Becker Muscular Dystrophy Treatment & Management

Physical Therapy

The role of physical therapy services is to address the functional needs of the patient as the disease progresses. Early interventions may focus on stretching tight muscles (which may initially be the only therapy goal). As the patient's weakness progresses, appropriate equipment and assistive devices will be required to enable the individual to maintain functional mobility and independence in daily living activities. Educational objectives include teaching the patient techniques for energy conservation, joint protection, and the prevention of overuse fatigue.

The greatest physical therapy benefits for patients with BMD may be derived from twice-weekly sessions of 30-45 minutes each (although the patient’s capacity, fatigability, and availability must be taken into account). Greater exercise precautions, including limitation of intense contractions and eccentric stresses and promotion of aerobic metabolism, are needed for the muscles that have been most affected (ie, those with a score of less than four on the Medical Research Council Scale for Muscle Strength). In addition, evaluation for and monitoring of BMD-associated disorders, including pain (rest and stress myalgia), respiratory or cardiac involvement, and swallowing or cognitive dysfunction (executive disorders), is required. ^[25]

Occupational Therapy

Activities of daily living skills are addressed, depending on the level of impairments, in occupational therapy. Specific adaptations (to aid, for instance, dressing and bathroom skills) may be provided. Such adaptations range from methods of buttoning and zippering clothes to grab bars and raised toilet seats in the bathroom. Mobility concerns are addressed, including the need for devices to assist with mobility, such as a scooter or a fully adapted wheelchair with a custom seat and back, custom supports, and electric power. ^[26]

Speech Therapy

Dysphagia concerns may be evaluated by a speech therapist. Progressive weakness toward the end of the disease process may lead to dysphagia and an increased risk of aspiration pneumonia. Clinical evaluation may result in the recommendation to avoid specific food textures and liquid viscosities, as well as to avoid certain positions during feeding. Videofluoroscopic evaluation may be performed to demonstrate the risk of aspiration.

Recreational Therapy

Specific planning for avocational needs and desires may be coordinated with a recreational therapist. Resources within the community, such as activity programs with the local parks and recreation department, may be explored. Educational institutions, from public schools to community colleges and universities, may have resources that can be utilized. Adaptive physical education programs and disabled student services are generally available for qualified individuals. Access and mobility concerns in the community invariably touch upon the adjustment issues faced by individuals with a progressive disability.

Potential complications of BMD include progressive weakness that results in orthopedic deformity and medical emergencies for cardiac and respiratory symptoms. Swallowing-related complications, from difficulties with mastication to problems in the pharyngeal phases, may arise with progressive weakness of the swallow mechanism.

A study by Yamada et al found that when patients with BMD were matched by physical function status to patients with DMD, both groups had similar swallowing problems. The investigators reported that BMD patients did not differ from those with DMD with regard to the rate of aspiration or scores on the penetration-aspiration scale or total videofluorographic dysphagia scale. ^[27]

Recurrent aspiration pneumonias from progressive dysphagia may eventually cause mortality in BMD. The progressive loss of safe swallowing may result in the need for gastrostomy tube placement. Constipation may be an associated problem, given poor fluid intake and progressive difficulty with commode transfers. Overuse syndromes may lead to complaints of muscle pain, prolonged fatigue, and myoglobinuria.

Progressive scoliosis and contracture formation may require surgical intervention. Spinal fusion to correct scoliosis may be scheduled based on the progression of spinal deformity and the age of the patient. Ankle contractures may be corrected with appropriate heel cord release and lengthening. Muscle transfers, such as with the posterior tibialis muscle, also may be considered to preserve functional mobility.

Subspecialty consultations depend on the patient's specific needs as related to the disorder. Appropriate consultations may include the following:

• Anesthesiologist - Preoperative management and planning for appropriate anesthesia are key reasons for consultation with an anesthesiologist. The risk of malignant hyperthermia is significant, given the intrinsic muscle disorder. Appropriate cautions must be taken to avoid medications that may precipitate malignant hyperthermia. ^{[28, 29]} Dantrolene sodium is probably the best medication to use if malignant hyperthermia arises.

• Cardiologist - Cardiac function requires ongoing follow-up care. Symptomatic patients with significant cardiomyopathy have undergone transplantation procedures.

• Pulmonologist - The need for management of pulmonary problems associated with muscle weakness and restrictive disease is a typical indication. ^[30] Formal pulmonary function testing may be used for preoperative care, as well as for the determination of need for ventilatory support.

• Orthopedist - The need for management of scoliosis and joint contractures are major indications for consultation with an orthopedist. ^[31] The period around puberty is generally the time for significant change in scoliosis, especially if the patient's ambulatory status is limited. Heel cord release is a commonly performed joint contracture procedure.

• Geneticist - Consultation regarding the carrier status of the patient's mother and siblings is important. Transmission risk to offspring should be discussed. Identifying mosaicism in the mother or father, as well as determining the risk of transmission, is another topic to consider in nonheterozygote carrier families or in isolated cases.

Because no cure exists for BMD, treatment is focused on controlling a patient's symptoms. Weakness progresses, and emergencies related to cardiac and respiratory symptoms are hallmarks of advance in the disease process. Possible future treatments for BMD include the following:

• Gene therapy may eventually lead to effective treatment, given proper identification of the gene defect and effective administration of the corrective gene to the muscle targets. ^{[32, 33]}

• Myoblast treatment, as well as the use of stem cells, also may be alternative modalities if proven successful.

• Steroids have been reported to show benefit in patients with DMD, but there are conflicting reports. No definitive evidence demonstrates that steroids are effective against BMD.