Life Céline Dion has stiff person syndrome, a rare neurological disorder. What is that? December 8, 2022January 5, 2023 Wyatte Grantham-Philips, USA TODAY Comments Off on Céline Dion has stiff person syndrome, a rare neurological disorder. What is that? Stiff person syndrome is a very rare neurological disorder. The disease's symptoms include progressive muscle stiffness and violent muscle spasms.