Effect of Tai Chi and transcranial direct current stimulation on spontaneous neural activity in patients with mild cognitive impairment: An exploratory resting-state fMRI study.

IntroductionInterventions at the mild cognitive impairment (MCI) stage prevent or delay the progression of cognitive decline. In recent years, several studies have shown that physical exercise combined with transcranial direct...

From the May Issue of JAMDA

Introduction: Engaging in a secondary task while walking increases motor-cognitive interference and exacerbates fall risk in older adults with mild cognitive impairment (MCI). Previous studies have demonstrated that Tai Chi (TC) may improve cognitive function and dual-task gait performance. Intriguingly, with emerging studies also indicating the potential of transcranial direct current stimulation (tDCS) in enhancing such motor-cognitive performance, whether combining tDCS with TC might be superior to TC alone is still unclear. The purpose of this study was to investigate the effects of combining tDCS with TC on dual-task gait in patients with MCI.Materials and Methods: Twenty patients with MCI were randomly assigned to receive either anodal or sham tDCS, both combined with TC, for 36 sessions over 12 weeks. Subjects received 40 min of TC training in each session. During the first 20 min, they simultaneously received either anodal or sham tDCS over the left dorsolateral prefrontal cortex. Outcome measures included dual-task gait performance and other cognitive functions.Results: There were significant interaction effects between groups on the cognitive dual task walking. Compared to sham, the anodal tDCS group demonstrated a greater improvement on cadence and dual task cost of speed.Conclusion: Combining tDCS with TC may offer additional benefits over TC alone in enhancing dual-task gait performance in patients with MCI.Clinical Trial Registration: [www.ClinicalTrials.gov], identifier [TCTR20201201007].

Pain in knee osteoarthritis (KOA) involves maladaptive neuroplastic adaptations within the pain matrix. Tai Chi and transcranial direct current stimulation (tDCS) each alleviate KOA pain, potentially by modulating the dorsolateral prefrontal cortex (DLPFC). Whether combining them yields superior analgesic and neuromodulatory effects remains to be established. In this four-arm, parallel-group randomized controlled trial, 152 participants with KOA were allocated to a 12-week intervention: (1) Tai Chi combined with tDCS, (2) Tai Chi, (3) tDCS, or (4) a Health Education Control group. The primary outcome was pain intensity assessed using the Pain subscale of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Secondary outcomes included the WOMAC Stiffness and Physical Function subscales, Visual Analogue Scale (VAS), Knee Injury and Osteoarthritis Outcome Score (KOOS), Timed Up and Go Test (TUGT), and the 36-Item Short Form Health Survey (SF-36). Resting-state functional connectivity (rsFC) between the right DLPFC and key regions of the pain matrix was analyzed using functional magnetic resonance imaging (fMRI). Assessments were conducted at baseline and post-intervention. The Tai Chi combined with tDCS group demonstrated a significantly greater reduction in WOMAC Pain subscores compared to the Health Education Control group (P < 0.001), the tDCS group (P = 0.003), and the Tai Chi group (P = 0.048). However, the combined intervention did not show statistically superior improvement over Tai Chi group in secondary outcomes. Neuroimaging results indicated that all active interventions decreased rsFC between the right DLPFC and several pain-matrix regions, including the left posterior cingulate cortex, bilateral thalamus, left precuneus, and left superior frontal gyrus. Furthermore, the extent of pain reduction was positively correlated with decreased connectivity between the right DLPFC and both the left posterior cingulate cortex and the left precuneus. This exploratory trial suggests that combining Tai Chi with tDCS provides superior pain relief compared to either monotherapy in individuals with KOA. Post hoc exploratory neuroimaging analyses further indicate that this analgesic effect may be associated with changes in rsFC between the right DLPFC and regions of the pain matrix. This study was registered with the Chinese Clinical Trial Registry (ChiCTR2100047287).

