Objectives: 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.
Methods: 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.
Results: 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).
Conclusions: 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.
Keywords: EEG; epilepsy; first seizure; long-term follow-up; syncope.
© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.