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Japanese doctor warns of potentially fatal COVID-related brain damage in children

Kazuhiro Muramatsu, associate professor at Jichi Medical University's department of pediatrics, speaks about the university hospital's first severe COVID-19 case involving a young child, at the university in Shimotsuke, Tochigi Prefecture, on May 9, 2022. (Mainichi/Eri Misono)

UTSUNOMIYA -- Following cases in east Japan's Tochigi Prefecture in which a young girl died and another suffered paralysis from "acute encephalopathy," a brain disease they developed after coronavirus infections, the Mainichi Shimbun asked a doctor about the characteristics of the disease and what to look out for.

    In late April, a girl aged under 10 died from "acute encephalopathy" and in mid-May, a girl aged under 5 who developed severe symptoms was left with paralysis in her body. The Japanese Society of Child Neurology is poised to investigate cases of acute encephalopathy following coronavirus infections nationwide.

    According to the Togichi Prefectural Government and Jichi Medical University, the young girl who died had initially been recuperating at home with mild symptoms, including a fever, after testing positive for the coronavirus. However, there was a sudden change in her condition, and she was sent to the hospital in an ambulance. She was treated in the intensive care unit, but was later confirmed dead. The girl had no preexisting illnesses. Kazuhiro Muramatsu, associate professor at Jichi Medical University's department of pediatrics, who treated the patient, said the case was believed to be the first in the country in which a child aged under 10 had died from acute encephalopathy caused by COVID-19.

    Meanwhile, the girl aged under 5 experienced severe spasms, a high fever, and impaired consciousness at home, and later tested positive for the coronavirus at the hospital. Though she survived, she was left with paralysis in her body. This girl also had no underlying diseases.

    Acute encephalopathy is a disease in which the brain becomes suddenly swollen due to a viral or bacterial infection or other causes. The main symptoms include impaired consciousness, and the disease is often seen in young children. It is believed that a cytokine storm, or an uncontrollable overreaction of the immune system, and excitotoxicity, in which neurotransmitters are excessively released due to convulsions, causing the death of nerve cells, trigger the brain malfunction.

    Muramatsu commented, "Since acute encephalopathy is caused by viral infections, I had predicted that if coronavirus case numbers rose, there would also be patients with the acute brain disease, and unfortunately we are now seeing such cases."

    In some cases, patients who develop acute encephalopathy experience a drastic deterioration in their health as well as severe convulsions. Muramatsu explained, "The girl who passed away was the type whose condition worsens drastically, and I think it would have been difficult to save her life even if she had been hospitalized from the onset."

    This girl was eligible for a COVID-19 vaccination children can receive from the age of 5, but had not been vaccinated. As vaccines have been reported to help prevent coronavirus infections to a certain extent, the associate professor recommends that children aged 5 or older get vaccinated. According to the Tochigi Prefectural Government, when it explained to the girl's guardians that it would disclose the girl's death to the public, they asked officials to "spread the message so people would consider vaccinations without getting scared."

    As of May 31, there had been 30,629 COVID-19 deaths reported across Japan, and of them, six people were aged under 10, according to the Ministry of Health, Labor and Welfare. There have also been reports of COVID-19 patients dying from encephalopathy in the United States.

    According to the Japan Pediatric Society's interim report dated Feb. 20, of the 5,129 registered COVID-19 cases involving individuals aged 15 or younger, there were two instances in which patients developed acute encephalopathy. The patients were respectively aged between 5 and 11, and 12 and 15, and reportedly developed symptoms during the early stages of the pandemic between February 2020 and July 2021.

    Though there are many unknown factors, what should be taken note of when children are recuperating from COVID-19 at home?

    Muramatsu said, "If you can notice a change in your child early on, they can be treated at an early stage, which can possibly help prevent severe symptoms." He said that it is important to carefully observe whether there are abnormalities in their condition, such as being languid, falling asleep if not being talked to, being unable to hold a conversation, and being in an excited state when the child is normally calm. In such cases, Muramatsu called on parents to have their children examined at medical institutions or dial the pediatric emergency number #8000 at night or on holidays.

    (Japanese original by Eri Misono, Utsunomiya Bureau)

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