Myopathy is the general name of diseases that primarily involve skeletal muscle. Progressive muscular dystrophy is the most common type of myopathies that may occur due to genetic, infectious, autoimmune or toxic causes in childhood. The severe form of the disease is called Duchenne muscular dystrophy (DMD) and the lighter form is called Becker muscular dystrophy (BMD).
Duchenne muscular dystrophy (DMD) is the most severe and most common form of myopathy in childhood.
Two of the three cases are X-linked recessive; one is due to mutations in those without a family history. The mutation in the dystrophin gene in the short arm of the X chromosome (Xp21) causes the disease. The incidence is approximately 1 in 3500 male births. Dystrophin proton is found in both skeletal and heart muscle. Dystrophin provides structural support during muscle contraction and regulates intracellular calcium levels. The production of dystrophin in DMD is almost nonexistent. If dystrophin is absent or structurally impaired, muscle contraction is impaired, intracellular calcium increases, resulting in cell necrosis and severe muscle degeneration.
Duchenne muscular dystrophy (DMD) is also known as pseudohypertrophic or progressive muscular dystrophy. The disease begins as insidious. It usually starts before the age of 3 years. The first symptom is the difficulty in walking due to the symmetrical weakness of the hip muscles. The child does not want to walk, has difficulty running and jumping, often falls. After leaning on the floor, the child clings to a place. Arm muscles weaken later than the leg, starting around the shoulder. Muscle weakness progressively progresses and a significant proportion of muscle mass is lost at age 4-5. False growth (pseudohypertrophy) is observed in some muscles. The most common site of false growth is the calf muscles. Joint movements are restricted within 3 years from the beginning. Without intensive rehabilitation, the child becomes wheelchair-dependent at age 8-9. Curvature of the back (scoliosis) develops. Gradually breathing difficulties, heart, gastrointestinal disorders occur.
The heart is more or less affected by 90%. Cardiac symptoms occur in the late stages of the disease. Heart involvement develops independently of muscle involvement. Arrhythmia, cardiomyopathy and consequently heart failure may occur.
As a result of weakness of the muscles between the diaphragm and ribs, lung capacity decreases and scoliosis decreases vital capacity and aggravates respiratory problems.
Becker muscular dystrophy (BMD) is milder and less common. Diagnosis is made between 5-25 years. Ambulation is maintained for up to 20 years after the onset of weakness. Life expectancy is normally normal unless there is a heavy heart condition.
Rare myopathies: Fascioscapulohumeral Muscular Dystrophy (FSHMD) is a dystrophic myopathy with slow progression involving the muscles of the face and shoulder girdle.
This disease is a group of limb-girdle muscular dystrophy (Limb-girdle muscular dystrophy) that causes weakness in the hips and shoulders, is linked to X, can show autosomal dominant and autosomal recessive transition and has different progression rates.
Emery Dreifuss Muscular Dystrophy (EDMD) is characterized by early contracture development in the elbow, achilles tendon, and neck extensors, distal muscle weakness and weakness, particularly in the humeroperoneal region, and severe cardiomyopathy.
Myotonic Muscular Dystrophy (MMD) is the most common slow-progressing dystrophy.
Polymyositis (PM) and dermatomyositis (DM) are idiopathic inflammatory myopathies thought to be caused by autoimmune mechanisms.
Corticosteroid myopathy can be seen in long-term moderate and high-dose oral or short-term parenteral corticosteroid users.
Although Duchenne muscular dystrophy is severe, treatment of DMD and BMD is similar. Multidisciplinary team approach is required for the treatment and optimal follow-up of complications. Rehabilitation aims to provide a quality life and to maintain functional independence. With the rehabilitation program, it is possible to prevent complications, maintain function and achieve a reasonable quality of life.
Exercise program should be started as soon as diagnosis is made. Aerobic and multiple repetitive exercises should be performed with submaximal strength. Since contractures are inevitable in patients with DMD, it is important to start the rehabilitation program early. Each exercise should be repeated 10-15 times in the morning and evening and should be counted up to 15 in the tense position.
In rehabilitation, suitable patients are taught to walk with a walking robot and to use their arms and hands with arm and hand robots.
Corticosteroids improve DMD progression, clinic and quality of life.
Stem cell and gene therapy options are at the experimental stage.
Patients should be checked periodically for deformity, respiratory and cardiac disorders and necessary precautions should be taken.
Similar applications are made for myopathies that are rarely seen in terms of rehabilitation..