This bibliometric study was conducted to identify and analyze the 100 most-cited papers in the field of neurosurgery. Initially, 17 neurosurgical journals were identified through a systematic search of the “Journal Citation Reports” database, using the keywords "neurosurgery" and "neurosurgical" in the journal titles. Additionally, three highly regarded neurosurgical journals, “Surgical Neurology” and “Acta Neurochirurgica”, which were not captured by the keyword search, were manually included in the analysis (Table 1). A citation search was then performed using the Thomson Reuters “Web of Science” (WoS) database for each identified journal, filtering the results by the "Publication Name" field. The search results were subsequently sorted by the “Times Cited” category to prioritize the most frequently referenced articles. To examine trends and shifts in global neurosurgical research over time, we conducted a comparative bibliometric analysis across two distinct decades: 2001–2011 (Group 2) and 2012–2022 (Group 1). The search for Group 2 was restricted to articles published between January 1, 2001, and December 31, 2011, while Group 1 included articles published from January 1, 2012, to December 31, 2022. Articles published in the “Journal of Neurology, Neurosurgery and Psychiatry” (JNNP) that focused exclusively on neurology or psychiatry were excluded from the study to maintain the focus on neurosurgical research. Two authors (RGA and ACPB) independently reviewed and screened the articles to identify the top 100 most frequently cited research papers. In cases of disagreement, the differences were resolved through discussion, with a third author (ARH) serving as an arbiter when necessary. The final set of 100 top-cited neurosurgical articles from each decade was then subjected to further in-depth analysis, including assessments of publication trends, geographic distribution, institutional contributions, and thematic areas of research.

Following the approval of the final list of the 100 most-cited articles, detailed information was collected for each paper. The collected data included: the article title, the total number of citations recorded in the “Web of Science” (WoS), average citations per year, and the names of the first author, corresponding author, and senior author (defined as the last author listed). Additionally, the origin of each paper was determined based on the corresponding author’s country or region and institutional affiliation. Further data points included the type of article (e.g., original research, review, case report), the primary citation topic, the relevant subspecialty or thematic field, the journal in which the article was published, and the journal's impact factor, as reported in the 2021 “Journal Citation Reports”. In cases where an article had multiple corresponding authors, affiliations, or categories, the first-listed entry was used for analysis.

To characterize the articles and journals included in the study, a descriptive statistical analysis was conducted, utilizing frequencies and percentages to summarize categorical data. Statistical significance was defined as a P < 0.05 (two-tailed). All statistical analyses were performed using Stata Statistical Software version 14.2 (StataCorp LLC, College Station, TX, USA), ensuring rigorous data processing and interpretation.

For the group of articles published between 2001 and 2011, the top 100 cited papers accumulated a total of 37,894 citations, with a median citation count of 379, ranging from 1,001 to 279. In contrast, for the group published between 2012 and 2022, the top 100 cited articles garnered a total of 24,710 citations, with a median citation count of 247, ranging from 1,544 to 152.

In the first group (2001–2011), the paper with the highest number of citations (1,001) was published in the Journal of Neurosurgery.4 This study aimed to evaluate the significance of the extent of resection in patients with newly diagnosed glioblastoma multiforme (GBM) within the context of modern neurosurgical practices. For the second group (2012–2022), the most frequently cited paper, published in Neurosurgery, received 1,544 citations.3 This paper focused on synthesizing the available evidence for the management of severe traumatic brain injury. In the earlier decade, the top 100 articles were cited on average 37 times per year, with individual articles receiving between 15 and 308 citations annually. In the more recent decade, the 100 most-cited articles were referenced an average of 40 times per year, with citations ranging from 14 to 91 per year.

The top 100 papers from each group were published across eight different journals, as summarized in Table 2. Notably, seven of the eight journals hosting the most-cited articles were the same across both groups. In group 2 (the earlier decade, 2001–2011), the Journal of Neurosurgery: Pediatrics was the unique inclusion, while in group 1 (the recent decade, 2012–2022), Neurosurgery Clinics of North America replaced it as one of the journals featuring articles within the top 100.

