neuromuscular disorders in children Flashcards
describe lower motor neurons
starts from anterior horn cells in spinal cord
comprised of cell bodies and axons all the way to NMJ
carries on to the muscle fibres
when to suspect neuromuscular disorders
- baby floppy from birth
- slips from hands when you pick them up
- lack of spontaneous limb movements
- alert infants but less motor activity
- delayed motor milestones
- able to walk but frequent falls and clumsiness
what is the gower’s sign
indicates weakness in proximal hip muscles - pelvic girdle and lower limb weakness
lie on back up then get up as quickly as possible - process of getting up in photo
what does Gower’s sign indicate
Duchenne muscular dystrophy
what causes Duchenne muscular dystrophy and who does it occur in
1/ 3500 male infants
Xp21 - dystrophin gene (x linked)
features of Duchenne muscular dystrophy
delayed motor skills and may walk late
symmetrical proximal weakness - waddling gait, calf hypertrophy, Gower’s sign +ve
elevated creatinine kinase levels - >1000
cardiomyopathy
resp involvement in teens
evidence of muscle weakness in Duchenne muscular dystrophy
facial muscle weakness - myopathic facies
- lack of muscle tone and power around the mouth
- open mouth and tented lip appearance
- drooped eyelids
- can’t maintain head control
what is myotonia
inability for the muscle to relax after contraction
what is Charcot-Marie-Tooth disease
- lack of muscle in feet, high arch, claw toes
- hereditary motor-sensory neuropathy
anatomical approach to neuromuscular conditions
- where is the site of the lesion
- what is the lesion
- muscle: muscular dystrophies, myopathies - congenital and inflammatory, myotonic syndromes
- NMJ: myasthenic syndromes
- nerve: hereditary or acquired neuropathies
- anterior horn cell: spinal muscular atrophy
neuropathy vs myopathy
NEUROPATHY:
- site of weakness: distal
- sensory: may have concomitant sensory symptoms and signs
- reflexes: lost early
- fasciculation: may be present
- contractures: not a feature
- myocardial dysfunction: not a typical feature
MYOPATHY:
- site of weakness: usually proximal
- sensory: usually pure motor
- reflexes: preserved till late
- fasciculation: not typical
- contractures: present
- myocardial dysfunction: may can accompanying cardiac dysfunction w/ muscle dystrophies