Basic research on postoperative cognitive dysfunction in the past decade: a bibliometric analysis

Objective: Postoperative cognitive dysfunction (POCD) is a prevalent complication following anesthesia and surgery that particularly affects elderly patients, and poses significant health risks. In recent years, there has been an increase in basic research on POCD, with a particular focus on its molecular mechanisms, which have become a prominent area of inquiry. However, no bibliometric analysis has been conducted in this field. This study aims to employ bibliometric methods to comprehensively summarize the current status and developmental trends of basic research on POCD, providing new ideas and strategies for future scientific investigations.

Methods: Relevant literature published between January 1, 2014, and October 30, 2024, was retrieved from the Web of Science Core Collection. Eligible articles were exported in plain text format. The annual output of published papers and data on authors, countries/institutions, journals, keywords, co-cited journals, and co-cited literature were analyzed and visualized using Microsoft Excel, VOSviewer, and CiteSpace software.

Results: A total of 479 papers from 13 countries were included, with a noticeable upward trend in publications over the past decade, particularly in the last 3 years. A total of 105 core authors published four or more papers, with Professor Zuozhiyi identified as the leading contributor. “The Journal of Neuroinflammation” emerged as the most prolific publication source, while Chinese scholars accounted for the highest number of contributions and Dutch scholars led in citations per article. The University of Virginia was the leading institution for publications. Analysis of research hotspots revealed “neuroinflammation,” “surgery,” “impairment,” “memory,” and “information” as frequently occurring keywords. Notably, “pyroptosis” was identified as a current research hotspot and “synaptic plasticity” as a rapidly emerging term. The top five cited journals were all ranked as Q1 journals, with “Anesthesiology” being the most cited. Within co-cited articles, the “hippocampal CA1 region” represented the largest cluster, and literature on “neuroinflammation” was a key reference in current discussions.

Conclusion: Over the past decade, basic research on POCD has steadily increased, particularly among Chinese scholars. Bibliometric analysis revealed that the molecular mechanisms underlying POCD are likely crucial focuses of current and future research. This field holds significant potential for further development.

1 Introduction

Postoperative cognitive dysfunction (POCD) is a common complication following anesthesia and surgery is characterized by declines in memory, orientation, language expression, and social skills. Its prevalence can reach as high as 36.3% among younger individuals and 42.4% among elderly (Monk et al., 2008; Needham et al., 2017). In 2018, perioperative neurocognitive disorders (PNDs) were formally proposed as a comprehensive diagnostic category encompassing cognitive impairment or alterations detected either preoperatively or postoperatively. As a specific subtype of PND, POCD is defined by measurable cognitive deficits emerging between 30 days and 12 months following surgical procedures (Evered et al., 2018). This condition poses significant risks, with studies linking it to prolonged hospital stays, adverse prognoses, diminished postoperative quality of life, and increased mortality rates (Rundshagen, 2014). Currently, the mechanisms underlying POCD remain unclear; however, previous research has suggested potential associations with neuroinflammation, neuronal apoptosis, synaptic plasticity impairment, pain, and mitochondrial metabolic disorders (Gao et al., 2021; Ding et al., 2021; Yang et al., 2022; Yuan et al., 2022; Bowman et al., 2018). Furthermore, Campbell and Figueiro (2024) reviewed evidence indicating that postoperative circadian rhythm disorder (CRD) may induce POCD by disrupting sleep architecture. Wei et al. (2024) further demonstrated that preoperative gut microbiota dysbiosis may serve as a significant contributing factor to the development of POCD.

As one of the most widely utilized statistical methods today, bibliometric analysis evaluates academic productivity, delineates academic frontiers and hotspots, and predicts scientific trends within research domains by leveraging scientific literature databases and bibliometric attributes (Ninkov et al., 2022). VOSviewer and CiteSpace are among the most frequently employed bibliometric tools for literature data analysis and visualization, as they effectively assess structured content and the evolution of topics to provide a clearer understanding for readers (van Eck and Waltman, 2010; Chen, 2006). In recent years, interest in research on POCD has been steadily increasing; however, comprehensive bibliometric analyzes, particularly those focused on basic research in this area, remain sparse. Therefore, this paper aims to employ bibliometric methods to summarize existing basic research on POCD, explore its underlying molecular mechanisms, thoroughly analyze the research results and quantitative data in this field, and provide a visual map. The goal is to offer valuable insights for scholars interested in this research domain, thereby ultimately contributing to more effective prevention and intervention strategies for POCD in clinical practice.

2 Methods

2.1 Data extraction

The Web of Science is widely recognized as a high-quality database, that is valued by researchers for its extensive subject coverage, rigorous journal screening, and rich collection of literature resources. It is considered the most suitable database for bibliometric analysis (Ding and Yang, 2020; Thelwall, 2008). This paper utilized the Web of Science Core Collection (WoSCC) as the source for literature data. To ensure the comprehensiveness and accuracy of the retrieval results, the citation index was set to the Science Citation Index Expanded. The retrieval formula employed was TS = (“postoperative cognitive dysfunction”), with the time frame specified from January 1, 2014, to October 30, 2024. For the literature type, only articles are selected.

2.2 Data cleaning

A total of 1,416 articles were retrieved from the database, after which duplicate entries were removed. Titles and abstracts were reviewed, and only those works directly related to basic research POCD were selected, while studies focused on clinical research or meta-analyzes were excluded. This process resulted in the removal of 934 articles, leaving a total of 479 relevant articles for inclusion. These files were then exported in “plain text” format and saved as “download_wos.txt.” To ensure the reliability of the results, the data extraction and screening process was conducted by two independent researchers. For a detailed overview of this process, please refer to Figure 1.

