Spinal Muscular Atrophy (SMA) Type 2

SMA Type 2, otherwise known as Intermediate Spinal Muscular Atrophy, is usually diagnosed before the age of 2. Every child is different and so lifespan can vary greatly from early childhood through to adulthood dependant of severity, but weakness does increase over time. There is a generalised weakness of muscles with the proximal muscles (those closest to the body) usually being more affected. The legs tend to be more impaired than the arms. Children with SMA Type 2 can sit unsupported and some are able to crawl and stand, but as the child grows these abilities can reduce over time as the weakness to the muscles in the legs and trunk become more apparent. Children with SMA Type 2 are not able to stand unassisted.

The muscles of the chest wall can be affected causing poor breathing function and susceptibility to respiratory infections. Although feeding and swallowing problems are not common they are possible later on. Tongue fasciculations are less often found in Type 2 children, but a fine tremor may be seen in outstretched fingers.

SMA Type 2 does not affect congnitive abilities. Type 2 children are often very bright, alert and intelligent and should be encouraged to reach their upmost potential. Their physical growth develops at a normal pace though scoliosis (curvature of the spine) can become a big problem, especially when wheelchair bound. This is caused by a weakness in the muscles supporting the bones of the spinal column. As this becomes worse it can cause problems with breathing and may be uncomfortable. Spinal fusion surgery may need to be considered. As well as scoliosis some children suffer from deformities to their hands and feet. Where joints are affected this can result in reduced movement of the limbs. Motorised wheelchairs can be considered as early as the age of 2, until then an appropriate buggy should be used.

Physiotherapy is very important to improve good posture, this will enable the child to breathe much easier and exercises will also help to maintain muscle strength. Respiratory exercises and breathing techniques may help to reduce the effects of chest infections. Swimming is a very good form of exercise that enables the child to move all limbs with ease.