Mitochondrial myopathy is a blanket term used to describe a series of neuromuscular diseases that affect a cell's mitochondria, which are responsible for producing the energy cells need to live, states MedicineNet. Some of the more common mitochondrial myopathies include mitochondrial encephalomyopathy and Kearns-Sayre syndrome.
Symptoms of mitochondrial myopathies include muscle fatigue or weakness, heart failure or other disturbances in the heart's rhythm, movement disorders and dementia, according to MedicineNet. Some people also experience drooping eyelids, deafness, blindness, limited mobility of the eyes, and symptoms that resemble strokes. The prognosis for these diseases ranges from progressive muscle weakness to death. Most mitochondrial myopathies occur before the age of 20 and often begin with muscle weakness or being intolerant of exercises. Headache, nausea and breathlessness are often associated with these conditions as well.
As of 2015, there are no specific treatments for any of the diseases and conditions that fall under the mitochondrial myopathy heading, states MedicineNet. However, physical therapy may increase the range of movement in some people, and vitamin therapies may improve a person's chronic weakness and fatigue. A person's specific prognosis and response to treatment can vary greatly when compared to another person, as it depends on what specific condition a person is suffering from as well as what organ and muscle groups are affected.