What is myotonic muscle dystrophy?
myotonic muscle dystrophy (MMD), also known as myotonica dystrophy (DM), is a type of muscle dystrophy where myotonia is a cardinal symptom. Myotonia is a permanent involuntary contraction of the muscle group, which means that there is an inability to voluntarily relax muscles. For example, there is difficulty releaseing adhesion on the handle or at hand. MMD is also characterized by muscle stiffness after use, progressive waste of muscles and muscle weakness. Two common types of myotonic muscle dystrophy with different genetic defects are myotonic dystrophy type 1 (MMD1 or DM1) and myotonic dystrophy type 2 (MMD2 or DM2). This is due to the mutation in the Dystrophy gene of myotonica protein kinase (DMPK), which is located in the long arm of the chromosome 19. DM2, also called the proximal myotonic myopathy, is caused by a mutation in the Zinc 9 protein (ZNF9). Both types of myotonic muscle dystrophy are autosomal dominant disorders. It means thatE One copy of the mutated gene in both parents is enough to cause a disorder in all their children.
myotonic muscle dystrophy often presents itself in adulthood and less commonly in late childhood. The muscles of the distal limbs and the muscles of the neck are involved at the beginning of the course, resulting in abnormality while walking, dropping legs and swallowing. A person with myotonic muscle dystrophy can also experience the weakness of the facial muscles leading to the typical appearance of face to face; weakness of muscles in the wrist, fingers and hands leading to deterioration of normal daily function; and the weakness of respiratory muscles affecting breathing and lung function. Constipation or diarrhea may occur due to the weakness of the digestive tract muscles and may fain or dizziness due to the weakness of the heart muscle. Other abnormalities found in the affected individuals are speech and voice problems, forehead bald, infertility, intellectual damage, eye lens, turbidity, andNzulin resistance and excessive daily drowsiness.
heart disorders, such as the heart block and the prolapse of the mitral valve, are more common in DM1 than in DM2. The heavy form of DM1 occurs in approximately 25% of infants affected by mothers. This is known as congenital myotonic dystrophy and is characterized by severe muscle weakness, mental retardation and difficulty in breathing, suction and swallowing. DM2 mainly affects the muscles near the center of the body. Heart disorders, ax face and front bald occurrence are unusual.
The diagnosis of myotonic muscle dystrophy is usually determined by history and physical examination. The doctor could apply for electromyogram and muscle biopsy. The electromyogram includes measuring the electrical activity of the muscles. Muscle biopsy involves tchurgical removal of a small piece of muscle for microscopic examination.
The aim of treatment is to minimize disability and also alleviate symptoms and discomfort. Phenytoin and Mexilenen are preferred antimyoton drugs. In patients with heart disorders and zak disordersAlena's eyes lens should be considered by cardiac pacemakers and surgery cataracts. The use of assistance devices for walking, such as sticks, pedestrians and pressed ankle orthoses, can help in mobility and walking problems. Sleep studies may be beneficial to prevent excessive daily drowsiness.