Mitochondrial Myopathy

Overview

Mitochondrial myopathies (MMs) are a classification of disorders that affect the mitochondria of the cell, which is responsible for generating a cell’s power through a process of digesting oxygen to produce energy. Because muscle and nerve cells require high levels of energy to carry on their tasks, these systems are impacted more frequently.

Dysfunction among mitochondria can lead to a number of neurological issues. In the case of MM, the muscular system is primarily affected. As a result, the patient’s vision, mobility, auditory function, cardiovascular strength and more are impacted.

Types

  • Barth syndrome
  • Kearns-Sayre syndrome (KSS)
  • Leigh syndrome
  • Maternally inherited deafness and diabetes (MIDD)
  • Maternally inherited Leigh syndrome (MILS)
  • Mitochondrial DNA depletion syndrome (MDS)
  • Mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS)
  • Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE)
  • Myoclonus epilepsy with ragged-red fibers (MERRF)
  • Neuropathy, ataxia and retinitis pigmentosa (NARP)
  • Pearson syndrome

Symptoms

  • Bilateral eyelid ptosis, a drooping of the upper eyelid
  • Cardiovascular distress or failure
  • Diabetes
  • Hearing and/or vision loss
  • Loss of motor function
  • Memory loss or dementia
  • Muscular weakness or involuntary contraction
  • Neurological issues, such as seizures

Prevention

Because they are genetically inherited through mutations in either nuclear DNA or mitochondrial DNA, MM and other mitochondrial diseases cannot be prevented.

Risk Factors

  • MM has an autosomal dominant genetic pattern, meaning that it only takes one copy of the mutated gene from one parent to cause MM.
  • In the case of mitochondrial DNA transmission, only a mother’s daughters are at risk due to the maternal inheritance pattern of MMs.
  • If a patient’s MM is caused by a nuclear DNA mutation, the condition may be transmitted with the appearance of either an autosomal recessive pattern or a dominant one.
  • X-chromosome-linked MM disorders will only affect men. His mother or female relatives are less likely to show symptoms while carrying the impacted gene.

Diagnosis

  • If a patient presents common symptoms, a physician will look to family medical history to indicate a presence of genetic or mitochondrial dysfunction.
  • Physical tests, such as reflex practice, basic motor function aptitude tests, vision performance exams and cognitive ability tests, will be conducted.
  • Medical tests will follow, including but not limited to a muscle biopsy, blood test or spinal tap to indicate elevated levels of lactic acid, MRI or MR spectroscopy scans, or other diagnostic imaging testing (CT or EEG scans).
  • As is the case with most hereditary conditions, genetic testing is conducted on candidates who are at risk for diagnosis.

Treatment

Although there is no cure for MM, there are ways to manage symptoms.

  • Neurological physical therapy, mobility aids, including walkers and wheelchairs, and assisted hearing/vision devices offer relief and support to current patients.
  • Certain vitamin- or supplement-based regimens known as “mito-cocktails” may stimulate adenosine diphosphate (ATP) production, a major source of energy for the body’s cells. Some of these vitamins and supplements include riboflavin, coenzyme Q10 and L-carnitine

Follow-up Care

  • Symptomatic care should accompany a spike in noticeable degradation of MM-affected systems.
  • As a result, constant monitoring is critical to observe changes or deterioration in a patient’s condition.
  • As with many genetic disorders, specialists are still learning information based on the latest clinical studies and this knowledge on this subject may improve.

Why Choose UK HealthCare for Neuromuscular Disorders?

If you or a loved one is living with a neuromuscular disorder, neuromuscular doctors with Kentucky Neuroscience Institute can offer the latest and most sophisticated care options. UK HealthCare’s ALS Multidisciplinary Clinic earned accreditation as a Certified Treatment Center of Excellence from the ALS Association. This honor is awarded to facilities that demonstrate competency meeting the clinical care and treatment standards set forth by the ALS Association. These facilities must also take part in ALS research and a comprehensive site review.

Additionally, the Kentucky Neuroscience Institute is ranked 44th in the country by U.S. News & World Report, and our physicians are regularly named to the Best Doctors in America List.