Half of the children who developed multisystem inflammatory syndrome children, associated with Covid-19, had neurological symptoms or signs when they entered hospital, new research indicates.

Experts found that patients with Paediatric Inflammatory Multisystem Syndrome Temporally associated with Sars-CoV-2 (PIMS-TS) presented with new symptoms involving both the central and peripheral nervous systems, in the absence of respiratory symptoms.

Neurological symptoms were seen more frequently in those with more severe disease.

The symptoms included headaches, encephalopathy – disease or damage to the brain, and hallucinations.

Children with neurological symptoms were more likely to need a ventilator and drugs to help stabilise their blood circulation than the children without neurologic symptoms, according to the study which will be presented at the American Academy of Neurology’s 73rd Annual Meeting.

However, there were no differences in terms of demographics, inflammatory markers, management or short-term outcomes between the two groups.

Study author Omar Abdel-Mannan, University College London, said: “With this new inflammatory syndrome that develops after children are infected with the coronavirus, we are still learning how the syndrome affects children and what we need to watch out for.

“We found that many children experienced neurologic symptoms involving both the central and peripheral nervous systems.”

Researchers reviewed the records of all children under age 18 admitted to Great Ormond Street Hospital in London between April 4 and September 1 last year, who met the criteria for multisystem inflammatory syndrome in children.

There were 46 children with an average age of 10.

Of those, 24 children had neurological symptoms or signs that they had not experienced previously.

Twenty-four had headaches, 14 had encephalopathy, six had voice abnormalities or hoarseness, six had hallucinations and five had ataxia, or impaired coordination.

In addition, three children had problems with their peripheral nerves and one child had seizures.

Dr Abdel-Mannan said: “Children who develop this condition should definitely be evaluated for neurologic symptoms and longer- term cognitive outcomes.

“More studies are needed involving more children and following children to see how this condition changes over time and if there are any longer-term neurocognitive effects.”

The study abstract has been peer-reviewed for the conference, and a larger paper which contains the data has been peer-reviewed, resubmitted with corrections and is currently in pre-print.