Muscular atrophy, or muscular dystrophy in technical terms, is a muscle disease caused mainly by heredity. Muscular atrophy can take various forms and differs in this regard in the course and prognosis. Unfortunately, muscular dystrophy cannot be cured yet. Therefore, the main focus of any treatment is to slow down the disease as well as alleviate discomfort associated with muscle atrophy.
What is muscle wasting (muscular dystrophy)?
Against pathological muscle atrophy and muscle weakness, targeted muscle building does not always help, but can serve supportive physiotherapeutic purposes. Muscular dystrophy (also muscle wasting) is an umbrella term for various primary (i.e., without other underlying disease) wasting muscle diseases. More than 30 different subclasses of muscular dystrophies are known. However, the most common are muscular dystrophy type Duchenne (with about 1:5000 the most frequent muscle disease in childhood) and type Becker-Kiener (adult form with a somewhat more favorable prognosis and slower course). Other subtypes are rare. All types have in common that the diseases are associated with progressive, usually symmetrical muscle weakness with subsequent muscle wasting.
Causes
There is no underlying external cause for muscle wasting or muscular dystrophy; it is almost exclusively inherited. The mode of inheritance is usually X-linked recessive, i.e. the gene defect is located accordingly on the X chromosome and in order to become ill, both X chromosomes would have to be affected. Therefore, usually only male individuals are affected, as they do not have a second X chromosome and thus a gene defect leads to the expression of the disease. The defective gene can only be transmitted by the mother (she is a conductor), but she herself is not manifestly affected. Of course, new mutations (i.e. gene defect present without any inheritance) are also possible. The genetic defect causes a reduced amount (Becker type) or a complete decay of dystrophin (Duchenne), a building block of the skeletal muscle, which is necessary for stability and contractility (i.e. the ability of the muscle to contract). This dystrophy deficiency ultimately leads to the muscle weakness and wasting. In order to differentiate a new mutation from a hereditary one (especially to determine the risk of recurrence in case of a new pregnancy), a genetic analysis of the mother can be performed. However, in many cases, an elevated muscle wasting enzyme (CK) is also detectable in the asymptomatic mother.
Symptoms, complaints, and signs
Muscular dystrophy is characterized by progressive muscle weakness. This predominantly affects certain regions of the body and usually occurs symmetrically. When and whether symptoms occur at all depends primarily on the form of muscular dystrophy. More than 30 different forms are known, each of which is associated with different symptoms. In the rather slowly progressing muscular dystrophy of the Becker-Kiener type, the muscle weakness first appears in the area of the thigh and pelvic muscles. The disease begins between the ages of six and twelve, so that the ability to walk is maintained in most patients until the age of 30 or even 40 due to the slow progression of the disease. Only in later stages does the muscle weakness also affect the function of the lungs and heart. Duchenne type muscle atrophy, on the other hand, progresses rapidly. The first symptoms appear in infancy. Affected children stumble more often and fall down quickly. Approximately one third of those affected also suffer from calf pain and a waddling gait. Due to the progressive muscle weakness, patients with Duchenne muscular dystrophy are dependent on a wheelchair and full nursing care before the age of 18. As a result of the dystrophy, breathing and cardiac performance are increasingly limited, so fatigue, headaches, and poor concentration may also occur.
Disease progression
The first symptoms of muscle wasting (muscular dystrophy) occur in early childhood (Duchenne type) or in adolescence to early adulthood. A characteristic feature is progressive muscle weakness, which usually begins symmetrically in the pelvic and shoulder girdles. Later, the actual muscle atrophy occurs. Fatty tissue serves as a placeholder, which leads to an optical hypertrophy (typical are the so-called gnome calves).In the further course, the children or adults lose the ability to stand up without help and finally to walk. Since the muscular dystrophies are not curable, death occurs after many years of progression (life expectancy for Duchenne type is about 25 years, for Becker type much longer). The cause of death is usually respiratory weakness with resulting infections.
Complications
Muscle atrophy can cause the heart muscle to thicken and weaken. Disturbances of the heart rhythm and breathing are the result. Furthermore, because the skeleton is no longer supported by the muscles, limbs may become deformed and the spine may curve in a pathological way. In this case, the affected person often suffers from severe back pain. Malpositions of the joints can also not be ruled out due to the severe shortening that results from the regression of the muscles. These can then usually no longer be corrected. In later stages of the course, problems with the respiratory muscles can arise. Breathing then becomes more difficult and there are nocturnal drops in oxygen supply. This is associated with an increased susceptibility to respiratory diseases. If patients no longer have the ability to change their lying position in bed, pressure sores on the overlying skin are the result. This is also known as bedsores. All complications can be limited by medical treatment, but usually not prevented. Generally, it is the complications, rather than the muscle atrophy itself, that ultimately lead to death.
When should you see a doctor?