Figure 1

Figure 1. Flowchart of articles extraction and screening process.

2.3 Data processing

Microsoft Office Excel 2021, VOSviewer1.6.19, and CiteSpace 6.4.R1 were used to visually analyze the final exported literature; summarize the trends in the number of published papers, high-yield authors, countries, institutions, and journals; and analyze the co-occurrence, clustering of keywords and co-citation information.

3 Results

3.1 Trends of published documents

The 479 articles included in this study were written by 2,271 authors from 13 countries, 393 institutions or organizations, published in 182 journals, and cited 13,361 references from 10,609 authors.

As illustrated in Figure 2, the number of papers focused on basic research of POCD has generally increased annually over the past decade, with a slight decline in 2021, and a peak in 2023. Notably, the papers published in the last 3 years account for approximately 43% of the total publications from the past decade, indicating that basic research on POCD has emerged as a hotspot and garnered increasing attention from scholars. However, since this study only included literature published before October 30, 2024, it is anticipated that the number of papers published in 2024 will continue to rise.

Figure 2

Figure 2. Document statistics on basic research of POCD from 2010 to 2024.

3.2 Author, journal, country, and institution information

3.2.1 Author information

Author analysis can identify the prominent scholars and core research contributors within a specific field. The renowned scholar Derek J. de Solla Price observed that within a given research topic, a significant portion of papers are authored by a relatively small group of highly productive researchers. He noted that the size of this group is approximately equal to the square root of the total number of authors involved. This principle has since been referred to as Price’s law (de Solla Price et al., 1986), that is

$\begin{array}{ll}{\displaystyle \sum }_{m+1}^{I}n\left(x\right)=\sqrt{n}& (1)\end{array}$

In Equation 1, (n(x)) represents the number of authors who have published (x) papers, whereas i = n_max denotes the number of papers authored by the most prolific researchers in the field (with n_max = 27 based on VOSviewer analysis). Here, (n) represents the total number of authors, and (M) is the minimum number of papers published by core authors. According to Price’s law, the minimum number of papers required for an author to be considered among the core contributors is as follows:

$\begin{array}{ll}m\approx 0.749\times \sqrt{(N_{\text{max}}})& (2)\end{array}$

According to Equation 2, m ≈ 3.89. Thus, authors with four or more published articles (including those with exactly four) are classified as core authors in this field, resulting in a total of 105 core authors. Figure 3 visualizes these core authors via VOSviewer. In the figure, larger circle nodes correspond to authors with a greater number of publications. The connections between nodes indicate the strength of collaboration, with thicker lines representing a greater number of co-authored papers between two authors. Additionally, the color of the nodes signifies different clusters. It is evident that several collaborative groups among authors have emerged; however, intergroup collaboration remains relatively limited.

Figure 3

Figure 3. Visualization analysis of all core authors.

Table 1 presents the top 10 high-yield authors in the field of basic research on POCD, covering the period from January 1, 2014, to October 30, 2024. Among these highly productive authors, Professor Zuozhiyi, an anesthesiology professor at the University of Virginia in the United States, holds the top position, with a total of 27 published papers and 820 citations, with an average of 30.37 citations per paper. Professor Zuozhiyi is dedicated to research on brain protection and POCD and has achieved significant international recognition for his contributions. Professors Guoxiangyang and Lizhengqian, both affiliated with the Department of Anesthesiology at the Third Hospital of Peking University, rank second and third, respectively. They have frequently collaborated on research focused on perioperative brain health and brain function. These studies investigated the potential relationships between POCD and related signaling molecules in the hippocampus, such as hypoxia-inducible factor-1 alpha (HIF-1α) and vascular endothelial growth factor (VEGF) (Cao et al., 2019; Cao et al., 2018), as well as the effects of isoflurane anesthesia on POCD in elderly rats (Ni et al., 2015). Notably, most of the top 10 authors are Chinese researchers, highlighting their emphasis on elucidating the molecular mechanisms underlying POCD.

Table 1

Table 1. Top 10 contributing authors in POCD basic research.

3.2.2 Journal information

Basic research on POCD over the past decade has been published primarily in medical journals, with a few exceptions for comprehensive journals. Notably, journals focused on neuromedicine and geriatrics are predominant. Table 2 lists the top 10 journals in this field, all of which are medical journals. Among them, the “Journal of Neuroinflammation” stands out as the leading publication, with a total of 22 articles and the highest impact factor among the top 10 journals. In addition to the “Molecular Medicine Reports” (medicine, research, and experimental), “Experimental and Therapeutic Medicine” (medicine, research, and experimental), and “Aging US” (cell biology and genetics), the remaining seven journals also encompass various aspects of neuroscience. Citation analysis revealed that the “Journal of Neuroinflammation” not only has the highest number of published articles but also has the highest total number of citations, suggesting that high-quality of research is disseminated in this journal and that significant attention within the field is given to basic research on POCD. The “Behavioral Brain Research” journal ranks second in terms of citations and citations per article, also indicating that this topic has garnered considerable interest from the research community.

Table 2

Table 2. Top 10 journals with the highest publication output in POCD basic research.

