Abstract

Background: A new method to measure the cholinergic status with quantitative electroencephalography (qEEG) to distinguish healthy from early dementia patients and identify responders of Acetylcholinesterase inhibitor treatment. The objective is to evaluate cognition via Mini Mental Score Examination (MMSE) at baseline and follow-up examination after approximately 2 years for patients with suspected dementia and comparison with the predictive baseline values for (qEEG) and Cerebro-spinal fluid (Csf) biomarkers. If qEEG predicts the cognitive decline best, a noninvasive and inexpensive method is offering the possibility to start Acetylcholinesterase inhibitor treatment early in the dementia disease course.
Methods: The average power of four qEEG epochs with eyes closed (E.Cl.) and open eyes (E.O.), and the ratio of E.O. / E.Cl. (Vigilance-index), and average peak frequency of E.Cl. epochs, calculated. The Csf parameters; total-Tau, phospho-Tau, and Amyloid β^-42 analyzed. The correlation between the number of pathological MMSE-scores and pathological values of baseline biomarkers evaluated.
Results: The Spearman rank correlation between MMSE revealed no linear relation for the examined biomarkers. When comparison of pathological values for MMSE at follow up after approximately 2 years the sensitivity to identify from the baseline values for qEEG and Csf biomarkers, found Vigilanceindex to have the highest sensitivity (1.0) then total-Tau (0.5) and the rest parameters lower, lowest for the combination of Csf parameters (0,09) to predict cognitive decline. The specificity for the baseline Vigilance-index was (0.87) and for total-Tau (0.39) and lower for the other parameters at the follow-up examination.
Conclusion: Vigilance-index best reflects the cognitive decline after two years in early dementia disease, by measuring cholinergic deficit, compared to Csf biomarkers to measure total-Tau, phospho-Tau, and Amyloid β^-42.