Muscle Diseases – Basics of Neuromuscular Myopathy

Muscle Diseases refer to all pathological, neurological and metabolic conditions that affect the functioning of human muscles. There are many ways of defining and grouping such illnesses. The most common classification includes primary and secondary muscle diseases. The primary group refers to disorders caused by inherent problems in the functioning of the muscles. A good example of such conditions is metabolic myopathies that surface due to the inability of the energy metabolizing cells of the body to direct sufficient fuel to the muscle fibers. The secondary group of conditions refers to conditions that have another, principal reason of origin which eventually induce muscular problems. This is best exemplified by neurological muscular myopathies that have an origin in the problems of the nervous system.

Basics of Neuromuscular Myopathy

Among the many types of muscles in the human body, the skeletal fibers are regarded as most critical. This is because we perform our voluntary bodily movements via these fibers. Whenever we want to make a voluntary movement like walk or move our arms, a nerve signal is sent to the skeletal musculature that acts accordingly. When the conduction of the never impulses, that are essentially small, electrical impulses, from the nerve to the skeletal fibers is impaired and thus, it cannot execute the desired action properly. This is how a neuromuscular myopathy develops. Due to this, overall activity of the muscles is compromised. The affected patient finds it hard to perform the most basic of movements without feeling cramps, stiffness or pain. The increased state of inactivity of the musculature makes its weaker, which in turn induces a process of wasting and loss of tone.

Understanding Neuromuscular Disorders with an Example

The most well documented example of neuromuscular disorders is that of Muscular Dystrophy or MD. This is a genetic disease that has an inconsistent onset, i.e. it can surface at the time of birth, childhood or even among young adults. This is a progressive condition which means that the musculature get increasingly weaker. The voluntary musculature gradually loses more control and the patient develops typical coordination problems such as the inability to move the neck or head in the wanted direction. The movement of the shoulders too becomes labored and the upper back, hips and pelvis might feel cramped. Such patients develop a characteristic abnormality in their gait wherein they might tend to walk on their toes. Simple, coordinated body movements such as climbing the stairs become difficult. There are some variations in the niche of muscular dystrophy. For example, FSH Dystrophy usually tends to affect one side of the body.

Understanding Other Types of Muscle Diseases:

  • Congenital Myopathies
    This refers to disorders present at the time of birth. Such children show distinct, impaired development in their physical and mental growth wherein their motor skills such as the ability to sit or walk is delayed. Such children are prone to having pronounced facial abnormalities.
  • Mitochondrial Myopathies
    This is an example of metabolic myopathy wherein the muscle tissue are not supplied the basic energy they need. This is caused by genetic irregularities in the mitochondria of the cells. Mitochondria are the main energy-producing part of the human cell. Due to energy deprivation, there is widespread weakness in the musculature of the patient.
  • Glycogen-related Muscular Myopathy
    This is another type of metabolic myopathy that is caused by genetic causes. Here, mutations in some genes cause enzymes to irregularly metabolize glycogen/glucose deposits. Established examples of this condition include Cori’s diseases.