Frequency of attacks in patients with psychogenic non-epileptic seizures

The aim of this study was to investigate the frequency of attacks (psychogenic seizures) in patients with psychogenic non-epileptic seizures (PNES) and to characterize factors potentially associated with attack frequency. In this retrospective study, all patients with PNES, who were studied at Shiraz Comprehensive Epilepsy Center at Shiraz University of Medical Sciences, Iran, from 2008 until 2018, were reviewed. We categorized the attack frequency in the patients as (1) daily; (2) weekly; and (3) frequency of less than one per week. Three hundred and ten patients were studied. Attack frequency in patients was 34 ± 67 per month. One hundred and eleven patients (36%) had daily attacks, 93 (30%) had weekly attacks, and 106 (34%) had less than weekly attacks. Sixty-five patients (21%) reported having more than one attack per day. Demographic variables, attack-related variables, PNES associated factors, and use of AEDs were not significantly associated with attack frequency in the patients. We observed that two thirds of the patients with PNES had frequent daily or weekly attacks. The findings of our study could be helpful in designing future clinical trials. First, attack frequency is an unbiased outcome measure in the design of such studies. Second, it is easily measurable using attack calendars; we suggest that attack frequency be assessed daily using daily attack calendars. Finally, it is very easy to recruit patients with PNES for clinical trials (with regards to their attack frequency) since many of them have frequent attacks.