Muscular Dystrophy

What is Muscular Dystrophy?

Muscular dystrophy is a group of inherited disorders that affect the muscles and cause progressive weakness and wasting. These disorders result from genetic mutations that interfere with the production or function of proteins needed to form healthy muscles.

Muscular dystrophy is a progressive condition, meaning that the symptoms worsen over time. In severe cases, it can lead to disability and a shortened lifespan. While there is no cure for muscular dystrophy, treatment can help manage the symptoms and improve quality of life. Physical therapy, medication, and assistive devices such as braces or wheelchairs may all be used to help individuals with muscular dystrophy maintain mobility and independence.

Are there different types/stages?

• Duchenne muscular dystrophy is the most common type, affecting about 1 in 5,000 boys. It is caused by a mutation in the gene that produces the protein dystrophin, which is needed for muscle cells to function properly. Symptoms typically appear in early childhood and progress rapidly, leading to weakness, difficulty walking, and eventually, loss of mobility.
• Becker muscular dystrophy: This is a less severe form of muscular dystrophy than Duchenne, but it is still a progressive condition. It is caused by a mutation in the same gene that causes Duchenne, but the symptoms are milder and progress more slowly. It usually appears in adolescence or early adulthood.
• Limb-girdle muscular dystrophy: This group of several related disorders that affect the muscles of the hips and shoulders, causing progressive weakness and wasting. Many different genes can cause limb-girdle muscular dystrophy, and the severity and progression of the disease can vary depending on the specific genetic mutation involved.
• Facioscapulohumeral muscular dystrophy: This is a form of muscular dystrophy that primarily affects the face, shoulders, and upper arms. It is caused by a genetic mutation that leads to the abnormal production of a protein called DUX4, which damages muscle cells over time. Symptoms typically appear in adolescence or young adulthood.
• Myotonic dystrophy: This type of muscular dystrophy affects both the muscles and other organs of the body, including the heart and the brain. It is caused by a genetic mutation that interferes with myotonic dystrophy protein kinase (DMPK) production. Symptoms can vary widely, including muscle weakness, myotonia (prolonged muscle contractions), and other symptoms.
• Congenital muscular dystrophy is a group of disorders present at birth or develop very early in life. They are caused by genetic mutations that affect the production or function of proteins needed for normal muscle development. Symptoms vary widely depending on the genetic mutation involved but typically include muscle weakness, wasting joint contractures, and respiratory problems.

Causes of Muscular Dystrophy

Some of the causes of muscular dystrophy include:

• Inherited genetic mutations: Most cases of muscular dystrophy are inherited in an autosomal recessive or X-linked recessive pattern, meaning that a person must inherit two copies of a mutated gene (one from each parent) to develop the condition. In some cases, however, the condition may arise due to a new mutation in a gene.
• Spontaneous genetic mutations: Some cases of muscular dystrophy may be caused by spontaneous mutations that occur in the egg or sperm cells or the early embryo rather than inherited from a parent.
• Defects in protein production or function: Some types of muscular dystrophy may be caused by defects in proteins involved in muscle function, such as dystrophin, which is mutated in Duchenne and Becker muscular dystrophy.
• Abnormal immune system response: Some types of muscular dystrophy may be caused by an abnormal immune system response that attacks the body’s muscle tissue.
• Other genetic or environmental factors: In some cases, other genetic or environmental factors may contribute to the development or progression of muscular dystrophy, though the exact causes of these cases are unclear.

Signs & Symptoms

Some of the most common signs and symptoms of muscular dystrophy include:

• Progressive muscle weakness: This is the hallmark symptom of muscular dystrophy, and it typically begins in the muscles of the hips, legs, and shoulders. Over time, the weakness may spread to other muscles throughout the body.
• Muscle wasting: As the muscle fibers break down and are replaced by fat and connective tissue, affected muscles may appear smaller and weaker.
• Difficulty walking: Many people with muscular dystrophy have trouble walking or may become wheelchair-bound as the condition progresses.
• Poor balance and coordination: Maintaining balance and coordination can become more complex as the muscles weaken.
• Delayed motor milestones: In some cases, infants and young children with muscular dystrophy may experience delays in reaching motor milestones such as sitting, crawling, or walking.
• Muscle cramps and stiffness: Some types of muscular dystrophy can cause muscle cramps, stiffness, or myotonia (prolonged muscle contractions).
• Respiratory problems: As the muscles in breathing weaken, people with muscular dystrophy may experience respiratory problems such as shortness of breath, difficulty breathing, or sleep apnea.
• Scoliosis: Some people with muscular dystrophy may develop a curvature of the spine.
• Cardiac problems: Some types of muscular dystrophy can also affect the heart muscle, leading to cardiomyopathy (weakened heart muscle) or other cardiac issues.

Diagnosis and Treatment

Diagnosis of muscular dystrophy typically involves a combination of medical history, physical examination, and laboratory tests. A healthcare provider may ask about a person’s family history of muscular dystrophy and any symptoms they are experiencing. They may also perform a physical exam to assess muscle strength, tone, and reflexes. Laboratory tests may include genetic testing to look for mutations in genes associated with muscular dystrophy and blood tests, electromyography (EMG), or muscle biopsy to evaluate muscle function and structure.

There is currently no cure for muscular dystrophy, but various treatments are available that can help manage symptoms and improve quality of life. These may include:

• Physical therapy and exercise: Regular physical therapy and exercise can help maintain muscle strength, flexibility, and function and can also help prevent complications such as joint contractures or scoliosis.
• Bracing and mobility aids: Bracing or using mobility aids such as canes or wheelchairs can help improve mobility and prevent falls or other injuries.
• Medications: There are a variety of medications that may be used to treat the symptoms of muscular dystrophy, including corticosteroids to help slow the progression of the disease and alleviate inflammation and medications to manage pain, cramps, or other symptoms.
• Surgery: In some cases, surgery may be necessary to address complications such as scoliosis or contractures.
• Assistive devices: Various assistive devices can help people with muscular dystrophy maintain independence and improve their quality of life, such as voice-activated technology, specialized computer software, or communication aids.

Can medical cannabis help?

There is some evidence to suggest that medicinal cannabis may provide relief for some of the symptoms of muscular dystrophy, particularly those related to pain and muscle spasms. However, more research is needed to fully understand the potential benefits and risks of using medicinal cannabis to treat muscular dystrophy.

Some studies suggest that cannabis-based medications, such as delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), may relieve some of the symptoms of muscular dystrophy. THC is the compound responsible for the psychoactive effects of cannabis, while CBD is a non-psychoactive compound with anti-inflammatory and pain-relieving properties. Both THC and CBD can be found in various forms of medicinal cannabis, such as oils, tinctures, and edibles.