The impact factor of the journals publishing the top 100 papers from each group ranged from 1.885 to 5.526. The Journal of Neurosurgery and Neurosurgery represented the two largest clusters of referenced papers. In the second group (2001–2011), the Journal of Neurosurgery accounted for the highest number of citations, with 10,035 citations across 39 articles. In contrast, in the first group (2012–2022), Neurosurgery had the highest number of references, amassing 17,968 citations from 45 articles. During this recent 10-year period, the majority of highly cited papers were published in 2012 and 2013 (n = 23; 5,070 citations in 2012, n = 23; 5,425 citations in 2013). In the preceding decade, 2008 saw the largest number of highly cited papers (n = 17; 7,176 citations) (Table 3).

Interestingly, while the top 100 most-cited publications from group 2 (2001–2011) originated from eight different countries or regions (Table 4a), the most recent decade's top papers were distributed across 18 countries or regions (Table 4b). The four most productive regions across both decades were the USA (n = 75 for group 2; n = 83 for group 1), Europe (n = 38 for group 2; n = 52 for group 1), Canada (n = 12 for group 2; n = 13 for group 1), and Australia (n = 3 for group 2; n = 4 for group 1). Notably, India contributed two papers to the top 100 in the second group, while Colombia ranked fifth in the first group with three papers. The remaining regions contributed no more than two publications to the top 100 in either decade.

Mitchel S. Berger was the only author to contribute to the 100 most-cited publications across both decades under investigation, with five publications in the earlier decade (2001–2011) and four in the more recent decade (2012–2022). In terms of institutional contribution, a total of seven institutions, six of them from the USA, contributed more than five publications each to the top 100 most-cited list in the first group (2012–2022). In contrast, 22 institutions, of which 21 were also from the USA, contributed more than five works in the earlier decade (2001–2011) (Table 5). Overall, the University of California emerged as the most productive institution, with 18 publications in the second group and 28 publications in the first group. Regarding funding, the National Institutes of Health (NIH) in the USA was identified as the most significant funding agency, supporting 13 studies in the second group and 18 studies in the first group. Additionally, the US Department of Health and Human Services (DHHS) also contributed substantially, funding 13 studies in the earlier cohort and 18 studies in the most recent cohort (Table 6).

The distribution of study types was comparable across both decades under investigation. In the 2001–2011 group (referred to as Group 2), there were 88 original articles, 18 review articles, 5 proceeding papers, 1 editorial, and 1 reprint article. Similarly, in the 2012–2022 group (Group 1), there were 80 original articles, 10 reviews, 1 editorial, 1 letter, and 1 proceeding paper. Notably, original articles received significantly more citations than reviews in both decades, with 33,239 citations for original articles in Group 2 and 20,334 citations in Group 1. Reviews, in contrast, accumulated 4,920 citations in the earlier decade and substantially fewer citations in the most recent decade.

In terms of subspecialty focus, the articles were categorized into trauma, tumors, cerebrovascular pathology, functional neurosurgery, CSF pathology, and infectious disorders (Table 7). Tumor-related research consistently dominated both decades, comprising the largest number of top 100 cited articles: 35 in Group 2 and 30 in Group 1. Glioblastoma research accounted for a significant proportion of these articles, with 14 papers in Group 2 and 15 papers in Group 1, indicating a continued focus on this aggressive tumor. Acromegaly was another prominent topic, with 11 papers in Group 2 and 5 in Group 1. Both groups also featured three articles each on vestibular schwannoma. Additionally, in the more recent decade (Group 1), meningioma research emerged as a notable topic with four articles, while two papers focused on the PD-1 protein, reflecting increasing attention toward immunological targets in oncology.

