This study investigated differences in event-related potential (ERP) parameters among early vascular dementia (VD) patients, healthy elder controls (ECs), and young controls (YCs). A visual “oddball” color identification task was performed while individuals' electroencephalograms (EEGs) were recorded. Approximate entropy (ApEn), a nonlinear measure, along with P300 latencies and amplitudes were used to analyze ERP data and compare these three groups. The patients with VD showed more complex ERP waveforms and higher ApEn values than did ECs while performing the visual task. It was further found that patients with VD showed reduced P300 amplitudes and increased latencies. The results indicate that patients with VD have fewer attention resources to devote to processing stimuli, lower speed of stimulus classification, and lower synchrony in their cortical activity during the response period. We suggest that ApEn, as a measure of ERP complexity, is a promising marker for early diagnosis of VD.
*The Key Laboratory of Biomedical Information of Ministry of Education, Institute of Biomedical Engineering, Xi'an Jiaotong University, Xi'an, China
†The First Hospital of Xi'an Jiaotong University, Xi'an, China.
Address correspondence and reprint requests to Jin Xu, PhD, Institute of Biomedical Engineering, Xi'an Jiaotong University, Xi'an, ShaanXi Province, China, 710049; e-mail: email@example.com.
Funded by the National Natural Science Foundation of China (grant 30400101) and the Fundamental Research Funds for the Central Universities (grant xjj20100047 and xjj20100185).