Muscular dystrophy

Muscular dystrophy refers to several genetic diseases that cause muscle weakness. You’ll find compassionate care from neuromuscular experts and gene specialists at Atrium Health Floyd and Harbin Clinic.

What is muscular dystrophy?

Muscular dystrophy is a group of more than 30 neuromuscular diseases. These diseases cause a range of muscular problems, including muscle weakness and muscle loss over time.

Most types of muscular dystrophy damage skeletal muscles, which connect to your bones. Some types also affect other muscles in your body, including heart (cardiac) muscles or smooth muscles. Smooth muscles line many organs, including your respiratory and digestive tracts.

Cause of muscular dystrophy

Muscular dystrophy is a genetic disease, meaning the condition gets passed down in families through a gene abnormality. Different gene changes (mutations) cause different types of muscular dystrophy.

Muscular dystrophy symptoms

Signs of muscular dystrophy usually appear during childhood. But some types don’t cause symptoms until adolescence or adulthood.

Muscular dystrophy mainly causes muscle weakness in your lower body. Many people lose their ability to walk as the disease worsens over time.

Damage to muscles in your legs and pelvis can cause:

• Difficulty walking, running, hopping, jumping or climbing stairs
• Frequent falls
• Reduced muscle mass
• Trouble getting up from the floor
• Walking on your toes

Muscular dystrophy can also affect muscles in your upper body, such as your arms and neck. But this weakness is usually less severe than lower body weakness.

Muscular dystrophy types

There are more than 30 types of muscular dystrophy. Some forms start to cause symptoms during infancy or childhood, while others may not appear until later in life.

Muscular dystrophies also vary in what symptoms they cause and how the disease affects your muscles. Some forms worsen slowly over time, while others cause severe muscular damage quickly.

The main types of muscular dystrophy include:

• Duchenne muscular dystrophy (DMD): This is the most common type and appears in childhood. It causes severe and rapidly worsening muscle weakness.
• Becker muscular dystrophy (BMD): BMD is similar to DMD but worsens slowly over time.
• Congenital muscular dystrophy (CMD): This form includes several subtypes of muscular dystrophy that are present at birth or appear during infancy.
• Distal muscular dystrophy (distal myopathy): This type usually appears between ages 40 and 60. It mainly causes muscle weakness in your forearms, hands, lower legs and feet.
• Emery-Dreifuss muscular dystrophy (EDMD): EDMD usually appears during childhood. It causes muscle weakness, stiffness and heart problems.
• Facioscapulohumeral muscular dystrophy (Landouzy-Dejerine disease): This type first causes muscle weakness in your face, shoulders and upper arms. Muscle weakness worsens and affects other areas over time.
• Limb-girdle muscular dystrophy (LGMD): LGMD mainly affects your hips and shoulders. It causes muscle weakness that slowly worsens.
• Myotonic dystrophy (Steinert's disease): This is the most common form of muscular dystrophy that starts in adulthood. It affects muscles and organs, which causes problems in many bodily systems.
• Oculopharyngeal muscular dystrophy (OPMD): OPMD usually develops later in life, between ages 40 and 60. It mainly causes drooping eyelids and weakened throat, tongue and face muscles, which leads to swallowing problems.

Muscular dystrophy diagnosis

Your doctor will review your symptoms and medical history, including your family history. They will do a neurological exam and a muscle exam to check for signs of muscular dystrophy. These exams can help rule out other possible diseases that can cause similar symptoms.

Your doctor may also order several tests to help diagnose muscular dystrophy, including:

• Blood and urine tests, which can check for signs of muscle damage
• Electromyography (EMG) muscle testing, which measures the electrical activity of your muscles
• Genetic testing, which involves checking a blood sample for specific gene mutations linked to muscular dystrophy
• Imaging tests, such as MRI or ultrasound, to see any abnormalities in your muscles
• Muscle biopsy, a procedure to take a sample of your muscle tissue and look at it under a microscope
• Nerve conduction study, which checks for nerve damage by measuring how your nerves respond to a small electrical pulse

If you’re pregnant, genetic tests can tell whether your baby has muscular dystrophy or other genetic diseases. Your doctor may recommend:

• Amniocentesis, which involves taking a sample of the fluid that surrounds your baby in the womb
• Chorionic villus sampling, which involves taking a sample of your placenta 

Muscular dystrophy risk factors

Your chance of developing muscular dystrophy depends on your genetics and your assigned sex at birth. Having a family history of the disease increases your risk because muscular dystrophy genes are passed down through families.

Males are much more likely to develop muscular dystrophy. The disease rarely affects females, even when they have an associated gene mutation.

Your doctor may recommend genetic counseling to help you understand your risk, especially if you have a family history of Becker muscular dystrophy. Genetic testing can also help you learn whether you carry a gene mutation that could be passed on to a future child.

Muscular dystrophy complications

These diseases mainly affect your skeletal muscles. But they can also cause complications in other body parts. Muscular dystrophy may lead to:

• Breathing problems
• Extreme tiredness (fatigue)
• Heart problems
• Loss of balance and coordination
• Muscle and bone deformities
• Thinking and memory problems