Spinal Muscular Atrophy

By | June 10, 2022

Spinal muscular atrophy ( SMA ) is a group of disorders characterized by muscle wasting. SMA is caused by the loss of motor nerve cells in the spinal cord.

What is Spinal Muscular Atrophy?

The term progressive spinal muscular atrophy was coined by the neurologist John Hoffmann in Heidelberg in 1893. Spinal muscular atrophies are diseases that are based on the destruction of the alpha motor neurons. Alpha motor neurons are nerve cells in the central nervous system (CNS). For what does the abbreviation btc stand for, please visit usvsukenglish.com.

They are located in the brainstem and in the anterior horn of the spinal cord and are responsible for the innervation of the skeletal muscle fibers and thus also for muscle contraction. Motor neuron decline in SMA is progressive. Due to the loss, the impulses from the nervous system can no longer be transmitted to the muscles. This leads to paralysis with muscle atrophy and reduced muscle tension.


Spinal muscular atrophy is an inherited disease. Like most neuromuscular diseases, spinal muscular atrophy is rather rare. The most common form is the infantile form. One child in every 25,000 births falls ill here. In the juvenile form, only one child per 75,000 births is affected. The acute infantile form of SMA begins even before birth in the womb. In the juvenile form, the symptoms only begin in childhood or adolescence.

Symptoms, Ailments & Signs

The loss of motor nerve cells leads to muscle atrophy and muscle weakness. Normally, the muscles contract when activated by the supplying nerves. The muscle contracts, shortens and tightens. In this way, the intended movement can be carried out. Muscles that are no longer innervated due to the SMA can no longer contract.

The muscle can no longer be used. He is getting weaker and weaker due to the sedation. If a larger number of muscle fibers are affected by the paralysis, a loss of substance of the entire muscle can be observed. In contrast to muscular dystrophy, the muscle itself is not diseased. That is why this muscle wasting is also known as muscle atrophy. Muscle strength and endurance decrease as the disease progresses.

The affected patients can no longer perform certain movements or only for very short periods of time. The muscles tire much faster than in healthy people. The acute infantile form of SMA is already noticeable in the womb. Babies move very little in the womb. Reduced muscle tension is evident at birth. Spontaneous movements rarely occur.

The children cannot keep their heads free and cannot sit freely either. Within the first two to three years of life, the affected children die of respiratory failure. In the intermediate form, the first symptoms appear in the first months or years of life. The children can no longer walk or stand. Spinal curvature and deformation of the chest occur. Most patients do not reach the age of 20.

The juvenile form of progressive spinal muscular atrophy begins in late childhood or adolescence. The first muscle weaknesses usually affect the muscles of the pelvic girdle. Clumsy climbing stairs is one of the first symptoms. Over time, however, the muscle weakness also spreads to the rest of the muscles. Occasionally, a very strong calf can be observed in affected patients. This contains increased fat and connective tissue.

Adult spinal muscular atrophy begins in adulthood and progresses at a much slower rate than other forms of SMA. They often begin with weakness and wasting of the hand muscles. Weakness in the foot muscles can also be a first indication of adult SMA.

When the cranial nerves are affected by the condition, there is also difficulty swallowing, chewing, or speaking. Cranial nerve involvement is most commonly referred to as Kennedy-type spinobulbar muscular atrophy (SBMA) or progressive bulbar palsy.

Diagnosis & course of disease

When making the diagnosis, the detailed anamnesis of the patient with the description of the functional disorder is first taken into account. A detailed physical and neurological examination is then carried out. These include procedures such as electroneurography or electromyography. Electroneurography measures nerve conduction velocity. Electromyography measures muscle currents.

Both methods can be used to distinguish spinal muscular atrophy from multifocal motor neuropathy. In addition, procedures such as needle electromyography, motor electroneurography or sensitive electroneurography can be performed.

Parameters such as blood sedimentation rate, creatine kinase, vitamin B12, vitamin D, thyroid hormones or parathyroid hormone are determined in the laboratory. An examination of the cerebrospinal fluid can also provide information. X-rays of the cervical spine or tomograms of the brain and cervical spine may also have to be taken. Muscle biopsy or nerve biopsy provide further information.


First and foremost, those affected by this disease suffer from severe muscle weakness and muscle wasting. This leads to significant limitations in everyday life and thus to complications. Normal activities are no longer easily possible for those affected, so that in many cases the patients are dependent on the help of other people.