Using VOSviewer, we visually analyzed journals with at least four publications, identifying a total of 36 journals that met the criteria, as illustrated in Figure 4. (A) The graph presents the co-occurrence network view of these journals, with different colors representing distinct clusters. The red clusters are predominantly composed of journals within the field of neuroscience, whereas the green clusters mainly include journals focusing on immunology and cell biology. The blue and yellow clusters encompass a variety of disciplines, including neuroscience, geriatrics, behavioral medicine, pharmacology, and anesthesiology. (B) The timeline chart shows the publication activity of 34 journals, revealing that since approximately 2020, neuroscience journals have increasingly become the preferred choice for scholars in this domain. (C) The density view of the 34 journals is depicted in the figure, where the brightness of the colors reflects the number of published papers. A brighter color indicates a greater volume of publications. Notably, the three journals with the most publications are the “Journal of Neuroinflammation,” “Behavioral Brain Research,” and “Molecular Medicine Reports.”

Figure 4

Figure 4. (A) Co-occurrence network view of journals (B) time view; (C) density view.

3.2.3 Country and institutional information

To identify which countries have made the most significant contributions to basic research on POCD, this study analyzed the number of papers published by 13 countries. Table 3 presents the top five countries in terms of number of publications. Chinese scholars have led the field, with an impressive total of 444 articles published over the past decade, significantly outpacing other countries. This highlights the extensive attention given to POCD research by Chinese scholars during this period. The United States ranks second, with a total of 56 articles published. Notably, among the top 5 countries, only China and the United States have published more than 10 articles, indicating a stark imbalance in the distribution of research contributions within this field, with a few countries dominating the output. In terms of citations, the published works of Chinese scholars have garnered a remarkable total of 7,713 citations; however, the average citations per article stand at only 17.37, placing China fourth among the top five countries in this regard. In contrast, Dutch scholars, despite publishing only five articles, achieved an average of 71.8 citations per article, ranking first for this metric. This result suggests that the literature produced by Dutch scholars is recognized for its authority and impact within the research community.

Table 3

Table 3. Top five countries by publication output in POCD basic research.

Analysis of the affiliations of authors in this field was performed, and Table 4 presents the top 10 organizations on the basis of publication output. Each of these institutions has published more than 15 articles, with the University of Virginia in the United States ranking first. Notably, nine of the top 10 institutions are located in China, highlighting the significant interest in this research area among Chinese scholars. Additionally, we utilized CiteSpace to analyze the collaboration networks of these publishing institutions, with the results displayed in Figure 5. In the figure, larger nodes represent a greater number of published papers, and the gradual color change of the nodes indicates the year of publication, spanning from 2014–2024, as reflected in the legend in the lower left corner. The University of Virginia is at the center of the largest institutional collaboration network, extending its connections to Fudan University, Peking University, Shanghai Jiao Tong University, and other Chinese institutions. Furthermore, China boasts the most extensive collaboration network, with Peking University, Shanghai Jiao Tong University, Fudan University, Nanchang University, and Capital Medical University each maintaining their collaborative links. Additionally, Duke University and Assistance Publique-Hôpitaux de Paris (APHP) also feature distinct collaboration networks.

Table 4

Table 4. Top 10 institutions by publication output in POCD basic research.

Figure 5

Figure 5. Cooperation network view of document publishing institutions.

3.3 Keyword information analysis

Keywords encapsulate the essence and themes of an article. The co-occurrence analysis of keywords can reveal hotspots within a research field. In this study VOSviewer was employed to analyze keywords from 479 published works with a focus on those that appeared 10 times or more. Since “postoperative cognitive dysfunction” as a keyword is inevitably the most frequently used keyword, “postoperative cognitive dysfunction” and some high-frequency synonyms were deleted in this analysis to avoid their impact on the statistical results. A total of 72 keywords were selected and the analysis results are shown in Figure 6A. The circular node represents keyword frequency. The larger the node is the more the keyword appears and the more it can represent hot spots in the field. The node connection represents the correlation strength. The thicker the connection is the more frequently keywords appear concurrently in a document. The node color represents different clusters that is the research topic. The red and blue clusters focus mainly on the risk factors and potential mechanisms of POCD, respectively, such as the role of some signaling molecules in POCD. The green cluster involves mainly the inducement of POCD and the research linking general anesthesia drugs (such as dexmedetomidine propofol and sevoflurane) and POCD. The yellow cluster focuses mainly on the research linking POCD and changes in the nervous system. The purple and gray clusters primarily investigate the common factors in basic research on POCD. Figure 6B shows the time distribution view of the basic research field on POCD. In the past decade basic research on POCD has focused on incentives and risk factors and has gradually transitioned to etiological research such as enhanced hippocampal neuroinflammation and synaptic plasticity damage and then to specific molecular mechanism research. The current research focuses on cell death and POCD. Figure 6C shows the density view. The brighter the color is the more frequently the keywords appear. The five most frequent keywords are “neuroinflammation,” “surgery,” “impairment,” “memory,” and “inflammation.”

Figure 6

Figure 6. (A) Co-occurrence network view of keywords, (B) time view; (C) density view; (D) top 10 keywords with explosive intensity.

