O176 LTP-like cortical plasticity in ad patients: A novel biomarker of disease progression

Abstract

Our aim is to establish the predictive value of LTP-like cortical plasticity as a prognostic biomarker of disease progression in terms of cognitive decline. We applied different neurophysiological protocols in a sample of 60 AD patients and 30 age matched healthy controls. Results: We found that area under curve (AUC) was 0.90 for LTP, indicating an excellent diagnostic accuracy of this biomarker, but only 0.64 for SAI. We performed univariate regression analyses for LTP, SAI, CSF biomarkers, APOE4 genotype, neuropsychological evaluation, disease duration, education and demographic factors. Results showed that LTP was the only significant predictor of disease progression ( p = 0.02), while there was no effect for SAI ( p = 0.84), CSF total tau ( p = 0.10), CSF p-tau ( p = 0.21), CSF A β ( p = 0.54), APOE4 genotype ( p = 0.32), neuropsychological battery and other demographic factors. The probability of disease progression significantly decreased with every point increase of LTP ( p = 0.04). ROC curve was also performed to evaluate the sensitivity and specificity of LTP biomarker in predicting cognitive decline in AD patients. We found an AUC = 0.71 indicating a fair prognostic accuracy of this biomarker in discriminating among AD patients those with faster disease progression. LTP impairment can be considered as a biomarker of progression in AD patients.