Cognitive training and physical exercise have shown positive effects on delaying progression of mild cognitive impairment (MCI) to dementia. We explored the enhancing effect from Tai Chi when it was provided with cognitive training for MCI. In the first 12 months, the cognitive training group (CT) had cognitive training, and the mixed group (MixT) had additional Tai Chi training. In the second 12 months, training was only provided for a subgroup of MixT. In the first 12 months, MixT and CT groups were benefited from training. Compared to the CT group, MixT had additional positive effects with reference to baseline. In addition, Compared to short-time training, prolonged mixed training further delayed decline in global cognition and memory. Functional magnetic resonance imaging showed more increased regional activity in both CT and MixT. Tai Chi enhanced cognitive training effects in MCI.Moreover, Tai Chi and cognitive mixed training showed effects on delaying cognitive decline.

Studies have revealed that Tai Chi can enhance cognitive functions among patients with mild cognitive impairment (MCI). However, the precise mechanisms underlying this improvement remain elusive. Consequently, we conducted a study involving 54 elderly inpatients with MCI residing in a combined medical and elderly care facility in Chengdu, who were randomly divided into three groups: a control group engaging in daily living activities, a Tai Chi group that performed Tai Chi exercises in addition to control group activities, and a walking group that undertook walking activities as a supplement to the control group regimen. The intervention period lasted for 24 weeks, comprising 12 weeks of exercise and an additional 12 weeks of follow-up. The Montreal Cognitive Assessment (MoCA), Trail Making Test-A (TMT-A), Auditory Verbal Learning Test (AVLT), and biochemical assessments (measuring brain-derived neurotrophic factor, BDNF, and platelet factor 4, PF4) were administered to investigate overall cognitive function, executive function, memory capacity, and changes in serum concentrations of BDNF and PF4 before, after, and during the follow-up period. Data were analyzed using IBM SPSS 26.0, with statistical methods encompassing descriptive analysis, ANOVA, rank-sum test, repeated measures ANOVA, and generalized estimating equations. Our findings indicated that after 24 weeks of intervention, the Tai Chi group exhibited improvements in cognitive function, executive function, and memory compared to the control group. This enhancement may be attributed to an increased expression of serum BDNF. In conclusion, our study underscores the potential of Tai Chi in ameliorating cognitive function among elderly patients with mild cognitive impairment, thereby offering significant implications for clinical prevention and treatment strategies targeting this condition.

Sleep disorders and mild cognitive impairment (MCI) commonly coexist in older adults, increasing their risk of developing dementia. Long-term tai chi chuan has been proven to improve sleep quality in older adults. However, their adherence to extended training regimens can be challenging. Repetitive transcranial magnetic stimulation (rTMS) is a neuromodulation technique that may enhance the benefits of exercise. To investigate whether 1-Hz rTMS of the right dorsolateral prefrontal cortex could enhance the clinical benefits of tai chi chuan in improving sleep quality and cognitive function among older adults with sleep disorders and MCI. This 2-arm, sham-controlled, assessor-masked randomized clinical trial was conducted at a university hospital in China between October 2022 and February 2024. Adults aged 60 to 75 years with sleep disorders and MCI were eligible. Data analysis was performed from February to May 2024. Participants were randomized in a 1:1 ratio to an experimental group (tai chi chuan and 1-Hz rTMS) or a sham group (tai chi chuan and sham rTMS). Each participant received 30 sessions of personalized rTMS targeting the right dorsolateral prefrontal cortex, and the sham group underwent the same procedure. The 2 groups received 30 sessions of 60 minutes of the 24-form simplified tai chi chuan, 5 times per week for 6 weeks. The primary outcomes were subjective sleep quality assessed by the Pittsburgh Sleep Quality Index (PSQI), in which scores range from 0 to 21, with lower scores indicating a healthier sleep quality, and global cognitive function assessed by the Montreal Cognitive Assessment (MoCA), in which scores range from 0 to 30, with higher scores indicating less cognitive impairment. The secondary outcomes included measures of objective sleep actigraphy, anxiety and depression scales, and other cognitive subdomains. Assessments were performed at baseline, 6 weeks after the intervention, and at the 12-week follow-up. A total of 110 participants (mean [SD] age, 67.9 [4.6] years; 68 female [61.8%]) were randomized to the experimental group (n = 55) and the sham group (n = 55) and included in the intention-to-treat analysis. At 6 weeks after the intervention, compared with the sham group, the experimental group showed a lower PSQI score (between-group mean difference, -3.1 [95% CI, -4.2 to -2.1]; P < .001) and a higher MoCA score (between-group mean difference, 1.4 [95% CI, 0.7-2.1]; P < .001). The per-protocol dataset analyses and 12-week follow-up showed similar results. The generalized estimated equation model revealed an interaction effect between the PSQI score (mean difference, -2.1 [95% CI, -3.1 to -0.1]; P < .001) and the MoCA total score (mean difference, 0.9 [95% CI, 0.1-1.6]; P = .01). There were 7 nonserious, unrelated adverse events (experimental group: 2; sham group: 5) with no significant difference between the 2 groups. In this randomized clinical trial, the findings suggest that 1-Hz rTMS enhanced the clinical benefits of tai chi chuan in improving sleep quality and cognitive function among older adults with sleep disorders and MCI, which may be related to alterations in neural plasticity. These findings provide novel data on nonpharmacologic strategies for the rehabilitation of sleep disorders and may delay or even prevent MCI. Chinese Clinical Trial Registry Identifier: ChiCTR2200063274.

