The effect of moxibustion on brain functional connectivity and effective brain networks in patients with amnestic mild cognitive impairment: study protocol for a randomized controlled trial and preliminary results

Abstract

Background and objectives: Mild cognitive impairment (MCI) is an intermediate state between normal aging and dementia, and can be divided into amnestic and non-amnestic types. Patients with amnestic MCI present with memory impairments that are often considered as the early manifestation of Alzheimer’s disease. Patients with amnestic MCI are more likely to progress to Alzheimer’s disease than patients with non-amnestic MCI. The U.S. Food and Drug Administration has not yet approved any drug that can treat amnestic MCI. Moxibustion is a common noninvasive traditional oriental intervention, which uses mainly the heat generated by burning herbal preparations containing moxa and mugwort (Artemisia vulgaris) to simulate acupoints for alleviating the symptoms. To date, many clinical studies have investigated the clinical use of moxibustion to improve memory impairments of Alzheimer’s disease, but these have failed to make a distinction between amnestic and non-amnestic MCI. Therefore, this trial has been designed to assess the effectiveness of moxibustion on amnestic MCI using the Montreal Cognitive Assessment Scale. We will also assess the safety of moxibustion in healthy controls, and analyze the variation of brain functional connectivity and effective brain networks in patients with amnestic MCI undergoing moxibustion using function magnetic resonance imaging. Design: This is a prospective, single-center, randomized controlled clinical trial. Methods: This study will enroll 64 patients with amnestic MCI and 48 healthy controls at Baoan People’s Hospital, Shenzhen, China. The first 64 recruited patients with amnestic MCI will be randomly divided into moxibustion, placebo moxibustion, drug, and control groups (n = 16 per group). In the moxibustion group, patients will be given moxa-wool moxibustion for 12 consecutive weeks. The placebo moxibustion group will receive placebo moxibustion on the same acupoints. Patients in the drug group will be given oral administration of donepezil hydrochloride tablets, 5 mg daily, for 12 consecutive weeks. The control group will receive no intervention. Forty-eight healthy controls will also be randomly assigned into moxibustion, placebo moxibustion, and control groups (n = 16 per group). Interventions will be the same as those received by the patients with amnestic MCI. Evaluators will be blind to group allocation. Outcome measures and preliminary results: The primary outcome measure will be the improvement in cognitive function 12 months after treatment. Secondary outcome measures will be the scores on the Montreal Cognitive Assessment Scale, Clinical Dementia Rating Scale, Mini-Mental State Examination Scale, and Activity of Daily Living Scale before treatment, after 12 weeks of treatment, and 6 months after the end of treatment, as well as brain function analysis before treatment and after 12 weeks of treatment and adverse events during treatment and follow-up. A correlation analysis between cognitive function scores and brain function results will be performed. Results of our preliminary study involving 60 patients with amnestic MCI who experienced moxibustion or received no treatment showed that moxibustion on acupoints significantly improved cognitive ability and quality of sleep in patients relative to the baseline and compared with the control group. Moreover, the scores on attention and delayed recall in the moxibustion group after treatment were significantly higher than those at base line. In the control group the scores on visual space, execution, and delayed recall were significantly lower than those at baseline. These findings indicate that moxibustion improves patient’s attention and delayed recall. If not, visual space, execution, and delayed recall in MCI patients tend to be declined over time. No obvious adverse responses to moxibustion treatment occurred in the preliminary study. Discussion: This proposed trial has the potential to uncover that moxibustion will enhance cognitive-related brain function connections and effector brain networks, which is not yet known. If moxibustion is shown to be an effective and safe treatment strategy in patients with amnestic MCI, then this may pave the way for use of this treatment in clinic amnestic MCI. Ethics and dissemination: This study was approved by the Medical Ethics Committee of the Chinese Clinical Trial Registry (approval No. ChiECRCT-2017018) in October 2016, and registered on April 2017. The study was designed in June 2016. Patient recruitment was initialized in October 2016. Data analysis will be completed in December 2019. Results will be disseminated through publication in a peer-reviewed journal. Protocol version: 1.0. Trial registration: This trial was registered with the Chinese Clinical Trial Registry (registration number: ChiCTR-POC-17011162).