In a tearful Instagram video, the singer revealed that the incurable condition has caused painful spasms and impacted her ability to walk and sing. “As you know, I’ve always been an open book, and I wasn’t ready to say anything before, but I’m ready now,” Dion said in the video. “I’ve been dealing with problems with my health for a long time, and it’s been really difficult for me to face these challenges and to talk about everything that I’ve been going through. “Recently, I’ve been diagnosed with a very rare neurological disorder called the stiff-person syndrome, which affects something like one in a million people,” Dion continued. “While we’re still learning about this rare condition, we now know this is what’s been causing all of the spasms that I’ve been having. Unfortunately, these spasms affect every aspect of my daily life, sometimes causing difficulties when I walk and not allowing me to use my vocal cords to sing the way I’m used to.”

What Is Stiff-Person Syndrome?

Stiff-person syndrome impacts approximately one in a million people, according to the National Organization for Rare Disorders (NORD). It strikes women more often than men, and symptoms typically emerge during middle age. The condition is also more common in people with autoimmune diseases such as rheumatoid arthritis and lupus. RELATED: Celebrities With Rheumatoid Arthritis Hallmarks of stiff-person syndrome include progressive muscle stiffness and repeated episodes of debilitating muscle spasms. But the progression of symptoms isn’t linear, and the severity and frequency of symptoms vary from one patient to the next. People tend to go through repeated cycles where the condition worsens and then improves, according to NORD. Muscle spasms can be random, and they can also be triggered in some people by a range of sensory experiences, such as exposure to an unexpected noise or sudden physical contact. “People with stiff-person syndrome can run the spectrum from mild to severe, and a personalized approach to treating the disease is the best way to ensure an improved outcome,” explained Richard Nowak, MD, a neurologist at Yale Medicine in New Haven, Connecticut, in an online article about the condition.

What Causes Stiff-Person Syndrome?

While the exact cause is unknown, some scientists suspect the syndrome may be a type of autoimmune disorder that develops when the immune system mistakenly attacks cells in the brain and spinal cord. The immune system appears to attack a protein known as glutamic acid decarboxylase (GAD), which aids in production of a protein called gamma-aminobutyric acid (GABA), according to Yale Medicine. GABA regulates motor neurons that control movement throughout the body, and when there’s not enough of this protein, the nervous system can shift to overdrive and interfere with normal movement. Up to 80 percent of patients with stiff-person syndrome have antibodies in their blood and spinal fluid that show their immune system is attacking GAD proteins.

How Is Stiff-Person Syndrome Diagnosed?

A stiff-person syndrome diagnosis involves blood tests and spinal fluid analysis to look for GAD antibodies. Patients may also undergo what’s known as electromyography (EMG) testing, which examines the electrical activity of skeletal muscles and can help identify spasms. In addition, doctors work to rule out other potential causes of muscle spasms and pain, such as Parkinson’s disease, multiple sclerosis, fibromyalgia, or anxiety, according to Yale Medicine.

How Is Stiff-Person Syndrome Treated?

There is no cure for stiff-person syndrome, and there is not any clear way to prevent the condition, either. Treatment instead focuses on symptom management and minimizing disability related to the condition. Patients might be prescribed medicines known as benzodiazepines — such as diazepam and clonazepam — or the muscle relaxant baclofen to reduce muscle stiffness and spasms, according to the Cleveland Clinic. In addition, some people may take anti-seizure medicines, anti-inflammatories, or corticosteroids to reduce pain. Other treatment options include intravenous immunoglobulin (IVIG), an infusion of antibodies from healthy donors that can prevent the body from attacking itself; plasmapheresis, a procedure that removes and replaces a patient’s blood plasma; rituximab, a biologic drug that treats several autoimmune disorders; and autologous stem cell transplant, a procedure that removes healthy blood-forming cells from a patient and then replaces them after treatment. Beyond this, there are approaches designed to improve muscle function and minimize pain, such as physical therapy, massage, water therapy, heat therapy, and acupuncture, according to the Cleveland Clinic.

Celine Dion Says Living With Stiff-Person Syndrome Has Been Difficult

“I have a great team of doctors working alongside me to help me get better, and my precious children, who are supporting me and giving me hope,” Dion said in the video. She didn’t specify what treatments she is undergoing for stiff-person syndrome. But she did say her path to recovery has been challenging. “I’m working hard with my sports medicine therapist every day to build back my strength and my ability to perform again, but I have to admit it’s been a struggle,” she said. “I always give a hundred percent when I do my shows, but my condition is not allowing me to give you that right now.”