About 30% of adult patients with newly diagnosed epilepsy are not initially treated with anti-seizure medication.

The untreated patients include about equal numbers of patients where immediate treatment was not recommended and patients who declined treatment. 

In a study of 610 patients presenting to a first seizure clinic in Perth between 1999 and 2016, all patients were found to satisfy ILAE criteria for epilepsy.

Patients with more than one seizure before diagnosis were more likely to start therapy at diagnosis than patients with a single seizure (OR 3.48) as were those with a cluster of seizures prior to diagnosis (OR 2.57).

Older patients (≥65 years) were more likely to be treated immediately than younger patients (OR 3.06) and those with epileptogenic neuroimaging abnormalities at the time of diagnosis were more likely to begin treatment (OR 2.15).

Some of the reasons given by clinicians for not recommending treatment at diagnosis included only a single seizure, waiting for further results, the presence of avoidable lifestyle factors associated with seizures or infrequent seizures not thought to warrant treatment. 

Reasons given by patients for declining treatment included not being convinced of the need for treatment or the diagnosis, the presence of avoidable lifestyle factors and fear of medication adverse effects. 

During follow-up, the majority of initially untreated patients (61.2%) were started on anti-seizure medications – usually because of further seizures. 

The study, published in Epilepsia, said most previous cross-sectional studies in high-income countries have generally reported untreated epilepsy rates of less than 10%. However recent  data from insurance claims databases in the US had put the untreated proportion of patients recently diagnosed with epilepsy at over 50%.

Speaking to the limbic, senior investigator Professor Patrick Kwan said the 30% untreated figure can probably be extrapolated from WA to other specialist centres in Australia.

“We feel it pretty much reflects what is going on in the rest of Australia given WA is one of the main centres and closely linked to other epilepsy centres around the country. We can’t say for sure this is the same case at GP level or general neurology.”

And he said the study was “describing the reality” rather than criticising current practice.

He said what was important was to look at outcomes – to determine if the delay in initiating treatment might affect future response to treatment or lead to injuries following subsequent seizures.

Professor Kwan said data from a New Zealand study, also published recently in Epilepsia, provided some clues. 

The study found most of the 3,366 patients commenced treatment within 30 days of diagnosis (92.5%). 

People of Maori ethnicity were less likely to receive treatment and had a higher mortality rate than other patients.

However overall hospitalisation, comorbidity and mortality rates were mostly similar in untreated, delayed treatment or immediate treatment groups.