They call Nick “Fit-face”. At 15 he has missed so much school that he won’t be able to take his GCSEs with the others of his age. As if that isn’t humiliating enough, no one in his school seems to know what to do when he has a seizure.

Once they called an ambulance; another time they just left him, to wake up with wet trousers and blood on his lips. “It seems,” he says, “as if they are frightened of me.”

People think it’s unnatural, the work of the devil. Julius Caesar, Dostoievsky, that girl in the Exorcist. Is it, parents ask, contagious?

So, what do you do if a child goes into status epilepticus and has convulsions? Answer: summon immediate medical assistance for any seizure lasting more than five minutes. Otherwise, brain damage may ensue.

Nick has a friend, 16-year-old Marie. She did not display classic Dostoievskian symptoms - eyes rolled back, limbs twitching. Yet for much of each day from the age of six, she was withdrawn, “absent”, rocking, thumb-sucking, her eyes adrift. Then she went for a brain scan, which showed non-convulsive status epilepticus, a seizure every 10 seconds. On medication, she is a different girl - lively, switched on, but with 10 years’ schooling and social life to catch up on.

Epilepsy affects more than 300,000 people in the UK, at least 70,000 of them schoolchildren. Abnormal discharges from the brain, caused by congenital conditions, by head injury, or by disease, affect control of mind and body. Of the many forms of epilepsy, tonic-clonic seizures, popularly known as “grand mal” with twitches and jerks of the body, are among the easiest to diagnose and treat. Absences - known as “petit mal” - can be harder to identify and are more resistant to drug therapy. During an “absence” a child will be unteachable, unreachable.

But epilepsy doesn’t mean lack of ability. Although many children with severe learning difficulties have epilepsy (from 50 to 80 per cent), only 15 per cent of those with epilepsy have innate learning difficulties. Which is not to say that schooling is easy for them.

“The teachers come over,” says Nick, “and all they say is, ‘Here’s the textbook, try and catch up’. But I’ve missed so much. A textbook is not going to help if I’ve missed the explaining.”

Nick has missed schooling not only because of the distress and worry of frequent seizures, but also because in the “prodromal” (before seizure) time, lasting up to two days, he may be weepy or angry, prone to mood swings and with low self-esteem. Then, in the “post-ictal” (after seizure) stage, he suffers from lethargy, mood swings, depression, and feelings of worry and shame. That doesn’t leave a lot of time for learning and getting on with others.

Yet as Nick says, “A lot of people say I am quite intelligent, but from the teacher’s point of view I am at the back. I don’t want to be at the back for the rest of my life.”

British Epilepsy Association, helpline Freephone: 0800 30 90 30.National Society for Epilepsy, Chalfont St Peter, Gerrards Cross, Buckingham-shire SL9 0RJ; helpline: 01494 601300.Details on training days for Supporting Pupils with Medical Needs in Schools, from 01622 618678