Concussion symptoms slipping past many Aussie parents, study shows

New research shows some of the symptoms of concussions in children are slipping past parents.

Research from Melbourne's Royal Children's' Hospital shows a large portion of adults aren't familiar with the vast non-physical side effects involved in head knocks.

It comes amid revelations around 14 per cent of children are affected by the health concern.

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When Leon Bernstein was 11, he suffered a concussion after falling from a trolley, tripping over and hitting his head on a planter box.

In the days and weeks that followed he wasn't able to attend school regularly and experienced memory loss.

"It was a bit scary, not knowing," he told 9News.

But the symptoms Leon experienced were some that not all parents are aware of.

The Royal Children's Hospital survey of almost 2000 parents showed one third had little knowledge of concussions and even more didn't realise they could cause non-physical side effects.

Another little known fact is that concussion doesn't always involve blacking out and symptoms may not present straight away.

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Researcher Dr Anthea Rhodes said there were a range of symptoms that presented.

"They can be things like irritability, mood changes, low moods, difficulty concentrating," she said.

She also said that helmets don't always prevent concussions.

"They don't prevent concussion because the brain moves inside the skull and bumps against the hard, bony surface."

Experts say even if a head knock seems mild, children should still temporarily halt playing sport and recovery can take up to four weeks.