Muscular dystrophies comprise a group of genetic diseases characterized by atrophy of muscle tissue and progressive weakness. There are nine clinically distinct muscular dystrophies.

• Duchenne muscular dystrophy (DMD), the most common form of muscular dystrophy in children
• Becker muscular dystrophy (BMD), identical to DMD except for age at onset
• myotonic muscular dystrophy (DM), the most common form of muscular dystrophy in adults
• congenital muscular dystrophy (CMD), a severe form of DM in infants
• limb-girdle muscular dystrophy (LGMD)
• facioscapulohumeral muscular dystrophy (FSH)
• oculopharyngeal muscular dystrophy (OPMD)
• distal muscular dystrophy (DD)
• Emery-Dreifuss muscular dystrophy (EDMD).

DMD, BMD, DM, and CMD will serve as the focus of this information. The incidences for DMD, BMD, and DM are 30 in 100,000, 3 in 100,000, 13.5 in 100,000, respectively.

All of the muscular dystrophies are caused by gene mutations. DMD and BMD are characterized by an X-linked recessive mutation of the dystrophin gene, affecting males only. DM is an autosomal dominant disorder that is transmitted by a mutation of the gene on chromosome 19, affecting males and females. The mutation consists of an unstable expansion of the trinucleotide sequence (cytosine, thymine, guanidine, or CTG) in muscle cells.

Individuals from families in which muscular dystrophy has been identified are at increased risk of passing the disease to their offspring. Genetic counseling can help these families make informed reproductive decisions. One-third of cases are sporadic with no family history.

DMD: Although the disease is present at birth, signs and symptoms are not usually evident until age 3 to 5. These include frequent falls; difficulty running, jumping, and getting up from a sitting or lying-down position; a waddling gait; large calf muscles (pseudohypertrophy from adipose and connective tissue replacing muscle); toe walking; pronounced weakness in the proximal lower extremities; and mild mental retardation. Respiratory difficulties, often the result of thoracic scoliosis, and cardiomyopathy develop during adolescence, usually after patients become wheelchair-bound.

BMD: Early signs resemble those of DMD but occur later between ages 5 and 15 and progress gradually. Cardiac problems may result in heart failure. Patients may be ambulatory into their 30s and 40s.

DM: Myotonia, delayed muscle relaxation after contraction, and dystrophic changes in nonmuscular tissue are the hallmarks of DM. Atrophy of facial muscles resulting in a "hatchet face"; baldness in men and women; weakness in the distal muscles of the extremities, resulting in weak hand muscles and footdrop; weakness of pharyngeal, tongue, palatal, and esophageal muscles, affecting speech and swallowing; cataracts; testicular atrophy or ovarian insufficiency; intellectual impairment; respiratory insufficiency; and cardiac abnormalities present in early adulthood.

CMD: Children are severely hypotonic, with facial diplegia, respiratory difficulties, feeding difficulties, skeletal deformities, and developmental delay.

• Neuromuscular disease
• Dermatomyositis
• Polymyositis
• Spinal muscular atrophy
• Metabolic and inflammatory myopathies
• Centronuclear and mitochondrial myopathies

Children often present with delay in walking, and adults and adolescents present with progressive muscle weakness. Considerable clinical variability exists, making sophisticated testing mandatory for a definitive diagnosis.

Measurement of serum creatine phosphokinase levels, which are elevated 20 to 100 times normal in DMD and BMD.

Used to assess specific deformities such as equinocavovarus foot.

• Electromyography (EMG)–detects myopathy in DMD and myotonia in DM
• Electrocardiogram (ECG)–determines the extent and type of cardiac abnormalities
• Muscle biopsy—in DMD, identifies disorganization of muscle fibers and necrosis; in DM, identifies muscle atrophy
• Western blot analysis—identifies protein products from muscle cells and determines dystrophin levels in DMD and BMD to confirm the diagnosis and to predict the severity
• Polymerase chain reaction and Southern blot analysis—in DMD and BMD, determines the mutation of the dystrophin gene (e.g., deletion, duplication, point mutation); in DM, determines the number of CTG repeats and predicits the severity of the phenotype
• Linkage analysis—finds genetic loci on DNA and identifies at-risk female relatives

Muscular dystrophies are incurable, progressive, and fatal. Treatment regimens are designed to maintain optimal physical and emotional health by preventing joint and spinal deformities in order to prolong ambulation for as long as possible. Assisted ventilation is introduced as needed, usually to treat hypoxia at night but eventually progressing to daytime use as well.

Lifelong physiotherapy is essential to prevent or delay complications such as painful contractures, loss of ambulation, scoliosis, hypoventilation, and respiratory failure. Daily passive stretching exercises and orthopedic appliances (e.g., braces, calipers, night splints), which are used for support when the muscles become too weak, may prolong ambulation. Hydrotherapy helps to maintain full range of joint motion.

