Neural oscillatory signatures of working memory dysfunction in coronary microvascular disease
L Feng, T C Tu, S X SongAbstract
Background
Coronary microvascular dysfunction (CMD) has been associated with subtle cognitive deficits, but its underlying neural oscillatory mechanisms during working memory remain unclear.
Purpose
We aimed to characterise working memory–related neural oscillations in CMD patients and examine their association with task performance.
Methods
In this prospective study, 194 patients referred for coronary angiography due to suspected ischemic heart disease were recruited. CMD was quantified using the angiography-derived index of microcirculatory resistance (Angio-IMR); 99 patients met CMD criteria. Participants completed a working memory task during magnetoencephalography recording. Sensor-level time–frequency analyses were performed for encoding (0–4000 ms), maintenance (4000–7000 ms), and retrieval (7000–8500 ms) phases, focusing on alpha (8–12 Hz) and beta (13–30 Hz) bands. Group comparisons were conducted using ANCOVA adjusting for age, education, and other covariates; FDR correction was applied for multiple comparisons. Correlations between phase-specific beta desynchronisation and task accuracy were examined.
Results
Overall task performance was good (mean accuracy 80%, reaction time 1158.65 ms). CMD patients showed lower accuracy (0.78 ± 0.04 vs. 0.81 ± 0.06, P<0.001) and longer reaction times (1222 ± 174 ms vs. 1093 ± 238 ms, P<0.001). Sensor-level analyses revealed alpha–beta desynchronisation during encoding, synchronisation during maintenance, and re-emerging desynchronisation during retrieval across participants. CMD patients exhibited weaker and spatially restricted modulation, especially during encoding and retrieval, predominantly in occipital and posterior parietal regions. Whole-brain comparisons identified significant group differences only in retrieval-phase beta activity (FDR-corrected P<0.05), with CMD patients showing reduced desynchronisation in bilateral parahippocampal gyri, posterior cingulate, and caudal middle frontal regions. Reduced retrieval-phase beta desynchronisation in the left parahippocampal gyrus (r = −0.169, P=0.020) and left caudal middle frontal cortex (r = −0.164, P=0.024) correlated with lower task accuracy.
Conclusions
CMD is associated with impaired retrieval-phase beta oscillatory dynamics and working memory deficits, suggesting that microvascular dysfunction alters neural oscillatory signatures underlying cognitive processing. These findings provide novel mechanistic insights into the brain–heart axis in CMD.neural activity during working memory tasks