Progressive muscle atrophy is a rare condition characterized by deterioration of the lower motor nerve cells. It is most often associated with amyotrophic lateral sclerosis (ALS) or Lou Gehrig’s disease and motor neuron disease (MND). Progressive muscular atrophy is an active and advanced disease, although its progression is usually slow and is distinguished by the gradual wasting of the muscles in the extremities, which slowly spreads to other areas of the body.

From a pathological perspective, progressive muscle atrophy takes hold when ganglion cells (nerve cells within a mass of tissue) begin to deteriorate. The muscles gradually shrink and pale as use becomes increasingly limited until it is impossible to use the muscles. Due to its slow wear and tear on the muscular system, the disease is sometimes referred to as degenerative paralysis.

Research suggests that there may be two subtypes of progressive muscle atrophy. In the first type, the distribution of the disease is random throughout the body, making it difficult to detect. The second type progresses differently. The disease will affect one limb before entering a long dormant period and then spread to another limb.

ALS and other forms of MND are the main conditions that cause progressive muscle atrophy. It has been shown to have strong hereditary roots and has also developed as a result of physical injury, prolonged exposure to cold temperatures, and extreme muscle strain. The condition can also be caused by various types of infection, such as influenza, diphtheria, measles, and typhoid fever.

Progressive muscular atrophy, or PMA, is predominantly an adult disease. The average age range of PMA patients is between 30 and 50 years. Studies have shown that the condition affects men at a much higher rate than women.

The main symptom of PMA is a noticeable weakening of a muscle or muscles. This often occurs first on the hand. The thumb muscles may atrophy, followed by the other fingers, until the hand takes on a claw-like appearance and is virtually unusable. Hand in hand, PMA climbs up the arm to the shoulder. These muscles also begin to wear out before the disease progresses through the rest of the body; it generally affects the right hand before the left.

The lower extremities may be affected first, although in general, they are the last areas affected by PMA. In its later stages, the condition will take over the muscles in the lower body. When it hits the diaphragm, breathing becomes difficult, if not impossible, for the patient.