Acupuncture on mild cognitive impairment: A systematic review of neuroimaging studies

Abstract

Mild cognitive impairment (MCI) is a multifactorial and complex central neurodegenerative disease. Acupuncture appears to be an effective method for cognitive function improvement in MCI patients. Neural plasticity remaining in the MCI brain implies that acupuncture-associated benefits may not be limited to the cognitive function. Instead, neurological alternations in the brain play a vital role in corresponding to the cognitive improvement. However, previous studies have mainly focused on the effects of cognitive function, leaving neurological findings relatively unclear. This systematic review summarized existing studies that used various brain imaging techniques to explore the neurological effect regarding acupuncture use for MCI treatment. Potential neuroimaging trials were searched, collected, and identified independently by two researchers. Four Chinese databases, four English databases, and additional sources were searched to identify studies reporting the use of acupuncture for MCI from the inception of databases until 1 June 2022. Methodological quality was appraised using the Cochrane risk-of-bias tool. In addition, general, methodological, and brain neuroimaging information was extracted and summarized to investigate the potential neural mechanisms by which acupuncture affects patients with MCI. In total, 22 studies involving 647 participants were included. The methodological quality of the included studies was moderate to high. The methods used included functional magnetic resonance imaging, diffusion tensor imaging, functional near-infrared spectroscopy, and magnetic resonance spectroscopy. Acupuncture-induced brain alterations observed in those patients with MCI tended to be observable in the cingulate cortex, prefrontal cortex, and hippocampus. The effect of acupuncture on MCI may play a role in regulating the default mode network, central executive network, and salience network. Based on these studies, researchers could extend the recent research focus from the cognitive domain to the neurological level. Future researches should develop additional relevant, well-designed, high-quality, and multimodal neuroimaging researches to detect the effects of acupuncture on the brains of MCI patients.

Global trends and development of acupuncture for stroke: A review and bibliometric analysis

“…Multiple systematic reviews and meta-analyses of randomized controlled trials [16,59,60] have shown that acupuncture can effectively promote the rehabilitation of patients with cognitive impairment after cerebral infarction and improve their scores on the Mini-Mental State Examination, the Montreal Cognitive Assessment, and Hasegawa Dementia Scale. In a systematic review [61] of 22 studies (with a total of 647 patients) that used neuroimaging to investigate the therapeutic mechanisms of acupuncture for mild cognitive impairment, researchers found that the cingulate cortex, hippocampus, and prefrontal cortex were the 3 brain regions most influenced by acupuncture. However, the correlation between brain responses and clinical outcomes remains to be investigated.…”

Safety and efficacy of acupuncture for mild cognitive impairment: a study protocol for clinical study

“…Acupuncture was safe and effective for MCI when used as an alternative or adjunctive treatment compared with that observed when sham acupuncture, medication, and usual care were used as treatment (12)(13)(14)(15)(16). A systematic review of neuroimaging studies revealed that acupuncture may have an effect on the regulation of the central executive network, salience network, and default mode network, especially in the prefrontal cortex, cingulate cortex, and hippocampus in patients with MCI (17). Moreover, acupuncture was found to have modulatory effects on various regions of the brain in patients with MCI in a regional homogeneity-based metaanalysis (18).…”

“…Several studies have been conducted on the efficacy of acupuncture for MCI; however, the methodological quality of these studies has been insufficient in providing convincing evidence (12)(13)(14)(15)(16)(17)(18). Our manuscript describes the protocol for a rigorously designed clinical study that aims to explore the effects of acupuncture on MCI.…”

Effects of acupuncture on the brain in primary insomnia: a coordinate-based meta-analysis of fMRI studies

“…Previous studies on the mechanisms of acupuncture have shown that acupuncture can affect brain activity and have long-lasting and significant effects on neural functions ( 14 ). As the number of clinical trials using acupuncture to treat PI continues to increase, a number of studies have confirmed the hypothesis that the activity of specific brain areas was related to sleep and shown that acupuncture could alter these regions ( 15 , 16 ).…”