(304) Brain derived Neurotrophic factor (BDNF): A potential biomarker for seizure associated cognitive impairment in adult persons with epilepsy (PWE)

Background: BDNF has never been evaluated for serum-based diagnosis of cognitive impairment in adult PWE in India.

Objectives: 1) To evaluate the cognitive impairment in PWE through the Montreal Cognitive Assessment (MoCA) scale
2) To investigate the relationship between cognitive impairment and BDNF in PWE.

Methods: An observational, Cross-sectional study of A total of 74 PWE were included in the study from November 2022 to February 2023 from the Epilepsy OPD of All India Institute of Medical Science (AIIMS), New Delhi, India. An oral and written Informed consent was obtained before the subjects were enrolled in the study. Patients aged between 18 to 50 years with a diagnosis of epilepsy according to the ILAE criteria and having at least 5 years of education if not, then a caregiver who could ensure compliance with the study. Having experienced at least one seizure within 12 months was included. Patients with a history of severe neurological, uncontrolled diabetes, thyroid disease, abnormal renal, and liver function were excluded.

The Wilcoxon Rank sum (Mann Whitney U) test is used to assess differences between two groups in case of non-normal distribution. We conducted the Pearson’s test used to assess the correlation between Biomarkers and MoCA and its domains. We conducted a linear regression analysis between Biomarkers and Total MoCA to examine the predictor. A P< 0.05 was considered statistically significant. Multivariate regression analyses were performed to test the association between MoCA and sociodemographic variables. The area under the ROC (AUROC) curve and sensitivity analysis was performed to measure the diagnostic power and optimal cut-off value respectively.

Results: Out of 74 PWE, 61 were found to be cognitively impaired. MoCA subscale visuospatial & executive, attention, language, abstraction, delayed recall, and Total MoCA were found to be statistically significant (P <0.001). MoCA scale was found to have good internal consistency & an excellent scale in the assessment of cognitive impairment with Cronbach’s alpha = 0.8, AUROC=1 respectively. BDNF levels were significantly reduced in the cognitively impaired group of PWE (P <0.001). A Moderate and significant (P <0.005) correlation was found between BDNF and Total MoCA with Spearman analysis. Univariate analysis showed total MoCA score positively correlated with education. In multivariate regression analysis total MoCA with education (B= 10.27, P= 0.000, σ2=7%) marital status (B=3.56, P = 0.022, σ2=15%), occupation (B= 5.94, P= 0.001,σ2=35%). AUROC curve ( 0.8550) states BDNF is the useful biomarker with a sensitivity cutoff value of 132.07501 pg/ml.

Conclusions: We conclude that adult PWE in India demonstrate a significant cognitive impairment (82.4%) and that MoCA is an excellent scale with good internal consistency /reliability and BDNF is a useful biomarker for assessment of cognitive impairment in adult PWE. Further education, marital status and occupation were found to be risk factor for cognitive impairment in PWE.