Muscles make up half the body's weight. They are necessary for movement, opening and closing the eyes, chewing, facial expressions, protection of organs and contraction of organs like the heart. Diseases of the muscles may be inherited, may be caused by infections or diseases of the nerves or may be the result of medications. Muscular diseases caused by nerve damage often lead to muscular degeneration, also known as muscular atrophy.
Rhabdomyolysis
The three types of muscles in the body are the voluntary skeletal muscles, involuntary smooth muscles and the involuntary cardiac muscles. The involuntary muscles cannot be consciously controlled; the voluntary muscles can. In rhabdomyolysis, the skeletal muscles are destroyed due muscular injury or taking certain medications. When muscle is broken down in rhabdomyolysis, its components are released into the bloodstream. This can lead to kidney damage as the kidneys have to rid the body of the products of rhabdomyolysis--muscle components. Some signs of this disease are pain, weakness and swelling of the affected muscles. Swelling of the muscles may lead to a complication called compartment syndrome.
Amyotrophic Lateral Sclerosis
The muscles are controlled by nerves. Nerves send electrical signals to the muscles, which then contract or produce certain movements in response. In amyotrophic lateral sclerosis, also known as Lou Gehrig's disease, the nerves that transmit electrical signals from the brain and spinal cord to the voluntary muscles start to degenerate or die off. When the muscles cease to receive stimulation from the nerves, they grow weak, begin to twitch and eventually atrophy or degenerate. The Mayo Clinic states that as many as one in 10 cases of ALS is genetic in nature, while the rest are due largely to unknown causes. People who suffer from this disease may develop respiratory difficulties when the muscles required for breathing become paralyzed.
Charcot-Marie-Tooth Disease
The Charcot-Marie-Tooth Association states that Charcot-Marie-Tooth disease is found worldwide and is the most common inherited neurological disease. It was discovered by three physicians named Jean-Martin-Charcot, Pierre Marie and Howard Henry Tooth. This disease causes degeneration of the nerves that control the muscles in the hands and legs. It results in weakness and atrophy of the muscles located in the front of the legs and below the knees. It also causes high arches in the feet, hammertoes, problems with walking or other leg movements due to muscle wasting, issues with hand movements due to muscle degeneration in this area, scoliosis and occasionally weak respiratory muscles.
References
- "Principles and Practice of Critical Care"; Verma; 2006
- Charcot-Marie-Tooth Association: An Overview of Charcot-Marie-Tooth Disorders
- Medline Plus: Muscles
- Mayo Clinic: Amyotrophic Lateral Sclerosis
