education / SYMPTOMS
Patients with mitochondrial disease can have a wide variety of signs and symptoms. Some of them include as follows:
Muscle Fatigue
Patients with mitochondrial disease often find that they are unable to perform normal levels of physical activity. For example, they often feel fatigued after walking long distances, upstairs, or up an incline. They may find that they are unable to perform exercise at a level that they previously could do prior to the onset of their illness. Patients with mitochondrial disease may have been active in sporting activities during childhood, school and university days. However, with the onset of their illness they find that they are unable complete levels of physical activity that they previously found easy to achieve. This often leads to frustration and the assumption of more sedentary ways of living.
Hearing loss
Hearing loss is probably the commonest symptom of patients with mitochondrial disease. Hearing loss may occur in early, middle or later life. Often it may affect one ear more than the other. On occasions it may occur suddenly and recover. It is easily improved by the use of hearing aids.
Migraine
Migraine occurs commonly in the community. However, patients with mitochondrial disease may suffer from throbbing headaches which may affect the back of the head, the side of the head or the front part of the head, particular behind the eyes. Headaches may be associated with nausea, vomiting, or intolerance of bright light or noise.
Strokes
This is a rare symptom of mitochondrial disease. Typically, affected patients develop a focal neurological deficit such as loss of speech, loss of vision, weakness, or sensory loss. Strokes may be preceded by nausea, vomiting, headaches, confusion or loss of consciousness. These signs may act as a warning. They may be associated with seizures. Unlike other types of strokes, patients who have strokes as part of their mitochondrial disease often recover well.
Diabetes
Diabetes can occur early, late, or in middle life. Symptoms may include increased thirst and having to go to the toilet frequently. Affected individuals may feel tired. Diabetes is usually diagnosed by a blood test. Treatment is usually with tablets are changing diet and, in advanced cases, the use of insulin. Often treatment such as insulin is not required until very late on in the course of the illness. Drugs that cause lactic acidosis should be avoided in patients with mitochondrial diabetes.
Heart Disease
Patients with mitochondrial disease may develop palpitations (rapid or forceful beating of the heart). This may reflect an abnormal beating of the heart. If the heart does not beat regularly, affected individuals may feel light headed or faint. Other heart problems include a failure of the heart muscle to beat properly. If the heart is not beat properly, symptoms such as shortness of breath or ankle swelling may develop.
Gastrointestinal symptoms
Patients with mitochondrial disease may develop symptoms of constipation and abdominal swelling. On rare occasions, a blockage of the bowel may occur. This is referred to as abdominal pseudo-obstruction.
Eye disease
Patients with mitochondrial disease may often have droopy eyelid (ptosis). This means that affected individuals often till their heads back in order to see. It may affect one side more than the other. It may become worse during periods of tiredness. It may be associated with weakness of the eye muscles. This results in a lack of eye movements of an affected individual. Often those affected will move their head from side to side when looking in different directions. As a result affected persons may develop dry eyes or find that their eyes tear more frequently.