Celine Dion has been diagnosed with a rare neurological condition called stiff person syndrome. This condition causes muscle rigidity and spasms, which can affect every aspect of daily life, including walking and vocal cord use. Dion has described her symptoms as "severe and persistent muscle spasms". The syndrome can also cause anxiety. There is no cure for stiff person syndrome, but treatments such as immunotherapies and benzodiazepines can help manage symptoms.