What Is Stiff-Person Syndrome?

Earlier this month, Celine Dion announced that she has been diagnosed with stiff-person syndrome (SPS), a progressive neurological disorder, and as a result would have to reschedule her 2023 European tour dates to 2024. It’s a rare diagnosis — only about one or two out of every million people have it. For many people, this was the first time hearing that SPS even exists. People who have SPS get severe muscle spasms and stiff muscles in the torso, arms, and legs. For Dion, SPS is even affecting her vocal cords, which makes her unable to sing. The disorder can also lead to increased sensitivity to sound, stress, and physical contact. Sometimes, that increased sensitivity can trigger the spasms. It can get so bad that people with it can have trouble walking or even become disabled. Because SPS is such a rare disorder, doctors and scientists don’t know exactly what causes it. Yale Medicine researchers, however, are getting close. One theory is that it’s an autoimmune reaction attacking the body’s glutamic acid decarboxylase (GAD) protein, which regulates motor neurons in the brain. Less GAD causes the neurons to overreact, leading to spasms. SPS is twice as common in women than it is in men, and symptoms normally start to show between the ages of 30 and 60. Unfortunately, SPS doesn’t have a cure. It is, however, treatable with medication, immunotherapy, and some types of physical therapy.