Myopathy Mitochondrial

The term “myopathy” refers to a group of neuromuscular diseases. Muscle weakness is what characterizes a myopathy. Typically, the cause is a defect in muscle fiber.

Mitochondrial myopathies are a distinct class of myopathies. Instead of being caused by dysfunction of muscle fiber, these disorders are caused by damage to the mitochondria.

A number of different mitochondrial myopathies can occur. Most of them are caused by a genetic defect and will appear before a person reaches age 20. However, there have been cases of mitochondrial myopathy in adults as well. Mitochondrial myopathies include:

  • Kearns-Sayre syndrome (KSS)
  • Leigh’s syndrome
  • mitochondrial DNA depletion syndrome (MDS)
  • mitochondrial encephalomyopathy, lactic acidosis and strokelike episodes (MELAS)
  • myoclonus epilepsy with ragged red fibers (MERRF)
  • mitochondrial neurogastrointestinal encephalomyopathy (MNGIE)
  • neuropathy, ataxia and retinitis pigmentosa (NARP)
  • Pearson syndrome
  • progressive external ophthalmoplegia (PEO).

Each of these types of mitochondrial myopathy may cause a different set of symptoms and can vary in severity from person to person.

In this section, we’ll discuss all aspects of mitochondrial myopathies, including what to do if you or a family member is diagnosed, the symptoms of mitochondrial myopathies, treatment options, prognosis and more.

Mitochondria

Mitochondria are small particles found in all cells that affect muscle function. They are essentially tiny energy factories and are particularly important to the function of the brain and the muscles of the body.

Symptoms of Mitochondrial Myopathies

Mitochondrial myopathy symptoms can start out slowly. Muscle fatigue and weakness are often observed, especially during physical activity. Other symptoms include:

  • breathlessness
  • headache
  • nausea.

As the disease progresses, these symptoms may also occur:

  • blindness
  • deafness
  • dementia
  • difficulty moving the eyes
  • drooping eyelids
  • episodes of stroke-like symptoms
  • gastrointestinal disorders
  • heart failure or problems with heart rhythm
  • movement disorders
  • problems with the nervous system
  • seizures
  • vomiting.

Muscle weakness may worsen over time. In severe cases, mitochondrial myopathies can result in death.

As early diagnosis and treatment can greatly affect prognosis of ,it is important to watch out for early symptoms of mitochondrial myopathy.

Treatment for Mitochondrial Myopathies

While there is no one specific treatment for mitochondrial myopathies, there are some treatment methods that can help.

Mitochondrial Myopathy and Hips and Shoulders

Physical therapy may be helpful for those who have muscle difficulty in the areas of the hips and shoulders caused by mitochondrial myopathy.

Physical therapy and vitamin therapies are the most common treatments for mitochondrial myopathies. Vitamin therapy can improve muscle function and lessen fatigue in some cases. Vitamin therapy includes:

  • carnitine
  • coenzyme Q
  • riboflavin.

In cases where respiratory problems are present, a ventilator or supplementary oxygen may be used as treatment. If cardiac problems occur with mitochondrial myopathies, use of a pacemaker may be necessary.

Research is being done on a number of other treatments that may later be effective at lessening symptoms or even curing mitochondrial myopathies.

Progression of mitochondrial myopathies can be rapid in some cases, so it’s important to be diligent in seeking treatments for mitochondrial myopathy.

Resources

MDA (2006). Facts About Mitochondrial Myopathies. Retrieved January 3, 2008, from the MDA Web site: http://www.mda.org/publications/mitochondrial_myopathies.html#specialissues.

MDA (2006). Mitochondrial Myopathies. Retrieved January 3, 2008, from the MDA Web site: http://www.mdausa.org/disease/mito.html.

National Institute of Neurological Disorders and Stroke (2007). Mitochondrial Myopathies Information Page. Retrieved January 3, 2008, from the NINDS Web site: http://www.ninds.nih.gov/disorders/mitochondrial_myopathy/mitochondrial_myopathy.htm.