Functional connectivity of the retrosplenial cortex in rats with ischemic stroke is improved by electroacupuncture

Global trends and hotspots in research on acupuncture for stroke: a bibliometric and visualization analysis

Acupuncture has been widely used in stroke and post-stroke rehabilitation (PSR), but there is no literature on the bibliometric analysis of acupuncture for stroke. This study aimed to characterize the global publications and analyze the trends of acupuncture for stroke in the past 40 years. We identified 1157 publications from the Web of Science Core Collection. The number of publications grew slowly in the first three decades from 1980 until it started to grow after 2010, with significant growth in 2011-2012 and 2019-2020. China, the USA, and South Korea are the top three countries in this field, and China has formed good internal cooperative relations. Early studies focused on the clinical efficacy of acupuncture for stroke. In the last five years, more emphasis has been placed on the effectiveness of acupuncture in treating sequelae and complications, combined with neuroimaging studies to explore the mechanisms of brain injury repair and neurological recovery. Acupuncture for stroke has a vast research potential, and researchers from different countries/regions and organizations still need to remove academic barriers to enhance communication and collaboration.

Efficacy and safety of acupuncture combined with rehabilitation training for poststroke cognitive impairment: A systematic review and meta-analysis

BACKGROUND

Accumulated evidence has proven that both acupuncture and rehabilitation therapy are beneficial for stroke sequelae. However, there is no systematic review to identify the efficacy and safety of acupuncture combined with rehabilitation training for poststroke cognitive impairment (PSCI). Therefore, the aim of this study was to assess the efficacy and safety of acupuncture combined with rehabilitation therapy for patients with PSCI.

METHODS

We searched nine databases, including PubMed, Embase, Scopus, Web of Science, EBSCO, Cochrane Library, China National Knowledge Infrastructure (CNKI), China Science and Technology Journal Database (VIP), and Wan Fang, from their inception to September 2022. Randomized controlled trials (RCTs) examining the effect of acupuncture combined with rehabilitation on PSCI were included. The primary outcomes were the Mini-Mental State Examination (MMSE) score, Montreal Cognitive Assessment (MoCA) score, Modified Barthel Index (MBI) score, and Fugl-Meyer Assessment (FMA) score. The quality of the methodology was evaluated by Cochrane's risk of bias tool. Meta-analyses were performed by Revman 5.3 software.

RESULTS

A total of 18 RCTs involving 1654 patients were included. The overall methodological quality of the included studies was low. Pooled results demonstrated that acupuncture combined with rehabilitation could significantly improve the clinical efficacy of PSCI (OR=3.23, 95% CI: 2.13 to 4.89), MMSE score (MD= 2.85, 95% CI: 2.56 to 3.15), MoCA score (MD= 2.18, 95% CI: 1.38 to 2.97), MBI score (MD= 9.23, 95% CI: 5.62 to 12.84), and FMA score (MD=5.72, 95% CI: 3.48 to 7.96).

CONCLUSIONS

Acupuncture combined with rehabilitation may produce better outcomes than rehabilitation alone in the treatment of PSCI. However, the safety of combined interventions is still unclear. Therefore, research with more rigorous study designs and RCTs with larger sample sizes is still needed.

The neuroprotective and neural circuit mechanisms of acupoint stimulation for cognitive impairment

Cognitive impairment is a prevalent neurological disorder that burdens families and the healthcare system. Current conventional therapies for cognitive impairment, such as cholinesterase inhibitors and N-methyl-d-aspartate receptor antagonists, are unable to completely stop or reverse the progression of the disease. Also, these medicines may cause serious problems with the digestive system, cardiovascular system, and sleep. Clinically, stimulation of acupoints has the potential to ameliorate the common symptoms of a variety of cognitive disorders, such as memory deficit, language dysfunction, executive dysfunction, reduced ability to live independently, etc. There are common acupoint stimulation mechanisms for treating various types of cognitive impairment, but few systematic analyses of the underlying mechanisms in this domain have been performed. This study comprehensively reviewed the basic research from the last 20 years and found that acupoint stimulation can effectively improve the spatial learning and memory of animals. The common mechanism may be that acupoint stimulation protects hippocampal neurons by preventing apoptosis and scavenging toxic proteins. Additionally, acupoint stimulation has antioxidant and anti-inflammatory effects, promoting neural regeneration, regulating synaptic plasticity, and normalizing neural circuits by restoring brain functional activity and connectivity. Acupoint stimulation also inhibits the production of amyloid β-peptide and the phosphorylation of Tau protein, suggesting that it may protect neurons by promoting correct protein folding and regulating the degradation of toxic proteins via the autophagy-lysosomal pathway. However, the benefits of acupoint stimulation still need to be further explored in more high-quality studies in the future.

