The story of Eva Perón—the actress-turned-First Lady of Argentina—has been told numerous times. The Broadway musical Evita and the movie adaptation cover her rise to power and her untimely passing, but they leave out what may be the most tragic part of her life. During her final months, Perón likely underwent a secret, forced lobotomy that possibly hastened her death.

Perón was diagnosed with advanced cervical cancer in August 1951 and died in July 1952 at age 33. For years, her death was thought to be the direct result of her disease, but a study published in 2015 complicates that narrative.

For his study published in the journal World Neurosurgery, Yale neurosurgeon Daniel Nijensohn used medical records and firsthand accounts to flesh out the details surrounding Perón's lobotomy. He claims Perón received the procedure in May or June 1952, just weeks before her death. Perón reportedly suffered greatly throughout her battle with cancer, and doctors may have recommended the lobotomy as a treatment for pain.

A lobotomy is a type of brain surgery that involves severing connections between the prefrontal cortex and the rest of the brain. This dulls the patient's emotions, which is why it was used to dampen pain—or at least moderate the response to it. The operation is regarded as dangerous and inhumane today, but in the 1950s, it was fairly common.

Lobotomies were also used to treat mental health issues, especially in women. One analysis found that the majority of lobotomies carried out in France, Switzerland, and Belgium between 1935 and 1985 were performed on female patients. In his study, Nijensohn alleges that Perón's surgery was not merely a treatment for pain, but a way to control her erratic behavior.

Perón's politics grew more inflammatory as her condition worsened. In her last public speech delivered on May 1, 1952, she targeted her enemies, and she even attempted to organize armed workers' militias from her sickbed. The operation she received may have been a drastic attempt by Juan Perón—Eva Perón's husband and the President of Argentina—to prevent a civil war. Regardless of the motives, the lobotomy was likely performed without the First Lady's knowledge or consent.

Perón made her last public appearance at her husband's second inauguration in June 1952. Though the surgery she received possibly calmed her anxieties, it also may have worsened her physical health. After the lobotomy, she stopped eating, and by the time of the event she weighed just 78 pounds. She was so frail that she needed a cage-like contraption made of plaster and wire to stand.

Eva Perón died on July 26, 1952. Though she was a controversial figure in politics, she was also regarded as a saint by many Argentinians, and her funeral was attended by millions. The true nature of her final months add another wrinkle to her fascinating legacy.