Many diseases can cause muscle twitches. According to the U.S. National Library of Medicine and the National Institutes of Health, or NIH, muscle twitches are "fine movements of a small area of muscle." They can be benign or can signal an underlying nervous system disorder. The NIH says muscle twitches may be caused by minor, localized muscle contractions or uncontrollable twitching of a muscle group served by a single motor nerve fiber.
Amyotrophic Lateral Sclerosis
Amyotrophic lateral sclerosis or ALS, also known as Lou Gehrig's disease, is a disease that can cause muscle twitches. According to the Mayo Clinic website, ALS typically begins with muscle twitching and weakness in the arm or leg, along with slurred speech, and progressively impairs a person's ability to control muscles--including those muscles needed for moving, speaking, eating and breathing. The Mayo Clinic website says that one to three people per 100,000 worldwide suffer from ALS, and that an inherited form of ALS is responsible for about 5 percent to10 percent of cases. Along with muscle cramps and twitching in the arms, shoulders and tongue, common ALS symptoms include the following: footdrop or difficulty lifting the front part of the foot and toes, weakness in the leg, feet or ankles and difficulty swallowing. As ALS progresses, muscles become weaker until they're paralyzed.
Muscular Dystrophy
The University of Maryland Medical Center, or UMMC, says muscular dystrophy--a nervous system disorder--is a common cause of muscle twitching and that symptoms of a nervous system disorder include the following: alterations in sensation, muscle atrophy or wasting and weakness. The National Institute of Neurological Disorders and Stroke, or NINDS--a division of the National Institutes of Health--says muscular dystrophy refers to a group of more than 30 genetic diseases that cause skeletal muscle weakness and degeneration. The NINDS notes that all types of muscular dystrophy are characterized by progressive muscle weakness and degeneration, and that most people with muscular dystrophy eventually lose the ability to walk. The NINDS says numerous cases of muscular dystrophy arise from spontaneous mutations in the genes, and that the gene defect can be passed to the next generation.
Peripheral Neuropathy
According to the Mayo Clinic website, peripheral neuropathy is characterized by damage to a nerve that runs from the spinal cord to a muscle. It can be caused by trauma, infections, metabolic problems and toxin exposure. Diabetes-related peripheral neuropathy is one of the most common causes of this neuromuscular disorder. The NINDS says common peripheral neuropathy symptoms include the following: muscle weakness; painful muscle cramps and fasciculations or uncontrolled muscle twitching that's visible under the skin; muscle wasting; bone degeneration; and skin, hair and nail changes. According to the Mayo Clinic, people with peripheral neuropathy often describe it as burning or tingling pain, and that the loss of feeling or sensation occurs in a stocking- or glove-like distribution pattern.