Application of diffusion tensor imaging and functional alterations in evaluating brain alterations related to heatstroke in a rat model

OBJECTIVES

To assess the alterations in resting-state functions and neural structures in the brain of a heatstroke rat model and explore the underlying relationship.

METHODS

In total, 17 male Sprague Dawley rats were randomly divided into a control group (CTRL, n = 7) and a heatstroke group (HS, n = 10). All rats underwent 7.0 T magnetic resonance imaging (MRI). T2-weighted imaging, resting-state functional MRI (rs-fMRI), and diffusion tensor imaging (DTI) were obtained. On day 25, the surviving HS group rats (the follow-up group, FU, n = 7) were scanned again.

RESULTS

Heatstroke resulted in functional alterations and structural damage in the cerebellar molecular layer (CML), right perirhinal area (PA), pretectal region (PR), right dentate gyrus, and external cortex of the inferior colliculus (ECIC). Further functional changes occur in the right temporal associative cortex (TAC), left retrosplenial cortex (RC), and CML during convalescence. The fractional anisotropy values were significantly positively correlated with the amplitude of low-frequency fluctuation (ALFF) (HS-CML: r = 0.746, p = 0.034; right PR: r = 0.648, p = 0.049; FU-right PA: r = 0.817, p = 0.025)/regional homogeneity (ReHo) ratio (HS-CML: r = 0.833, p = 0.008; ECIC: r = 0.678, p = 0.045) and negatively correlated with the ALFF (FU-left RC: r = -0.818, p = 0.024; right TAC: r = -0.813, p = 0.049).

CONCLUSION

DTI and rs-fMRI allow meticulous monitoring of the progression of neurological and functional alterations in the brain after heatstroke.

The impact of acupuncture on neuroplasticity after ischemic stroke: a literature review and perspectives

Ischemic stroke is common in the elderly, and is one of the main causes of long-term disability worldwide. After ischemic stroke, spontaneous recovery and functional reconstruction take place. These processes are possible thanks to neuroplasticity, which involves neurogenesis, synaptogenesis, and angiogenesis. However, the repair of ischemic damage is not complete, and neurological deficits develop eventually. The WHO recommends acupuncture as an alternative and complementary method for the treatment of stroke. Moreover, clinical and experimental evidence has documented the potential of acupuncture to ameliorate ischemic stroke-induced neurological deficits, particularly sequelae such as dyskinesia, spasticity, cognitive impairment, and dysphagia. These effects are related to the ability of acupuncture to promote spontaneous neuroplasticity after ischemic stroke. Specifically, acupuncture can stimulate neurogenesis, activate axonal regeneration and sprouting, and improve the structure and function of synapses. These processes modify the neural network and function of the damaged brain area, producing the improvement of various skills and adaptability. Astrocytes and microglia may be involved in the regulation of neuroplasticity by acupuncture, such as by the production and release of a variety of neurotrophic factors, including brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF). Moreover, the evidence presented indicates that acupuncture promotes neuroplasticity by modulating the functional reconstruction of the whole brain after ischemia. Therefore, the promotion of neuroplasticity is expected to become a new target for acupuncture in the treatment of neurological deficits after ischemic stroke, and research into the mechanisms responsible for these actions will be of significant clinical value.

