WHAT IS SMA?

Brainstem is a neurodegenerative disease characterized by atrophy and progressive weakness of skeletal muscles secondary to anterior horn cell degeneration of motor nuclei and lower motor neurons.

The severity of SMA varies considerably. Clinical features can be classified into four main phenotypes considering the age at onset and the maximum motor function obtained.

SMA CLASSIFICATION

Type 0

Age of onset: Prenatal

Life expectancy: <6 months

Chronic Obstructive Pulmonary Disease

• Severe neonatal hypotension
• Serious weakness
• Respiratory failure at birth
• Facial diplegia
• Decreased fetal movements
• Atrial septal defects
• Arthrogryposis
• Absence of reflexes

TYPE 1 ( Werdnig Hoffmann)

Starting age: <6 months

Lifespan: 1-3 years

It is the type of SMA that makes up the heaviest table.

Chronic Obstructive Pulmonary Disease

• Loss of head control
• Mild joint contractures
• Variable absorption and swallowing disorders
• Hypotonic
• Respiratory muscle weakness
• Protected diaphragm respiration
• Bell-shaped chest
• Inability to walk
• Rarely able to sit
• Quick fatigue
• Weakness in crying
• Abduction in the hip -external rotation- frog position characterized by flexion in the knees
• Eye contact and hearing normal
• Cognition normal

TYPE 2 (Dubowitz)

Starting age: 6-18 months

Lifespan: 70% of them live until the age of 25.

Chronic Obstructive Pulmonary Disease

• Developmental delay with loss of motor skills
• Deep tendon reflexes with or without decreased
• Proximal muscle weakness
• Tremor in the upper extremity
• Kyphoscoliosis
• Chest cage anomalies
• Joint contractures
• Respiratory muscle weakness and related respiratory tract infections
• Ability to sit without support
• Crawl ( sometimes)
• Supported standing
• Inability to walk
• Cognition normal

 TYPE 3 (Kugelberg-Welander)

Starting age: >18 months

Lifespan: Normal

Chronic Obstructive Pulmonary Disease

• Weakness in proximal muscles
• Loss of motor skills
• Compensatory lordotic posture due to weakness of hip muscles
• Ambulation losses between the ages of 20-30
• Osteoporosis and obesity due to ambulatory losses
• Mild weakness in respiratory muscles
• Scapula Alata due to weakness in Serratus Anterior muscle

TYPE 4

Age of onset: Adulthood

Lifespan: Normal

It is the lightest table among SMA types.

Chronic Obstructive Pulmonary Disease

Proximal muscle weakness

ACCOMPANYING COMPLICATIONS

Gastrointestinal / Nutrition

Infants with Type 1 SMA usually have longer feeding times and get tired quickly. Their nutrition decreases due to fatigue during the feeding process.  This decrease in nutrition can lead to progressive weakness, developmental retardation and aspiration. Gastrointestinal dysfunction includes feeding and swallowing difficulty due to bulbar dysfunction. Weakness in the tongue manifests itself as difficulty opening the mouth and poor head control. Other associated problems include gastrointestinal reflux, delayed gastric emptying, and constipation. These complications are less common in outpatients with SMA.

For some children and adolescents with type 2 SMA, malnutrition may be a insidious problem due to decreased oral intake. Malnutrition and starvation periods should be avoided. Because these behaviors may contribute to the decrease in muscle mass and consequently to dysfunction.

Respiratory

The ultimate cause of death in infants and children with Type 1 and 2 SMA is usually respiratory failure. All children with SMA type 1 and approximately one-third of children with type 2 will experience respiratory failure in childhood. There is early involvement of the expiratory muscles of ventilation with relative preservation of the diaphragm. This can lead to difficulties in secretion management before ventilation failure.

