Assessing the prefrontal functional connectivity using wavelet coherence analysis of oxygenation signals

• Published in: Proceedings of the International Conference on Biomedical Engineering and Informatics pp. 273 - 277
• Main Authors: Qingyu Han, Yuanjin Gao, Wenhao Li, Zengyong Li, Qing Xin
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.10.2014
• Subjects: brain connectivity; cerebral infarction; cerebral oxygenation; Coherence; Oscillators; Senior citizens; Time-frequency analysis; Wavelet analysis; wavelet coherence; Wavelet transforms
• ISSN: 1948-2914
• DOI: 10.1109/BMEI.2014.7002784

This study aims to assess the prefrontal functional connectivity using wavelet coherence analysis of cerebral tissue oxyhaemoglobin concentrations (Delta [HbO 2 ]) signals in subjects with cerebral infarction(CI) during the resting state. Continuous recordings of near-infrared spectroscopy (NIRS) signals were gained from the right and left prefrontal lobe in 15 elderly subjects with CI (age: 75.1 ± 9.2 years) and 18 healthy elderly subjects (age: 69.9 ± 7.3 years) during the resting state. The coherence between right and left prefrontal lobe Delta [HbO 2 ] oscillations in 4 frequency intervals (I, 0.6-2 Hz; II, 0.145-0.6 Hz; III, 0.0520.145 Hz; IV, 0.021-0.052 Hz) was analyzed by the wavelet coherence analysis. In healthy subjects, the Delta [HbO 2 ] were significantly wavelet coherent in interval I (0.6-2 Hz) and III (0.052-0.145 Hz) (p<;0.05). In elderly subjects with CI, the left and right Delta [HbO 2 ] were significantly wavelet coherent in interval I (0.6-2 Hz) (p<;0.05). The wavelet coherence was significantly lower in interval II (F=6.658, p=0.014), III (F=18.164, p=0.000) and IV (F=4.295, p=0.046). The difference using the wavelet coherence of the CI subjects and the healthy subjects demonstrates an vary cerebral autoregulation caused by CI. This research gives a original insight into the dynamics of Delta [HbO 2 ] oscillations. This method may be beneficial in detecting the risk for alter cerebral autoregulation. This might indicate a damaged brain functional connectivity due to CI in the subjects.