Abstracts

Rationale:
It is well known that many patients with psychogenic non-epileptic seizures (PNES) are treated with anti-seizure medications (ASMs) for years prior to their diagnosis is established. Yet, the frequency of this problem, its determinants and its impact to the families living with PNES has not been well characterized. Using a cohort of patients with epileptic seizures (ES) and their caregivers as controls, we aimed to achieve these goals related to the use of ASMs in PNES.
Method:
Patients with PNES and ES and their caregivers completed surveys about demographic, clinical and psychosocial characteristics during their EMU admission. Cross reference with medical records was performed. The frequency of use of ASMs was assessed before and after a diagnosis was established. Side effects were assessed using the Liverpool Adverse Events Profile (LAEP, 19-item self-reported questionnaire, total score ranges from 19 to 76, higher scores suggest more side effects). Univariate associations were assessed between the collected characteristics and the patient LAEP scores. The variables identified as statistically significant in the univariate analysis were used in subsequent multivariate regression analysis to identify determinants of higher patient LAEP scores. Impact to the patient was assessed by evaluating the correlation between LAEP scores and patient overall quality of life (QOL) scores. Impact to the caregiver was assessed by evaluating the correlation between LAEP scores and Zarit caregiver burden inventory (ZCBI) scores. Results43 patients with PNES and 165 patients with ES were recruited. Compared to patients with ES, patients with PNES had shorter disease duration, higher seizure frequency, normal diagnostic data and poorer psychosocial health. Additionally, 28 caregivers of patients with PNES and 99 caregivers of patients with ES were recruited. They did not differ significantly in their demographic and caregiving characteristics. Most patients (93%) with PNES were on ASMs on admission and the majority (60%) were treated with two or more ASMs. Despite being on fewer ASMs compared to patients with ES (p=0.007), patients with PNES experienced more side effects as indicated by their LAEP scores (p=0.0003). PNES and ES patients demonstrated comparable drug allergies counts and compliance rates. Higher LAEP scores correlated with poorer QOL both in PNES (Spearman R=-0.71, p< 0.0001) and in ES (Spearman R=-0.72, p< 0.0001) patients. Higher LAEP scores correlated with higher caregiver burden in PNES (Spearman R=0.49, p=0.01) but not in ES (Spearman R=0.14, p=0.14). Upon discharge, 44% of PNES patients were still on ASMs, but for approximately 3/4 of them these were maintained for non-seizure indications.