Health, wellbeing and lived experiences of adults with SMA: a scoping systematic review

Table 4 Adult phenotypes of spinal muscular atrophy

Functional classification^a	Non-sitters	Sitters	Walkers
Traditional classification^b	Types I, II and some IIIa	Type II and some IIIa	Type IIIb, IV and some IIIa
Physical manifestations	Very severe weakness: -Quadriplegia -Weakness of face and bulbar muscles -Small movements of distal limb muscles -Areflexia	Very severe weakness: -Paraplegia -Distal arm movement -Areflexia	Pattern of weakness: Legs>arms Proximal>distal Reduced or absent reflexes in legs, may be normal in arms Calf hypertrophy No facial or bulbar weakness
Complications/ comorbidities	-Severe restrictive respiratory disease Ventilator support, Recurrent pneumonia/aspiration ±tracheostomy -Severe scoliosis /spinal fusion Contractures	Respiratory disease Non-invasive ventilation Scoliosis	Normal respiratory function

^a Functional classifications compiled from adult SMA descriptions in the literature [2, 22, 25,26,27]
^b Traditional SMA classifications: Type I - symptom onset < 6 months, unable to sit independently; Type II - symptom onset between 6 and 18 months, achieved ability to sit independently; Type IIIa - symptom onset < 3 years, achieved ability to walk independently; Type IIIb – symptom onset > 3 years, achieved ability to walk independently; Type IV - adult onset SMA

ISSN: 1750-1172