What rare brain condition did Sienna contract?

Sienna contracted Acute Necrotising Encephalitis (ANE), a rare and severe brain condition.

Can the flu cause Acute Necrotising Encephalitis (ANE)?

While the flu doesn't directly cause ANE, it can be a triggering factor for this rare brain condition.

Why is Sienna Dunion spending Christmas in the hospital?

Sienna is in the hospital due to a critical battle with a rare brain condition and subsequent intestinal surgery, requiring ongoing treatment and rehabilitation.

Home / Health / Girl's Flu Ignites Rare Brain Battle

Girl's Flu Ignites Rare Brain Battle

21 Dec, 2025

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Summary

Four-year-old Sienna contracted a rare brain condition after a flu diagnosis.
She was placed in an induced coma and faces long-term recovery.
Her father urges parents to vaccinate children against the flu.

A young girl's life has been irrevocably altered after contracting a severe brain condition, Acute Necrotising Encephalitis (ANE), following a flu diagnosis. The four-year-old, Sienna Dunion, was rushed to the hospital after experiencing flu-like symptoms, which rapidly escalated, leading to her being placed in an induced coma to protect her brain.

Further complications arose as Sienna also suffered from intestinal issues, requiring emergency surgery that removed 60% of her intestines. Doctors predict she will live with short bowel syndrome, potentially impacting her nutrition and eating habits for life. Her health battle means she will remain hospitalized through the Christmas period, missing festive activities.

Sienna's father, Gary Dunion, has shared his family's harrowing experience, emphasizing the rarity of ANE and urging other parents to ensure their children are vaccinated against the flu. While Sienna's recovery is expected to be a long journey, potentially spanning several more months, the family remains dedicated to her care and rehabilitation.