A feature published in the Journal of the American Medical Association reports on the curious case of an avalanche victim who developed seizures in his left arm every time he tried to solve a Sudoku puzzle.
The subject of this study is a 25-year-old right-handed student who was buried under the snow during a skiing trip. He experienced 15 minutes of generalized hypoxia, a condition in which the entire body is deprived of sufficient oxygen.
Hypoxia can affect the human body severely, potentially leading to organ and neurological damage, and even death. Some athletes train at higher altitudes to reach a mild state of hypoxia in an effort to get their muscles used to lower levels of oxygen, thus gaining an advantage in competitions.
The student's prompt rescue reduced the amount of brain damage, but soon after recovery the patient developed brief, involuntary twitching of the legs when walking and of the mouth when talking.
A few weeks later, while trying to solve a Sudoku puzzle, he developed clonic seizures in his left arm that only ceased when he stopped trying to solve the puzzle.
Clonic seizures are involuntary spasms of the muscles that can either be localized (like in this case) or general. The seizures more people might be familiar with are the tonic-clonic seizures, which affect sufferers of epilepsy.
According to the paper's researchers – Berend Feddersen of the University of Munich, Germany, and his co-authors – the oxygen deficiency caused a limited amount of damage to his brain. Similar seizures, known as reflex seizures, could also be triggered in the patient by other visual-spatial tasks (e.g. sorting random numbers in a certain order) but not by reading, writing, or solving math problems. This is not the first study to record such a condition; calculations, card games and board games have also been reported to induce epilepsy in patients in the past.
The researchers also reported that the patient stopped solving Sudoku puzzles over five years ago and that he has been seizure-free ever since.
Image Credit: Sudoku by Chotda via Flickr. CC BY-NC-ND 2.0