Introduction
Myotonic dystrophy refers to an inherited muscle wasting and weakness disorder that is characterized by unrelenting involuntary muscle contractions. The involuntary contractions come as a response to the voluntary use of muscle or the muscle percussion. Clinically, the condition is classified under muscular dystrophy although the mechanism of the disease is unique and distinct from the mechanism of other muscular dystrophies. One distinct feature of myotonic dystrophy is that it has widespread effects all over the systems of the body. Myotonic dystrophy is caused by defective genes. This form of muscle dystrophy distinct is also followed by myotonia (a delayed muscle relaxation after contraction), as well as a number of abnormalities apart from those of the muscle. This makes myotonic dystrophy different from all other types of dystrophies. The condition exhibits an early muscle wasting pattern unique among the key muscular dystrophies. Unlike other muscular dystrophies, the condition first affects muscles in the feet, forearms, hands, neck and face, rather than the shoulder and hip muscles. This condition is also known as multisystemic since its effects are not limited to the voluntary muscle systems.
Causes
As stated earlier, myotonic dystrophy is an inherited condition. It is linked to defective genes for proteins that manage the charged particle’s flow within muscle cells. The gene defect is known as triple retreat, implying that it incorporates extra DNA code triplets. There exists a possibility that the mutation also affects the nearby genes. It is also possible that the prevalent symptoms of the condition result from numerous genetic disruptions.
Diagnosis of Myotonic Dystrophy (Chronic and End Stage OF disease)
The case presented involves a 47-years old man suffering from end-stage myotonic dystrophy. Varied methods of diagnosis may be used in determining the ailment from which he is suffering. Since the disease in this man is at the end-stage, a neurological examination cannot be used. Neurological examination is used in the initial stages since the principal diagnostic feature of the condition is a significant, transient increased in the muscle tone, brought about by the use or percussion of the muscle. Other features of the condition of the disease include muscle weakness, male testicular atrophy, muscle atrophy and haggard faces. In addition, the involvement of the distal muscle precedes that of the proximal muscle. However, in the late stages as in this man’s case, the prominence of the increased tone reduces in which case the diagnosis cannot be done on the basis of neurological exam alone. Nevertheless, various diagnosis methods may be used including the following.
1. Electromyography (EMG) – this method of diagnosing the condition is crucial in confirming the diagnosis. It indicates a typical myotonic discharge that has a waning and waxing quality. The predictable variability in the frequency and amplitude of the myotonic muscle action potential differentiates it from that of the Complex Repetitive Discharge (CRD) which exhibits a continuous amplitude and frequency.
2. Genetic testing- Individuals who have myotonic dystrophy have a different DNA from the normal population in that a component of Chromosome 19 is expanded. This expansion can be readily detected by the use of standardized genetic material tests.
How Myotonic Dystrophy Affects The Respiratory System
Newsom1 states that, while myotonic dystrophy affects numerous systems in the body, the respiratory system is the most affected and the most likely to cause an individual’s death. This is because of the weakness of the diaphragm, which is the sheet of muscles situated at the top of one’s abdomen and carries out the key job of coughing and breathing. The weakness of the diaphragm results in a reduction of stamina and energy, as well as an increased lung infection due to the inability to cough in the right manner. In essence, the old man will have to be provided with mechanical ventilation assistance, as well as an appropriate respiratory hygiene.
Rehabilitation programs for the condition
Given the advanced stage of the condition in this case, the condition cannot be treated using medication. In essence, any rehabilitation programs offered to the man will only be meant to ease the pain and enhance his life. Wolf, Shochina and Ferber3 state that, the treatment is mainly aimed at preventing complications that come with weaknesses including decreased dexterity and mobility, scoliosis, contractures, respiratory insufficiency and heart defects. The appropriate programs would be the following.
1.Physical therapy
Physical therapy is used to sustain the affected muscle’s range of motion, as well as delay or prevent contracture. Strenuous exercises, however, would not be recommended as they may increase the damage. During these exercises, braces are used on the feet, as well as ankles to prevent equinus. In addition, full-leg braces would be used to lengthen the period of independent walking. It may, however, not be possible to strengthen other muscles since the condition in this case is in the last stages.
2.Surgery
Tenotomy surgery is performed when the contracture are increasingly pronounced. During the surgery, the contracted muscle’s tendon is cut and the limb braced in its usual resting position as the tendon regrows. When any surgery is being carried out on individuals with muscular dystrophy, it is imperative that anesthesia is carefully selected. This is because individuals with the condition are vulnerable to a severe reaction called hypothermia, when a halothane anesthetic is administered.
3.Nutrition
Good nutrition assists in promoting general health in all muscular dystrophies including myotonic dystrophy. Brown and Mendell4 assert that no supplement or uncommon diets have been shown to uplift any of the dystrophies. Nevertheless, the weakness of the throat muscles may make it necessary for a gastronomy tube to be used. This tube would be inserted into one’s stomach to provide the nutrition directly.
4.Occupational therapy
Occupational therapy incorporates tools and techniques to compensate for the loss of dexterity and strength. The strategies used in this case include changes in the man’s home, dressing aids, adaptive utensils, wheelchair accessories, communication aids, as well as compensatory positioning and movement.
5.Cardiac care
Antiarrhythmia medications such as nifedipine and mexiletine may be used to treat the arrhythmias that come with the condition. In addition, doctors may implant a pacemaker if the drugs do not offer sufficient control. However, the age of the man and the advanced nature of the condition would limit the need to install heart transplants.
6.Respiratory care
Since the man has a weak diaphragm and other ventilatory muscles, it is imperative that a mechanical ventilator is installed to ensure that he continues breathing deeply enough. A tracheostomy tube may be used to administer air through a mouthpiece or nasal mask. The tube is inserted via a surgical incision in the neck and to the windpipe. However, supplementary oxygen would not be necessary. Emery2 states that, it is imperative that proper hygiene of the lungs is maintained for the long-term survival and health of the individual. In addition, assisted cough machines may be used to clear the secretions present in the airways.
Bibliography
Newsom Davis J. The respiratory system in muscular dystrophy. Br Med Bull 1980
Emery, Alan E. Muscular Dystrophies. Cary, NC: Oxford University Press, 2003.
Wolf E, Shochina M, Ferber I, Phrenic nerve and diaphragmatic involvement in progressive muscular dystrophy. Electromyogr Clin Neurophysiol 1981;
Brown, R H., and Mendell, J R. “Muscular Dystrophies and Other Muscle Diseases. New York: McGraw-Hill, 2001
Barohn, Richard J. “Muscle Diseases.” Philadelphia: Saunders, 2003
