
Others: 10-30 years of age

10

Where is primary weakness in Duchenne/ Beckers?

pelvic region first

11

Where is primary weakness in Myotonic dystrophy?

-distal

12

Which muscular dystrophies involve the face?

-FSH, myotonic
-Later in disease Duchenne, Becker
-None in limb girdle

13

What EKG abnormality is seen in muscular dystrophies? Which major dystrophy is an exception?

Deep narrow Q waves in L precordial leads
(except FSH which has normal EKG)

14

Which of the muscular dystrophies have elevated CK?

Duchenne, Becker, Limb Girdle
(Normal in FSH, myotonic)

15

Duchenne:
-biopsy appearance
-specific gene involved

-macs invade necrotic muscle fibers, missing dystrophin on stain
-dystrophin out of frame mutation

16

Contrast Duchenne mutation w/ Beckers

Duchenne: out of frame mutation
Beckers: in frame mutation

17

Classic symptomatic features of DMD:

-waddling gait
-lumbar lordosis
-calf pseudohypertrophy

18

Life threatening complications of DMD (2)
+ life expectancy

-cardiomyopathy
-intestinal pseudo-obstruction

(death by cardiorespiratory failure around age 20)

19

Treatment for DMD

No cure, can prolong course with steroids if started at 4-7 years of age.

(stabilizes sarcolemma, increases muscle mass)

20

Female DMD carrier symptoms

mild compared to diseased males
-risk CVD, weakness, cognitive/behavioral issues
-myalgia, ^^CK/ aldolase are are possible

21

Beckers:
-life expectancy
-onset

-live beyond 30 (DMD death by 20)
-Does not onset until ~12 years
-less likely to have complications outside of weakness

22

FSH:
-muscle groups involved
-life expectancy

-facial
-scapular
-humeral
-peroneal

-normal life expectancy

23

Clues to FSH on exam

-down sloping shoulders
-winged scapula
-prominent clavicles

24

Contrast Myotonic Dystrophy types 1 and 2

-Type 1: Distal weakness, common
-Type 2: Proximal, rare

25

Gene assc with MD1

CTG repeat at DMPK gene
(Cats Throw Goldfish) and (Dumb Mammals Punch Kids)

26

MD1:
-personality
-assc findings (6)

-avoidant personality

-early cataracts
-hypersomnia
-hypogonad
-ID
-insulin resistance
-cardiac arrhythmia

27

What muscle groups are atrophied in MD?

-face
-neck
-finger

28

"Limb Girdle" refers to what part of the body?

hip and shoulders

29

What proteins are most common disordered in LGMD?

-sarcolemmal proteins

30

Typical course of LGMD

-slow
-symmetric
-proximal

31

What are the two types of LGMD?

-LGMD1 dominant
-LGMD2 recessive

32

Emery Dreiffus Types 1 and 2:
genetic defect

Type 1: Emerin mutation, Recessive
Type 2: Lamin A/C mutation, may be dominant or recessive

*alphabetic order (1 emerin --> 2 lamin)

33

What ED type is assc with contractures and cardiac abnormalities:?

-ED1

34

Oculopharyngeal Muscular Dystrophy:
mutation

-AD mutation in PABN1 (GCG) or PABN1 (GCA)

**Gag Cough Gag or Gag Cough Aspirate

35

OPMD Clinical Features

-Ptosis
-EOM weakness
-Dysphagia
-Reduced Gag

36

Treatment OPMD

-oculoplasty
-PEG

37

What are the three inflammatory myopathies?

-dematomyositis
-polymyositis
-inclusion body myositis

38

Which inflammatory myopathy is assc with rash and responds to steroids?

DERMATOmyositis

39

Distribution of weakness in Inflammatory myopathies:

-proximal in dermatomyositis and polymyositis
-distal and proximal/ assymetric in inclusion body

40

Which of the three inflammatory myopathies has an unequal sex distribution?

-Inclusion body is more common in males
-dermato and poly are either more common in female or equal (her slides are contradictory)

41

Which of the two inflammatory myopathies may be assc with cancer?

-dermato vs poly myositis

42

Three tests for inflammatory myopathies:

-CK
-EMG
-Biopsy

43

CK findings in the three inflammatory myopathies

-^^ in dermato/polymyositis
-may or may not be elevated in inclusion body myositis

44

EMG/ NCS findings in inflammatory myopathies

-myopathic in all three
-also neuropathic in inclusion body

45

Biopsy findings for:
-dematomyositis
-polymyositis
-inclusion body myositis

-dermatomyositis: perifasicular atrophy
-polymyositis: inflammatory (endomysial inflammation) v normal
-inclusion bodies: bodies + rimmed vacuoles

46

Which of the inflammatory myopathies may be seen in children?