The purpose of pulmonary intervention in type 1 infants is to improve the quality of life and not necessarily to prolong life. For example, non-invasive ventilation can prevent and reverse chest wall compliance and changes in lung development. However, ultimately, it should be decided what to do when non-invasive respiratory support is not sufficient. The use of tracheostomy and permanent ventilator support can be successfully performed in individuals with SMA. However, commitment to lifelong, full-time respiratory support is an individual choice for the child’s family that should be discussed in a multidisciplinary setting, ideally involving a palliative care team.

Management of pulmonary function in type 2 or non-patient SMA children (i.e., type 3 children who eventually lose their ambulation with disease progression) is similar to that in type 1 infants, but the complications are less severe. Physical examination and evaluation of cough effectiveness and respiratory muscle function should be routinely monitored. For children older than 5 years, challenging vital capacity can be routinely monitored and non-invasive respiratory support can be managed for a long time. Night hypoventilation should also be treated with non-invasive ventilation.

Orthopedic and Musculoskeletal System 

Weakness and impaired mobility, which are the main features of SMA, pave the way for a large number of musculoskeletal problems. Early recognition and proper management help maintain function, prevent deterioration in vital capacity, and improve quality of life.

Contractures are common in individuals with SMA who cannot walk. The use of manual or electric wheelchair for independent mobility can be initiated as early as 18 to 24 months. Physical therapy can help maximize durability and safety.

In addition to weakness, neuromuscular fatigue appears to contribute to functional limitation.  For long-distance mobility and independence, wheelchairs, changes in the environment and at home should be considered. Strategies to ensure long-term joint protection should be encouraged.

Scoliosis is an important musculoskeletal problem that mostly affects intermediate forms of the disease. It is universally available in outpatient patients with type 2 and 3 SMA. When untreated, scoliosis causes chest deformities and respiratory problems. Scoliosis progression rate is faster in patients who lose their ambulation in or before puberty. This suggests that maintaining standing and/or walking ability may help delay scoliosis progression. Therefore, physical therapy and other interventions should be used to help maintain ambulation.

EVALUATION

Muscle Strength Assessment

Muscle strength can be evaluated by many methods. Among these, clinicians generally prefer manual muscle testing, which is easy and inexpensive to do. Although it is an expensive method, dinonometric measurement is also frequently used because it provides better data.

Proximal joints should be stabilized and compensations should be prevented while performing muscle test in SMA. For the therapist, the timing, quality, active range of motion of the joint, and the ability to maintain contraction are more important than strength. Because this evaluation allows us to get an idea of what the reason is that limits the force.

Functional Evaluation

The results of muscle strength measurements do not reflect the functional status of the patient. This is due to the heterogeneity of muscle involvement, compensations, joint limitations, personal differences and environmental factors. Therefore, functional test must be added to the program. Functional Motor Scale is used for SMA.

Normal Joint Movement 

It is important for biomechanical analysis of movement and monitoring progress in treatment. Both active and passive range of motion should be evaluated. The feeling at the end of the joint movement should be noted. Proximal joints that are especially at risk in SMA should be evaluated.

Environmental Measurement

It should be performed to determine and monitor the status of pseudohypertrophy and atrophy in SMA. Perimeter measurements are made with a tape measure from the head, neck, chest, waist, abdomen, hip, thigh, leg, ankle, shoulder, arm, forearm and wrist. In SMA, circumference should be measured especially in the hip, thigh and shoulder regions.

Fatigue Assessment

The most commonly used scale in the literature for the evaluation of fatigue is the Fatigue Severity Scale and the Fatigue Impact Scale.

 Posture Evaluation 

It is evaluated based on observation. In lateral posture analysis, pes planus-pes cavus, genuine hyperextension-flexion in the knees, anteior-posterior pelvic tilt in the pelvis, lordosis in the vertebral column,kyphosis, kypho- lordosis,round back and flat back, protraction-retraction in the shoulders, head position and jaw up-down prohibition are evaluated. In anterior posture analysis, hallux valgus and hammer finger in the toes, inversion-eversion in the feet, tibial torsion in the knees, genu varum and genu valgum, height difference in the hips, abdominal region, deformities in the thoracic cage, height difference in the shoulders, lateral flexion and rotation appearance at the beginning, bearing angle and length difference in the arms, waist levels are evaluated. In posterior posture analysis, pronation-supination in the feet, knee line level, gluteal line level and scoliosis are evaluated.