Objective To assess the efficacy of shortened neuropsychological tests for discernment of mild cognitive impairment (MCI) by comparing 3 shortened tests [Animal Fluency Test (AFT), Color Trail Test (CTT) B and Bells Test (BT)], and to provide information for developing brief cognitive screening tool. Methods One hundred and twenty MCI patients and 180 cognitive normal controls (NC) were assessed by a set of standardized comprehensive neuropsychological evaluation including Mini⁃Mental State Examination (MMSE), Auditory Verbal Learning Test (AVLT), Logical Memory Test (LM), Rey⁃Osterrieth Complex Figure Test (ROCFT), Clock Drawing Test (CDT), AFT, Boston Naming Test (BNT), Cancellation Test (CT), Digit Span Test (DS), Stroop Color ⁃ Word Test (CWT), CTT A and B, Similarity Test, BT, Clinical Dementia Rating Scale (CDR), Activities of Daily Living Scale (ADL), Self ⁃ Rating Depression Scale (SDS) and Geriatric Depression Scale (GDS). Results 1) AFT: the greatest difference was seen between MCI (12.65 ± 2.83) and NC (14.93 ± 2.49) in 45 s fluency test version (t = 7.315, P = 0.000). 2) CTT: there was significant difference between MCI (9.28 ± 3.53) and NC (13.43 ± 4.12) in terms of 1 min CTT version (t = 9.356, P = 0.000), and in which the differential efficacy nearly approached the full length version. 3) BT: there were significant differences between MCI and NC groups in all 4 scores including accuracy score, time, post⁃ advising accuracy score and total time (t = 4.164, 3.427, 3.616, 5.102, respectively; P = 0.000, for all). The average time for recancellation was 100 s. However, discerning efficacy was not obviously improved after recancellation. Conclusion Appropriately shortened version of Animal Fluency Test, Color Trail Test and Bells Test prensents the same discerning efficacy for MCI as the original versions. It is feasible for MCI screening. DOI：10.3969/j.issn.1672-6731.2010.03.014