-dermatomyositis
(also seen in 40+)
-poly in adults
-inclusion body in elderly

dermato --> poly --> inclusion body

47

What is a sign of proximal muscle weakness?

difficult standing from seated position or trouble lifting arms above head

48

Polymyositis treatment

-immunosuppression

49

Why might dermatomyositis be more common in women?

assc with breast and gyne cancers
(also lung)

50

Describe dermatomyositis rash

-Grottons sign (rash at hands)
-helipotrope (rash at eyes)
-also cape like distribution rash

51

In addition to weakness and rash, what are features of dermatomyositis?

-cardiorespiratory involvement

52

Inclusion Body Myositis:
muscle groups involved

finger and wrist flexors
quads

53

Treatment Inclusion Body Myositis

Poor response to steroids/ immunosuppression

54

What systems are altered in metabolic myopathies? What is the typical inheritance pattern?

glycogen metabolism
lipid metabolism
electrolyte imbalance
mitochondria

AR

55

What are the four glycogenoses + their assc enzymes

-McArdles (=myophosphorylase)
-Pompes (=acid maltase)
-Tauri (= PFK Def)
-Cori-Forbes (debrancher deficiency)

56

Two lipidoses leading to myopathies

-carnitine deficiency
-carnitine palmitoyl transferase deficiency

57

Four Channelopathies leading to myopathies

1) hyperkalemic perioidic paralysis
2) hypokalemic PP
3) Myotonia congenita
4) Paramyotonia congenita

58

Three mitochondrial myopathies

-Kearns Sayre
-MERRF
-MELAS

59

Characteristic of weakness in glycogenoses/ lipidoses

exercise intolerance

60

Diagnoses of glycogenoses/ lipidoses?

-myoglobinuria following exercise
-elevated CK
-EMG myopathies featuers
-biopsy (biochemical analysis)

61

What are types II, III, V, VII glycogen storage diseases?

II- Pompes
III- Cori/Forbes
V- McArdles
VII- Tauri

PLEASE CUT MY TAG! = 2 3 5 6

62

Pompes (II, acid maltase) 2 characteristics

1) fixed proximal weakness
2) early cardiorespiratory insufficiency (Pompes effects the pump-heart)

63

Cori-Forbes (III, debrancher) 2 features

1) distal weakness
2) cardiomyopathy

64

McArdles (V, myophosphorylase) 3 features

1) cramps
2) myoglobinuria
3) second wind phenomenon

65

Tauri Disease (VII, PFK Def) 2 characteristics

1) exercise intolerance
2) myoglobinuria
(true of most glycogen storage diseases....)

66

Lipid Storage disease:
-when are symptoms worst?
-biopsy findings?

-flares with fasting
-lipid storage vacuoles

67

Four features of lipid storage disease?

-proximal weakness
-swollen muscles w/ exercise
-high CK
-myoglobinuria

68

Channels involved in hypokalemic and hyperkalemic periodic paralyses

-hypo: L type Ca Channel
-hyper: SCN4A (Na) Channel

69

Contrast weakness in hyper/hypokalemic PP:

-hypo: lasts hours- days
-hyper: relieved quickly by eating or exercise

both occur after rest following carb load or exercise

70

Channels involved in myotonia congenital/ paramyotonia congenital

-myotonia: CLCN1- hypertrophy
-paramyotonia: CLCN1 or SCN4A

71

What triggers paramyotonia congenital?

-exercise
-cold

72

Mitohondrial myopathies:
-deficiency of ____
-two organ systems most effected
-inheritance pattern

-ATP
-brain, muscle
-maternal

73

Biopsy findings in mitochondrial myopathies

ragged red fibers

74

Provoked necrotizing polymyopathy is also known as?

-rhabdomyolsis with myoglobinuria

75

Cause of provoked necrotizing polymyopathy

crush injury
extreme exertion

76

Who is most susceptible to necrotizing polymyopathy?

glycogen disorders

77

Defect in phosphodiesterase makes patient susceptible to?

Malignant hyperthermia

78

What anesthetics should be avoided in RYR1 mutation?

-halothane
-succinylcholine

79

What are four systemic illnesses that may lead to myopathy?

-hypothyroid
-critical illness
-acromegaly
-cushings

80

Muscle biopsy findings in critical illness myopathy

loss of myosin

81

Acromegaly/ Cushings:
distribution of weakness

-proximal

*Cushings mainly of lower extremities

82

Common feature of hypothyroid + critical illness myopathy

-loss of DTRs

83

EMG findings in myopathies

1) low amplitude
2) short duration
3) polyphasic + rapid recruitment

84

Six meds that cause myopathy

1) steroids
2) statins
3) AZT
4) colchicine
5) chloroquine
6) rifampin
(Some Sucky Asians Cant Cook Rice)

++ alcohol

85

Why do statins lead to myopathy?

-inhibit synthesis of mevalonic acid = no coenzyme Q needed for ATP production

86

Myopathy type assc with AZT

mitochondrial