Respiratory Evaluation

Functional lung tests other than the classical lung examination are used to determine the factors affecting respiration, to understand the degree and to plan the treatment. The most commonly used functional lung tests in the clinic are spirometric measurements, cardiopulmonary exercise tests, evaluation of respiratory muscles and thoracic circumference measurements. Cardiopulmonary exercise tests can be applied for SMA Type 3 and 4. Thoracic circumference measurements can be applied for Type 1 and 2 in terms of practical application.

Gait Analysis

It is an evaluation made to determine the deviations in gait in SMA 3 and 4 types. Although there are many technological opportunities, observational gait analysis is preferred in clinics because it requires less equipment, is cheap and is easy.

PHYSICAL THERAPY AND REHABILITATION

Aims:

• Maintain Current State
• To prevent limitations and deformities that may occur by protecting muscles and joints
• Reducing the care burden of the family
• Keeping respiratory functions at the best level and protecting from lung complications
• To increase the quality of life and social participation of patients.

Rehabilitation programs are personalized. From the moment a patient is diagnosed with SMA, both he and his family should be informed about the problems that the disease may cause and the expected results. The patient’s and family’s expectations should be evaluated and a rehabilitation program should be established in this direction.

Rehabilitation program according to the current status of the patient;

 1) For Protection: To protect the physical and mental capacity of the patient
during the disease period

2) For Development: To increase the physical and mental capacity of the patient

3) For Slow down: To slow down the rate of progression of symptoms and to maintain the physical and mental well-being of the patient for the longest possible time.

Rehabilitation Program in Type 1 SMA

For Respiratory Problems

Postural Drainage: It includes appropriate positions made using gravity to remove involuntary secreted secretions from the lungs.The purpose of postural drainage is to increase the air flow behind the mucus and to ensure that secretions are transported to the central airways and sent out. It consists of specialized assisted positions. Since it is a passive application, it is not preferred to be used alone .

Percussion: It is defined as rhythmic strokes applied on the chest wall by bringing the hand into the shape of a dome in order to facilitate the dissolution of secretions. It is applied throughout the inspiration and expiration. When it is applied to babies, the 2nd, 3rd and 4th fingers are brought into the shape of a dome and applied.

Positioning: It should be laid in the prone position for half an hour a day. The baby’s lying position should be changed every two hours. The moon should be supported with a pillow so that the head and shoulder are in the protraction in the supine position, support should be placed from the thigh lateral to prevent the legs from abduction and external rotation, and support should be placed under the feet to provide a neutral position to prevent the feet from escaping the plantar flexion. Care should be taken not to jam the lower arm when tilting. Again in this position, a thin pillow can be placed between the legs. Children who can sit can sit with support for 15 minutes a day.

 

For Musculoskeletal Problems

Normal Joint Movement : 3-7 repetitions should be performed twice a day to prevent joint contractures.

Stretching Exercises: If joint contractures have begun to form, they should be worked by waiting for 15 seconds at the last point with 3-5 repetitions 1-2 times a day in order to slow down the progression or if not, to prevent it. In thesupine position, slight aproximation can be performed from the front of the body so that the head and shoulders come into contact with the back and pelvis while the moon is supported with a pillow and the body is symmetrical. Eye contact with the baby in the same position and object tracking with the eye can be studied. In the same position, it can be tried to join the hands in the midline with the stimulus and to reach in different directions with the hands. Pressing the bed from the dorsal face of the feet can be tried to help the development of bridge building activities in the same position.

