Mitochondrial Myopathies (MM)
While mitochondrial myopathies and encephalomyopathies are relatively rare, some of their potential manifestations are common in the general population. Consequently, those complications (including heart problems, stroke, seizures, migraines, deafness and diabetes) have highly effective treatments (including medications, dietary modifications and lifestyle changes).
It’s fortunate that these treatable symptoms are often the most life-threatening complications of mitochondrial disease. With that in mind, people affected by mitochondrial diseases can do a great deal to take care of themselves by monitoring their health and scheduling regular medical exams.
Ataxia and mobility issues
Often, mitochondrial encephalomyopathy causes aaxia, or trouble with balance and coordination. People with ataxia are usually prone to falls. Sometimes, people with mitochondrial myopathies experience loss of muscle strength in the arms or legs. These problems can be partially avoided through physical and occupational therapy, and the use of supportive aids such as railings, a walker, a cane, braces, or — in severe cases — a wheelchair.
Sometimes, mitochondrial diseases can cause weakness in the breathing muscles or brain abnormalities that alter the brain's control over breathing. Those with mild respiratory problems might require occasional respiratory support, such as pressurized air, while someone with more severe problems might require permanent support from a ventilator. Those with mitochondrial disorders should watch for signs of respiratory insufficiency (such as shortness of breath or morning headaches), and have their breathing checked regularly by a specialist.
Mitochondrial disease can affect the heart, often by causing an interruption in the heartbeat called a conduction block. Although dangerous, this condition is treatable with a pacemaker, which stimulates normal beating of the heart. Cardiac muscle damage also may occur. People with mitochondrial disorders may need to have regular examinations by a cardiologist.
Children with mitochondrial diseases may have delays in reaching motor milestones such as sitting, crawling and walking. As they get older, they may have trouble moving around, speech problems, and/or learning disabilities. Children who are severely affected by these problems may benefit from services such as physical therapy, speech therapy and possibly an individualized education program (IEP) at school.
Instead of focusing on specific complications of mitochondrial disease, some newer, less-proven treatments aim at fixing or bypassing the defective mitochondria. These treatments are dietary supplements based on three natural substances involved in ATP (an energy molecule) production in our cells.
One substance, creatine, normally acts as a reserve for ATP by forming a compound called creatine phosphate. When a cell’s demand for ATP exceeds the amount its mitochondria can produce, creatine can release phosphate (the “P” in ATP) to rapidly enhance the ATP supply. In fact, creatine phosphate (also called phosphocreatine) typically provides the initial burst of ATP required for strenuous muscle activity.
Another substance, carnitine, generally improves the efficiency of ATP production by helping import certain fuel molecules into mitochondria, and cleaning up some of the toxic byproducts of ATP production. Carnitine is available as an over-the-counter supplement called L-carnitine.
Finally, coenzyme Q10, or coQ10, is a component of the electron transport chain, which uses oxygen to manufacture ATP. Some mitochondrial diseases are caused by coQ10 deficiency, and there’s good evidence that coQ10 supplementation is beneficial in these cases. Some doctors think that coQ10 supplementation also might alleviate other mitochondrial diseases.
Creatine, L-carnitine and coQ10 supplements often are combined into a “cocktail” for treating mitochondrial disease. Although there’s little scientific evidence that this treatment works, many people with mitochondrial disease have reported modest benefits. Consult your doctor or MDA clinic director before taking any medication or supplement.
Headaches and seizures
Often, headaches can be alleviated with medications, and seizures can be prevented with drugs used for epilepsy (anti-epileptics).
Speech and swallowing issues
Mitochondrial myopathies can cause weakness and atrophy (shrinking) of the muscles of the face and neck, which can lead to slurred speech and difficulty swallowing. In these instances, speech therapy or changing the diet to easy-to-swallow foods can be useful.
Vision and hearing issues
Although progressive external ophthalmoplegia (PEO) — gradual paralysis of the eye muscles — is a common feature of mitochondrial myopathies, people automatically compensate for PEO by moving their heads to look in different directions and might not even notice any visual problems.
Ptosis (droopy eyelids) is potentially more frustrating because it can impair vision and also cause a listless expression, but it can be corrected by surgery, or by using glasses that have a “ptosis crutch” to lift the upper eyelids.
PEO or ptosis can sometimes cause damage to the developing brain's visual system, so it’s important for children with signs of PEO or ptosis to have their vision checked by a specialist.
Hearing impairment can be managed using hearing aids and alternate forms of communication.