A teenager who ran over a pedestrian just seconds after she inhaled nitrous oxide from a balloon at the wheel has been detained for 20 months. Louisa Tunstall, 19, inhaled from gold balloons while driving her Fiat 500 in Wigan, causing her car to veer onto the pavement and hit teaching assistant Tracey Holman, 50, who sustained severe injuries. Tunstall admitted to serious injury by dangerous driving and was sentenced at Bolton Crown Court, with the judge noting the inherent dangers of consuming nitrous oxide while driving.