Parkinson’s disease primarily affects people over 50 years of age. It is characterized by uncontrollable contractions of skeletal muscles, producing tremors and rigidity of the muscles. There is often a decrease in normal muscular activities that are usually related to other movements. For example, a person with Parkinson’s Disease may not swing their arms while walking. The changes in the muscular system are only symptoms of this condition. The true causes lie in the central nervous system.
Myasthenia gravis can occur at any age, but it is more prevalent in older persons. The condition is an autoimmune disease which disrupts the normal contraction of muscles by interfering with the neurotransmitter acetylocholine. As a result, the muscles do not contract as they normally would in response to stimulation. The condition is characterized by drooping of the upper eyelid, difficulty swallowing and speaking, chronic generalized muscular weakness, and fatigue.
Muscle cramps are not unique to older persons, but are more common in them. Causes of muscle cramps include low oxygen supply to the muscle, over stimulation from then nervous system, and low blood sugar, sodium, and/or calcium. The sever, sustained contraction of a muscle may last from a few seconds to several hours.
Polymyositis most commonly affects adults in their 30s, 40s, and 50s. It is an autoimmune that causes inflammation of muscles resulting in weakness of the muscles of the hips, thighs, and extensor muscles of the neck. The condition is characterized by difficulty in rising from squatting, in kneeling, or in climbing and descending stairs.
Polymyalgia rhumatica is ten times more common in those over 80 years of age as in those aged 50 to 59 and twice as common in woman as in men. The condition is characterized by bilateral pain and stiffness of the shoulders and thighs. The discomfort my be so severe that it causes immobility, depression, weight loss, and fever. Fortunately, the condition responds dramatically to treatment with corticosteroids.