The effect of exercise interventions on increasing and sustaining moderate to vigorous physical activity (MVPA) among older adults with mild cognitive impairment (MCI), who are at heightened risk of dementia, remains unclear. To examine whether participation in a 6-month, supervised, home-based tai ji quan intervention increases MVPA among US community-dwelling older adults at 1 year. This study was a secondary analysis of a parallel-group, outcome assessor-blinded, randomized clinical trial conducted virtually at participants' homes. Eligible participants were aged 65 years or older, lived independently, and had a baseline Clinical Dementia Rating (CDR) global score of 0.5 or less. Participants were enrolled between October 1, 2019, and June 30, 2022. Final follow-up occurred in May 2023. Participants were randomly assigned (1:1:1) to standard tai ji quan, cognitively enhanced tai ji quan, or stretching, and they exercised (via real-time videoconferencing) 1 hour semiweekly for 6 months. The primary outcome was self-reported time engaged in MVPA (in minutes per week), assessed with the International Physical Activity Questionnaire at baseline and at 4, 6, and 12 months following randomization. The Physical Activity Guidelines for Americans recommend that older adults achieve at least 150 min/wk of MVPA, and the number of participants meeting this recommendation was also assessed. Analyses followed the intention-to-treat principle. Among the 318 participants enrolled, 107 were randomized to standard tai ji quan, 105 to cognitively enhanced tai ji quan, and 106 to stretching. Their mean (SD) age was 76 (5) years, 212 (66.7%) were women, and 247 (77.7%) had a CDR global score of 0.5. A total of 304 participants (95.6%) completed the trial, and 299 (94.0%) had complete data on the primary outcome at the 12-month follow-up. At 12 months, both tai ji quan groups had increased MVPA levels compared with the stretching control group, with mean differences from baseline of 66 min/wk (95% CI, 25-108 min/wk; P = .002) with standard tai ji quan and 65 min/wk (95% CI, 24-108 min/wk; P = .002) with cognitively enhanced tai ji quan. Odds ratios for meeting the recommended amount of MVPA (≥150 min/wk) were 3.11 (95% CI, 1.75-5.53; P < .001) for the standard tai ji quan group and 3.67 (95% CI, 2.02-6.65; P < .001) for the cognitively enhanced tai ji quan group compared with the stretching group. In this secondary analysis of a randomized clinical trial involving older adults with MCI or self-reported memory concerns, home-based tai ji quan training (delivered via videoconferencing) increased MVPA 6 months following cessation of the intervention compared with stretching. These findings suggest that tai ji quan may be promoted as an avenue to achieve physical activity guidelines for older adults with MCI or subjective memory concerns. ClinicalTrials.gov Identifier: NCT04070703.

Practice effects have been widely reported in healthy older adults, but these improvements due to repeat exposure to test materials have been more equivocal in individuals with mild cognitive impairment (MCI). The current study examined short-term practice effects in MCI by repeating a brief battery of cognitive tests across one week in 59 older adults with amnestic MCI and 62 intact older adults. Participants with amnestic MCI showed significantly greater improvements on two delayed recall measures (p < 0.01) compared to intact peers. All other practice effects were comparable between these two groups. Practice effects significantly improved scores in the MCI group so that 49% of them were reclassified as "intact" after one week, whereas the other 51% remained "stable" as MCI. Secondary analyses indicated the MCI-Intact group demonstrated larger practice effects on two memory measures than their peers (p < 0.01). These results continue to inform us about the nature of memory deficits in MCI, and could have implications for the diagnosis and possible treatment of this amnestic condition.

Tai Chi Chuan (TCC) is assumed to exert beneficial effects on functional brain activity and cognitive function in elders. Until now, empirical evidence of TCC induced intra-regional spontaneous neural activity and inhibitory control remains inconclusive. Whether the effect of TCC is better than that of other aerobic exercises is still unknown, and the role of TCC in younger adults is not yet fully understood. Here we used resting-state functional MRI (fMRI) to investigate the effects of 8-week TCC (n = 12) and brisk walking (BW, n = 12) on inhibitory control and fractional amplitude of low-frequency fluctuations (fALFF). The results found that TCC had significant effects on inhibitory control performance and spontaneous neural activity that were associated with significantly increased fALFF in the left medial superior frontal gyrus (Cohen’s d = 1.533) and the right fusiform gyrus (Cohen’s d = 1.436) and decreased fALFF in the right dorsolateral superior frontal gyrus (Cohen’s d = 1.405) and the right paracentral lobule (Cohen’s d = 1.132).TCC exhibited stronger effects on spontaneous neural activity than the BW condition, as reflected in significantly increased fALFF in the left medial superior frontal gyrus (Cohen’s d = 0.862). There was a significant positive correlation between the increase in fALFF in the left medial superior frontal gyrus and the enhancement in inhibitory control performance. The change in fALFF in the left medial superior frontal gyrus was able to explain the change in inhibitory control performance induced by TCC. In conclusion, our results indicated that 8 weeks of TCC intervention could improve processing efficiency related to inhibitory control and alter spontaneous neural activity in young adults, and TCC had potential advantages over BW intervention for optimizing spontaneous neural activity.

