Spinal muscular atrophy (SMA) is a neurological condition that can lead to difficulty in control over muscle movement. It causes muscle wasting and has no cure, though it is possible to slow down the disease progress. This article explains the stages and symptoms of spinal muscular atrophy.

Stages and types
While discussing the stages and symptoms of spinal muscular atrophy, we need to know the various types of SMA. There are four types of SMA. They are:

Type 1: Type 1 SMA is also known as Werdnig-Hoffmann disease. This usually occurs before the age of six months and is the most serious form of SMA. Inability to move the limbs, spine curvature problem, muscle weakness, and difficulty swallowing and breathing are the symptoms here. Most children do not survive beyond the age of 2.

Type 2: This is usually seen in children between the ages of 6 to 18 months. While the infant may be able to sit, standing up and walking is almost impossible due to muscle weakness. If breathing problems are present, then survival becomes difficult.

Also known as chronic infantile SMA, the disease affects the legs rather than the arms. Most of those who suffer from Type 2 would survive until adolescence.

Type 3: Also known as Kugelberg Welander disease, type 3 SMA is usually seen once the child crosses 18 months of age. It is the mildest form of SMA. Standing up and walking is not usually a problem in such children. However, running and climbing stairs can become difficult for the child.

Tremors may be observed in some children. Respiratory problem is a complication that can happen. Most children can expect a full life expectancy with Type 3 SMA.

Type 4: Type 4 SMA is also known as adult SMA and is usually seen in adults after they cross 21 years of age. The common symptoms seen are muscle weakness, twitching, and breathing problems. Upper arms and legs are usually affected.

Since this is also a mild form of SMA, it is unlikely to have an impact on life expectancy.

Symptoms
As seen above, the symptoms of SMA would depend on the stage or type of SMA. Further, symptoms can vary in intensity from one patient to another. The major symptoms in SMA are related to the muscles and lead to muscle weakness and wasting of the muscles. It is a degenerative disease and usually becomes worse over time.

The common symptoms of SMA include:

• Weakness in muscles
• Twitching of muscles
• Change in the shape of the limbs
• Spine curvature changes due to muscle problems
• Change in the shape of the chest wall
• Difficulty in sitting up from a sleeping position
• Difficulty in standing up and walking

The information on stages and symptoms of spinal muscular atrophy would help in understanding more about this condition. This information will be helpful in ensuring early diagnosis of the condition so that treatment can commence early to reduce the progress of this disease.