Neuromuscular Disorders Flashcards
Symptoms of neuromuscular disorders?
progressive weakness, muscle atrophy, contracture, deformity, and progressive disability
Goals of PT in neuromuscular disorders:
prevent deformity prolong functional capacity improve pulmonary function facilitate development and assistance of family support control pain
When is the onset of Duchenne, DMD?
1-4 years
rapid progression
When is the loss of walking in Duchenne DMD?
9-10 years
death in late teens
Average IQ in Duchenne?
average IQ 85, 30% of boys have IQ<70 related to loss of dystrophin in brain.
Onset of Becker, BMD?
onset 5-10 years
slowly progressive
Function in Becker, BMD?
walking maintained past early teens, survival into 30’s
Congenital MD:
birth, variable progression, shortened life span
Congenital myotonic MD:
birth, slow progressions, significant intellectual impairment
What lab tests are evaluated with diagnosis of MD?
high serum creatine kinase, CK level
Primary impairments in MD:
insidious muscle weakness secondary to progressive loss of myofibrils
Secondary impairments in MD:
contractures and postural malalignment in sitting and standing, scoliosis, decreased respiratory capacity, easily fatigued, occasional obesity; increasing caregiver assistance for ADL
Clinical Presentation
Children with MD
Symptom onset 2-5 yrs., diagnosed 5 yrs.
Early proximal muscle weakness
Posture of children presenting with MD:
Increased lordotic posture with mild scapular winging to keep COM behind hip joint for standing stability.
Scoliosis typically develops just before or during adolescence
Pseudohypertrophy
enlarged posterior calf due to infiltration of fatty and connective tissue
Gait of children presenting with MD:
broad BOS, waddling
delayed until 18 months- 50% of children
PT in early symptom management:
Baseline strength, ROM data, monitor progression of muscle weakness.
Family support and education.
Address activity level, peer interactions, prognosis, coping support (family-centered care).
Where is muscle weakness in early staged in MD?
progressive, proximal muscles weaker early, progress faster
Where do contractures usually develop in MD?
in plantar flexion and inversion of the foot, the hip and knee flexion contractures worsening with w/c use
Where are early limitation in ROM in early stages of MD?
hamstrings, hip flexors, ITBs, and heel cords; contractures of hips and knees with increased time sitting
Gowers sign
use of arms to push on thighs to attain standing from floor
Symptoms in early school age period in MD:
initial evidence of disability, functional activities slower.
clumsiness, falling, inability to keep up with peers
Gait in early school age period in MD:
mildly atypical gait, increased lateral trunk sway (waddling) that increases with running attempts
increase size of gastrocnemius muscles, ‘pseudohypertrophy’.
When are children with MD most likely to lose independent ambulation?
by 9-10 years
Gait deviations of MD:
Exaggerated lumbar lordosis – weakness of hip and knee extensors.
Gait deviations: increased BOS, pronounced lateral trunk sway, toe walking, shoulder retraction with lack of reciprocal arm swing
Functional Grade 1
walks and climbs stairs without assistance
Functional Grade 2
walks and climbs stairs with the aid of railing
Functional Grade 3
walks and climbs stairs slowly (>12 sec, 4 stairs) without railing
Functional Grade 4:
Walks unassisted and rises from chair, cannot climb stairs.
Functional Grade 5:
Walks unassisted but cannot rise from chair or climb stairs.
Functional Grade 6:
Walks only with assistance or walks independently with long leg braces
Functional Grade 7:
Walks in long leg braces, but requires assistance for balance.
Functional Grade 8:
Stand in long leg braces, but is unable to walk even with assistance
Functional Grade 9:
uses a wheelchair
Functional Grade 10:
confined to bed
10 Meter walks test greater than 12 seconds:
predictive of loss of ambulation within 1 year
What do sitting to standing transitions predict?
inability to transition predicts LOA within 2 years
Muscle groups targeted for strengthening
Abdominals
Hip extensors and abductors
Knee extensors
Exercises to avoid:
Avoid high resistance and eccentric exercise.
Participation in endurance exercises, e.g., cycling and swimming for overall conditioning, standing or walking daily (2-3 hours).
Home stretching program:
1-2 times daily, slow, pain free stretch 5-10 repetitions, 10 sec hold, 10 minutes.
Characteristics of pre-adolescent period:
8-10 years of age - increasing falls, c/o fatigue require guarding during walking, stair climbing
wheelchair fitting
difficulty standing
Why is there difficulty standing in pre-adolescent period?
inability to maintain COG behind hip or in front of knee due to hip extensor and quadriceps weakness.
Characteristics of adolescent period:
Increased difficulty with transfers; instruct in body mechanics, safety
Significant progression of disability, trunk weakness > loss of sitting balance
loss of walking by 10-12 years
Indications for surgery:
Ankle plantar flexion contractures >10°
ITB contractures >20° but <45°
Posterior tibialis transfer for equinovarus foot.
Segmental spinal instrumentation early may improve sitting posture and alignment, quality of life
Post-surgery PT:
standing in casts
gait training as tolerated
conditioning exercises for hips, trunk, UE’s
breathing exercises
Sciolosis:
50% prevalence in 12-15 year-olds, 90% by 17 years
Key muscles to maintain strength for transfers
Shoulder depressors, triceps – self-feeding, hygiene.
Shoulder flexors and abductors, elbow flexors
Spinal Muscular Atrophy
Rare, autosomal recessive genetic defect on chromosome 5q13.
Abnormality of large anterior horn cells in spinal cord, with reduced number and progressive degeneration of remaining cells leading to muscle atrophy
Which muscles are affected first in spinal muscular atrophy?
Proximal muscles and lung muscles
Subtypes of SMA
Type I
Type II
Type II
Type IV
SMA Type I:
0-6 mo
child is very weak, does not learn to sit
SMA Type II:
(6-18 mo)
child sits but does not walk without AMD.
SMA Type III:
(>12 mo)
child walks independently
SMA Type IV:
adult onset
Characteristics of SMA Type I:
Supine - hips flexed and abducted, elbows supported on surface.
Head lag in pull to sit.
Inability to attain Landau position.
Intolerance for prone position due to respiratory limitations, unable to prop, turn head to sides
Characteristics of SMA Type II:
Initial presentation late in first year, infant is not pulling to stand.
Proximal weakness and wasting of extremity and trunk musculature.
Prone, quadruped difficult due to long lever arm.
Transitions to and from sitting difficult.
Delayed acquisition of motor skills, 90% sit by one year of age, 75% remain independent sitters until age 7, 50% until age 14.
Decline of abilities in second year.
Fine resting tremor, tongue fasciculations.
Characteristic SMA Type III:
Progressive weakness, muscle wasting, onset toddler years into adulthood.
Proximal muscles affected first, may be confused with MD.
Absent reflexes and fasciculations.
Contractures and progressive spinal deformities are uncommon when ambulatory.
Symptom onset prior to age 2 have poorer prognosis, stop walking after 12 years.
PT to maintain function and flexibility, bracing for standing, walking
Charcot-Marie-Tooth Disease
Hereditary motor and sensory neuropathy, HMSN.
Slowly progressive neuropathy affecting peripheral nerves.
Sensory loss, weakness, muscle wasting in distal muscles of feet, lower leg, hands, and forearms
