karpatkin's class - krasilovsky - muscular dystrophies

  1. MDs - which type of fiber?
    type II - fast, phasic
  2. generally in MDs, which muscles are involved first?
    • axial & proximal
    • extensors before flexors
  3. what kind of inheritance for Duchenne MD?
    • x-linked recessive (50% are affected)
    • males get it, females are carriers
  4. DMD presentation and posture
    • enlarged calves
    • shoulder and arm weakness noted soon after leg weakness
    • hip flexion contracture, abd legs, increased lordosis, knee flexion, equinovarus
  5. DMD in WC by when?
    10-12 y/o
  6. meryon sign
    • meryon - try to lift kid by armpits...
    • gower's - kid pushing self up from floor to stand...
  7. in DMC, how does the body compensate for decreased quad strength?
  8. DMD, when does amb end?
    when hip extension lag plus knee ext lag = 90 degrees
  9. 3 biggies to stretch in DMD, and at what age to start each?
    • 2-3 y/o: hip flexors / iliopsoas
    • 3-4: heel cords / gastroc w knee straight, soleus w knee bent
    • 4: TFL (prone, hip ext w add and knee ext)
  10. 3 associated med problems w DMD
    • cardiomyopathy and respiratory
    • obesity
    • contractures
  11. post op management for MD pts (after something like a muscle lengthening to fight contractures)
    • same day: stand in long leg cast
    • next day: ambulate (bc w 3% reduction  in strength per day, can't afford a delay)
  12. Becker's MD
    how is it inherited
    • benign DMD
    • x-linked recessive
  13. Becker's MD - presentation
    proximal weakness w ambulation until mid-teen yrs

    works like DMD, but slower
  14. Facioscapulohumeral MD (FSH) inheritiance?
    autosomal dominant w strong penetrance (highly hereditary)
  15. FSH onset
    0-adulthood, but 75% are symptomatic by 20 y/o
  16. presentation of FSH - weak where? progresses where?
    • face: particularly orbicularis oculi and oris, transverse smile, can't wrinkle forehead
    • upper arms and shoulders: scap elevated, arms IR, pec M atrophy,
    • ant tib: atropy --> foot drop
    • ( and also, abdominal weakness --> increased lordosis)

    • starts w ant tib and shoulder weakness, then face, then pelvic girldle, then more distal
    • (wrist ext often involved early)
  17. scapuloperoneal / early presentation of FSH
    • shoulder weakness and foot drop are earliest signs
    • facial comes later
  18. special problem of FSH?
    sever back pain 2/2 lordosis (caused by weak abs) -- may need bracing, but can't do it while ambulatory
  19. who would need a clavicular strap
    FSH pts 2/2 serratus weakness
  20. things a pt w FSH MD may need
    • cavicular strap for scap
    • AFO for ankle (weak tib ant)
    • eye drops (dry eye 2/2 weak orbic oculi)
  21. limb girdle MD inheritance
    all types of inhertiance, but most commonly autosomal recessive
  22. limb girdl MD onset
    2nd to 3rd decade
  23. presentation of limb girdle MD
    • weak hip muscles --> gait & climbing difficulties
    • shoulder weakness - esp pecs and biceps, but Popeye arms for some reason
  24. which MD pts can get steroids
    DMD, not the others, bc they're slower progressing and you can't have someone on steroids that long
  25. limb girdle MD progression
    • slow, over decades, eventually reaching distal muscles
    • WC ~20 yrs post diagnosis
  26. special problems of limb girdle MD
    • anti-gravity muscles esp affected
    • ADL affected 2/2 difficulty reaching & rising from chair
  27. special things for limb girdle MD pts
    • raised toilet seat
    • elevating chair
    • elevate furniture
    • spring assist "cushion"
    • stair glide (chair for stairs)
  28. myotonic dystrophy inheritance
    autosomal dominant, but severity can vary in one fam
  29. onset of myotonic dystrophy
    teen yrs, give or take
  30. first sign of myotonic dystrophy, and what is it?
    myotonia: inability to relax a muscle after a contraction or stimulation -- muscle stays contracted for a few seconds
  31. presentation of myotonic dystrophy
    increases w cold or fatigue

    myotonia may present early, go undiagnosed

    • then weakness in hands, feet, facial muscles, neck flexors
    • ptosis, bland expression, temporal atrophy

    slowly involves all muscle groups ...

    bulbar, difficulty chewing, swallowing, speech
  32. special features of myotonic dystrophy
    • associated w endocrine abnormalities: pancriatic, adrenal, gonadal
    • cataracts
    • frontal balding
    • cardiac conduction defects
    • arrhytmias
Card Set
karpatkin's class - krasilovsky - muscular dystrophies
spring 2013