Type 2 diabetes (T2D) is associated with the progression of cognitive dysfunction. Physical activity benefits cognition, but no evidence from randomized clinical trials has shown whether tai chi chuan has better long-term benefits than fitness walking in cognitive function for patients with T2D and mild cognitive impairment (MCI). To compare the effectiveness of tai chi chuan, a mind-body exercise, for improving cognitive function in older adults with T2D and MCI, with fitness walking. This randomized clinical trial was conducted between June 1, 2020, and February 28, 2022, at 4 sites in China. Participants included 328 adults (aged ≥60 years) with a clinical diagnosis of T2D and MCI. Participants were randomized in a 1:1:1 ratio to a tai chi chuan group, a fitness walking group, or a control group. The tai chi chuan group received 24-form simplified tai chi chuan. The fitness walking group received fitness walking training. Both exercise groups took the training for 60 min/session, 3 times/wk, for 24 weeks in a supervised setting. All 3 groups were provided with a 30-minute diabetes self-management education session, once every 4 weeks for 24 weeks. The participants were followed up for 36 weeks. The primary outcome was the global cognitive function measured at 36 weeks by the Montreal Cognitive Assessment (MoCA). Secondary outcomes included MoCA at 24 weeks and other cognitive subdomain measures and blood metabolic indices at 24 and 36 weeks. A total of 328 participants (mean [SD] age, 67.55 [5.02] years; mean [SD] T2D duration, 10.48 [6.81] years; 167 [50.9%] women) were randomized to the tai chi chuan group (n = 107), fitness walking group (n = 110), or control group (n = 111) and included in the intention-to-treat analysis. At 36 weeks, the tai chi chuan group showed improved MoCA scores compared with the fitness walking group (mean [SD], 24.67 [2.72] vs 23.84 [3.17]; between-group mean difference, 0.84 [95% CI, 0.02-1.66]; P = .046) in the intention-to-treat analysis. The per-protocol analysis data set and subgroup analysis at 36 weeks showed similar results. Based on the generalized linear models, the treatment effects were similar in each group after adjusting for self-reported dietary calories and physical activity. There were 37 nonserious adverse events (tai chi chuan group, 8; fitness walking group, 13; control group, 16) unrelated to the study with no statistically significant difference among the 3 groups (P = .26). In this randomized clinical trial including older adults with T2D and MCI, tai chi chuan was more effective than fitness walking in improving global cognitive function. The findings support a long-term benefit, suggesting the potential clinical use of tai chi chuan as an exercise intervention to improve cognitive function for older adults with T2D and MCI. ClinicalTrials.gov Identifier: NCT04416841.

Mild cognitive impairment (MCI) has been proposed as a condition of intermediate symptomatology between the cognitive changes of ageing and fully developed symptoms of dementia. Treatment in the stages of MCI may delay the deterioration of cognitive impairment and delay the progression to dementia. Currently, the treatments for Alzheimer's disease have been focused on increasing acetylcholine levels in the brain. However, these drugs have not been proven to be effective for MCI and have numerous side effects. Huperzine A may have some beneficial effects in MCI. To assess the clinical efficacy and safety of huperzine A for the treatment of patients with MCI. We searched ALOIS: the Cochrane Dementia and Cognitive Improvement Group's Specialized Register on 23 May 2011 using the terms: huperzine, ayapin, scoparon. ALOIS contains records of clinical trials identified from monthly searches of a number of major healthcare databases, numerous trial registries and grey literature sources. Additional searches were also performed separately in MEDLINE, EMBASE, PsycINFO, LILACS, clinicalTrials.gov, the ICTRP (WHO portal), CENTRAL (The Cochrane Library) and Web of Science with Conference Proceedings.The following Chinese databases were searched: The Chinese Biomedical Database, VIP Chinese Science and Technique Journals Database, China National Knowledge Infrastructure and The Chinese Clinical Trials Register. In addition, we handsearched 20 Chinese traditional medicine journals from between 1970 and 1989. Randomised, parallel-group, placebo-controlled trials comparing huperzine A with placebo in patients with MCI were eligible for inclusion. Two review authors independently assessed studies for their eligibility for inclusion. No eligible trials were identified. In the absence of any suitable randomised placebo-controlled trials in this area, we were unable to perform a meta-analysis. The currently available evidence is insufficient to assess the potential for huperzine A in the treatment of MCI. Randomised double-blind placebo-controlled trials are needed.

