Becker Muscular Dystrophy (BMD)
Thanks to general medical advances, particularly in cardiology, people with Becker muscular dystrophy (BMD) are living longer in the 21st century than in previous decades. As of 2011, most therapies are supportive in nature, although truly disease-modifying therapies are the subject of intense research.
MDA clinic physicians can provide referrals to specialists and therapists for these forms of care. The use of available therapies can help maintain comfort and function and prolong life expectancy.
To view a presentation on medical management of BMD by pediatric neurologist Brian Tseng, see the August 2012 Taking the Reins of Your Medical Care and Participating in Clinical Trials.
People with BMD may have unexpected adverse reactions to certain types of anesthesia. It's important that the surgical team know about that the patient has BMD so that complications can be avoided or quickly treated.
Braces, scooters and wheelchairs
Braces, also called orthoses, can support just the ankle and foot or extend over the knee. Ankle-foot orthoses are sometimes prescribed for night wear to keep feet from pointing downward and keep the Achilles tendon stretched. (Orthoses also are known as orthotics.)
To view an August 2012 video presentation on this topic, see Functional Treatment Considerations: Orthotics.
Some people with BMD ultimately require wheelchairs or scooters. Although some look at these devices as symbols of disability, most users find they're actually more mobile, energetic and independent when using a wheelchair than when trying to walk on very weak legs. Scooters and wheelchairs are especially valuable when covering long distances.
To view a presentation by an occupational therapist, see the August 2012 video Functional Treatment Considerations: Occupational and Physical Therapy.
Cardiomyopathy, which means deterioration of the heart muscle, is common in Becker MD. The American Academy of Pediatrics recommends that those with BMD have cardiac evaluations at least every other year beginning at age 10.
Carriers of BMD also are at higher-than-average risk of developing cardiomyopathy. The Academy suggests that carriers should undergo a complete cardiac evaluation in late adolescence or early adulthood, or sooner if symptoms occur, and should be evaluated every five years starting at age 25 to 30.
Some people with BMD who have cardiomyopathy but generally good health have been successfully treated with heart transplants.
- Revising Cardiac Care in Muscular Dystrophies
- Doctors Talk Heart to Heart (pediatric cardiologists and other experts at an MDA-sponsored meeting exchanged information and planned studies regarding the heart in DMD and BMD)
- DMD Clinical Research Network Studying Dystrophin-Deficient Heart
- Cardiac Complications and Management in BMD (a 2012 video presentation about cardiac care in BMD)
As muscle deteriorates, a person with muscular dystrophy often develops fixations of the joints, known ascontractures. If not treated, these can become severe, causing discomfort and restricting mobility and flexibility. The impact of BMD can be significantly minimized by keeping the body as flexible, upright and mobile as possible.
There are several ways to minimize and postpone contractures. Range-of-motion exercises, performed on a regular schedule, help delay contractures by keeping tendons from shortening prematurely. It’s important that a physical therapist demonstrate the correct way to do range-of-motion exercises.
Braces on the lower legs help keep the limbs stretched and flexible, delaying the onset of contractures.
When contractures have advanced, surgery may be performed to relieve them. A tendon release procedure, also called heel cord surgery, can treat ankle and other contractures while the child is still walking.
- Helping Kids Understand: I Don't Wanna! (help your child comply with medical regimens, such as exercises to help prevent contractures)
No special dietary restrictions or additions are known to help in BMD. Most doctors recommend a diet similar to that for any growing boy, but with a few modifications.
A combination of immobility and weak abdominal muscles can lead to severe constipation, so the diet should be high in fluid and fiber, with fresh fruits and vegetables dominant.
For boys and men who use power wheelchairs, aren’t very active or who take prednisone, excessive weight gain can occur. Caloric intake should be restricted to keep weight down, as obesity puts greater stress on already weakened skeletal muscles and the heart. Doctors have found that a low-calorie diet doesn’t have any harmful effect on the muscles.
Those on prednisone and those with cardiomyopathy may require a sodium-restricted diet.
- Nutritional Considerations While on Corticosteroids (includes meal planning guides and suggested food options)
- Weighing Your Options
- Nutritional Needs in Neuromuscular Disease (a 2012 video about nutritional considerations in BMD and other disorders)
Exercise can help build skeletal muscle, keep the cardiovascular system healthy and contribute to feeling better. But in muscular dystrophy, too much exercise could damage muscle. Consult with your doctor about how much exercise is best. A person with BMD can exercise moderately but shouldn’t go to the point of exhaustion.
Some experts recommend swimming and water exercises (aquatic therapy) as a good way to keep muscles as toned as possible without causing undue stress on them. The buoyancy of the water helps protect against certain kinds of muscle strain and injury.
Before undertaking any exercise program, make sure to have a cardiac evaluation.
Dystrophin deficiency can cause some cognitive problems in some people. Children and adults with BMD who are suspected of having a learning disability can be evaluated by a neuropsychologist through a school system’s special education department, or at a medical center with a referral from the MDA clinic.
If a learning disability is diagnosed, educational and psychological interventions can begin right away. The specialist may prescribe exercises and techniques that can help improve these deficits, and schools can provide special help with learning.
Medications that lessen the workload on the heart are sometimes prescribed for BMD. There’s some evidence that treatment with angiotensin converting enzyme (ACE) inhibitors and beta blockers can slow the course of cardiac muscle deterioration in BMD if the medications are started as soon as abnormalities on anechocardiogram (imaging of the heart) appear, but before symptoms occur.
Medications belonging to a group known as corticosteroids have been found effective in slowing the course of Duchenne muscular dystrophy. Data for or against the use of corticosteroids in BMD are lacking. However, some physicians prescribe corticosteroids for severe BMD in much the same way as they would for DMD, if the patient or family wants to try this type of medication.
Prednisone is by far the most commonly prescribed corticosteroid for DMD/BMD in the United States. When taking at relatively high doses for long periods of time, it can have significant side effects, such as weight gain, decreased bone density, behavioral abnormalities, cataracts and growth retardation.
Physical and occupational therapy
A physical therapy program is usually part of the treatment for BMD. Your MDA clinic physician will refer you to a physical therapist for a thorough evaluation and recommendations.
The primary goals of physical therapy are to allow greater motion in the joints and to prevent contractures and scoliosis (spinal curvature). Occupational therapy focuses on specific activities and functions, such as work tasks, recreation, driving, dressing or using a computer.
For an August 2012 video on this topic, see Functional Considerations: Occupational and Physical Therapy.
In some people with BMD, particularly as they age, breathing muscles can weaken, resulting in less than optimal breathing, particularly during sleep. This can be treated by a noninvasive strategy known as bilevel positive airway pressure. Coughing muscles also can become weak, allowing mucus to build up in the respiratory tract, which can lead to obstruction and infection. A device known as a CoughAssist can help with this problem.
To see a presentation by a pulmonary medicine specialist, see the August 2012 video Lung Health in Neuromuscular Disease.