The term explosive words refers to the phenomenon of a keyword frequently appearing in a specific period. This phenomenon can not only reflect the evolution of research hotspots over time but also the development of research trends in recent years and may indicate future research directions. Therefore, using the explosive word detection function of CiteSpace, we calculated the top 10 keywords with explosive intensity, which are shown in Figure 6D. Research has shown that elderly patients are at high-risk group for POCD, and old age is also the most common high-risk factor for POCD (Rundshagen, 2014). Elderly rats are often used as ideal models to study cognitive decline in elderly patients because of their similar performance to that of elderly humans in term of cognitive function, learning and memory ability, and physiological changes. Therefore, “aged rats” has become one of the keywords with the highest outbreak intensity. Between 2014 and 2016, “noncardiac surgery” and “nitrous oxide anesthesia” became two keywords associated with increased outbreak intensity. Since 2015, research on the relationship between general anesthesia and POCD has become mainstream (Zhang J. et al., 2015; Zhang Y. et al., 2015), especially between inhalation general anesthesia and POCD (Wang et al., 2018). The establishment of animal models under isoflurane anesthesia has been favored by relevant scholars (Tanino et al., 2016; Li et al., 2017). In recent years, research on the deep molecular mechanism of POCD has gradually increased, and research on the role of hippocampal receptor proteins and signaling pathways in POCD has also significantly increased (Li et al., 2022; Qiu et al., 2020). Moreover, “synaptic plasticity,” an important mechanism of POCD, has been explored by many scholars. Studies have shown that SIRT3 may alleviate POCD in elderly mice by alleviating synaptic plasticity damage and inhibiting hippocampal neuritis (Liu et al., 2021). In addition, a study by Wu et al. (2024) revealed that a decrease in SIRT1/BDNF levels in the hippocampal CA1 region led to the impairment of synaptic plasticity in elderly mice, which may be an important factor leading to POCD.

3.4 Analysis of co-citation

VOSviewer was used to analyze the co-cited journals in this research field. Table 5 shows the journals with the top 5 rates of co-citation. Each of the five journals had a co-citation count exceeding 400, and “Anesthesiology,” the top journal in the field of anesthesia, ranked first.

Table 5

Table 5. Top five journals most frequently co-cited in POCD basic research.

Figure 7 is a cluster view of 141 co-cited journals with 30 or more citations. Different color regions in the figure represent different clusters. The figure shows that the cited journals can be divided into four approximate clusters, with the red cluster being the largest. The journals cover a wide range of disciplines, including cell biology, molecular biology, neuroscience, and pharmacology. The main purpose of citing these journals is to provide theoretical support for research in multiple fields and disciplines. Green clusters comprise the second-largest cluster. Most of the journals included are high-quality and authoritative journals, including “Cell,” “Nature,” and “Science,” which are recognized as the three major journals in the global academic field, and the “New England Journal of Medicine” and “Lancet,” which are well known in the medical field. The purpose of quoting these journals is to reflect the most authoritative and advanced research directions. Blue and yellow clusters contain fewer journals. The blue cluster refers mainly to certain journals in the fields of anesthesia and neuromedicine, whereas the yellow cluster includes only includes “Journal of the American Medical Directors Association.”

Figure 7

Figure 7. Clustering network view of co-cited journals.

Figure 8 shows the clustering analysis of all co-cited literature by CiteSpace, where (A) is the clustering view of co-cited literature, (B) is the corresponding heatmap, and (C) is the timeline view of co-cited literature, in which the co-cited literature is divided into 11 clusters. “Microglial activation,” “mitochondria ROS generation,” the “endoplasmic reticulum stress pathway” and “suppressing neuroinflammation” are all related to the mechanisms of POCD. In Figure 8C, each circular node in the figure represents a reference, and the position of the node on the horizontal axis corresponds to the time at which the reference was first cited. The larger the node is, the more times the reference was co-cited. The node color represents the time at which the reference was cited. It corresponds to the legend in the lower left corner, while the cluster label on the right represents the subject of the field. “Microglial activation,” the “endoplasmic reticulum stress pathway,” and “cognitive deficit” were the first research hotspots, and “hippocampal CA1 region” and “pharmaceutical innovation” are the current research hotspots. In addition, according to Figure 8B, the “hippocampal CA1 region” is the cluster with the most references. The explosive analysis of cited references can reflect the importance of the literature and the time at which it is most popular. Figure 9 shows the top 15 references in terms of burst intensity. The popularly cited literature on basic research on POCD in the last 3 years is related mainly to research on the specific mechanisms of POCD, especially the role of neuroinflammation in POCD.

Figure 8

Figure 8. (A) Clustering information of co-cited literature; (B) clustering heat map; (C) timeline view of co-cited literature.

Figure 9

Figure 9. Co-cited references with burst intensity in the top 15.

Table 6 shows the top 10 co-cited references, and analyzes the sources, impact factors, research types, and research results of the references.

Table 6

Table 6. Top 10 most frequently co-cited references in POCD basic research.

4 Discussion

In recent years, with the progress of anesthesia/surgery concepts and technology, POCD has received increasing attention worldwide. At the same time, there is increasing research on POCD. POCD is a complication after anesthesia/surgery characterized by memory impairment, decreased information processing ability, and inattention (Lin et al., 2020). Currently, the identified risk factors for POCD include advanced age, low educational level, alcohol abuse, depression, type and duration of surgery, and anesthesia methods (Bhushan et al., 2021). The purpose of this study is to investigate the relevant literature on basic research on POCD published in the past decade; review the development trends of this research field; discuss and analyze the core authors in this research field, high- productivity countries, and institutions, key journals, high-frequency keywords, and co-citations; and provide a visual map. Through the bibliometric analysis of basic research on POCD, this study can provide researchers with a general understanding of POCD.

