Effect of acupuncture on episodic memory for amnesia-type mild cognitive impairment: study protocol of a multicenter, randomized, controlled trial

BACKGROUND

Amnesic mild cognitive impairment (aMCI) is the main subtype of mild cognitive impairment (MCI) and has the highest risk of conversion to Alzheimer's disease (AD) among all MCI subtypes. Episodic memory impairment is the early cognitive impairment of aMCI, which has become an important target for AD prevention. Previous clinical evidence has shown that acupuncture can improve the cognitive ability of MCI patients. This experiment aimed to observe the efficacy and neural mechanism of TiaoshenYizhi acupuncture on the episodic memory of patients with aMCI.

METHODS

In this multicenter, parallel-group, double-blind, randomized controlled trial, 360 aMCI participants will be recruited from six subcenters and randomly assigned to the acupuncture group, sham acupuncture group, and control group. The acupuncture group will receive TiaoshenYizhi (TSYZ) acupuncture, the sham acupuncture group will use streitberger sham acupuncture, and the control group will only receive free health education. Participants in the two acupuncture groups will receive real acupuncture treatment or placebo acupuncture three times per week, 24 sessions over 8 consecutive weeks. The primary outcome will be global cognitive ability. Secondary outcomes will be a specific cognitive domain, including episodic memory and execution ability, electroencephalogram, and functional magnetic resonance imaging data. Outcomes will be measured at baseline and the fourth and eighth weeks after randomization. Repeated measurement analysis of variance and a mixed linear model will be used to observe the intervention effect.

DISCUSSION

The protocol will give a detailed procedure to the multicenter clinical trial to further evaluate the efficacy and neural mechanism of TiaoshenYizhi acupuncture on episodic memory in patients with aMCI. From this research, we expect to provide clinical evidence for early aMCI management.

TRIAL REGISTRATION

http://www.chictr.org.cn/edit.aspx?pid=142612&htm=4 , identifier: ChiCTR2100054009.

Platelet Amyloid-β Protein Precursor (AβPP) Ratio and Phosphorylated Tau as Promising Indicators for Early Alzheimer's Disease

To identify whether platelet amyloid-β protein precursor (AβPP) ratio, phosphorylated-tau (P-tau) 231, P-tau181, and serine 396 and 404 (Ser396/404) phosphorylated tau are potential peripheral indicators for early Alzheimer's disease (AD). Forty-three amnesic mild cognitive impairment (aMCI) patients and 45 normal controls were recruited. Peripheral venous blood was drawn and platelets were collected and evaluated for potential indicators by Western blot analysis. Subsequent meta-analysis was completed on these selected indicators. In platelets of aMCI patients, the AβPP ratio level was significantly lower and levels of P-tau231 and Ser396/404 phosphorylated tau were significantly higher. Moreover, in aMCI patients, a negative correlation was observed between platelet P-tau231 level and the Trail Making Tests A score, and it was found that higher platelet P-tau231 levels significantly associated with a worse performance of information processing speed. Furthermore, values of the area under the curve of platelet P-tau231 and Ser396/404 phosphorylated tau were 0.624 and 0.657, respectively. Finally, a meta-analysis indicated platelet AβPP ratio level was significantly lower in MCI cohorts. In conclusion, platelets of aMCI subjects showed a lower AβPP ratio and higher levels of P-tau231 and Ser396/404 phosphorylated tau when compared to normal controls, which may be critical in identifying early AD.

Plasma Aβ42 as a Biomarker of Prodromal Alzheimer's Disease Progression in Patients with Amnestic Mild Cognitive Impairment: Evidence from the PharmaCog/E-ADNI Study

It is an open issue whether blood biomarkers serve to diagnose Alzheimer's disease (AD) or monitor its progression over time from prodromal stages. Here, we addressed this question starting from data of the European FP7 IMI-PharmaCog/E-ADNI longitudinal study in amnesic mild cognitive impairment (aMCI) patients including biological, clinical, neuropsychological (e.g., ADAS-Cog13), neuroimaging, and electroencephalographic measures. PharmaCog/E-ADNI patients were classified as "positive" (i.e., "prodromal AD" n = 76) or "negative" (n = 52) based on a diagnostic cut-off of Aβ42/P-tau in cerebrospinal fluid as well as APOE ε 4 genotype. Blood was sampled at baseline and at two follow-ups (12 and 18 months), when plasma amyloid peptide 42 and 40 (Aβ42, Aβ40) and apolipoprotein J (clusterin, CLU) were assessed. Linear Mixed Models found no significant differences in plasma molecules between the "positive" (i.e., prodromal AD) and "negative" groups at baseline. In contrast, plasma Aβ42 showed a greater reduction over time in the prodromal AD than the "negative" aMCI group (p = 0.048), while CLU and Aβ40 increased, but similarly in the two groups. Furthermore, plasma Aβ42 correlated with the ADAS-Cog13 score both in aMCI patients as a whole and the prodromal AD group alone. Finally, CLU correlated with the ADAS-Cog13 only in the whole aMCI group, and no association with ADAS-Cog13 was found for Aβ40. In conclusion, plasma Aβ42 showed disease progression-related features in aMCI patients with prodromal AD.