This study evaluated the effectiveness of tai chi, enhanced by communication technologies, in improving cognitive and physical functioning in patients with mild cognitive impairment, and to compare these effects with traditional tai chi. A systematic search across four academic databases identified 16 studies with 1,877 participants. Data were expressed as weighted or standardized mean differences with 95% confidence intervals. A meta-analysis revealed significant improvements in Mini-Mental State Examination scores and Timed Up and Go results in patients with mild cognitive impairment following tai chi intervention. Subgroup analysis indicated that both communication technology-based tai chi and traditional tai chi produced varying improvements in cognitive and physical function. This study confirms the importance of tai chi for cognitive and physical functioning in patients with mild cognitive impairment. Compared with traditional tai chi, communication technology-based tai chi showed greater benefits in promoting rehabilitation. The effective and feasible interventions could improve the physical health of many older adult patients, these findings provide valuable insights and decision-making guidance for clinical practice and public health with older patients with mild cognitive impairment. PROSPERO, CRD42023449711, available from: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023449711.

BackgroundTai Chi integrates multisensory stimuli, including olfactory cues, to enhance cognitive functions such as working memory. This study evaluated the effects of eight-form Tai Chi combined with olfactory stimulation on working memory in older adults with mild cognitive impairment (MCI).MethodsThis study used a 2 (time) × 3 (group) mixed design. Of 267 screened patients with MCI, 93 were deemed eligible and randomly assigned to one of three groups: Tai Chi group (TCG), Tai Chi combined with olfactory stimulation group (TCOG), or control group (CG). The TCG and TCOG participated in three weekly 60 min sessions for 26 weeks. The TCOG was exposed to four fragrances. Primary outcomes were the N-back task and the digit span test (DST). Secondary outcomes included the MoCA, MMSE, CSIT, GDS, SAS, and PSQI.ResultsPost-intervention, both intervention groups outperformed the CG in 0-back accuracy (TCG: +0.118, 95% CI: 0.048–0.188, p < 0.001; TCOG: +0.118, 95% CI: 0.048–0.187, p < 0.001) and total DST scores (TCG: +1.321, 95% CI: 0.250–2.393, p = 0.009; TCOG: +1.535, 95% CI: 0.602–2.467, p < 0.001). They also exhibited significant improvements in MoCA (TCG: +3.07, 95% CI: 0.89–5.25, p = 0.002; TCOG: +3.42, 95% CI: 1.22–5.62, p = 0.001) and CSIT scores (TCG: +3.29, 95% CI: 1.56–5.01, p < 0.001; TCOG: +3.86, 95% CI: 2.28–5.44, p < 0.001) compared with the CG. Furthermore, the TCOG showed superior gains over the TCG in 1-back accuracy (+0.156, 95% CI: 0.044–0.269, p = 0.003), forward digit span (+0.613, 95% CI: 0.156–1.070, p = 0.004), and backward digit span (+0.921, 95% CI: 0.117–1.726, p = 0.018). It likewise showed significantly greater reductions in GDS (−1.46, 95% CI: −2.78 to −0.15, p = 0.024) and PSQI scores (−2.04, 95% CI: −3.89 to −0.19, p = 0.008) compared with the other groups, with the TCOG versus TCG in PSQI being significant (−1.47, 95% CI: −2.98 to −0.04, p = 0.020).ConclusionTai Chi improved working memory and global cognition in older adults with MCI. Combining Tai Chi with olfactory stimulation yielded additional benefits, demonstrating superior efficacy in alleviating depressive symptoms and enhancing sleep quality.Clinical trial registrationhttps://www.chictr.org.cn/index.html, Chinese Clinical Trial Registry (ChiCTR2400083424).