Atrophy
Atrophy refers to the reduction in size or wasting away of an organ or tissue, commonly resulting from inadequate nutrition, inactivity, or various pathological conditions. Muscle atrophy is a prevalent form, often caused by diseases affecting the nervous and musculoskeletal systems and can lead to significant loss of function and mobility. Symptoms can vary depending on the affected organ, with muscle atrophy manifesting as fatigue and increased risk of falls, particularly when the lower extremities are involved. Treatment strategies are tailored to the specific organ impacted and may include restoring circulation, nerve supply, or hormonal support, which can facilitate recovery and return to normal function. Rehabilitation techniques such as overload training and neuromuscular electrical stimulation (NMES) are increasingly utilized to help strengthen atrophied muscles. Advances in medical research, including functional electrical stimulation and gene replacement therapies, offer promising prospects for improving outcomes in individuals affected by atrophy. Overall, understanding atrophy is crucial for developing effective treatment and rehabilitation strategies.
Subject Terms
Atrophy
Also known as: Muscle wasting
Anatomy or system affected: Musculoskeletal system, nervous system, spine
Definition: A wasting away or decrease in size or activity of a body part because of disease or other influences, such as inactivity
Causes and Symptoms
Atrophy of any body organ can result from inadequate nutrition and lack of activity. However, other pathological conditions resulting in poor circulation, an interruption of nerve supply to the affected organ, and disease of the organ tissue itself can also cause atrophy. Muscle atrophy is a common form of atrophy that can result from various diseases of the nervous and musculoskeletal systems. The body’s metabolism of protein is also directly related to the condition of muscle atrophy, as muscle and liver protein can be used for energy. This research supports the finding that muscles atrophy during periods of inactivity. Muscle weakness can also be an early manifestation of thyroid or parathyroid disease.
The symptoms of atrophy are dependent upon the organ affected. Muscle atrophy is most evident with loss of function and general mobility. When muscles of the lower extremities become atrophied, the individual becomes easily fatigued with activity and may be at risk for falls.
Treatment and Therapy
The organ that is affected by atrophy dictates the treatment and therapy to be provided. Once any loss of circulation, nerve, or hormone support is regained, the atrophy normally diminishes and is replaced by growth to allow the return of normal function. As a general rule, muscles worked close to full capacity will increase in strength. The overload can be applied with standard weights, pulleys, springs, or a variety of isokinetic devices. Muscle growth in response to overload training occurs primarily from an enlargement of the individual muscle fibers.
Neuromuscular electrical stimulation (NMES) is the application of electrical current to elicit a muscle contraction. The use of NMES in orthopedic and neuromuscular rehabilitation has increased significantly over the years. A nerve action potential may be elicited either by a command originating in the motor cortex of the brain or by an electrically induced stimulus at the periphery. In either case, the action potential and release of transmission substances are the same.
Perspective and Prospects
Advances in medicine and rehabilitation have helped individuals afflicted with atrophy. The development of functional electrical stimulation allows individuals to carry out tasks by artificially stimulating muscles that have become too weak to carry out normal activity. Research in the area of spinal cord injuries is ongoing and advancing, addressing the causes and results of muscle atrophy from an interruption in nerve input. New drugs, as well as techniques in gene replacement therapy, are being developed to treat certain types of atrophy.
Bibliography
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Schorling, David C et al. “Advances in Treatment of Spinal Muscular Atrophy - New Phenotypes, New Challenges, New Implications for Care.” Journal of Neuromuscular Diseases, vol. 7,1 (2020): 1-13. doi:10.3233/JND-190424