The cause of Constance Wilde's death at age 40 has long been a mystery, but now, 116 years later, it appears to have been solved. Family letters unveiled by Oscar Wilde's grandson suggest that the writer's wife died within days of a gynecological operation gone wrong, the Guardian reports.

An expert concluded as much after investigating the letters, which discuss her trouble walking and her medical treatment. Constance Wilde showed symptoms of what today would be considered multiple sclerosis.

The disease was noted in 1868, some 30 years before her death, but it wasn't well understood, the New York Times reports—especially, it seems, by her doctors.

One of them, Luigi Maria Bossi, thought that gynecological surgery could treat neurological problems. Previous studies suggest Constance Wilde had a spinal injury and an operation.

But "people somehow never put two and two together and thought: ‘Why is a gynecologist operating on her spine?’" says her grandson, Merlin Holland. With a clinical pharmacologist, Holland co-wrote a paper in the Lancet journal explaining the findings, the Times reports.

He hopes they "will put Constance to rest, poor thing." (The author himself experienced a vindication of sorts just a few years ago.)

This article originally appeared on Newser: Discovered: How Oscar Wilde's Wife Died

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