What is Muscular Dystrophy?

What is Muscular Dystrophy?

Muscular Dystrophy refers to a progressive neuromuscular genetic disorder where the muscles gradually lose their strength leading to complete immobility and dependence on others for everyday activities.

At what age does Muscular Dystrophy occur?

Muscular Dystrophy can occur at any age. Sometimes it affects more than one sibling in a family. Muscular Dystrophies can be broadly divided into 9 categories, each influencing different muscle groups, signs and symptoms, age of onset and varying in severity. The 9 categories have been summarised in the table below.

How many types of Muscular Dystrophies are there?

These is a vast diversity in how Muscular Dystrophies are presented. Some neuromuscular conditions are so severe that babies die within the first few years of life, whereas others only affect people in old age and don’t cause severe disability. Most of the conditions have a genetic cause and are passed down through families (inherited) but sometimes the genetic change occurs spontaneously in an individual without a family history of muscle disease. Other conditions are autoimmune or the cause is unknown or poorly understood.

There are nine major forms of muscular dystrophy:

  1. Duchenne muscular dystrophy
  2. Becker muscular dystrophy
  3. Congenital muscular dystrophy
  4. Emery Dreifuss muscular dystrophy
  5. Facioscapulohumeral muscular dystrophy
  6. Limb-Girdle muscular dystrophy
  7. Myotonic muscular dystrophy
  8. Oculopharyngeal muscular dystrophy
  9. Distal muscular dystrophy

What symptoms are typically observed in Muscular Dystrophy?

Symptoms vary with different types of muscular dystrophies that include:

  • Muscle weakness that slowly gets worse
  • Bulged out calf muscles
  • Drooping Shoulders
  • Scoliosis of Spine
  • Frequent falls
  • Wadding Gait
  • Loss in muscle size
  • Loss of strength in a muscle or group of muscles as an adult

Where can the weakness occur?

The source of the muscle weakness within the body differs too. For example, Muscular Dystrophy is primarily a disease of muscle, often caused by the lack of an important structural protein and as a result, the muscles are fragile and easily damaged. In other types of Muscular Dystrophy such as Facioscapulohumeral Muscular Dystrophy (FSHD) the genetic change results in the production of a substance that is toxic to muscle.

For some other neuromuscular conditions the muscle weakness originates in the nerves that control the muscles. For example, amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA) affect the motor neurons in the spinal cord. Others, such as Charcot-Marie-Tooth disease affect the peripheral nerves which carry signals from the spinal cord to the limbs. A structure called the ‘neuromuscular junction’ that connects the nerves to the muscles is affected in some conditions, for example myasthenia gravis.

Each neuromuscular condition causes a characteristic pattern of muscle weakness: it could be just the legs or the muscles around the eyes and throat. The most severe conditions affect all the muscles of the body, including the heart and the muscles used for breathing. In most cases intelligence is not affected. Some conditions such as myotonic dystrophy affect many parts of the body as well as the muscles. This results in very diverse care needs depending on the condition and the stage of progression. Often the management of symptoms is complex requiring input from a wide variety of health care professionals.

Is there a cure?

There are no specific treatments for most neuromuscular conditions but considerable research efforts are working towards developing them and encouragingly, many clinical trials are now starting. Treatments, such as gene therapy to specifically target the underlying cause are being developed for some conditions, as well as more generalised treatments which aim to reduce the severity of symptoms by, for example, boosting muscle regeneration.

How can one live life with Muscular Dystrophy?

Early diagnosis, intervention, medications and therapy may help manage symptoms and potentially slow the progression of the disease and extend the time a person with the disease can remain mobile.

In India, more than 4,000 children are born with Muscular Dystrophy each year. Indian Association of Muscular Dystrophy is working for rehabilitation and awareness generation of Muscular Dystrophy in the country.