Available on DVD: “Declaration of War”

Sick children and their struggling parents rarely make for a lively film. But Declaration of War does just that in an unusual French mashup of stylized techniques and stinging blows of emotion.

The mix doesn’t always work; it could have used fewer montages set to spiky electronica, and a duet sung by the leads was unnecessary. But what a treat to find a movie so bright-eyed and true — without a trace of bathos — in its depiction of such a harrowing subject.

The film tips its hand in the first scene, as we meet a school-age boy named Adam and his mother (Valérie Donzelli) in a hospital waiting room. Moments later, Adam is getting wheeled into an MRI, magnets clacking loudly as maman looks on with love and concern. The story then zips back to the moment, years earlier, when she first locked eyes with Adam’s father (Jérémie Elkaïm) at a party. His name is Romeo, he says. Hers is Juliette.

"So we’re doomed to a terrible fate?" he asks, and she replies: "I don’t know," the first admission of blind ignorance in a film absolutely riddled with it.

Their story, Adam’s story, is told with a frankness and empathy that holds us fast through the ordeal — from colicky newborn to wobbling toddler to a child with a tumor requiring nine hours of surgery.

As they move from doctor to doctor and hospital to hospital, kissing their son through thin protective masks, Donzelli and Elkaïm behave with all the flailing uncertainty of parents facing the worst possible fate for their child. This is their film, in more ways than one: Not only did Donzelli direct and co-write the script with Elkaïm, but the couple’s own son battled a life-threatening illness.

"We have to be strong," says Romeo to Juliette, and in any other film, spoken by any other characters, the line would sound banal. In Declaration of War, it’s a declaration of fact — clear, irrefutable, painful.