Theta Oscillation and Functional Connectivity Alterations Related to Cerebral Small Vessel Disease with Working Memory Impairment
Abstract Background Impaired working memory (WM) is an important clinical symptom of cognitive dysfunction associated with cerebral small vessel disease (CSVD). Theta oscillations play an important role in the regulation of learning, WM and synaptic plasticity. Therefore, we speculate that theta oscillation may play an important role in the process of working memory impairment in CSVD. Methods Seventy-eight patients with CSVD (mean age 66.18 ± 1.42) and 49 healthy controls (HCs) (mean age 66.53 ± 1.3) were recruited to perform the WM task. Neural oscillations and functional connectivity during the encoding, maintenance, and retrieval phases of WM were evaluated during performance of WM test. Results Compared with the control group, the working memory behavior of the CSVD group showed a significantly longer reaction time and lower accuracy rate. The energy density and functional connection (FC) strength of the theta band in frontal region of the CSVD group were significantly lower than those of the control group, and the theta oscillation in the retrieval phase was significantly higher than that in the coding phase. However, there was no significant change in FC strengths among three phases. Both in the two groups, the FC was significantly positively correlated with accuracy and negatively correlated with reaction time (RT). Conclusion Our results indicated that CSVD patients have significant working memory impairment, and the lack of theta oscillation in the frontal region and the abnormal functional connection of the brain network may be one of its potential neurophysiological mechanisms.