Long-term outcome of 200 patients referred to a first seizure clinic

To determine what proportion of our First Seizure referrals reflected true unprovoked first seizures or epilepsy, and to assess the long-term diagnostic accuracy of our First Seizure Clinic (FSC) by quantifying the risk of subsequent seizures in our FSC cohort.

We prospectively collected data of 200 adult patients referred to the FSC between May 2014 and December 2015. We reviewed clinical notes, electroencephalography (EEG) data and performed telephone follow-up at 28-month post-diagnosis.

Of the 200 patients referred to the FSC, 181 attended. At the initial assessment, 39 of these patients were diagnosed with epilepsy, with most of these patients (59%) found to have a history of previous seizures. Fifty patients were diagnosed with a first seizure, of which 28% were labelled as provoked seizures. Sixty nine of the patients received another diagnosis and 23 were labelled as indeterminable. At 28 months follow-up, 11 (22%) of patients who received a diagnosis of first seizure subsequently received a diagnosis of epilepsy. In the remaining groups, only 5 (5%) patients were diagnosed with epilepsy (of these three were in the indeterminable group).

Our study shows that 50% of the patients referred to a FSC had not experienced a seizure but were given an alternative diagnosis. Secondly, our study indicates that the risk of seizure recurrence following a first seizure is quite low (22%). This is because a substantial proportion of the patients were diagnosed with epilepsy already at the first assessment. The high proportion of patients being diagnosed with epilepsy was mainly due to a history of previous seizures. Thirdly, patients who were given an alternative diagnosis at the first assessment had a low probability (5%) for seizure recurrence.