Abstracts

Rationale: In epilepsy patients, not only seizures but also various factors affect their quality of life. Psychiatric comorbidities are such factors and depression and anxiety are well-known as the comorbidities. In depressive patients with pleomorphic clinical features, irritability is one of frequently seen disabling symptoms. There are various sources inducing irritability in epilepsy patient. They include epilepsy itself, underlying brain injury, antiepileptic drugs etc. The aim of this study is to identify frequency of irritability and its predictors in epilepsy patients. Methods: Epilepsy patients who had had antiepileptic medication for at least 1 year were consecutively enrolled in this study. The patients were asked to complete self-report questionnaires of Korean versions. The questionnaires were the Italian instrument for the assessment of irritability in adult patients with epilepsy (I-Epi), the Neurological Disorders Depression Inventory for Epilepsy (NDDI-E), the Generalized Anxiety Disorder-7 (GAD-7) scale, the Epworth Sleepiness Scale (ESS), and the Insomnia Severity Index (ISI). For the selection of subjects, the patients were excluded if they were younger than 19 years old and older than 70 years old, or have severe neurological, psychiatric or other disorders. Finally, 276 patients were recruited after the exclusions. For the enrolled patients, we gathered information about patient-related, epilepsy-related, and psychosocial variables from electronic medical records. We also found out whether each patient had been using levetiracetam. We performed a stepwise multiple regression to identify the best combination of predictors for high scores of I-Epi in epilepsy patients. We set statistical significance at a p-value of 0.01. Results: The age of the enrolled patients was 40.31 12.8 (Mean SD) years old. 39.5% of them were revealed to have moderate to high level of irritability by I-Epi. In the stepwise multiple regression to predict I-Epi score, the analysis produced a model with four variables explaining 47.4% of the variance. The strongest predictor of the I-Epi score was the NDDI-E score (ߠ= 0.410) and followed by the ISI score (ߠ= 0.225), the ESS score (ߠ= 0.171) and seizure control (ߠ= 149). Conclusions: Irritability is a frequent psychiatric comorbidity in Korean epilepsy patients. This study showed that depression, insomnia, sleepiness and poor seizure control may induce irritability in epilepsy patients. However, the levetiracetam which have potentiality of inducing irritability as a side effects did not associate with irritability in our multiple regression analysis. We may reduce irritability of epilepsy patients by reducing depression and seizure frequency and improving sleep hygiene. This information may be especially useful when we consider AEDs which have potentially of inducing irritability such as levetiracetam, perampanel et al. for epilepsy patients. Funding: None