If American actor Michael J. Fox's Parkinson's Disease prevents him from staying still, singer Celine Dion's rare medical condition is said to be the exact opposite.

Dion has revealed that she was diagnosed with Stiff Person Syndrome, an untreatable disease that causes muscles to get tense, locking the body into a rigid position and making the afflicted unable to move.

A report in The Economic Times said SPS causes Dion to look like a human statue. The disease also causes spasms that prevent Dion from performing, according to TET.

Consequently, the 54-year-old was forced to cancel her concert tour in Europe to the dismay of her fans.

If Dion becomes motionless due to SPS, it would likely be a medical emergency that needs an immediate response. But it's not always emergency responders who come to the rescue in such cases.

A passerby recently saw a woman, who seemed to have passed out with her head on a desk, through the window of the Laz Emporium gallery in London.

Upon noticing that the woman had not moved for two hours, the onlooker thought she suffered a medical emergency and called the police.

Police rushed to the locked gallery and unhinged its door to enter and rescue the apparently unconscious woman.

Gallery employee Hannah Blakemore was shocked upon seeing the police, the New York Post reported.

The rescuers were also shocked when they realized that the person they thought had a heart attack or had overdosed was just a hyper-realistic statue made by artist Mark Jenkins displayed there.

It was the second time the statue named Kristina caused a false alarm.