Many of those affected also suffer from psychological complaints or depression and need psychological treatment. As a rule, this disease does not heal itself and the patient’s muscle strength continues to decrease as a result of the disease. Breathing is also significantly weakened, so that those affected suffer from breathing difficulties and possibly dizziness or loss of consciousness.

Furthermore, there is a curvature of the spine and severe deformations in the back. These also have a very negative effect on the quality of life of the patient. In most cases, the life expectancy of those affected is limited to 20 years. Since a causal treatment of the disease is not possible, only the symptoms can be limited. There are no particular complications. However, this disease does not lead to a completely positive course of the disease.

When should you go to the doctor?

With this disease, direct treatment by a doctor is necessary in any case. As a rule, self-healing cannot occur, so that the patient is always dependent on early examination and treatment.

The earlier the disease is recognized and treated, the better the further course of the disease. A doctor should be consulted if the person affected suffers from severe muscle weakness. In most cases, the patient can no longer carry out heavy activities and often feels tired and exhausted. Difficulty breathing can also often indicate muscle atrophy and should also be examined by a doctor. Some sufferers also suffer from a curvature of the spine and also from a deformed chest. If these symptoms occur, a doctor must be consulted in any case.

Muscle atrophy can usually be detected by a general practitioner. There are no special complications during the treatment. Life expectancy is also not affected by this disease. However, whether a complete cure is possible cannot be universally predicted.

Treatment & Therapy

The goal of SMA therapy is to improve muscle function. The affected patients should remain independent and self-sufficient for as long as possible. Treatment is usually provided by a team of doctors, physiotherapists, speech therapists, occupational therapists and social workers.

Physiotherapy, ergotherapy and speech therapy are carried out on an outpatient basis and serve to maintain the skills that are still available. The course of the disease can be positively influenced by inpatient rehabilitation measures. Since the main cause of clinical problems is muscle weakness, targeted muscle training can be helpful. In individual cases, orthoses can bring about a functional improvement.

According to scientists at the Freiburg University Hospital, children with spinal muscular atrophy benefit from maintaining their motor skills if they start treatment with Nusinersen (Spinraza) at an early stage.


Because spinal muscular atrophy is inherited, prevention is not possible.


Spinal muscular atrophy sufferers need to do special training sessions to support the muscles as follow-up care. In addition to further medical treatment, those affected can independently carry out exercises recommended by the doctor at home. Those affected should urgently avoid overexertion or excessive strain.

Otherwise, the disease and symptoms may worsen. In order to be able to cope with the disease in everyday life, those affected need emotional stability. Above all, however, the disease can be overcome with the support and help of family and relatives. Those affected should have an intact social environment so that help can be sought at any time.

Since the disease cannot be cured, those affected should undergo ongoing psychological counseling. In this way, those affected can learn how best to live with the disease. A support group can also be helpful. There, those affected can compare their lifestyle with other sufferers and do not feel alone with the disease.

In addition, those affected can learn other methods of dealing with the disease. In order to increase the quality of life, activities should be chosen that gave them pleasure before the illness. It would be advisable to do this together with people from the familiar, social environment.

You can do that yourself

Various studies have shown that the progression of the disease can be delayed if targeted training sessions are carried out to support the muscular system.

In addition to the physiotherapeutic sessions offered, the person concerned can independently carry out regular exercises to maintain and improve the muscular system in everyday life. Individual training sessions are developed in cooperation with the physiotherapist, which the affected person can use independently at any time at home or on the go. Avoid overuse or overload situations. You can revise training successes and contribute to a worsening of the situation.

The disease poses a particular challenge due to the visual changes and abnormalities. Emotional stability is therefore particularly important in order to cope with the disease in everyday life. Self-confidence is to be encouraged and dealing openly with the complaints and their causes is helpful. The progressive course of the disease should be discussed with the patient at an early stage. This is the only way that unpleasant situations can be avoided and the person concerned can mentally prepare for possible developments in good time.

Since it is a hereditary disease, no relief or cure of the disease can be expected. The patient must therefore learn to structure his lifestyle as optimally as possible with the health restrictions. Contact with other sick people or with self-help groups can be helpful.

Spinal Muscular Atrophy