BDNF as potential biomarker of epilepsy severity and psychiatric comorbidity: pitfalls in the clinical population

authors

• Mcgonigal Aileen
• Becker Christel
• Fath Julia
• Hammam Kahina
• Baumstarck Karine
• Fernandes Sara
• Giusiano Bernard
• Dufau Stéphane
• Rheims Sylvain
• Maillard Louis
• Biraben Arnaud
• Benoliel Jean-Jacques
• Bernard Christophe
• Bartolomei Fabrice

keywords

• BDNF
• Epilepsy
• Anti-seizure medication
• Depression
• Anxiety
• Stress

document type

abstract

Background Several studies implicate brain-derived neurotrophic factor (BDNF) in the pathophysiology of epilepsy. In particular, preclinical data suggest that lower serum BDNF is a biomarker of epilepsy severity and psychiatric comorbidities. We tested this prediction in clinical epilepsy cohorts. Methods Patients with epilepsy were recruited from 4 epilepsy centers in France and serum BDNF was quantified. Clinical characteristics including epilepsy duration, classification, localization, etiology, seizure frequency and drug resistance were documented. Presence of individual anti-seizure medications (ASM) was noted. Screening for depression and anxiety symptoms was carried out in all patients using the NDDI-E and the GAD-7 scales. In patients with positive screening for anxiety and/or depression, detailed psychiatric testing was performed including the Mini International Neuropsychiatric Interview (MINI), STAI-Y, Holmes Rahe Stressful Events Scale and Beck Depression Interview. Descriptive analysis was applied. Spearman’s test and Pearson’s co-efficient were used to assess the association between BDNF level and continuous variables. For discrete variables, comparison of means (Student’s t-test, Mann-Whitney u-test) was used to compare mean BDNF serum level between groups. Multivariate analysis was performed using a regression model. Results No significant correlation was found between serum BDNF level and clinical features of epilepsy or measures of depression. The main group-level finding was that presence of any ASM at was associated with increased BDNF; this effect was particularly significant for valproate and perampanel. Conclusion Presence of ASM affects serum BDNF levels in patients with epilepsy. Future studies exploring BDNF as a possible biomarker of epilepsy severity and/or psychiatric comorbidity must control for ASM effects.

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