Celine Dion made her first public appearance in nearly four years, defying the challenges of her battle with stiff person syndrome.

The 55-year-old "My Heart Will Go On" singer, who was diagnosed with the rare neurological disorder in December 2022, attended an NHL game at T-Mobile Arena in Las Vegas on Monday night, showing her unwavering spirit and resilience.

The event featured a thrilling matchup between the Vegas Golden Knights and her hometown team, the Montreal Canadiens. Celine, a staunch Canadiens supporter, attended the game with her son René-Charles and twins, Eddy and Nelson.

The singer's radiant spirit shone as she posed for photos with several players and delighted fans with her presence.

Despite her serious health issues, Celine appeared to be in tremendous spirits as she engaged in an enthusiastic post-game chat with the players in the Canadiens' locker room. 

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Celine's stiff person syndrome diagnosis forced her to cancel various concerts and ultimately led to the discontinuation of her Courage World Tour, which she last performed in March 2020. 

Stiff person syndrome is a "rare, progressive neurological disorder" that can cause stiff muscles in the torso, arms, and legs, according to the National Institutes of Health.

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In August, Celine's sister, Claudette Dion, publicly shared her sister's ongoing struggle with the ailment. Despite working with "the top researchers in the field" and trying various treatments, Claudette acknowledged the lack of a definitive cure.

She expressed her support for Celine's decision to cancel her tour, emphasizing the importance of listening to one's body and taking the necessary time to rest.

Claudette highlighted the debilitating nature of stiff person syndrome, describing the constant muscle spasms and the inability to control them. She likened the experience to the sudden leg cramps that jolt people awake at night, but in Celine's case, it affects all muscles.

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Since Celine's diagnosis, her sister, Linda Dion, has moved into her Las Vegas home to provide care and support during her challenging journey.