Myopathies are muscle diseases. In most cases, the striated skeletal muscles are affected. Muscular dystrophies or myotonic syndromes, for example, belong to the group of myopathies.
What are myopathies?
The term myopathy comes from the Greek and means muscle disease. Accordingly, myopathies are diseases of the muscles. They usually affect the striated muscles of the skeleton. But also diseases of the heart muscle, the so-called cardiomyopathy, belong to the group of myopathies. See sciencedict for Introduction to Cryptococcosis.
Myopathies are to be differentiated from other diseases that are also associated with muscle weakness. For example, amyotrophic lateral sclerosis or spinal muscular atrophy are not myopathies. They belong to the diseases of the motor neuron. Myopathies can be divided into primary and secondary myopathies.
Causes
Primary myopathies are primarily based on diseases of the muscles. So you are not suffering from any other disease. Muscular dystrophies belong to the degenerative primary myopathies. These include:
- the limb girdle dystrophy,
- facioscapulohumeral muscular dystrophy
- the congenital muscular dystrophy.
Most muscular dystrophies are genetic. Myotonic syndromes such as myotonic dystrophy type 1, myotonic dystrophy type 2, paramyotonia congenita Eulenburg or myotonia congenita Thomsen are also inherited. Congenital myopathies are already evident in newborns. Disease patterns such as nemaline myopathy, central core myopathy or myopathy with congenital fiber type disproportion are also caused by genetic defects.
The same applies to the mitochondrial myopathies. Due to a [[[mutation]] in the DNA of the mitochondria, the mitochondria are reduced or altered. This leads to a disruption in the energy metabolism within the cell organelles. Myopathies also occur in the context of other underlying diseases. These muscle diseases are also referred to as secondary myopathies. Secondary myopathies are often the result of diseases of the endocrine system.
They occur in hyperthyroidism or hypothyroidism, in Cushing’s disease and in diseases of the parathyroid gland (hypo- or hyperparathyroidism (parathyroid gland hyperfunction)). Metabolic diseases can also make themselves felt through myopathies. The muscles require a lot of energy. This is why disturbances in the energy metabolism in particular are expressed in the muscles. Important diseases here are the lipid storage disease or the glycogen storage disease.
Myopathies can also result from nutrient deficiencies. This is how muscle diseases occur with vitamin D deficiency or selenium deficiency. Inflammatory myopathies arise in autoimmune diseases or infectious diseases. Trichinosis is an infectious disease that often leads to myopathies. Autoimmune diseases with myopathies are polymyositis and inclusion body myositis. However, myopathies can also be triggered by drugs, alcohol abuse or other exogenous toxins.
Symptoms, Ailments & Signs
A characteristic symptom of all myopathies is muscle weakness. In muscular dystrophies, muscle degeneration occurs in addition to progressive muscle weakness. Congenital myopathies begin immediately after birth or in the first few months of life. Musculature develops too slowly or incompletely. The children cannot work their muscles against gravity.
Myotonic syndromes are characterized by a pathologically prolonged period of muscle contraction. Inflammatory myopathies are based on an inflammatory process. In addition to muscle weakness, there is reddening and overheating of the muscles. Pain is also possible. If the heart muscle is affected by the myopathy, the conduction is impaired. The result is cardiac arrhythmia.
As a result of mitochondrial myopathy, brain function may be impaired. Stroke-like symptoms may occur. These phenomena are also known as MELAS syndrome. Mitochondrial myopathy is a multisystem disease. The eyes and inner ear can also be affected. Damage to the retina and optic nerve can lead to blindness. The development of diabetes mellitus is also favored by mitochondrial myopathy.
Diagnosis & course of disease
Muscle weakness as a characteristic syndrome provides the first indications of a myopathy. In a detailed anamnesis, the doctor clarifies possible risk factors or causes. If muscle disease is suspected, a blood test may be performed. In muscular dystrophy, serum creatine kinase (CK) is elevated. This increases with the loss of skeletal muscle fibers.
The increase in creatine kinase in the blood is called hypercreatinemia. Aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT) and lactate dehydrogenase (LDH) are also elevated but are not as sensitive and specific as serum creatine kinase. The level of creatine kinase differs quite significantly between the individual muscular dystrophies. The value can therefore also be used for differential diagnosis.
Muscle biopsy is performed to confirm the diagnosis for most myopathies. Depending on the type of disease, various typical structures appear in the histological examination.
Complications
The primary cause of myopathy is severe muscle weakness. The resilience of those affected drops significantly and there are severe restrictions in everyday life. Those affected appear tired and exhausted as a result of the disease and are no longer able to carry out normal everyday activities. It is not uncommon for myopathy to also lead to heart problems, which can lead to cardiac arrhythmias.
In the worst case, the person affected can also die of sudden cardiac death as a result of this complaint. The heart complaints continue to have a negative effect on the conduction of stimuli. In some cases, the myopathy leads to paralysis and further limitations in sensitivity. Motor skills can also be negatively affected by this disease. It is not uncommon for those affected to continue to suffer from diabetes.