Continued decline in physical performance should be discussed with a physician. If accustomed athletic or daily responsibilities can no longer be performed, a follow-up visit with a physician is advised. Pain in the muscles, rapid physical overload of the affected person, fatigue and exhaustion are indications of a health impairment. If there are frequent headaches, a general feeling of malaise, an increased need for sleep, and inner restlessness, a doctor is needed. If there is trembling of the limbs, poor posture of the body, or limitations of movement, a doctor should be consulted. An irregularity in respiratory activity, a general feeling of illness, and visual abnormalities in locomotion must be examined. Affected persons are often conspicuous by a waddling gait during forward movement. If additional behavioral abnormalities, mood swings or other psychologically induced irregularities occur, a visit to the doctor is recommended. The physical changes threaten psychological or emotional problems, which should be prevented in time. An increased risk of accidents or falls must be taken into account in the case of muscle atrophy. Therefore, a doctor should be informed of the specifics if repeated injuries occur. If the attention or concentration of the affected person decreases, he also needs medical help.
Treatment and therapy
Therapy for muscle atrophy (muscular dystrophy) is primarily aimed at preserving muscle strength (and thus independence) for a long time, compensating for pre-existing deficits, and preventing complications. Interdisciplinary therapy is unreservedly useful. Thus, the family doctor, neurologist, physiotherapist, nursing staff and, of course, the parents should be involved. Likewise, the affected person should be enabled to lead a normal life as far as possible. School attendance and work (e.g. in a special workshop for affected persons) are to be aimed for. In addition to physiotherapeutic exercises, various aids should be offered to compensate for deficits (e.g. electric wheelchair, lifter for transfers, eating and washing aids, etc.). It is not uncommon for weakened back and abdominal muscles to cause spinal curvatures. These should be surgically corrected to preserve the ability to sit. Decisive for the prognosis is the therapy of the respiratory weakness. In addition to physiotherapy and physiotherapeutic interventions, nocturnal positive pressure ventilation can significantly improve the prognosis and quality of life. Psychological adjunctive therapy should be offered to patients who are often depressed.
Outlook and prognosis
A cure for muscular dystrophy is not yet possible today. However, it is possible to significantly improve the quality of life of patients through treatment of symptoms and professional physiotherapy.Respiratory therapy, heat applications, tapping-pressure massage, electrotherapy, and the combination of dynamic and isometric exercises are particularly helpful to those affected. However, it should be noted that overstraining and overexertion of the muscles should be avoided, as this could accelerate the course of the disease. According to recent studies, the use of so-called creatine monohydrate, in the milder cases of muscular dystrophy, can also increase the strength of patients for some time. It is also important to provide professional psychological support for patients and their families, as this incurable disease is a heavy burden. Self-help groups can also provide good support in this regard. In addition, tendon lengthening surgery, if performed in time, can prolong the patients’ ability to walk. The developing spinal curvature, which becomes apparent after a few years, should also be corrected surgically in time, because it has a negative influence on breathing. As soon as the disease has affected the respiratory muscles, nocturnal home respiration should be used to achieve the improvement of breathing. Due to the fact that there is no possibility of curing the disease yet, the life expectancy of patients with muscular dystrophy rarely exceeds 25 years.
Follow-up
Aftercare for muscular dystrophy essentially consists of alleviating the symptoms and disabilities that occur. Physiotherapy is of great importance in this regard. Via physiotherapy and occupational therapy, the mobility as well as residual functions of the muscles can be promoted. However, physiotherapy should not be too strenuous, as one cannot necessarily be sure that this will not have a negative effect in the end. Patients are also given hand splints or walking aids. This enables them to compensate for the loss of individual muscle groups for as long as possible. Later, the treatment of disorders with regard to swallowing and speech proves to be important and necessary. Nevertheless, these measures cannot avoid later feeding via tubes – in this way, potential penetration of food into the airways is to be prevented. Support of the respiratory function reduces the effort for the patient to breathe. Light strokes via the palms of the hands prove to be extremely beneficial. The same is true of gentle water pours – all the more so as the sensitive nerves remain intact for the rest of the patient’s life. Diet is also an important factor – the right foods can certainly provide relief. For example, protein-rich drinks can improve muscle strength and quality of life in older, sicker people. But it also seems important to properly educate and motivate the mostly elderly to prevent them from the downward spiral of aging – including muscle atrophy.
Here’s what you can do yourself
With muscle atrophy, there are things people can do to ease the discomfort and maintain their quality of life for as long as possible. Aids such as a grab bar or even a rollator promote independence and make everyday life easier. A toilet seat raiser and a bathtub seat are also sometimes useful. Exercise, for example in the form of physiotherapy, is at least as important in slowing down muscular dystrophy. However, any kind of sport should be discussed with the attending physician, because: The tissue is very sensitive to stretching in muscular atrophy, so not every type of sport is suitable. In principle, it is essential for patients with muscular dystrophy to follow the doctor’s instructions and, for example, to take the prescribed medication regularly. Physiotherapists can apply tapping-pressure massages and guide the patient to perform some exercises independently at home. Since the diagnosis of muscle atrophy can also affect emotional stability, it is also advisable to seek out a self-help group. Here, those affected can make contact with other sufferers and talk about their everyday lives with muscular dystrophy. Regular attendance at a self-help group also helps patients to stay active, which is also of great importance in muscular dystrophy.
