MDs - which type of fiber?
type II - fast, phasic
generally in MDs, which muscles are involved first?
- axial & proximal
- extensors before flexors
what kind of inheritance for Duchenne MD?
- x-linked recessive (50% are affected)
- males get it, females are carriers
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
DMD in WC by when?
- meryon - try to lift kid by armpits...
- gower's - kid pushing self up from floor to stand...
in DMC, how does the body compensate for decreased quad strength?
DMD, when does amb end?
when hip extension lag plus knee ext lag = 90 degrees
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)
3 associated med problems w DMD
- cardiomyopathy and respiratory
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)
how is it inherited
- benign DMD
- x-linked recessive
Becker's MD - presentation
proximal weakness w ambulation until mid-teen yrs
works like DMD, but slower
Facioscapulohumeral MD (FSH) inheritiance?
autosomal dominant w strong penetrance (highly hereditary)
0-adulthood, but 75% are symptomatic by 20 y/o
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)
scapuloperoneal / early presentation of FSH
- shoulder weakness and foot drop are earliest signs
- facial comes later
special problem of FSH?
sever back pain 2/2 lordosis (caused by weak abs) -- may need bracing, but can't do it while ambulatory
who would need a clavicular strap
FSH pts 2/2 serratus weakness
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)
limb girdle MD inheritance
all types of inhertiance, but most commonly autosomal recessive
limb girdl MD onset
2nd to 3rd decade
presentation of limb girdle MD
- weak hip muscles --> gait & climbing difficulties
- shoulder weakness - esp pecs and biceps, but Popeye arms for some reason
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
limb girdle MD progression
- slow, over decades, eventually reaching distal muscles
- WC ~20 yrs post diagnosis
special problems of limb girdle MD
- anti-gravity muscles esp affected
- ADL affected 2/2 difficulty reaching & rising from chair
special things for limb girdle MD pts
- raised toilet seat
- elevating chair
- elevate furniture
- spring assist "cushion"
- stair glide (chair for stairs)
myotonic dystrophy inheritance
autosomal dominant, but severity can vary in one fam
onset of myotonic dystrophy
teen yrs, give or take
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
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
special features of myotonic dystrophy
- associated w endocrine abnormalities: pancriatic, adrenal, gonadal
- frontal balding
- cardiac conduction defects