Spinal muscular atrophy (SMA)

I. Definition of spinal muscular atrophy

Spinal muscular atrophy is a rare neuromuscular disease. Nerve cells that control muscle movement (motor neurons) are damaged. This leads to muscle weakness and muscle atrophy (wasting). At a later stage, damage to organs such as the heart or lungs is also possible.

II. Causes of spinal muscular atrophy

The cause is a genetic change or the loss of a gene. The gene that produces the protein SMN is affected. SMN is responsible for communication between nerves and muscles.

III. Impact on patients/types of SMA

Traditionally, SMA is divided into different types depending on age and severity. Recent advances in gene therapy have resulted in innovative medicine that offers new treatment options. As a result, treatment successes can be achieved that were previously not possible.

A positive response to medication can significantly improve the patient’s development. The successes of drug therapy that may be possible as a result offer a better basis for follow-up therapies. For example, patients that are strengthened by medication can be mobilised using medical devices.

IV. Symptoms and functional impairments

In severe forms, there is a slow progressive loss of strength and thus:

  • Progressive muscle weakness
  • Poor head control
  • Trunk instability/progressive scoliosis
  • Progressive instability of the leg axis with inability to stand and walk
  • Hyperlordosis of the lumbar spine
  • Progressive loss of strength in the upper extremity with impaired grip and support
  • Cardiovascular complications
  • Respiratory complications
  • Difficulty swallowing and eating

V. Goal of therapy in SMA

  • Stabilization of the torso
  • Prevention of negative joint developments
  • Treatment of muscle imbalance
  • Maintaining of the ability to transfer
  • Prevention of muscle shortening
  • Communication and e-mobility via the upper extremity

VI. Course of SMA

The course of spinal muscular atrophy depends on the form and varies for each patient. In general, it can be said that the course is better the later symptoms appear.

With an early diagnosis, treatment measures can be initiated in a timely manner. In this case, treatment can take place before the motor neurons are damaged.

New medication is very promising, especially when treatment is started early. Accompanying physiotherapy is also important, for example to maintain the mobility of the joints, to learn the right breathing exercises or to maintain or learn the ability to transfer.

Also, the use of medical devices is useful as an addition to therapy as well as support in everyday life. Specially adapted wheelchairs, positioning orthoses, functional orthoses, corsets, standing devices and walking trainers can complement therapy effectively.