General
Myopathy

Muscle Weakness Abnormal Gait or Difficulty Walking Elevated Creatine Kinase Respiratory Insufficiency Difficulty Swallowing Exercise Intolerance
Myopathy, General Mobile_LightDot Mobile_LightDot Mobile_LightDot Mobile_LightDot Mobile_LightDot
Pompe disease
2.5 per 100,000
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Overview

  • Myopathy is a broad term that refers to muscle weakness, generally in skeletal muscles, which are muscles used for voluntary movements
  • Many signs and symptoms of general myopathy can overlap with Pompe disease

Signs and Symptoms

  • Myopathy has symptoms that can also occur in Pompe disease, including:
    • Weakness throughout the body
    • Muscle pain
    • Decreased ability, or inability to perform exercise, also known as exercise intolerance
    • Fatigue
  • Similar to Pompe disease, most myopathies affect those muscles closest to the midline of the body
  • A characteristic walking pattern (e.g., waddling, walking on the balls of the feet, difficulty running) that may be observed in Pompe disease can be seen in myopathy, especially in the early stages of the disease
  • Other symptoms which may make a doctor suspect myopathy are: muscle wasting and shrinkage (atrophy), myoglobin (an oxygen-carrying protein in the muscles) in the urine, dysfunction in how muscles relax after they contract (myotonia), muscle weakness that lessens after rest, and muscle weakness appearing in discrete patterns
  • As observed in Pompe disease, severity, when the disease starts, and which signs and symptoms occur will vary in myopathy
  • Myopathies are classified based on whether they are acquired throughout life or are inherited like Pompe disease
  • Typically, an inherited myopathy will affect a longer portion of life while a sudden occurrence of signs and symptoms later in life is more indicative of an acquired myopathy
  • While some forms of myopathy may have minimal impact to the patient, other causes of the disorder may be progressive, severely disabling, or life-threatening, similar to Pompe disease

Diagnosis

  • As in Pompe disease, genetic testing is currently available for many disorders that may cause various types of myopathies
  • When determining the extent of myopathy and what the underlying disorder may be, healthcare providers may use similar tools used on the path to a Pompe disease diagnosis such as studying the electrical activity of the muscles (electromyography) or laboratory tests including measuring creatine kinase levels in the blood

The information presented is intended as a brief overview. It is not an exhaustive summary of general myopathy. For more information on general myopathies, visit: https://www.ninds.nih.gov/Disorders/All-Disorders/Myopathy-Information-Page

For more information on the diagnosis of Pompe disease, visit Diagnosis of Infantile-Onset Pompe Disease and Diagnosis of Late-Onset Pompe Disease