Muscular dystrophy

Muscular dystrophy (MD) is the name of a group of inherited conditions that cause muscle weakness that gets worse over time. Although there is no cure, there are treatments that help you manage your symptoms.

Key points

  • MD is caused by mutations (changes) in genes you inherit from your parents. This means that one of the proteins needed by muscle cells cannot be made correctly. This leads to damaged muscle fibres and to muscle weakness.
  • Depending on the exact type of faulty gene and faulty protein, different types of muscle weakness result. This is why there are different types of MD.
  • These types of MD vary in terms of when symptoms are most likely to emerge, which muscles they affect, how severe the symptoms are and whether they affect your life expectancy.
  • There is no cure for MD, but there is treatment and support to help you manage your condition.

What are the causes of muscular dystrophy?

In most cases, MD runs in families. That means it occurs because you have inherited a faulty gene from one or both of your parents. Occasionally, a spontaneous gene mutation can occur in someone with no family history of MD.

The mutations (changes) are in the genes responsible for healthy muscle structure and function. They lead to the cells that should maintain your muscles no longer being able to do so. The cells affected determine which type of MD you develop.

What are the different types of muscular dystrophy?

The main types of muscular dystrophy are:

  • Becker Muscular Dystrophy
  • Congential Muscular Dystrophy
  • Duchenne Muscular Dystrophy
  • Emery-Dreifuss Muscular Dystrophy
  • Facioscapulohumeral Muscular Dystrophy
  • Limb-Girdle Muscular Dystrophy
  • Manifesting carrier of Becker or Duchenne Muscular Dystrophy
  • Myotonic Dystrophy
  • Occulopharyngeal Muscular Dystrophy.

Learn about the types of muscular dystrophy


Source: Muscular Dystrophy Association of New Zealand, 2016

What are the symptoms of muscular dystrophy?

The main symptom of MD is muscle weakness. Different types of MD affect different muscle groups in your body. The muscle weakness may be mild, moderate or severe. The different types of MD vary as to how quickly or slowly the weakness progresses.

Symptoms can start anywhere between birth and middle age, depending on the type of MD. In young babies, the muscle weakness may be noticed as floppiness. In older babies and young children, the weakness may show up as a delay in learning to hold up their head, sit up, crawl or walk.

Other symptoms include:

  • muscle wasting – your muscles become thin
  • muscle hypertrophy – bulkier than normal muscles, even though they work less well
  • aches or pains in your muscles
  • contractures – tight joints, due to tightness of your muscles or reduced movement of your joints
  • in some cases, symptoms of heart disease without much muscle weakness.

How is muscular dystrophy diagnosed?

MD is diagnosed based on the specific presentation of muscle weakness, with the pattern determining the type of MD. Diagnosis can now generally be confirmed by gene tests. Other people in the family can also be tested to see if they have a muscular dystrophy gene.

How is muscular dystrophy treated?

As there is currently no cure for MD, treatment is aimed at helping you to manage the condition. As different types of MD can cause different issues, the treatment you receive will be tailored to your needs.

Treatments can include physiotherapy to help you maintain muscle function. Starting exercises early on can help keep your muscles flexible and strong. You may need braces, which can help keep your muscles and tendons stretched and flexible, slowing the progression of contractures. Braces can also aid movement by providing support for weakened muscles. Depending on the extent of your mobility, you may be advised to use different mobility aids such as canes, walkers and wheelchairs.

To help you maintain your independence, occupational therapy is important to learn new ways of doing things, make adjustments to your immediate living area and provide you with appropriate equipment to assist you.

With time, your respiratory muscles also weaken putting you at risk of chest infections, sleep apnoea and respiratory failure. To prevent infections, it's important to be vaccinated for pneumonia and to keep up to date with influenza shots. For sleep apnoea, to help you breathe, you may need a device to improve oxygen delivery to your lungs.

Some types of MD may mean that you are at increased risk of heart problems, because of the weakening of your heart muscles. It's important that your heart function is assessed regularly once MD has been diagnosed. For Duchenne and Becker MD, an electrocardiogram (ECG) examination of your heart rhythm will be carried out at regular intervals, and you may also have an echocardiogram from time to time. If any damage to your heart is detected, you may be referred to a cardiologist (heart specialist) for further tests and possibly more frequent monitoring.

In some types of MD, such as Oculopharyngeal muscular dystrophy, that affect the throat and eye muscles, you may experience swallowing difficulties and droopy eyelids. There are various treatments that can help with these problems. 

What is the life expectancy with muscular dystrophy?

Life expectancy varies depending on the type of MD. However, due to advances in treatment and care, people with MD now live longer. With the most common type of MD, Duchenne muscular dystrophy, survival into the early 30s is becoming more common, and there are cases of men living into their 40s and 50s.

How can I care for myself with muscular dystrophy?

Get support for yourself and your family through counseling, joining Muscular Dystrophy New Zealand, talking to friends and family about your experience.

Exercise as much as you are able to. The health benefits can impact on maintaining your mobility, managing your pain levels and helping with your general standard of living.

Get the recommended vaccinations for people with neuromuscular diseases, such as the annual flu and pneumococcal vaccines.

What support is available with muscular dystrophy?

The Muscular Dystrophy Association New Zealand offers educational, emotional, financial, personal and workplace assistance. MDA has a support network of more than 600 members throughout New Zealand who want to be in touch with others living with neuromuscular conditions. There are regional branches and you can phone the national office on 09 624 2148.

Learn more

Neuromuscular conditions A-Z Muscular Dystrophy New Zealand, 2016
Muscular dystrophy NHS Choices, UK, 2015
Muscular dystrophies: an overview Patient Info, UK, 2016

References

  1. Muscular dystrophies: an overview Patient Info, UK, 2016
  2. Muscular dystrophies Muscular Dystrophy New Zealand, 2016
  3. Duchenne muscular dystrophy MDA, US
  4. Vaccination recommendations Muscular Dystrophy New Zealand
Credits: Health Navigator Editorial Team.