Treatment of myopathy can take place with the help of medication and through therapy and exercise. This can limit and reduce many complaints. However, it cannot usually be predicted whether complete healing will occur. Complications can occur if a tumor has also developed. This may reduce the life expectancy of the patient.
When should you go to the doctor?
A persistent general feeling of illness and an inner weakness should be clarified by a doctor. If there are disturbances in the metabolism or irregularities in the heart rhythm, a doctor should be consulted to clarify the cause. Sleep disorders, a lack of concentration and attention as well as a decrease in general performance must be examined and treated. If you have an increased energy requirement, tire quickly or are less able to work under pressure, there is a health impairment that should be clarified. If there are general functional disorders, loss of vision or hearing, a doctor is needed.
Internal irritation, sensory disturbances, numbness on the skin and hypersensitivity to temperature or touch should be discussed with a doctor. Inflammation of the muscles, an internal development of heat, an increased need for fluids and headaches are signs of the organism for an existing disease. If there is an interruption in consciousness, muscle weakness or if you feel unwell, you should consult a doctor. Discoloration of the skin is considered a warning and should be presented to a doctor.
Heart palpitations, sleep disorders, restlessness and emotional abnormalities should also be discussed with a doctor. Changes in behavior, a depressive appearance or mood swings can result in side effects that must be taken into account when making the diagnosis. They can indirectly worsen an existing disease or trigger other disorders that should be treated.
Treatment & Therapy
As a rule, the primary myopathies cannot be treated causally, since they are based on a genetic defect. Depending on the myopathy, different medications are used to treat the symptoms. Physiotherapy can also help those affected. In the case of secondary myopathies, the focus is on treating the underlying disease. Hypothyroidism is treated with thyroid hormone preparations.
In the case of hyperthyroidism, antithyroid drugs are administered. Cushing’s disease is treated with synthetic glucocorticoids. If Cushing’s syndrome is caused by a tumor, it must of course be removed. Nutritive myopathies require substitution of the nutrient. Cardiac myopathy is usually treated with additional heart-strengthening drugs and antiarrhythmics.
Outlook & Forecast
Myopathy is unlikely to be fully cured for years to come, with advances in genetics. With some forms of myopathy, the prospect of a cure is rather poor, since there are cases with a fatal outcome. This is especially the case in infants and newborns who are born with congenital myopathy and other health disorders at the same time.
In contrast, those affected with myopathies who show only minimal symptoms have a normal life expectancy. These milder myopathies do not progress and can also be easily managed with today’s modern treatment methods. Affected children also cope well with some forms of myopathy up to adulthood and often get along well into old age.
In particular, the life expectancy and the quality of life of patients with congenital and non-congenital muscle wasting have improved in recent years. Life-threatening symptoms are extremely rare and only occur in isolated cases. The majority of myopathies today are seeing increasing rates of recovery and marked improvements in well-being, even if a cure is not always possible. The prognosis of myopathy is therefore extremely variable and individual. In addition, the myopathies can only be treated causally or, depending on the type, only predominantly symptomatically.
Prevention
Primary myopathies are inherited. Prevention is not possible here. Secondary myopathies can be prevented by early detection and treatment of the underlying disease. Adequate intake of nutrients and vitamins such as vitamin D or selenium can reliably prevent nutritional myopathies.
Aftercare
In the case of myopathy, the measures or the options for direct follow-up care are in most cases significantly limited. For this reason, the affected person should ideally consult a doctor at an early stage in order to prevent the occurrence of other symptoms and complications. As a rule, it cannot heal on its own, so that treatment by a doctor is always necessary.
The earlier a doctor is consulted in the case of myopathy, the better the further course of the disease, so that early diagnosis is the priority. As a rule, patients with myopathy are dependent on taking various medications.
It is important to ensure the correct dosage and regular intake. Most of those affected are dependent on regular examinations and checks by a doctor so that other tumors can be detected at an early stage. The myopathy may lead to a reduced life expectancy for the patient, with the further course depending very much on the exact severity of the disease.
You can do that yourself
In the case of genetic myopathy, treatment can only relieve symptoms and aim to improve quality of life. This includes regular participation in physiotherapy. Very good results were achieved in the area of muscle building, especially with water aerobics. A balanced diet and a healthy balance between stress and relaxation generally have a supporting effect.
In the case of a secondary myopathy, the underlying disease can be treated and thus the muscle weakness can be corrected. Those affected should first check their consumption of medication, alcohol and other stimulants. If there is a nutrient deficiency, it can be easily compensated for by a targeted diet by those affected. Targeted nutrient therapy may also be used. Taking selenium has been shown to help with this form of muscle weakness. Selenium is also recommended as a supplement to hormone intake in the case of an existing hypothyroidism. Especially in the case of an existing autoimmune disease, a healthy lifestyle with sufficient sleep, fluid intake and stress reduction (autogenic training, yoga) fundamentally important.
Since myopathy is usually inherited and even small children show symptoms, parents of affected children should seek advice at an early stage or seek support themselves in a self-help group or psychological support. The emotional burden on those affected and their parents should not be underestimated. Affected families can also apply for household support from the statutory health insurance companies.
