Multivariate granger causality analysis of acupuncture effects in mild cognitive impairment patients: an FMRI study.

Shangjie Chen,Fang Wang,Maosheng Xu,Xinghua Chen,Liang Yin,Lijun Bai,Xuming Peng,Xuemin Shi

doi:10.1155/2013/127271

Abstract

Evidence from clinical reports has indicated that acupuncture has a promising effect on mild cognitive impairment (MCI). However, it is still unknown that by what way acupuncture can modulate brain networks involving the MCI. In the current study, multivariate Granger causality analysis (mGCA) was adopted to compare the interregional effective connectivity of brain networks by varying needling depths (deep acupuncture, DA; superficial acupuncture, SA) and at different cognitive states, which were the MCI and healthy control (HC). Results from DA at KI3 in MCI showed that the dorsolateral prefrontal cortex and hippocampus emerged as central hubs and had significant causal influences with each other, but significant in HC for DA. Moreover, only several brain regions had remarkable causal interactions following SA in MCI and even few brain regions following SA in HC. Our results indicated that acupuncture at KI3 at different cognitive states and with varying needling depths may induce distinct reorganizations of effective connectivities of brain networks, and DA at KI3 in MCI can induce the strongest and more extensive effective connectivities related to the therapeutic effect of acupuncture in MCI. The study demonstrated the relatively functional specificity of acupuncture at KI3 in MCI, and needling depths play an important role in acupuncture treatments.

Highlights

Mild cognitive impairment (MCI) is the key and hot point in cognitive-brain study
We explored the causal interactions within and among the resting brain networks modulated by acupuncture at KI3 in MCI and healthy control (HC), for DA and SA
According to the multivariate Granger causality analysis (mGCA) results following acupuncture at KI3 in MCI-Deep, we identified that brain regions have extensive causal interactions, mainly locating at the dorsolateral prefrontal cortex (DLPFC), Hipp, Thalamus, Insula, Declive, middle temporal gyrus (MTG), anterior cingulate cortex (ACC), orbitofrontal cortex (OFC), and Caudate

Summary

Introduction

Mild cognitive impairment (MCI) is the key and hot point in cognitive-brain study. Incidence of dementia is widely acknowledged to increase greatly with advancing age. MCI is an intermediate state between normal aging and Alzheimer’s disease (AD) which is the world’s most common dementia [5, 6]. Further research is needed on treatments of delaying the conversion from MCI to AD [4]. There is no sufficient evidence that drug can delay long-term progression and conversion to dementia [1, 6]. Feasible complementary and alternative therapies with low side effects, such as acupuncture and exercise, have shown some benefits [8, 9]. The use of acupuncture as a complementary therapeutic way to treat a variety of neurologic diseases, including MCI and AD, is popular in certain parts of the world [10]. In spite of its public acceptance and promising effect, the underlying neural mechanism is still elusive

Methods

Discussion

Conclusion