TOKYO - More than 10 percent of Japanese youngsters who acquired acute brain syndrome after contracting COVID-19 have passed away, according to the findings of a recent national survey released by a study team from the health ministry.

Between January 2020 and May 2022, the survey discovered 34 cases of acute encephalopathy linked to COVID-19 infection in individuals under the age of 18.

The team looked at 31 patients who had no underlying conditions that might have contributed to the brain damage.

Of the 31 children, 19 made a full recovery, but four of them did not, and problems were identified in eight more. Of the eight, five were said to be suffering from severe side effects, including being bedridden and unconscious.

Seizures, which roughly half of the patients had, diminished consciousness, and altered speech or behavior were the main initial symptoms, according to the survey.

When the Omicron coronavirus strain became common in January 2022 or later, the majority of individuals experienced acute encephalopathy.

The ratio of children with COVID infection who experienced brain symptoms before and after 2022, however, showed no appreciable difference, suggesting that Omicron may not necessarily be making the brain disease more likely to manifest, the study showed.