Spinal Muscular Atrophy (SMA)

neuromuscular disease

disorders affecting the motor neurons and neuromuscular junction - anterior horn cells and peripheral cells

characterized by weakness, muscle atrophy, contracture and deformity

physiotherapy is integral to prevent complications, preserving function and maximizing children’s QOL, promoting activity, provide education to client and family, employ a family centered approach

spinal muscular atrophy (SMA) cause

caused by a defect of the survival motor neuron 1 (SMN1 gene)

dechenne muscular dystrophy (DMD)

caused by a mutation in the dystrophin gene

spinal muscular atrophy

recessive inherited neuromuscular disease characterized by degeneration of spinal cord motor neurons, resulting in progressive atrophy and weakness

deficiency of survival motor neuron (SMN1) protein causing reliance on identical gene SMN2

SMN protein

this protein is important for neuron function and survival

lack of this protein causes degeneration of the anterior horn motor neurons causing premature cell death and progressive muscle weakness and atrophy

Incidence of SMA

~1 in 11,000 live births

no current cure

Diagnosis of SMA

Genetic testing of SMN1/SMN2 and newborn screening programs

Types of SMA

Type 1 (severe) - Werdnig-Hoffman Disease

Type 2 (intermediate)

Type 3 (mild) - Kugelberg-Welander Disease

Type 4 (adult onset)

SMA Type 1

0-6mo

Never sits

Rapidly progressive

Developmental progress seen with treatment

SMA Type 2

6-19mo

Never stands

Slowly progressive

Gain of motor skills with evidence

SMA Type 3

>18mo

Stands and walks

Slowly progressive

Improved ambulatory ability with treatments

SMA Type 4

2nd or 3rd decade

walks during adult years

mild symptoms

warning signs of SMA

“floppy baby”

• feels like they will slip out of your hands when holding

• no head movement

  • motor delays / missed milestones

health care team for SMA

support worker

GP

neurologist

pediatrician

respiratory physician

nurse clinician

physio

OT

SLP

dietitian

orthopedic surgeon

genetic counselor

signs and symptoms - non-sitters

muscle weakness

postural control- poor head control

contractures

scoliosis

chest wall deformities

plagiocephaly

pain

fatigue

mobility

hip dislocation

skin breakdowns

pelvic obliquity

fractures

hypotonia in limbs and trunk

weak cry and cough

tongue fasciculations

unable to roll / sit up independently

signs and symptoms- sitters

muscle weakness (proximal)

hypotonia

postural control

contractures

scoliosis and pelvic obliquity

pulmonary function

mobility

chest wall deformities

deformation of feet

hand tremors

fractures

delayed motor milestones

difficulty coughing / clearing secretions

signs and symptoms- walkers

muscle weakness- lower extremity

scoliosis

swallow, cough and nocturnal hypoventilation

asymmetry

mobility

fatigue

falls

contractures

inflexibility

endurance

evaluations- non-sitters

CHOP INTEND

postural control

pulmonary tests

ROM / gonio

sitting tolerance

caregiver burden

pain

pain scales

TIMPSI

strength tests

RULM / UL function

pelvic obliquity

fractures

HFMSE

evaluations- sitters

postural control

HFMSE

RULM / UL function

ROM / gonio

sitting tolerance

pulmonary tests

chest wall deformities

strength tests

pain scales

caregiver burden

MFM

fatigue scales

mobility / gait evaluation

evaluations- walkers

timed test of function

6MWT

mobility / gait evaluation

ROM / gonio

exercise tolerance

HFMSE

endurance

interventions - non-sitters

stretching / ROM

seating systems / postural and positioning supports

play / toys

education

assistive technology / adaptive equipment

bracing

wheelchairs

chest physical therapy

transfer and mobility training

mobile supports

exercise

aquatic therapy

HFSME

interventions - sitters

stretching / ROM

wheelchairs

play / toys

bracing

seating systems / postural and positioning and positioning supports

standers

transfer and mobility training

mobile arm supports

aquatic therapy

caregiver burden

MFM

fatigue scales

mobility / gait evaluation

interventions- walkers

exercise

transfers and mobility training

stretching / ROM

ROM / gonio

aquatic therapy

balance exercise

bracing

fatigue management

ADL management

assessment - non-sitters

parent interview - subjective assessment

physiotherapy assessment and movement patterns - objective assessment

• neuromuscular assessment

• joint ROM - gonio

• tone

• strength

physio management- non-sitters

stretching

• AROM / PROM stretches

positioning and bracing

• support of position with wedges, pillows, beanbags

mobility and exercise

• assistive technology, wheelchairs, play with toys with switches/lights

chest physiotherapy

assessment - sitters

parent interview - subjective assessment

physiotherapy assessment and movement patterns - objective assessment

• neuromuscular assessment

• joint ROM - gonio

• tone

• strength

physio management - sitters

stretching

• daily stretching- AAROM, positioning

positioning and bracing

• static, dynamic, functional orthoses for positioning and standing and supported ambulation

mobility and exercises

• electric / power, lightweight WC

• aquatic therapy

• concentric and eccentric exercise, aerobic, general conditioning

chest physiotherapy

assessment- walkers

parent interview - subjective assessment

physiotherapy assessment and movement patterns - objective assessment

• neuromuscular assessment

• joint ROM - gonio

• tone

• strength

also functional assessment

• 6MWT

• Timed function tests (time up/down, gowers, 10m run/walk)

• HFSME

Respiratory assessment as indicated

physiotherapy assessment- walkers

exercise and activity:

• swimming, walking, cycling, yoga, rowing, elliptical /cross trainers

stretching and rom:

• passive stretching and aarom

• LL orthoses used for maintaining flexibility, posture, function at ankle/knee

mobility:

• ensure functional independence, lightweight manual WC or power assisted WC when endurance is limited

• Electric WC over long distances

adult onset signs and symptoms

onset in 2nd or 3rd decade of life

mild muscle weakness without respiratory or GI problems

adult onset treatment

stretching and strengthening muscles

swimming and hydrotherapy, adaptive sport exercises

energy conservation management and falls prevention

equipment prescription

modifications of home and work environment to maintain independence