According to the analysis of the authors, journals, countries, and institutions in this research field, there are 105 core authors in total, and relatively stable author collaboration groups have formed. Professor Zuozhiyi, a professor in the Department of Anesthesiology at the University of Virginia, is the most prolific author. Among the top 10 journals with the largest number of articles, most belong to the field of neuroscience. “The Journal of Neuroscience” has the most papers published in this field, and its number of overall citations and number of citations per article are the highest. Chinese scholars have contributed the most papers, but their number of citations per article is very low, which demonstrates that Chinese scholars still need to improve the authority and recognition of the published literature. In terms of the number of citations per article, the literature published by Dutch scholars has the highest recognition and authority. Among the top 10 institutions with most publications, except for the University of Virginia, the other nine institutions are located in China. There have been many instances of collaboration between the issuing agencies in this research field, and a stable collaboration network has formed. China has the most extensive institutional collaboration network.

The analysis of high-frequency keywords identified, several stable research topics in this field; “neuroinflammation,” “surgery,” “impairment,” “memory,” and “inflammation” are the five keywords with the highest frequency. In recent years, many studies have shown that the enhancement of neuroinflammatory response may be an important potential mechanism of POCD, including the involvement of a variety of receptors and related signaling molecules. A study by Sun et al. (2022) and other scholars in 2021 revealed that electroacupuncture may alleviate the related neuroinflammatory response by inhibiting NLRP3 inflammatory bodies, thus improving POCD in elderly mice. Another recent study published in the “Journal of Neuroinflammation” reported that 4-octyl itaconate can limit neuroinflammation and promote neurogenesis by stabilizing the intestinal microbiota and activating Nrf2 signal transduction, thereby reducing POCD (Kong et al., 2024). In addition, since 2024, research on the relationship between pyroptosis and POCD has gradually increased and has become a hot spot in basic research on POCD. Shen et al. (2024) reported that the intraperitoneal injection of carnosine can inhibit NLRP3 mediated astrocyte apoptosis and neuroinflammation to improve POCD in elderly rats. In contrast, hippocampal histone deacetylase 6 (HDAC6) can induce microglial cell death by activating NLRP3 inflammatory bodies, hence contributing to POCD in elderly mice. In short, whether it is neuroinflammation or cell death, research on the specific molecular mechanisms of POCD has remained the focus of current research and is likely to continue, even in the future.

On the basis of the co-citation statistics for the basic research literature on POCD from the past decade, “Anesthesiology” is the most frequently cited journal; “Long-term postoperative cognitive dysfunction in the elderly ISPOCD1 study. ISPOCD investigators. International Study of Post-Operative Cognitive Dysfunction” published in “Lancet” is the most frequently cited reference; and “Lancet” (IF: 98.4) is also the most influential journal among all the co-cited journals. The cluster of the “hippocampal CA1 region” contains the most co-cited studies, such as the study “Activation of astrocyte GQ pathway in hippocampal CA1 region attenuates anesthesia/surgery induced cognitive dysfunction in aged mice” published by Wang et al. (2022) in “Frontiers in Aging Neuroscience,” which reveals that the activation of the GQ pathway in hippocampal CA1 region astrocytes can improve the learning and memory ability of POCD aged mice and synaptic plasticity. Notably, recent advances in basic research are increasingly driving clinical translation. For example, clinical studies have identified neuroinflammation-related biomarkers, such as CRP and IL-6, as potential indicators of POCD (Zhang J. et al., 2015; Zhang Y. et al., 2015). Additionally, elevated preoperative serum levels of phosphorylated neurofilament-H have been validated as a biomarker for POCD in elderly patients undergoing hip replacement surgery (Zhang et al., 2019). These findings offer novel insights for the clinical diagnosis and early intervention of POCD. Nevertheless, the sensitivity and specificity of current biomarkers remain suboptimal, underscoring the need for future studies to integrate multiomics approaches for the identification of reliable diagnostic markers for POCD.

From a bibliometric perspective identifying the relevant research context for basic research on POCD is highly valuable. For example, the analysis of high-frequency keywords in this paper can provide scholars with the focuses and hot spots in this research field and provide ideas for their research topics. The analysis of core authors and journals with a large number of publications provided in this paper can help scholars quickly find the literature they want to reference in research and provide some suggestions for scholars on selecting journals when creating papers on this topic.

In addition, this study has several limitations. First, this study selected only the Web of Science Core Collection (WOSCC) as the literature data source, and the citation index was Science Citation Index Expanded, excluding other databases (such as Scopus), which inevitably leads to the problem of incomplete data. Second, when analyzing and interpreting the data, researchers need to have a comprehensive and in-depth understanding of the field; otherwise, subjectivity inevitably arises. Research on basic research on POCD still has significance and value for further exploration. Therefore, in future research, it will be necessary to integrate the literature from multiple databases to make the selected literature more comprehensive. Furthermore, it is necessary to actively communicate with relevant scholars in the field, understand the frontier dynamics of the field, improve the objective cognition regarding the field, and form an objective and rational cognition concerning the field.

Data availability statement

The original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding authors.

Author contributions

HW: Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Writing – original draft, Writing – review & editing. JS: Conceptualization, Funding acquisition, Investigation, Resources, Supervision, Validation, Writing – review & editing. ZH: Conceptualization, Data curation, Investigation, Supervision, Validation, Writing – review & editing. HL: Data curation, Funding acquisition, Investigation, Resources, Supervision, Validation, Writing – review & editing. QZ: Data curation, Formal analysis, Investigation, Writing – review & editing. CD: Conceptualization, Data curation, Formal analysis, Methodology, Writing – original draft. YG: Formal analysis, Methodology, Writing – original draft. WM: Conceptualization, Data curation, Investigation, Software, Writing – original draft.

