Different Types of Muscular Dystrophy

Hi everyone,

In this post, I am going to talk about the 9 major types of Muscular Dystrophy, the onset of each type. and the signs and symptoms. I will also talk about ALS which is similar to Muscular Dystrophy. Hope this is informative!

1. Duchenne Muscular Dystrophy(DMD)

This is the one I have. Duchenne Muscular Dystrophy is the most severe form of the disease and is caused by a mutation in the dystrophin gene. It was named after French Neurologist, Dr. Guillaume-Benjamin-Amand Duchenne, who described and detailed the illness in a young boy with the condition in his book in 1861

• Onset  

Between 2 and 6 years of age.

• Signs and Symptoms.

General muscle weakness and deterioration. Boys with DMD are usually late walkers. Initially the pelvis, upper arms, and upper legs are the first affected. Eventually it involves all the voluntary muscles throughout the body and the boys will require a wheelchair. Tightness in the joints may also occur. The cardiac and respiratory systems are eventually affected as well and will require mechanical ventilation. One third of boys with DMD experience learning disabilities. Life expectancy is usually into the early 20s but people are beginning to live decades longer now(I'm 41). Duchenne is only seen in boys but can rarely affect women who have much milder symptoms and a better prognosis.

2. Becker Muscular Dystrophy(BMD)

Becker Muscular Dystrophy is an inherited neuromuscular disease caused by a mutation in the dystrophin gene. It was named after Neurologist and Geneticist, Dr. Peter Emil Becker, who published an article about this type of the disease in 1955.

• Onset

Between adolescence to adulthood.

• Signs and Symptoms.

Since Becker is similar to Duchenne Muscular Dystrophy, the symptoms are almost identical but less severe. There is general muscle weakness and deterioration. It initially affects the pelvis, upper legs, and upper arms. It can affect the cardiac and respiratory system but usually later in adulthood. The rate of muscle deterioration can vary between patients. Typically BMD progresses a lot slower and the patient will maintain the ability to walk usually until 16 but sometimes well into adulthood. As with Duchenne, the disease is usually always limited to males due to it being an X-chromosome linked disorder. Life expectancy is between 40 and 60 years old

3. Congenital Muscular Dystrophy(CMD)

Congenital Muscular Dystrophy is actually a group of Muscular Dystrophies which begin at birth. DMD is caused by the loss of glycoproteins in cells due to the gene mutation which affects the normal function of muscles. This type of mutation causes an increased chance of the muscles becoming injured from normal use. It also reduces the muscles' ability to repair any damage. There are 30 different types of CMD all ranging in different severities.

• Onset

Begins at birth

• Signs and Symptoms
  

Most children with CMD exhibit progressive loss of muscle mass although the degree of severity and progression can vary. Symptoms are similar to other MDs. General muscle weakness, low muscle tone, possible joint tightness and deformities, respiratory problems, eye problems, and possible learning disabilities.

4. Distal Muscular Dystrophy(DD)

Distal MD was first described in 1902. It is a type of MD which affects the distal muscles, which are those of the lower arms, hands, lower legs, and feet.

• Onset

Between the ages of 40 to 60

• Signs and Symptoms

Weakness and wasting of muscles of the hands, forearms, and lower legs. In most cases, muscle mass in the affected areas become visibly wasted. In other cases arms, leg or trunk muscles may weaken to the point where mobility will become decreased. Some forms of Distal MD affect the muscles used for speaking and swallowing, and others may affect the heart. Intellect is not affected. Progression is slow. It rarely leads to total disability. 

 

5. Emery-Dreifuss Muscular Dystrophy(EDMD)

EDMD like all Muscular Dystrophies is genetic. It is caused by mutations in the genes that produce the proteins in the membrane surrounding the nucleus of each muscle cell. The illness is named after British Geneticist Alan Emery and American Neurologist Fritz E. Dreifuss who first described the condition in the 1960s.

• Onset

Childhood to early teens

• Signs and Symptoms

The symptoms of EDMD usually manifest by the age of 10 years old. Early symptoms include toe walking due to stiff Achilles tendons. Other symptoms include weakness and wasting of shoulder, upper arm, and shin muscles. Joint deformities are common and make arm, neck, heel, and spine movements difficult. But progression of muscle weakness is slow and these issues may not become difficult until later in life. Intellect is not affected by EDMD. Sudden death may occur from cardiac problems. Life expectancy is middle aged due to Pulmonary or Cardiac failure.

6. Facioscapulohumeral Muscular Dystrophy(FSHD)

FSHD is a form of Muscular Dystrophy which mostly affects the muscles of the face, shoulders, and upper arms. It can cause muscles weakness in other parts of the body. FSHD is the third most common type of Muscular Dystrophy behind Becker and Duchenne.

• Onset

Childhood to early adults

• Signs and Symptoms

The age of onset, severity, and progression vary significantly. Symptoms usually begin in the teen years. Symptoms include facial muscle weakness and weakness with some wasting of shoulders and upper arms. Abdominal weakness, hip and lower leg weakness, joint and spinal abnormalities, retinal abnormalities, and mild hearing loss can also be experienced. Progression is slow with periods of rapid deterioration. Life span may be many decades after onset. Intellect is not affected.

 

7. Limb-Girdle Muscular Dystrophy(LGMD)

LGMD usually affects the proximal muscles around the hips and shoulders. Proximal muscles are the ones closest to the center of the body. The shoulder girdle is the bony structure that surrounds the shoulder area. The pelvic girdle is the bony structure that surrounds the hips. These are known as the limb girdles and is where the weakness and atrophy of the muscles occur giving this type of MD it's name. LGMD is the fourth most common type of Muscular Dystrophy.

