An evaluation of a paediatric new-onset seizure clinic (NOSC) has found diagnostic accuracy is enhanced, reducing the risk of overtreating children with anti-epileptic medications.

A review of the first 200 patients seen at the clinic at the Princess Margaret Hospital for Children in Perth from 2011 showed just over half (55%) were classified as epilepsy positive (EP+) – either epilepsy or likely epilepsy.

Generalised epilepsy was diagnosed in 57 patients; focal epilepsy in 47 cases.

The remaining children were classified as epilepsy negative (EP-) – not epilepsy or not likely epilepsy. They included events such as vasovagal syncope, tics or sleep parasomnia referred as nocturnal seizures.

A third of the children had a family history of epilepsy and 20% also had developmental delay.

Video-EEGs were undertaken in most children and available prior to the consultation with the paediatric neurologist. MRI of the brain was available in about half the patients and abnormal in about 39% of those cases.

“A paediatric neurologist review, with integration of the clinical profile and information from EEG, results in a high level of accuracy of diagnosis in an NOSC: none of the children in our cohort had their initial EP+ or EP- diagnosis revised at follow-up,” the study authors said.

It said misdiagnosis rates from other studies were as high as 30-40%.

Dr Snehak Shah, from the Children’s Neuroscience Service at the hospital, told the limbic the clinic faced funding and staffing issues and was not continuing.

However it had highlighted the importance of specialist review and video-EEG in making an accurate early diagnosis.

“The most important outcome was that diagnostic accuracy was improved so patients suspected to have seizures did have epilepsy and most importantly that patients who were not epileptic were not treated as epilepsy.”

For example, some of the vasovagal syncope patients if misdiagnosed might have been treated with anti-epileptic treatment when it was not needed.

“With epilepsy you are labelling the child for life and initiating anti-epileptic medication for two years minimum, and all of them have a variety of side effects. So first we should do no harm. We were very accurate in picking out non-epileptic from epileptic children.”

“And when you pick up certain epilepsy quickly and make an accurate diagnosis, your choice of anti-epileptic medication is very precise and that improves outcomes.”

“If you treat it early and treat it appropriately, it improves the prognosis.”

The study showed that about 80 of 109 epilepsy-positive children (73%) were started on medication.

“In some epilepsy we don’t need to start on medications, for example, benign childhood epilepsy – they have very low seizure frequency and so you don’t need to put all on anti-epileptics unless their frequency is high or there are very prolonged seizures,” said Dr Shah.

“It is important not to overtreat patients just because an EEG is abnormal.”