WHEN Francesca Lobban passed out after falling off a low piece of equipment at a toddlers' gym class, her mother Trudie put it down to a freak accident. Two weeks later it happened again. Francesca was playing trains with her older sister, Charlotte. 'They were holding on to each other's dresses and she just toppled over,' Trudie Lobban recalls.

Without even banging her head, three-year-old Francesca again lost consciousness. Mrs Lobban was more concerned this time, but was advised by her doctor simply to keep a watchful eye on her little girl for the next 48 hours and to call if worried. 'And she seemed fine, albeit very sleepy,' Mrs Lobban says.

But six weeks later, two attacks occurred on the same day during a family holiday in Spain. While playing with a friend, Francesca tripped and knocked herself on the forehead; her heart stopped for several seconds and she then had a convulsion. That was when Mrs Lobban's concern turned to alarm. Within hours of returning to their Warwickshire home she went to her GP, who referred Francesca to a specialist. After ECGs and EEGs her condition was diagnosed as reflex anoxic seizure (RAS).

Since then Mrs Lobban has started a support group for other, similarly affected, families. The group also aims to heighten public awareness of RAS and to gather information to aid research into its cause and cure.

Reflex anoxic seizure is a rare complaint that can occur in babies as young as a few months old, sometimes when they are teething or having their nappies changed. The sudden shock of pain can precipitate an attack. It may not always be the pain from a fall; even a slight tap or jolt can bring on alarming symptoms.

The heart stops, the eyes roll, colour drains from the face, the jaw clenches and the body stiffens, with arms and legs jerking in spasm. This convulsion causes the heart to start beating again, and the child may remain unconscious for an hour or more.

RAS is also known as Stephenson's seizure, after Dr John Stephenson, a consultant in paediatric neurology at Glasgow's Royal Hospital for Sick Children. He is one of the few acknowledged British specialists in this condition, which he has researched extensively. It features a 'fast faint', not the 'limp swoon' associated with the more common type of faint, he explains. With the latter, there is a gradual loss of blood to the brain. In RAS sufferers there is a sudden elimination of blood from the brain, followed by 'convulsive activity, superficially like epileptic seizure'.

Indeed, RAS has frequently been misdiagnosed as epilepsy or temper tantrums: patently not true in Francesca's case, as the attacks mostly occur when she is playing. Most children, Dr Stephenson says, grow out of the condition completely. In others, attacks may resume in adulthood.

There is no cure and little effective treatment for RAS, apart from the drug atropine methonitrate, which, by increasing the heartbeat, helps to reduce the frequency of attacks. The long-term prognosis, however, appears to be fairly positive. 'We don't think people die of it or that there is any damage to their brains or hearts,' Dr Stephenson says. 'The children we see, when measured, are more intelligent than average.'

There are, however, more serious heart conditions with similar symptoms that may require special treatment to avoid fatalities. If in doubt, or if seizures mainly occur after fright, an ECG should be performed, says Dr Stephenson.

To see Francesca playing in her paddling pool in the garden, she seems like any other healthy three-year-old (she will be four on 25 August). But Mrs Lobban's first instinct is to wrap her in cotton wool and never let her out of her sight. She and Charles, her bank manager husband, have to be constantly vigilant. 'I have to know where she is, what she is doing . . . I try to let her do what the other children are doing, but I find it so difficult.'

Certain activities, such as playing in bouncy castles or riding piggyback with Charlotte, are off limits. So are the gym classes that Charlotte attends, although Francesca does go to a small ballet class. She sometimes misses out on birthday parties. 'People don't want the responsibility; it's bad enough having somebody else's child if they just fall over and graze their knee.'

Francesca attends a nursery in the village where the family lives. She is due to start school in September, but it has been agreed that she should complete her first 'infants' year at nursery school; thereby reducing the risk of an attack in a playground with 80 to 100 children up to 11 years old. If necessary, her mother says, she will do extra work with her at home.

Doctors have advised Mrs Lobban that in the event of an attack, Francesca should be put in the 'recovery' position, on her side, and watched to check that she isn't choking. 'I promise her sweets - anything that comes into my mind, because I've heard about playing music to people in comas and I can't sit there in silence. It's awful, you've got this lifeless rag doll in your arms and there's nothing you can do - except wait.

'At one point I thought she was dead because of her colour. It's the look, the colour that upsets me most.'

In Francesca's case the attacks - which come at unpredictable intervals, sometimes in batches - are followed by two or three weeks of 'night terrors'. 'She'll be sound asleep and suddenly start screaming. Her eyes are open but not focusing. I take her into another room, I sing, even shout at her, put her down, pick her up - nothing stops her screaming. After about 20 minutes, she sighs, sobs and goes straight back to sleep. The next day she doesn't remember a thing.'

Mrs Lobban has written to every paediatric neurologist in the UK, alerting them to RAS and informing them about the support group. She has also mailed questionnaires to other parents whose children suffer from RAS. She and her parents, who live in Bristol, have leafleted GPs.

She is now registering her support group as a charity and planning her first newsletter. She hopes to obtain sponsorship from companies for research and plans to set up local groups. 'I work every night until about midnight, which I'm more than happy to do.

'It may be years before we understand why it happens. But at least if I bring about public awareness I feel as if I'm doing something for Francesca. I couldn't sit back and do nothing.'

For information about the Reflex Anoxic Seizure Support Group send an SAE to Trudie Lobban, Tylwych House, Oxford Road, Newbold on Stour, Warwickshire CV37 8TR. Tel: 0789 450564.