Investigation of brain functional connectivity in patients with mild cognitive impairment: A functional near‐infrared spectroscopy (fNIRS) study. Issue 9 (17th May 2019)

• Record Type: Journal Article
• Authors: Nguyen, Thien; Kim, Minhee; Gwak, Jeonghwan; Lee, Jang J.; Choi, Kyu Y.; Lee, Kun H.; Kim, Jae G.
• Is Part Of: Journal of biophotonics. Volume 12:Issue 9(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-05-17
• Subjects: 1‐back task -- inter‐hemispheric connectivity -- oddball task -- resting state -- verbal fluency task; Photonics -- Periodicals; Optical materials -- Periodicals; Optics -- Periodicals; Medical instruments and apparatus -- Periodicals; 621.3605
• DOI: 10.1002/jbio.201800298
• Languages: English
• ISSNs: 1864-063X

Abstract

Abstract: This study examines brain functional connectivity in both cognitively normal seniors and patients with mild cognitive impairment (MCI) to elucidate prospective markers of MCI. A homemade four‐channel functional near‐infrared spectroscopy (fNIRS) system was employed to measure hemodynamic responses in the subjects' prefrontal cortex during a resting state, an oddball task, a 1‐back task, and a verbal fluency task. Brain functional connectivity was calculated as the Pearson correlation coefficients between fNIRS channels. The results show that during the verbal fluency task, while the healthy control (HC) group presents a significantly stronger inter‐hemispheric connectivity compared to intra‐hemispheric connectivity, there is no difference between the inter‐ and intra‐hemispheric connectivity in the MCI group. In addition, a comparison between the MCI and HC connectivity reveals that the MCI group has a statistically higher right and inter‐hemispheric connectivity during the resting state, but a significantly lower left and inter‐hemispheric connectivity during the verbal fluency test. These findings demonstrate the potential of fNIRS to study brain functional connectivity in neurodegenerative diseases. Abstract : Brain compensatory mechanism against cognitive decline is intact during a resting state, but it is broken during a task. Indeed, compared to the healthy controls, patients with mild cognitive impairment (MCI) have higher connectivity during a resting state, but a lower one during a verbal fluency task (VFT). Additionally, the significantly lower inter‐hemispheric connectivity in patients with MCI indicates a disruption of the MCI inter‐hemispheric communication during a VFT.