Celine Dion loses muscle control amid stiff-person syndrome battle.
Claudette, her sister, discloses the heartbreaking impact on Celine.
Stiff person syndrome, a progressive and incurable neurological disorder.
The disorder causes the body to attack its nerve cells, impacting mobility.
Slow progress in research due to the rarity of the condition.
Celine's family charity, Fondation Maman Dion, flooded with support.
Despite working with top researchers, Celine sees little health improvement.
Celine not reliant on a wheelchair yet, still planning a return to performing.
Stiff person syndrome turns sufferers into 'human statues.'
The condition affects approximately one in a million people.
Celine revealed her diagnosis in December 2022.
Despite rumors, Celine's sister denies wheelchair-bound status and depression.