Eight-year-old Sade Biggs is unable to play outside with friends or ride a bicycle safely because she nods off suddenly, up to 30 times a day.

A DALSTON schoolgirl is missing out on her childhood because she suffers from an extreme form of narcolepsy, which is rare at her age and is not easily treated.

Eight-year-old Sade Biggs is unable to play outside with friends or ride a bicycle safely because she nods off suddenly, up to 30 times a day.

She was diagnosed with the sleep disorder narcolepsy, as well as cataplexy, an associated condition concerning muscle control, in 2007 – making her one of just 25,000 people and fewer than 500 children affected in Britain. Now her mum – singer-songwriter Dana Thompson – is trying to raise awareness of the condition with a fundraising concert on Sunday, December 5.

“I noticed it really early on,” she said. “When she was two, I knew that something wasn’t right.

“She was sleeping through the day and the night. She would even fall asleep with food in her mouth.

“I was really scared.

“Once, she was riding her bike behind me and when I looked back she had just fallen off and was sleeping on the ground.”

Sade, a year four pupil at Colvestone Primary School in Colvestone Crescent, underwent three years of hospital tests for a diagnosis – but she cannot take medication as it is designed for adults and causes unpleasant side-effects.

She sleeps at random intervals, sometimes all day and all night, and loses control of her body.

“It feels fun, but not when my teacher gives me a look,” Sade said. “I like sleeping, but it means I can’t get my work done.”

She also suffers vivid nightmares, a common symptom of her disorder. “I see skeletons and witches and it feels like they are really there,” she revealed.

Dana, 37, of Charterhouse Road, has struggled to explain that Sade is not naughty or staying up late. Narcolepsy is caused by the brain’s inability to regulate sleep-wake cycles normally. It is currently incurable.

“She can’t go on school trips and I can’t even allow her to go outside to play with friends,” said Dana. “She has to be with me. Sometimes she gets really agitated and angry.”

Dr Parviz Habibi, a paediatric consultant at Imperial College Healthcare, said: “Many children with narcolepsy become very ‘cranky’ and have other behavioural problems, including hyperactivity and problems with attention and learning.”

Dana is donating money from her album launch at Bar Sequence in Essex Road, Islington, to the Narcolepsy UK charity and is hoping for more support for families.

John Cherry, chief executive of Narcolepsy UK, said Sade’s condition was unusual, but her early diagnosis could help her in the long run.

“If we can get to children quickly, there is a possibility that we can reduce the affects and possibly even cure it,” he said. “At the moment what we need to do is get the information out there.”

Tickets to Dana Thompson Live cost �15, with 10 per cent of sales going to Narcolepsy UK. You can also donate at uk.virginmoneygiving.com/danathompson.