Between 600 and 800 different diseases belong to the large group of neuromuscular diseases, which are associated with muscle wasting, can lead to slight limping, but also respiratory failure and for which there is no cure so far. Find out more about different types of muscle wasting, typical symptoms of muscle wasting and the treatment of the disease.
What is muscle atrophy?
Muscular atrophy is due to most hereditary causes to the regression of the muscles on the trunk, arms and legs, but also on the face, and inside the body like the swallowing muscles, the heart muscles or the eye muscles.
Muscular atrophy refers to a group of 600 to 800 very different diseases depending on the classification, in which a genetic defect either leads to the death of the muscle cells (myogenic muscle atrophy), where the nerve cells supplying the muscles die off (neurogenic muscle wasting) or in which transmission from nerve impulse to muscle eg by autoantibodies as in myasthenia (myasthenia gravis) is disturbed.
While diseases of the first group are usually called myodystrophies or myopathies, those of the second group are called (spinal) muscle atropias. Together they are called neuromuscular diseases.
Muscle wasting: shaping and naming
Musculoskeletal disorders are named either according to their discoverer (Werdnig-Hoffmann, Kugelberg-Welander, Duchenne, Becker-Kiener) or according to the body region in which they take place: Thus, in the fazio-scapulo-humeral type mainly the face, shoulder blade and upper arm affected in oculo-pharyngeal type eyes and swallowing muscles.
Depending on the form, the disease may already occur in the unborn or in the first months of life, other forms develop only in later years. The sooner the disease occurs, the more aggressive is its course. While early forms often lead to death in the first two decades of life, in the later onset of the disease usually only a few failures due to muscle atrophy and the life expectancy is not limited.
The exceptions are, on the one hand, the non-hereditary muscular atrophy amyotrophic lateral sclerosis, which usually occurs only in advanced age, has a rapid worsening of symptoms and leads to death after a few years, on the other hand, the myasthenia gravis, in which the body autoantibodies against the Überträgersynapsen on the muscle cells produced. In addition to rapid muscle fatigue, which usually manifests itself in double vision, there is often a thymus tumor.
Therapy and treatment for muscle atrophy
Therapeutically, those affected can often be helped with thymus removal and medications that suppress the immune system. Particularly problematic in muscle atrophy is the dying of the muscles that support breathing as respiratory aid muscles. The more these muscles are affected, the harder it is to breathe deeply - in the long run, too little oxygen gets into the body. In addition, the disease can also affect the swallowing and heart muscles - dysphagia and pronounced heart failure may be the consequences.
Of these diseases, the normal muscle atrophy is delineated, which occurs after prolonged immobilization of a body part, such as an arm fracture in a cast splint, or bedridden in a prolonged illness. However, no muscle cells perish, but the individual muscle cells simply shrink with the decrease in the demands placed on them in order to increase in size after the disease and the reloading.
Symptoms: How Does Muscle Attrition Express?
All muscle wasting illnesses have in common that movements, for which the affected muscles are needed, at first no longer liquid, later only incomplete or can no longer be executed. So when the leg muscles are affected, the first signs of muscle atrophy may be that you stumble more often, lose strength faster, and tire your legs faster.
If the disease starts in the first months of life, even learning to walk can be impossible. At a beginning in toddlerhood already learned skills such as climbing stairs are lost again, getting up from the squat is at some point only possible in which the affected person pulls up on himself (ie with the arms supported to achieve a vertical position).
Muscle loss in children
Children with muscle atrophy show a characteristic waddling and often have strong calves, which is not due to an increased musculature, but an accumulation of fatty tissue. In the more severe forms of muscular atrophy, restricted mobility inevitably leads to a curved posture and contractures of the musculature, so that walking becomes impossible at some point.
Sitting in a wheelchair and crooked posture promotes the progression of the disease in that posture can no longer support the respiratory muscles and breathing becomes increasingly difficult. The poor ventilation of the lungs leads to increased respiratory tract infections and reduced lung capacity. Chronic lung infections and increasing respiratory insufficiency are ultimately the main cause of decreased life expectancy.