Myopathy or muscular disease that includes muscle inflammation and muscle weakness. Myopathies affecting the skeletal muscle can have many origins - inherited, drug induced or endocrine issues. Mostly a Myopathy is transitory in nature and rarely results in complete loss of function. Muscular Dystrophy is possibly an exception in that it can be severe and sometimes even fatal if it occurs early in life.
These inherited Myopathies occur due to a genetic defect in the synthesis of a protein. There are many kinds in genetic Myopathies:
Endocrine related Myopathies : Hormone deficiency can cause Myopathies. Hyperthyroid Myopathy is the result of excess secretion of thyroxine from the thyroid gland affecting muscles in the shoulders, hips or eyes. Hypothyroid Myopathy occurs when too little hormone is secreted and results in stiffness, cramps and weakness of legs and arms muscles.
Inflammatory Myopathies : Some Myopathies result in inflamed, weakened or wasted muscles. Dermatomyositis affects the connective tissue and the severity of the affected muscle loss can result in crippling movement.
Chronic muscle inflammation is called as Myositis. It is usually caused due to allergic reaction, infectious disease or rheumatism. Sometimes Myopathies are hereditary. Symptoms of Myopathy can also include cramps, spasms and stiffness. There is progressive deterioration in muscle strength resulting in pain and fatigue on walking and tripping and falling. This is not due to nerve dysfunction. Some patients might notice facial weakness, foot drop, droopy eyelids and poor reflexes in affected muscles.
Tarui Disease or Phosphofructokinase Deficiency is a muscular metabolic disorder that interferes with the processing of food. It was first described by Japanese physician Seiichiro Tarui in 1965.
It is also known as phosphofructokinase deficiency or glycogen storage disease type VII. Deficiency of this enzyme leads to accumulation of glycogen in the tissues. There is inability to break down glycogen. It is a rare condition and is mostly inherited; worldwide very few cases have been reported. Uric acid production may go up; thereby leading to Gout and also to Hemolytic Anemia.
The disease is presented as:
Classic: most common type of this disease includes intolerance for exercises.
Late onset: sets in late and does not have many indications as present in the classic form other than muscle and limb weakness.
Infantile: sets in infants , infants with this condition hardly survive, this is condition is rarely reported.
Symptoms are very mild and may go completely unnoticed. There is intolerance for exercise as well as pain and cramps while exercising. In rare cases, there is acute muscle breakdown or myoglobinuria. A meal rich in carbohydrates can worsen the symptoms as it reduces the fat level in the blood.
In Classic cases, the symptoms appear in early childhood - nausea, vomiting after heavy exercise and jaundiced appearance. In late onset cases, weakness, fatigue and Myopathy are noticed. When there is Infantile form of Tarui Disease, the symptoms can vary. Phosphofructokinase deficiency infants exhibit respiratory issues. If it presents itself in the central nervous system, symptoms include seizures.
There is no specific treatment. Avoid strenuous exercises to avoid muscle cramping and pain. Reduce intake of carbohydrates. High protein intake helps in improving muscle function and slow progression of the disease. Ketogenic diet is prescribed that includes high fat and low carb thus enabling the body to derive energy from fatty acids instead of glucose.
Myalgia is a common clinical symptom of many patients especially in adults. The occurrence of muscular pain - Myalgia has predisposing factors such as viral infections, trauma or even conditions that are related to muscular dystrophy and dehydration. The identification of myalgia in association with other symptoms paves a clear diagnostic path to treat this disease.
Myalgia in some cases if untreated can be fatal as it is closely associated with the motor and sensory response of the patient. Consistent muscular weakness in a person can lead to a variety of medical complications. Myalgia associated with viral infections has to be treated immediately as it may interfere with day to day activities of the person. The etiologies related to myalgia can be of various types such as myopathy and myositis respectively. Fibromyalgia can lead to morbidity if not diagnosed and treated at an early stage. In many cases antimalarial drugs, corticosteroids have also been reported to cause myalgia. The most common group of drugs recommended for myalgia are analgesics such as acetaminophen.
Bibliography / Reference
Collection of Pages - Last revised Date: March 21, 2019