Treatment

There is no specific treatment that can stop or reverse the progression of any form of muscular dystrophy (MD). All forms of MD are genetic and cannot be prevented. Treatment is aimed at keeping the patient independent for as long as possible and preventing complications that result from weakness, reduced mobility, and cardiac and respiratory difficulties. Treatment may involve a combination of approaches, including physical therapy, drug therapy, and surgery.

Assisted ventilation is often needed to treat respiratory muscle weakness that accompanies many forms of MD, especially in the later stages. Oxygen is fed through a flexible mask (or, in some cases, a tube inserted through the esophagus and into the lungs) to help the lungs inflate fully. Since respiratory difficulty may be most extreme at night, some patients may need overnight ventilation. A mask worn over the face is connected by tube to a machine that puts out intermittent bursts of forced oxygen. Obese patients with Duchenne MD may develop obstructive sleep apnea and require nighttime ventilation. Patients on a ventilator may also require the use of a gastric feeding tube.

Drug therapy may be prescribed to delay muscle degeneration. Corticosteroids such as prednisone can slow the rate of muscle deterioration in Duchenne MD and help children retain strength and prolong independent walking by as much as several years. However, these medicines have side effects such as weight gain and bone fragility that can be especially troubling in children. Immunosuppressive drugs such as cyclosporin and azathioprine can delay some damage to dying muscle cells. Drugs that may provide short-term relief from myotonia (muscle spasms and weakness) include mexiletine; phenytoin; baclofen, which blocks signals sent from the spinal cord to contract the muscles; dantrolene, which interferes with the process of muscle contraction; and quinine. (Drugs for myotonia are not effective in myotonic MD but work well for myotonia congenita, a genetic neuromuscular disorder characterized by the slow relaxation of the muscles.) Anticonvulsants, also known as antiepileptics, are used to control seizures and some muscle activity. Commonly prescribed oral anticonvulsants include carbamazepine, phenytoin, clonazepam, gabapentin, topiramate, and felbamate. Respiratory infections may be treated with antibiotics.

Physical therapy can help prevent deformities, improve movement, and keep muscles as flexible and strong as possible. Options include passive stretching, postural correction, and exercise. A program is developed to meet the individual patient's needs. Therapy should begin as soon as possible following diagnosis, before there is joint or muscle tightness.

• Passive stretching can increase joint flexibility and prevent contractures that restrict movement and cause loss of function. When done correctly, passive stretching is not painful. The therapist or other trained health professional slowly moves the joint as far as possible and maintains the position for about 30 seconds. The movement is repeated several times during the session. Passive stretching on children may be easier following a warm bath or shower.
• Regular, moderate exercise can help MD patients maintain range of motion and muscle strength, prevent muscle atrophy, and delay the development of contractures. Persons with a weakened diaphragm can learn coughing and deep breathing exercises that are designed to keep the lungs fully expanded.
• Postural correction is used to counter the muscle weakness, contractures, and spinal irregularities that force MD patients into uncomfortable positions. When possible, patients should sit upright, with feet at a 90-degree angle to the floor. Pillows and foam wedges can help keep the person upright, distribute weight evenly, and cause the legs to straighten. Armrests should be at the proper height to provide support and prevent leaning.
• Support aids such as wheelchairs, splints and braces, other orthopedic appliances, and overhead bed bars (trapezes) can help maintain mobility. Braces are used to help stretch muscles and provide support while keeping the patient ambulatory. Spinal supports can help delay scoliosis. Night splints, when used in conjunction with passive stretching, can delay contractures. Orthotic devices such as standing frames and swivel walkers help patients remain standing or walking for as long as possible, which promotes better circulation and improves calcium retention in bones.
• Repeated low-frequency bursts of electrical stimulation to the thigh muscles can produce a slight increase in strength in boys with Duchenne MD.
• Speech therapy may help patients whose facial and throat muscles have weakened. Patients can learn to use special communication devices, such as a computer with voice synthesizer.
• Special exercises, or a special diet and feeding techniques, can help MD patients who have a swallowing disorder. Some patients may find it difficult to pass food or liquid from the mouth to the stomach, which can lead to poor nutrition and increased susceptibility to infection.

Dietary changes have not been shown to slow the progression of MD. Proper nutrition is essential, however, for overall health. Limited mobility or inactivity resulting from muscle weakness can contribute to obesity, dehydration, and constipation. A high-fiber, high-protein, low-calorie diet combined with recommended fluid intake may help. MD patients with swallowing or breathing disorders and those persons who have lost the ability to walk independently should be monitored for signs of malnutrition.

Occupational therapy may help some patients deal with progressive weakness and loss of mobility. Some individuals may need to learn new job skills or new ways to perform tasks while other persons may need to change jobs. Assistive technology may include modifications to home and workplace settings and the use of motorized wheelchairs, wheelchair accessories, and adaptive utensils.

Corrective surgery is often performed to ease complications from MD.

• Tendon or muscle-release surgery is recommended when a contracture becomes severe enough to lock a joint or greatly impair movement. The procedure, which involves severing a tendon or muscle to free movement, is usually performed under general anesthesia. Unfortunately, lengthening a muscle or tendon makes it weaker. Rehabilitation includes the use of braces and physical therapy to strengthen muscles and maintain the restored range of motion.
• Patients with either Emery-Dreifuss or myotonic MD may eventually require a pacemaker to treat cardiac problems.
• Surgery to reduce the pain and postural imbalance caused by scoliosis may help some patients. Scoliosis occurs when the muscles that support the spine begin to weaken and can no longer keep the spine straight. The spinal curve, if too great, can interfere with breathing and posture, causing pain. One or more metal rods may need to be attached to the spine to increase strength and improve posture. Another option is spinal fusion, in which bone is inserted between the vertebrae in the spine and allowed to grow, fusing the vertebrae together to increase spinal stability.
• Persons with myotonic MD often develop cataracts, a clouding of the lens of the eye that blocks light. Cataract surgery involves removing the cloudy lens to improve the person's ability to see.

Reference:

National Institute of Neurological Disorders and Stroke, USA.