Funding

The author(s) declare that financial support was received for the research and/or publication of this article. This research was sponsored by the Natural Science Foundation of Chifeng, under Project Number: SZR24087.

Conflict of interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Generative AI statement

The authors declare that no Gen AI was used in the creation of this manuscript.

Publisher’s note

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.

References

Bhushan, S., Li, Y., Huang, X., Cheng, H., Gao, K., and Xiao, Z. (2021). Progress of research in postoperative cognitive dysfunction in cardiac surgery patients: a review article. Int. J. Surg. 95:106163. doi: 10.1016/j.ijsu.2021.106163

PubMed Abstract | Crossref Full Text | Google Scholar

Bowman, G. L., Dayon, L., Kirkland, R., Wojcik, J., Peyratout, G., Severin, I. C., et al. (2018). Blood-brain barrier breakdown, neuroinflammation, and cognitive decline in older adults. Alzheimers Dement. 14, 1640–1650. doi: 10.1016/j.jalz.2018.06.2857

PubMed Abstract | Crossref Full Text | Google Scholar

Campbell, E., and Figueiro, M. G. (2024). Postoperative cognitive dysfunction: spotlight on light, circadian rhythms, and sleep. Front. Neurosci. 18:1390216. doi: 10.3389/fnins.2024.1390216

PubMed Abstract | Crossref Full Text | Google Scholar

Cao, Y., Li, Z., Li, H., Ni, C., Li, L., Yang, N., et al. (2018). Hypoxia-inducible factor-1α is involved in isoflurane-induced blood-brain barrier disruption in aged rats model of POCD. Behav. Brain Res. 339, 39–46. doi: 10.1016/j.bbr.2017.09.004

PubMed Abstract | Crossref Full Text | Google Scholar

Cao, Y., Li, Z., Ma, L., Yang, N., and Guo, X. (2019). Isoflurane-induced postoperative neurovascular and cognitive dysfunction is associated with VEGF overexpression in aged rats. J. Mol. Neurosci. 69, 215–223. doi: 10.1007/s12031-019-01350-8

PubMed Abstract | Crossref Full Text | Google Scholar

Chen, C. M. (2006). CiteSpace II: detecting and visualizing emerging trends and transient patterns in scientific literature. J. Am. Soc. Inf. Sci. Technol. 57, 359–377. doi: 10.1002/asi.20317

Crossref Full Text | Google Scholar

Cibelli, M., Fidalgo, A. R., Terrando, N., Ma, D., Monaco, C., Feldmann, M., et al. (2010). Role of interleukin-1β in postoperative cognitive dysfunction. Ann. Neurol. 68, 360–368. doi: 10.1002/ana.22082

PubMed Abstract | Crossref Full Text | Google Scholar

de Solla Price, D. J., Merton, R. K., and Garfield, E. (1986). Little science, big science—and beyond. New York, NY: Columbia University Press.

Google Scholar

Ding, X., Gao, X., Wang, Z., Jiang, X., Lu, S., Xu, J., et al. (2021). Preoperative chronic and acute pain affects postoperative cognitive function mediated by neurotransmitters. J. Mol. Neurosci. 71, 515–526. doi: 10.1007/s12031-020-01673-x

PubMed Abstract | Crossref Full Text | Google Scholar

Ding, X., and Yang, Z. (2020). Knowledge mapping of platform research: a visual analysis using VOSviewer and CiteSpace. Electron. Commer. Res. 22, 787–809. doi: 10.1007/s10660-020-09410-7

PubMed Abstract | Crossref Full Text | Google Scholar

Evered, L., Silbert, B., Knopman, D. S., Scott, D. A., Dekosky, S. T., Rasmussen, L. S., et al. (2018). Recommendations for the nomenclature of cognitive change associated with anaesthesia and surgery-2018. Anesthesiology 129, 872–879. doi: 10.1097/ALN.0000000000002334

PubMed Abstract | Crossref Full Text | Google Scholar

Gao, S., Zhang, S., Zhou, H., Tao, X., Ni, Y., Pei, D., et al. (2021). Role of mTOR-regulated autophagy in synaptic plasticity related proteins downregulation and the reference memory deficits induced by anesthesia/surgery in aged mice. Front. Aging Neurosci. 13:628541. doi: 10.3389/fnagi.2021.628541

PubMed Abstract | Crossref Full Text | Google Scholar

Hovens, I. B., Schoemaker, R. G., van der Zee, E. A., Absalom, A. R., Heineman, E., and van Leeuwen, B. L. (2014). Postoperative cognitive dysfunction: involvement of neuroinflammation and neuronal functioning. Brain Behav. Immun. 38, 202–210. doi: 10.1016/j.bbi.2014.02.002

PubMed Abstract | Crossref Full Text | Google Scholar

Kong, X., Lyu, W., Lin, X., Lin, C., Feng, H., Xu, L., et al. (2024). Itaconate alleviates anesthesia/surgery-induced cognitive impairment by activating a Nrf2-dependent anti-neuroinflammation and neurogenesis via gut-brain axis. J. Neuroinflammation 21:104. doi: 10.1186/s12974-024-03103-w

PubMed Abstract | Crossref Full Text | Google Scholar

Li, C., Li, Q., Liu, S., Li, J., Yu, W., Li, Y., et al. (2022). sVCAM1 in the hippocampus contributes to postoperative cognitive dysfunction in mice by inducing microglial activation through the VLA-4 receptor. Mol. Neurobiol. 59, 5485–5503. doi: 10.1007/s12035-022-02924-1

