States as a result of the game (roughly 1% of the deaths attributed to suicide by suffocation in the same age group), see chart. Of these 86.6% were male, and the mean age was 13.3. 95.7% of these deaths occurred while the youth was alone; parents of the decedents were unaware of the game in 92.9% of cases. Deaths were recorded in 31 states and were not clustered by location, season or day of week. Neurological damage is harder to attribute accurately because of the difficulty of linking generalised, acquired neurological disability to a specific past event. Incidental, or indirect, injuries may arise from falling or uncontrolled movements and crushing by a ligature or an assistant. Such injuries may include concussion, bone fractures, tongue biting and hemorrhaging of the eyes. The CDC encourages parents, educators and health-care providers to familiarize themselves with the signs of the game. These include discussion of the game, bloodshot eyes, marks on the neck, severe headaches, disorientation after spending time alone, ropes, scarves, and belts tied to bedroom furniture or doorknobs or found knotted on the floor, and unexplained presence of things like dog leashes, choke collars and bungee cords. In popular culture The choking game phenomenon was the subject of the 2014 television film The Choking Game, based on the novel Choke by Diana Lopez. See also Archie Battersbee case Asphyxia Blue Whale Challenge Death Momo Challenge hoax Blackout challenge Benadryl challenge Shallow water blackout – for further discussion on the hyperventilation mechanism References Further reading Youth culture Youth culture in the United States Symptoms and signs: Respiratory system