Photo/Illutration(The Asahi Shimbun)

Japanese and U.S. research teams have successfully visualized abnormal proteins in patients with brain disorder, opening up the path to early diagnosis.

People who receive head shocks in sports or car accidents can exhibit deteriorated cognitive functions or develop movement disorders such as hand tremors years or even decades later.

When patients with the chronic condition, known as “boxer’s encephalopathy,” are examined after their death, "tau" proteins are found to have accumulated in their brains. But such accumulation has been difficult to assess while patients are alive.

The U.S. research team, including scientists at Boston University, conducted PET exams of 26 former American football players given special drugs that attach to tau.

According to the team's announcement this past spring, three areas were identified in their brains in which most of the tau had accumulated.

The accumulation tended to increase the longer the playing career, the results showed.

The Japanese team, of the National Institutes for Quantum and Radiological Science and Technology (QST), announced Sept. 2 the results of its study of 27 people who received head shocks an average of 21 years earlier.

Reflecting the U.S. findings, the results showed that tau had accumulated in their brains, and that it tended to accumulate more among those who had already started to show symptoms of brain disorder.

Some people who had accumulated a large volume of tau in their brains, however, did not exhibit such symptoms.

"This is an important issue for players of sports--even after retirement--in which shocks to the head are likely," said Keisuke Takahata, a QST researcher. "I hope to develop a method to provide accurate diagnosis of brain disorders from an early stage."