PubMed Abstract | Crossref Full Text | Google Scholar

Li, Z., Ni, C., Xia, C., Jaw, J., Wang, Y., Cao, Y., et al. (2017). Calcineurin/nuclear factor-κB signaling mediates isoflurane-induced hippocampal neuroinflammation and subsequent cognitive impairment in aged rats. Mol. Med. Rep. 15, 201–209. doi: 10.3892/mmr.2016.5967

PubMed Abstract | Crossref Full Text | Google Scholar

Lin, X., Chen, Y., Zhang, P., Chen, G., Zhou, Y., and Yu, X. (2020). The potential mechanism of postoperative cognitive dysfunction in older people. Exp. Gerontol. 130:110791. doi: 10.1016/j.exger.2019.110791

PubMed Abstract | Crossref Full Text | Google Scholar

Liu, Q., Sun, Y. M., Huang, H., Chen, C., Wan, J., Ma, L. H., et al. (2021). Sirtuin 3 protects against anesthesia/surgery-induced cognitive decline in aged mice by suppressing hippocampal neuroinflammation. J. Neuroinflammation 18:41. doi: 10.1186/s12974-021-02089-z

PubMed Abstract | Crossref Full Text | Google Scholar

Moller, J. T., Cluitmans, P., Rasmussen, L. S., Houx, P., Rasmussen, H., Canet, J., et al. (1998). Long-term postoperative cognitive dysfunction in the elderly ISPOCD1 study. ISPOCD investigators. International Study of Post-Operative Cognitive Dysfunction. Lancet 351, 857–861. doi: 10.1016/S0140-6736(97)07382-0

PubMed Abstract | Crossref Full Text | Google Scholar

Monk, T. G., Weldon, B. C., Garvan, C. W., Dede, D. E., van der Aa, M. T., Heilman, K. M., et al. (2008). Predictors of cognitive dysfunction after major noncardiac surgery. Anesthesiology 108, 18–30. doi: 10.1097/01.anes.0000296071.19434.1e

PubMed Abstract | Crossref Full Text | Google Scholar

Needham, M. J., Webb, C. E., and Bryden, D. C. (2017). Postoperative cognitive dysfunction and dementia: what we need to know and do. Br. J. Anaesth. 119, i115–i125. doi: 10.1093/bja/aex354

PubMed Abstract | Crossref Full Text | Google Scholar

Ni, C., Li, Z., Qian, M., Zhou, Y., Wang, J., and Guo, X. (2015). Isoflurane induced cognitive impairment in aged rats through hippocampal calcineurin/NFAT signaling. Biochem. Biophys. Res. Commun. 460, 889–895. doi: 10.1016/j.bbrc.2015.03.083

PubMed Abstract | Crossref Full Text | Google Scholar

Ninkov, A., Frank, J. R., and Maggio, L. A. (2022). Bibliometrics: methods for studying academic publishing. Perspect. Med. Educ. 11, 173–176. doi: 10.1007/s40037-021-00695-4

PubMed Abstract | Crossref Full Text | Google Scholar

Qiu, L. L., Pan, W., Luo, D., Zhang, G. F., Zhou, Z. Q., Sun, X. Y., et al. (2020). Dysregulation of BDNF/TrkB signaling mediated by NMDAR/Ca²⁺/calpain might contribute to postoperative cognitive dysfunction in aging mice. J. Neuroinflammation 17:23. doi: 10.1186/s12974-019-1695-x

PubMed Abstract | Crossref Full Text | Google Scholar

Rosczyk, H. A., Sparkman, N. L., and Johnson, R. W. (2008). Neuroinflammation and cognitive function in aged mice following minor surgery. Exp. Gerontol. 43, 840–846. doi: 10.1016/j.exger.2008.06.004

PubMed Abstract | Crossref Full Text | Google Scholar

Rundshagen, I. (2014). Postoperative cognitive dysfunction. Dtsch. Arztebl. Int. 111, 119–125. doi: 10.3238/arztebl.2014.0119

PubMed Abstract | Crossref Full Text | Google Scholar

Shen, J., Xu, J., Wen, Y., Tang, Z., Li, J., and Sun, J. (2024). Carnosine ameliorates postoperative cognitive dysfunction of aged rats by limiting astrocytes pyroptosis. Neurotherapeutics 21:e00359. doi: 10.1016/j.neurot.2024.e00359

PubMed Abstract | Crossref Full Text | Google Scholar

Steinmetz, J., Christensen, K. B., Lund, T., Lohse, N., and Rasmussen, L. S. (2009). Long-term consequences of postoperative cognitive dysfunction. Anesthesiology 110, 548–555. doi: 10.1097/ALN.0b013e318195b569

PubMed Abstract | Crossref Full Text | Google Scholar

Sun, L., Yong, Y., Wei, P., Wang, Y., Li, H., Zhou, Y., et al. (2022). Electroacupuncture ameliorates postoperative cognitive dysfunction and associated neuroinflammation via NLRP3 signal inhibition in aged mice. CNS Neurosci. Ther. 28, 390–400. doi: 10.1111/cns.13784

PubMed Abstract | Crossref Full Text | Google Scholar

Tanino, M., Kobayashi, M., Sasaki, T., Takata, K., Takeda, Y., Mizobuchi, S., et al. (2016). Isoflurane induces transient impairment of retention of spatial working memory in rats. Acta Med. Okayama 70, 455–460. doi: 10.18926/AMO/54808

