Muscle twitches, also known as fasciculations, occur commonly in healthy people. Often these twitches have no known cause. Sometimes caffeine or stress can make them worse, as MedlinePlus explains. Twitches can come and go, and usually don't last more than a few days. Fasciculations can also indicate the presence of an underlying disease. In these cases, other symptoms associated with twitching may be present, though twitching itself might be the first symptom.
Amyotrophic Lateral Sclerosis
Amyotrophic lateral sclerosis, or ALS, is a degenerative disease that affects motor neurons in both the central and peripheral nervous systems. When the motor neuron that travels from the brain stem or spinal cord to the muscles degenerates, the muscles it innervates start to atrophy and become weak. These symptoms accompany the appearance of fasciculations. As the National Institute of Neurological Disorders and Stroke explains, ALS can cause a wide range of symptoms in different people--some become paralyzed early on, others develop weakness more gradually. Eventually, however, patients lose control over all voluntary muscle movement, including the muscles that control respiration. Respiratory failure is the most common cause of death in patients with ALS.
Werdnig Hoffman Disease
Werdnig Hoffman disease, or spinal muscular atrophy I, is a hereditary condition in which the motor neurons from the spine to the muscles degenerate. It manifests within the first few months after birth. As the National Institute for Neurological Disorders and Stroke explains, infants affected by this disease have low muscle tone, a poor sucking reflex, difficulty swallowing and weak movements. Fasciculations are also seen as the muscles lose their innervation. Prognosis is poor, with most children dying by two years of age.
Polio and Post Polio Syndrome
Symptoms of polio include fever, headache and vomiting. MayoClinic.com notes that less than 1 percent of those affected will develop paralytic polio. When paralysis does develop, the onset is acute. Polio can affect the neurons in the brainstem, leading to difficulty swallowing, speaking and fasciculations in the tongue. It can affect the nerve cells in the spinal cord, leading to paralysis of the legs, arms and respiratory muscles as well as twitches in the affected muscles.
Survivors may develop new neurological symptoms decades after the initial illness. Post-polio syndrome affects about one-quarter to one-half of people who survived polio. Symptoms include fatigue, muscle weakness, muscle atrophy, fasciculations, cold intolerance and joint pain. Post-polio syndrome can be mild or severe, but most often is not life threatening.
