Sudoku puzzles trigger seizures in German man

Sudoku puzzles can give the brain a hard time, but in the very rare case of a 25-year-old German man, solving the numerical grid puzzles triggered seizures in his left arm.
The young man did not always react this way to Sudoku, according to a report of his case published in the journal JAMA Neurology.
His problems began after he was trapped in an avalanche during a ski trip. The young man had been skiing with a friend in November 2008 when an avalanche occurred on the mountain.
The avalanche buried the man in the snow and knocked him unconscious. But his friend who was a paramedic rescued him and started cardiopulmonary resuscitation (CPR) immediately, said Dr Berend Feddersen, a neurologist at the University of Munich in Germany and lead author of the report.

The man suffered a ruptured spleen and hip fracture, Feddersen said. In addition, while he was buried under the snow, his body tissues and brain got too little oxygen, a condition known as hypoxia.
As his brain was deprived of oxygen for 15 minutes, the man developed myoclonic jerks, which are sudden muscle twitches.

In the hospital, the man started having a type of seizure called spontaneous tonic clonic seizures in his left arm, Feddersen told 'Live Science'.
This type of seizure involves the muscles stiffening and then jerking rapidly and rhythmically. The doctors prescribed anti-epileptic medication to keep the seizures under control, Feddersen said.

After the man was moved from the hospital to a rehabilitation facility to continue his recovery, he attempted to solve a Sudoku puzzle. But while doing the puzzle, he again began having clonic seizures, or muscle twitches, in his left arm.
The doctors figured out that these seizures were triggered because the man had a very intense three-dimensional imagination that activated whenever he solved a Sudoku puzzle.
Imagining the numbers three-dimensionally allowed him to sort them and put them in sequence, Feddersen told 'Live Science'.
The seizures did not occur when the man completed other types of math problems, or while he was reading, Feddersen said.

The seizures began only after the avalanche because the hypoxia had resulted in the death of inhibitory fibres, which slow down brain signalling, in the right centro-parietal region of the man's brain.
Normally, this area of the brain is activated when 3D imagination is used. But with fewer inhibitory fibres in this region, when the man used his 3D imagination, it led to an overactivation of this brain region, which resulted in clonic seizures in his left arm.
"When he stopped this 3D imagination, the seizures stopped immediately," Feddersen said.
The young man had no choice but to give up Sudoku.