• Onset

Late childhood to middle age

• Signs and Symptoms

Symptoms include weakness and wasting, affecting shoulder girdle and pelvic girdle first. Progression is slow. The Cardiac and Respiratory muscles can be affected sometimes but not as much as other types of Muscular Dystrophy. Intellect is usually not affected. Life expectancy is generally normal.

8. Myotonic(DM)

DM causes weakness of the voluntary muscles. The degree of progression and weakness vary to the type of DM and the age of the person with the disorder. Myotonia, the inability to relax muscles at will, is also experienced with DM. Like for example if someone with the disorder shakes another person's hand it may be difficult for them to let go.

• Onset

Ages 20 to 40

• Signs and Symptoms

Symptoms include weakness of all muscle groups and delayed relaxation of muscles after contraction. It affects the face, feet, hands, and neck first. Progression is slow, sometimes spanning 50 to 60 years. An infantile form causes more severe problems. Intellect is not affected in some forms of DM where in others it is. People with DM are more susceptible to cancer as well.

9. Oculopharyngeal Muscular Dystrophy(OPMD)

OPMD is a slow progressing type of Muscular Dystrophy that affects specifically the muscles of the eyelids and the throat. Additionally, the distal and proximal muscles can be affected.

• Onset

Ages 40 to 70

• Signs and Symptoms

Symptoms affect muscles of eyelids and throat causing weakening of throat muscles. Over time, this causes inability to swallow and severe weight loss from lack of food. Progression is slow. Other symptoms, can include weakness of the tongue, weakness of the proximal muscles of the lower extremities, pooling saliva in the throat, limited upward gaze, weakness of the facial muscles, and weaknesses of the proximal muscles of the upper extremities.

 

10. Amyotrophic Lateral Sclerosis (ALS) The disease from Hell

ALS is a relentless merciless disease of the nervous system that affects the nerves in control of voluntary muscle movement. With ALS, motor neurons, nerve cells that control muscle cells, are gradually lost. As these motor neurons deteriorate, the muscles they are in control of become weak and cease to function. Leading to muscle weakness, disability, and eventually death. ALS is the most common motor neuron disease. In the US, ALS is also called Lou Gehrigs disease, named after the New York Yankees baseball player who was diagnosed with ALS in 1939 and lived with it until 1941 when he passed. The disease was first described by Dr. Jean-Martin Charcot in the 19th century.

• Onset

Most people who get ALS are between the ages of 40 and 70, with an average age of 55 at the time of diagnosis. However, some cases of the disease do occur in people in their twenties and thirties.

• Signs and Symptoms

• Early stage

Muscles may be weak and soft, or they may be stiff, tight, and spastic. Muscle cramping and twitching occurs, as does atrophy of the muscles. Symptoms may be limited to a single body region or mild symptoms may affect more than one region. The person may experience fatigue, poor balance, slurred words, a weak grip, tripping when walking, or other minor symptoms. Sometimes this stage occurs before a diagnosis is made.

• Middle Stage

Symptoms become more widespread. Some muscles are paralyzed, while others are weakened or unaffected. Muscle cramping and twitching may continue. Unused muscles may cause contractures in the joints, in which the joints become rigid, painful, and sometimes deformed.  If the person falls they may not be able to stand back up alone and need assistance. Driving no longer becomes possible.Weakness in swallowing muscles will cause choking, difficulty eating, and managing saliva. Weakness in breathing muscles will cause respiratory issues, especially when lying down. Some people experience bouts of uncontrolled and inappropriate laughing or crying. Despite how it seems, the person usually doesn’t feel particularly sad or happy.

• Late Stage

Most voluntary muscles have become paralyzed. The muscles that help move air in and out of the lungs are severely compromised. Mobility has become extremely limited, and help is needed in caring for most personal needs. Poor respiration will cause fatigue, fuzzy thinking, headaches, and susceptibility to pneumonia. Speech, or eating and drinking by mouth, may not be possible.

• End stage

The vast majority of deaths in ALS are the result of respiratory failure, a process that progresses slowly over months. Medications can relieve discomfort, anxiety, and fear caused by respiratory insufficiency. Far less-common causes of death in ALS include malnutrition as a result of swallowing problems, pulmonary embolism (a blockage in one of the arteries of the lungs), abnormalities in the heart’s electrical pacing system called cardiac arrhythmias, and pneumonia as the result of aspiration (when food or fluid gets into the lungs). Hospice care, in a facility or in the home, focuses on providing comfort and maintaining quality of life by supporting the physical, emotional, and spiritual needs of the individual with ALS and their family members. Families should contact hospice early on to see what in-home services are available even before the most advanced stage.

    

At MDA clinics, physicians work closely with palliative care teams to coordinate treatment with in-home hospice care providers, assisted living facilities, or inpatient hospice settings. Such cooperation helps ensure the person with ALS has the most peaceful and painless experience possible.

The life expectancy of those with ALS is two to five years after diagnosis, some people live five years, 10 years or even longer. The British theoretical physicist, Stephen Hawking, had ALS for over 50 years.

 

That concludes this blog post. Thank you everyone for reading!

 

*The Information in this blog was provided by the Muscular Dystrophy association website as well as the Johns-Hopkins Medical website, the University of Rochester Medical Center website, the NHS Inform website, and the ALS Association website. Links below.

• Muscular Dystrophy Association - www.mda.org

• Johns-Hopkins Medical - www.hopkinsmedicine.org/

• University of Rochester Medical - www.urmc.rochester.edu/
  

• NHS Inform - www.nhsinform.scot/
  

• ALS Association - www.als.org