Factors predisposing patients with temporal lobe epilepsy to seizure cluster

We aimed to identify the potential risk factors associated with seizure clusters in patients with temporal lobe epilepsy (TLE). This retrospective cross-sectional study was performed on all the consecutive patients with TLE, who were admitted to the Epilepsy Monitoring Unit (EMU), Loghman-Hakim Hospital, Tehran, Iran. Seizure cluster was defined as three or more habitual seizures occurring within 24 hours, in over 50% of ictal events, with inter-seizure interval of less than 8 hours. The patients’ demographic data, epilepsy duration, seizure frequency, frequency of interictal epileptiform discharges (IEDs), and brain magnetic resonance imaging (MRI) findings were collected Among a total number of 124 patients with TLE, 62 (50.0%) patients reported seizure clusters. In addition, 44 (37.9%), 42 (36.2%), and 30 (25.9%) patients had normal-appearing brain MRI, mesial temporal sclerosis (MTS), and other brain pathologies, respectively. In terms of IEDs frequency, 35 (29.4%), 43 (36.1%), 17 (14.3%), and 24 (20.2%) patients had respectively frequent, occasional, rare, and no spikes in one-hour of interictal scalp electroencephalography (EEG) recording. In our study, seizure clusters were not associated with the epilepsy duration (P = 0.100), the amount of IEDs (P = 0.764), or MRI findings (P = 0.112). In patients with TLE, seizure clustering had no correlation with the epilepsy duration, the amount of IEDs, or brain MRI findings.