Right-left weight transfer can be performed with shoulder aproximation while the body is in the symmetrical position on the prone elbows.

Head control can be performed with stimulus in the same position.

While the weight is on one side in the same position, reaching for the object can be tried.

If the baby has difficulty standing on the elbows on its face for a long time, it can be tried to play with the object with both hands by placing a support under the body.

When the baby is pulled from the shoulders while facedown on the elbows, right-left weight transfer can be done with aproximation from the shoulder and reaching for the object while the weight is on one side.

In order to develop the protective extension reflex, it is possible to suddenly pull 5 cm from the shoulders and try to release it.

Rotation

The therapist starts the rotation movement by holding the proximal of the hip and shoulder with the stimulus that the baby can see on the side of the foot but cannot reach, and waits for the baby to participate. When baby comes to lying on the side, aproximation is performed from the shoulder and pelvis. Slight resistance is given since gravity will help the baby rotate after this point until he/she reaches the prone position. After turning, expected that the baby will remove the arm by performing elevation from the shoulder in order to remove the lower arm. If not, elevation is performed both in the shoulder and pelvis and the baby is expected to remove the arm. If baby doesn’t, the therapist will. In order to return to the starting position, the baby is stimulated with a stimulus to ensure the extension and rotation of the head, and rotation is initiated from the pelvis and the participation of the baby is expected. When baby comes to lying on the side, aproximation is performed from the shoulder and pelvis. Then the return module is completed with light resistance.

Rehabilitation in Type 2 SMA

In addition to Type 1 SMA rehabilitation;

Muscle Strengthening: The primary goal is not to strengthen the muscle, but to protect the existing strength and to prevent atrophies. Depending on the condition of the patient, it should be started initially with no resistance or very little resistance and with a small number of repetitions. It is important to maintain proximal muscle strength, especially in SMA.

Scoliosis: Posture exercises should be added to the program to prevent all posture disorders, including scoliosis. Especially in babies, stretching and strengthening exercises should be studied by maintaining bilateral and body symmetry.

Moving from the supine position to the sitting position :The therapist fixes the pelvis on the side where the patient will turn. Meanwhile, therapist takes the opposite arm and pulls the baby diagonally, leans over the other shoulder and waits. The therapist pulls forward again slightly, comes over the elbow and waits. The therapist pulls it forward once more, puts the baby on his/her hand and waits. Finally, the therapist pulls the baby forward from both hands and puts the baby in a sitting position. When returning to the starting position, therapist puts the same hand on the ground, pushes it from the diagonal arm and waits. Therapist pushes again and waits when the elbow hits him. Therapist pushes again and waits when he lies on his side.Finally the physiotherapist pushes and the child is laid in the supine position.

For those who can crawl, the therapist takes the baby from the SIAs while he/she is on his/her hands on his/her face and puts him/her in the crawling position without disturbing his/her body symmetry. Hands are expected to be pulled under the shoulder by the baby. If not, the therapist will help. After providing body symmetry in the crawling position, aproximation is applied from the shoulder and pelvis. The head control is activated by the stimulus. Right-left oscillation is made from the shoulders. When the weight is on one side, it is tried to reach first to the nearby object, then to the distant object, then to the distant and high object.

Rehabilitation in Type 3 and Type 4 SMA

In this patient group, ambulation is especially important. In these groups with better ambulance than other types, extra walking and balance trainings should be given.

Weakness in proximal extremity and trunk muscles causes deterioration of stability in the trunk and increase in lumbar lordosis. Weakness in the hip abductors causes Trendelenburg or Duck-like gait. As a result of dorsiflexor muscles remaining weaker than plantarflexors, tip-toeing may occur. Tip-toeing causes difficulty in cutting the contact of the foot with the ground during the rocking phase. In this case, patients perform exaggerated hip flexion to lift their feet off the ground (step walk). Weakness of the hip flexors and extensors causes the step length to shrink.