Crossref Full Text | Google Scholar

Terrando, N., Eriksson, L. I., Ryu, J. K., Yang, T., Monaco, C., Feldmann, M., et al. (2011). Resolving postoperative neuroinflammation and cognitive decline. Ann. Neurol. 70, 986–995. doi: 10.1002/ana.22664

PubMed Abstract | Crossref Full Text | Google Scholar

Terrando, N., Monaco, C., Ma, D., Foxwell, B. M. J., Feldmann, M., and Maze, M. (2010). Tumor necrosis factor-alpha triggers a cytokine cascade yielding postoperative cognitive decline. Proc. Natl. Acad. Sci. U.S.A. 107, 20518–20522. doi: 10.1073/pnas.1014557107

PubMed Abstract | Crossref Full Text | Google Scholar

Thelwall, M. (2008). Bibliometrics to webometrics. J. Inf. Sci. 34, 605–621. doi: 10.1177/0165551507087238

Crossref Full Text | Google Scholar

van Eck, N. J., and Waltman, L. (2010). Software survey: VOSviewer, a computer program for bibliometric mapping. Scientometrics 84, 523–538. doi: 10.1007/s11192-009-0146-3

PubMed Abstract | Crossref Full Text | Google Scholar

Vorhees, C. V., and Williams, M. T. (2006). Morris water maze: procedures for assessing spatial and related forms of learning and memory. Nat. Protoc. 1, 848–858. doi: 10.1038/nprot.2006.116

PubMed Abstract | Crossref Full Text | Google Scholar

Wan, Y., Xu, J., Ma, D., Zeng, Y., Cibelli, M., and Maze, M. (2007). Postoperative impairment of cognitive function in rats: a possible role for cytokine-mediated inflammation in the hippocampus. Anesthesiology 106, 436–443. doi: 10.1097/00000542-200703000-00007

Crossref Full Text | Google Scholar

Wang, X., Li, Y., Zhao, J., Yu, J., Zhang, Q., Xu, F., et al. (2022). Activation of astrocyte Gq pathway in hippocampal CA1 region attenuates anesthesia/surgery induced cognitive dysfunction in aged mice. Front. Aging Neurosci. 14:1040569. doi: 10.3389/fnagi.2022.1040569

PubMed Abstract | Crossref Full Text | Google Scholar

Wang, B., Zhu, C., Zhang, N., Li, L., Sun, L., and Xu, J. (2018). Nampt/RelB pathway protects learning and memory ability in aged rats after general anesthesia with sevoflurane and nitrous oxide. Int. J. Clin. Exp. Pathol. 11, 293–303

PubMed Abstract | Google Scholar

Wei, X., Xing, F., Xu, Y., Zhang, F., Cheng, D., Zhou, Y., et al. (2024). Preoperative gut microbiota of POCD patients induces pre- and postoperative cognitive impairment and systemic inflammation in rats. J. Neuroinflammation 21:221. doi: 10.1186/s12974-024-03220-6

PubMed Abstract | Crossref Full Text | Google Scholar

Wu, W. F., Chen, C., Lin, J. T., Jiao, X. H., Dong, W., Wan, J., et al. (2024). Impaired synaptic plasticity and decreased glutamatergic neuron excitability induced by SIRT1/BDNF downregulation in the hippocampal CA1 region are involved in postoperative cognitive dysfunction. Cell. Mol. Biol. Lett. 29:79. doi: 10.1186/s11658-024-00595-5

PubMed Abstract | Crossref Full Text | Google Scholar

Yang, Y., Liu, Y., Zhu, J., Song, S., Huang, Y., Zhang, W., et al. (2022). Neuroinflammation-mediated mitochondrial dysregulation involved in postoperative cognitive dysfunction. Free Radic. Biol. Med. 178, 134–146. doi: 10.1016/j.freeradbiomed.2021.12.004

PubMed Abstract | Crossref Full Text | Google Scholar

Yuan, N., Wang, X., Zhang, Y., Kong, L., Yuan, L., and Ge, Y. (2022). Intervention of Nf-Κb signaling pathway and preventing post-operative cognitive dysfunction as well as neuronal apoptosis. Iran. J. Public Health 51, 124–132. doi: 10.18502/ijph.v51i1.8303

PubMed Abstract | Crossref Full Text | Google Scholar

Zhang, Y., Guo, X., Zhang, Q., Yan, G., and Wang, T. (2015). Serum CRP and urinary trypsin inhibitor implicate postoperative cognitive dysfunction especially in elderly patients. Int. J. Neurosci. 125, 501–506. doi: 10.3109/00207454.2014.949341

PubMed Abstract | Crossref Full Text | Google Scholar

Zhang, J., Tan, H., Jiang, W., and Zuo, Z. (2015). The choice of general anesthetics may not affect neuroinflammation and impairment of learning and memory after surgery in elderly rats. J. Neuroimmune Pharmacol. 10, 179–189. doi: 10.1007/s11481-014-9580-y

PubMed Abstract | Crossref Full Text | Google Scholar

Zhang, H., Zheng, J., Wang, R., Wu, G., and Chen, J. (2019). Serum phosphorylated neurofilament heavy subunit-H, a potential predictive biomarker for postoperative cognitive dysfunction in elderly subjects undergoing hip joint arthroplasty. J. Arthroplast. 34, 1602–1605. doi: 10.1016/j.arth.2019.03.073

PubMed Abstract | Crossref Full Text | Google Scholar