• Prednisone (0.75 to 1.5 mg/kg/day)—to improve muscle strength in DMD for up to three years; side effects of obesity, hypertension, and diabetes limit its use
• Phenytoin (100 mg tid), quinine (300 to 400 mg tid), and procainamide (0.5 to 1 g qid)—to treat myotonia; caution is required as quinine and procainamide worsen cardiac conduction

• Spinal surgery—to correct scoliosis when the curve is more than 20 degrees
• Tenotomy—to release contractures of the hip, knees, and Achilles tendon

Diet and nutritional supplements may aid in optimizing overall health. Herbal treatments can be helpful in addressing symptomatic complaints.

• Emphasize an anti-inflammatory diet, including organic whole foods such as whole grains, vegetables, fruit, legumes, sea vegetables, and essential fatty acids (nuts, seeds, and cold-water fish).
• Avoid refined foods, saturated fats (dairy and other animal products), and all known food allergens.
• Essential fatty acids (e.g., flax, borage, evening primrose, cod liver) 1,000 to 1,500 mg bid to tid.
• Vitamin E (400 to 800 IU/day), selenium (100 to 200 mcg/day), coenzyme Q10 (100 mg one to three times/day) are antioxidant nutrients that are cardioprotective. Coenzyme Q10 also helps oxygenates tissues and alleviates pain and muscle fatigue while increasing endurance.
• L-carnitine (320 mg once to twice/day) improves the energy metabolism of the cell.
• B-complex vitamins, especially B12 (1,000 mcg/day) and B6 (100 mg/day), and minerals, such as calcium (1,000 mg/day), magnesium (500 mg/day), and potassium (100 mg/day), optimize nerve function and conductivity.
• Glutathione (500 mg bid) provides antioxidant protection. However, oral glutathione may be broken down to its constituent amino acids in the gut, decreasing its effectiveness.
• N-acetyl cysteine (500 mg bid) is a precursor to glutathione and enhances pulmonary function.
• Creatine (5 to 7 g/day) may improve intracellular metabolism and prevents muscle wasting.
• Consider branched chain keto-acids, which reduce muscle protein degradation.

Herbs may be used as dried extracts (pills, capsules, or tablets), teas, or tinctures (alcohol extraction, unless otherwise noted). Dose is 1 heaping tsp. herb/cup water steeped for 10 minutes (roots need 20 minutes).

Combine three of the following herbs in equal parts and add two to three others as needed.

• Mineral-rich herbs: horsetail (Equisetum arvense), nettles (Urtica dioica), oatstraw (Avena sativa), and kelp (Laminaria cloustonii)
• With spasm, add black cohosh (Cimicifuga racemosa), cramp bark (Viburnum opulus).
• With muscle pain, add Jamaica dogwood (Piscidia erythrina), meadowsweet (Filipendula ulmaria).
• With cardiac involvement, add hawthorn (Crataegus monogyna), rosemary (Rosemarinus officinalis).

May be helpful in strengthening overall health. An experienced homeopath would consider the individual's constitution.

Topical preparations containing Arnica may provide symptomatic relief of spasm and muscle pain.

• Causticum (30C) once or twice daily for incontinence
• Magnesia phosphorica (30C) bid for pain with cramps, neuralgic pain

Regular massage therapy is essential for minimizing spasm and contractures.

Physicians must perform electrocardiography, pulmonary function studies, and chest radiographs yearly to monitor cardiac and pulmonary function, and selective tests to monitor swallowing function. Treatment of respiratory conditions and typical childhood diseases must be aggressive and prompt, particularly in patients who are no longer ambulatory.

• Painful contractures complicate the course of muscular dystrophy.
• Impaired respiratory function (i.e., hypoventilation, difficulty clearing secretions) results from scoliosis and lack of ambulation
• Cardiomyopathy (10% of DMD patients) may cause death from congestive heart failure within two to three years; cardiac decompensation is common in CMD
• Obesity is common when patients stop walking, and malnutrition can appear later when swallowing disorders develop.

Prognosis is variable, depending on the type and severity of the particular muscular dystrophy. Death in most cases results from infections, respiratory insufficiency, or cardiac failure. DMD patients usually die in their 20s, BMD patients in their 50s (although some live a normal life span), and DM patients in their 40s or 50s. Many patients with CMD die in infancy, but if they survive to adolescence, they follow a clinical course similar to DM.

Amniocentesis or chorionic villi sampling can detect gene mutations for prenatal diagnosis. Successive generations of patients with DM have an increased severity of the clinical phenotype. CMD always occurs in the infants of affected mothers; thus, these mothers should be referred for genetic counseling.

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