Hit by daily episodes of dizziness, fatigue and nausea, Tracey Condron thought she had a virus. But alone at home, four months later, things suddenly took a turn for the worse.

A healthy toddler was given a 50/50 chance to live when doctors realised that a common illness had triggered a rare condition that attacks the brain ...

Scores on a memory test dropped as football experience rose, and the pattern held across thousands of former players. This trend was the focus of a large analysis of retired American football players ...