The current status and trend of the functional magnetic resonance combined with stimulation in animals

As a non-radiative, non-invasive imaging technique, functional magnetic resonance imaging (fMRI) has excellent effects on studying the activation of blood oxygen levels and functional connectivity of the brain in human and animal models. Compared with resting-state fMRI, fMRI combined with stimulation could be used to assess the activation of specific brain regions and the connectivity of specific pathways and achieve better signal capture with a clear purpose and more significant results. Various fMRI methods and specific stimulation paradigms have been proposed to investigate brain activation in a specific state, such as electrical, mechanical, visual, olfactory, and direct brain stimulation. In this review, the studies on animal brain activation using fMRI combined with different stimulation methods were retrieved. The instruments, experimental parameters, anesthesia, and animal models in different stimulation conditions were summarized. The findings would provide a reference for studies on estimating specific brain activation using fMRI combined with stimulation.

Electroacupuncture of Baihui and Shenting ameliorates cognitive deficits via Pten/Akt pathway in a rat cerebral ischemia injury model

Cerebral ischemic stroke is a huge threat to the health and life of many people. Electroacupuncture (EA) at Baihui (GV20) and Shenting (GV24) acupoints can notably alleviate cerebral ischemia/reperfusion injury (CIRI). However, the molecular basis underlying the effectiveness of EA at the GV20 and GV24 acupoints for CIRI remains largely unknown. Our present study demonstrated that EA treatment at the GV20 and GV24 acupoints markedly alleviated middle cerebral artery occlusion/reperfusion (MCAO/R)-induced cognitive deficits and cerebral infarction in rats. Proteomics analysis revealed that 195 and 218 proteins were dysregulated in rat hippocampal tissues in the MCAO/R vs. sham group and thhhe EA vs. MCAO/R group, respectively. Moreover, 62 proteins with converse alteration trends in MCAO/R vs. sham and EA vs. MCAO/R groups were identified. These proteins might be implicated in the EA-mediated protective effect against MCAO/R-induced cerebral injury. GO enrichment analysis showed that 39 dysregulated proteins in the MCAO/R vs. sham group and 40 dysregulated proteins in the EA vs. MCAO/R group were related to brain and nerve development. Protein–protein interaction analysis of the abovementioned dysregulated proteins associated with brain and nerve development suggested that Pten/Akt pathway-related proteins might play major roles in regulating EA-mediated protective effects against MCAO/R-induced brain and nerve injury. Western blot assays demonstrated that Pak4, Akt3, and Efnb2 were expressed at low levels in the MCAO/R group vs. the sham group but at high levels in the EA group vs. the MCAO/R group. In conclusion, multiple proteins related to the protective effect of EA at the GV20 and GV24 acupoints against CIRI were identified in our study.

Peering into the Brain through the Retrosplenial Cortex to Assess Cognitive Function of the Injured Brain

The retrosplenial cortex (RSC) is a posterior cortical area that has been drawing increasing interest in recent years, with a growing number of studies studying its contribution to cognitive and sensory functions. From an anatomical perspective, it has been established that the RSC is extensively and often reciprocally connected with the hippocampus, neocortex, and many midbrain regions. Functionally, the RSC is an important hub of the default-mode network. This endowment, with vast anatomical and functional connections, positions the RSC to play an important role in episodic memory, spatial and contextual learning, sensory-cognitive activities, and multi-modal sensory information processing and integration. Additionally, RSC dysfunction has been reported in cases of cognitive decline, particularly in Alzheimer's disease and stroke. We review the literature to examine whether the RSC can act as a cortical marker of persistent cognitive dysfunction after traumatic brain injury (TBI). Because the RSC is easily accessible at the brain's surface using in vivo techniques, we argue that studying RSC network activity post-TBI can shed light into the mechanisms of less-accessible brain regions, such as the hippocampus. There is a fundamental gap in the TBI field about the microscale alterations occurring post-trauma, and by studying the RSC's neuronal activity at the cellular level we will be able to design better therapeutic tools. Understanding how neuronal activity and interactions produce normal and abnormal activity in the injured brain is crucial to understanding cognitive dysfunction. By using this approach, we expect to gain valuable insights to better understand brain disorders like TBI.