CONDITIONS

Myopathy

 Myopathy refers to any disease that affects muscle tissue. Diseases of the muscle result in weakness, inflammation, tetany (spasms), or paralysis. Myopathy can be the result of either inherited or acquired causes.

Acute “acquired” myopathies, such as acute stiffness, spasm, or cramp, are common. Others are linked to exposure to an infectious agent, such as viruses or bacteria, or are inherited. However, certain cases of myopathy have no known associated risk factors.

Myopathy develops as the result of either inherited (congenital or genetic) disorders or acquired conditions of the muscles. Most commonly, people develop acquired myopathy from muscle fatigue, electrolyte imbalance, or dehydration, resulting in stiffness or cramping. Other causes of myopathy include immune disorders that cause inflammation and pain. Numerous inherited myopathies exist and may be associated with progressive weakness, atrophy (wasting), inflammation, muscle fiber metabolism dysfunction, muscle spasm, or rigidity.

Types of Myopathy

Myopathy is categorized by the affected muscles and muscle biopsy results. Some of the types of myopathy are:

Muscular Dystrophy

Muscular dystrophy is one of the most common types of muscle disorders that affects children. This genetic condition is present at birth, although symptoms do not usually begin until the child is a few years old. Muscular dystrophy may cause children to stumble, waddle and have trouble standing up and pushing things. Symptoms may vary depending on the individual type of muscular dystrophy.

Congenital Myopathy

Congenital myopathy is present at birth and usually caused by hereditary factors, but is not considered progressive. These conditions often affect the legs and cause a delay in the ability to walk or trouble climbing stairs.

Inflammatory Myopathy

Inflammatory myopathy is a muscle disorder that is a result of an immune system reaction in the muscles. These autoimmune disorders attack the body cells and cause overall muscle weakness. Drug-induced myopathy is caused from the use of certain medications, such as immunosuppressants, which can cause severe weakness in some cases.

Causes

Myopathy refers to any disease that affects the muscle tissue. Diseases of the muscle result in weakness, inflammation, tetany (spasms), or paralysis. Myopathy can be the result of either inherited or acquired causes.

Inherited causes of myopathy

Myopathy may be due to genetic conditions. Examples of some genetic conditions that result in myopathy include:

• Congenital myopathies, that are present at birth
• Familial periodic paralysis
• Glycogen storage disease of muscle (including Pompe’s disease)
• Mitochondrial myopathies (abnormalities of the cellular components known as mitochondria)
• Muscular dystrophy

Acquired or unknown causes of myopathy

Myopathy may have acquired or unknown causes. Examples include:

• Common muscle cramps
• Dehydration(loss of body fluids and electrolytes, which can be life threatening when severe and untreated)
• Endocrine disorders
• Infection
• Myositis (muscle inflammation)
• Neuron disorders (typically neuromuscular diseases)

Symptoms

Myopathy causes dysfunction of the muscles due to inflammation or disease and can cause a number of symptoms. The symptoms can vary in intensity among individuals.

Common symptoms of myopathy

You may experience myopathy symptoms daily or just once in a while. At times, any of these muscle symptoms can be severe:

• Cramping
• Pain
• Paralysis
• Rigidity
• Stiffness
• Swelling
• Wasting (atrophy)
• Weakness

Symptoms that might indicate a serious condition

In some cases, symptoms of myopathy can signal a serious condition that should be immediately evaluated in an emergency setting. Seek immediate medical care (call 911) if you, or someone you are with, have any of these serious symptoms including:

• Difficulty swallowing
• Muscle twitching or cramps in tongue, shoulders or arms
• Muscle weakness in ankles, feet or legs
• Slurred speech
• Sudden weakness on one side of the body
• Trouble raising the toes and foot

Diagnosis

After reviewing medical history and performing a medical examination, diagnostic tests will be conducted to confirm a diagnosis. Some of these tests may include:

• Blood test
• Muscle biopsy
• Electromyogram (EMG)

Genetic tests for mutated genes