Spinal Muscular Atrophy (SMA) Rehabilitation

SPINAL MUSCULAR ATROPHY (SMA)

It is a congenital disease of the motor nerves located in the anterior horn section of the spinal cord. The incidence of Spinal Muscular Atrophy (SMA) with genetic inheritance is 1-2 / 10,000.

What is Spinal Muscular Atrophy (SMA)?

In Spinal Muscular Atrophy (SMA), there is no response to the neural stimulation coming from the brain to the anterior horn cells of the spinal cord and enabling the voluntary muscles to work. Because, there is a genetic dysfunction in the motor anterior horn cells. Therefore, since these nerves are not stimulated to the peripheral (peripheral) muscles, the muscles cannot contract voluntarily and myolysis (atrophy) occurs. All arm and leg muscles, trunk and some respiratory muscles are affected by this disease.

What Causes Spinal Muscular Atrophy (SMA)?

There is a mutation in the motor nerve gene (SMA gene) in SMA disease, popularly known as “loose baby syndrome”. In normal healthy people, the motor neuron gene produces a protein critical to the function of the nerves that control our muscles. Thanks to this protein, nerves become strong and carry out orders from the brain. However, if this protein cannot be synthesized, motor neurons are broken down and destroyed. As a result, no signals can be sent to the muscles.

The main feature of all types of SMA is muscle weakness accompanied by muscle wasting.

How DoesSMA Appear?

SMA is examined in 4 different types, considering the age at which it starts and clinical symptoms. The earlier the symptoms of SMA appear, the more severe the course of the disease. SMA type 1 seen under 6 months shows the most severe form of the disease.

Type1 SMA is the most severe type, also called hypotonic baby. There is no head control and sitting without support in the sick baby. Even if there is no movement in the arms and legs, patients have eye contact and hearing is normal. Sucking and swallowing difficulties are also a problem in Type 1 SMA, which is one of the most common causes of infant deaths in the world. Frequent respiratory tract infections develop as a result of the respiratory muscles being affected. As a result, lung capacity gradually decreases and sick babies become dependent on breathing apparatus. Their prognosis is not good.
Type2 SMA is frequently seen in babies between the ages of 6-18 months. It is observed that the baby whose development is normal suddenly cannot develop and even goes backwards compared to his peers. These patients have head control and can sit alone. However, they cannot move from lying to sitting position. These patients can never stand and walk without support. Respiratory tract infections are frequently seen in these patients, and the risk of developing spinal curvature is also high. It is a relatively slow table.
Type 3 SMA is the form that starts in infants older than 18 months. It progresses slower than the other two types. Symptoms such as difficulty in walking, frequent falls, and inability to climb stairs occur due to muscle weakness in the child who was normal until the time of diagnosis. Symptoms can occur at any time until puberty. These patients can stand and walk and their respiratory muscles are not affected. Scoliosis is relatively more common in this group of patients. In advanced ages, they may need a wheelchair.
Type4 SMA is the type seen in adulthood and has a good prognosis.

What are the Symptoms ofSMA?

Although the symptoms vary according to the age at which the disease occurs, they may differ from person to person. Although the general symptoms vary according to the type of the disease;

Muscle weakness and debility leading to a lack of motor development. The weakness is usually symmetrical, often involving proximal muscles such as the shoulder and hip circumference. The weakness in the leg muscles is more than the arms,
They fall behind their peers in terms of motor function,
Frequent falls, difficulty climbing stairs, difficulty standing and walking,
Shaking hands, tongue twitching,
Decrease or loss in deep tendon reflexes (sensation is preserved),
Increased risk of aspiration due to feeding difficulties, swallowing and swallowing problems,
Failure to control head and waist.

The diagnosis of the disease can be made by genetic analysis and EMG. In genetic analysis, it is diagnosed by detecting the anomaly in the SMN (survivor motor neuron) gene located in the long arm of chromosome 5.

What Are the Treatment Methods of SMA?

Extensive research is ongoing for the treatment of SMA disease. SPINRAZA, the first drug to be approved by the FDA in 2016, is still used in the treatment of children, and losses in patients can be reduced or even stopped with this drug.

In addition to drug treatment, rehabilitation programs to be applied in SMA have very beneficial and positive effects. Purpose in rehabilitation;

Preserving the current situation, delaying the deterioration as much as possible,
Increasing or maintaining the independence of the child,
Reducing the family’s care burden,
Prevention of joint deformities,
Protection of muscles,
Elimination of respiratory complications,
The maintenance and provision of roles and life in social life.

SMA disease not only affects the musculoskeletal system in relation to the pathology it creates, but also brings many secondary problems. Treatment principles should be holistic and multidisciplinary, and each patient should be treated individually.

Considering the effects of SMA, orthosis may be required to prevent some problems that may arise in children due to muscle weakness. In addition, it is recommended to use walking devices such as walkers and wheelchairs in accordance with the functional state of the child in order to support independence.

Education of the family about the disease, and the importance of stretching and strengthening exercises to protect joints and muscles should not be forgotten.

The first step in the rehabilitation of SMA disease is to evaluate the patient’s current functional status. It should be repeated every 3-6 months. Because the functional state of the growing child will constantly change. Widespread weakness in muscles despite growth will have adverse effects on both bone and tendons. As a result, growth disorders will occur in the bone. A poorly developed hip joint is an example. Bilateral hip dislocation is a common finding in SMA cases.

The joints of SMA cases are also quite loose. In the early stage of the disease, the range of joint motion may even go beyond what is expected. This condition is a factor that increases spinal scoliosis. Loss of muscle strength, laxity in joints and limitation of movement, and changes in arms and legs due to growth are the main factors affecting functions in patients with SMA.

How is Respiratory Physiotherapy Applied in SMA?

Weakness of respiratory muscles reduces ventilation of the lungs in patients with SMA. This situation leads to frequent lung infections and diseases. As a result of the weakness of the cough-related muscles, secretions become difficult to expel. Children with widespread muscle weakness will also have an increased risk of aspiration.

Small oral foods, the use of straws, keeping the head upright during feeding and chin support, less and frequent feeding are practices that will help prevent the risk of aspiration.

From an early stage, it is important to develop muscle strength, maintain the flexibility of the rib cage, increase the range of motion and improve physical functions. Appropriate positions should be shown by physiotherapists for comfortable breathing.

Positioning and various drainage methods will be useful in the disposal of lung secretions. Appropriate postural drainage measures should definitely be taken to prevent aspiration in patients and the family should be educated on this issue.