In Group 2 (2001–2011), cerebrovascular disease was well-represented, with 19 articles among the top 100 most-cited. Of these, 10 studies focused on subarachnoid hemorrhage, 5 on arteriovenous malformation, 3 on stroke, 2 on moyamoya disease, and 1 on mesenchymal stem cells. In contrast, in the most recent decade (Group 1, 2012–2022), only 10 articles on cerebrovascular disease were included. Among these, 6 investigated subarachnoid hemorrhage, 3 addressed arteriovenous malformation, and 1 article focused on carotid endarterectomy. Regarding trauma research, Group 2 contained 19 articles, all of which focused on traumatic brain injury (TBI), underlining the centrality of TBI research during that period. In Group 1, trauma research decreased slightly, with 14 articles, 10 of which addressed TBI. The remaining 4 articles explored other trauma-related topics, including 2 studies on subdural hematoma, 1 on exosomes, and 1 on long non-coding RNA, indicating a diversification of trauma research topics in the past decade. Functional neurosurgery, an evolving field, had a similar number of top-cited articles across both decades, with 10 articles in Group 2 and 11 articles in Group 1. In Group 2, functional neurosurgery topics included neuropathic pain (n = 4), deep brain stimulation (DBS) (n = 2), and obsessive-compulsive disorder (OCD) or conversion disorder (n = 2). Additionally, single articles focused on epilepsy surgery, High-Intensity Focused Ultrasound (HIFU), nerve growth factor, and functional connectivity. In Group 1, the distribution shifted slightly, with 4 articles focusing on DBS, 3 on epilepsy surgery, and 2 on neuropathic pain. OCD and HIFU were represented by 1 article each.

Our research examined 17 neurosurgical journals, revealing that a significant concentration of the top 100 most-cited manuscripts were clustered within just eight of them. Notably, the Journal of Neurosurgery and Neurosurgery emerged as the two leading publications, consistently attracting the highest impact research. Our data suggest that neurosurgeons globally tend to prefer these prestigious journals both for submitting their most influential work and for sourcing references for their own publications.6 This pattern in neurosurgical bibliometrics may align with Bradford's Law, a concept proposed by Brookes,7 which posits that most researchers tend to concentrate their citations within a small set of core publications. Researchers may also exhibit a form of loyalty to these specific journals, as diverging from these high-impact outlets often results in diminished visibility and lower citation counts for their papers. This trend highlights the critical role of these core journals in shaping the dissemination and reception of neurosurgical research, and further underscores the potential challenges faced by newer or less established journals in achieving similar levels of impact.

Based on the distribution of papers in the top 100 most-cited articles for each decade, the highest scientific productivity was observed in 2008 for the second group (2001–2011) and in 2012 and 2013 for the first group (2012–2022). The reasons behind these peaks in productivity remain unclear, but they likely reflect a combination of factors such as advancements in research methodologies, increased collaboration, and a growing interest in particular topics during those periods. In contrast, 2020 and 2021 saw the lowest number of impactful publications, with no articles from these years making it into the top 100. While the shorter timeframe for recent articles to accumulate citations may partly explain this, the profound impact of the COVID-19 pandemic on global health systems and academic productivity is also a likely contributing factor. The pandemic disrupted research activities, reallocated resources, and shifted priorities toward urgent COVID-related studies, which may have led to a temporary decline in neurosurgical research output and its subsequent citation impact. This trend highlights the broader effects of global crises on scientific productivity and the delayed influence they can have on scholarly recognition.8

In terms of publication origin, the United States remained the dominant country across both decades studied. The University of California, San Francisco (UCSF), emerged as the leading institution, contributing the highest number of top-cited papers in both periods. Among individual authors, Mitchel S. Berger stood out as the most productive, with a substantial influence on the field. The continued dominance of the U.S. in neurosurgical research can likely be attributed to significant government and private investment in science and technology. For example, in 2015 alone, the U.S. spent approximately $500 billion on research and development, surpassing other nations in terms of budget and funding allocation. This consistent investment in R&D, coupled with well-established research infrastructures and collaborations between academia and industry, has helped maintain the U.S.'s position as a global leader in scientific output. Additionally, American institutions and researchers benefit from access to cutting-edge technologies, vast research networks, and high levels of publication support, all of which contribute to the high visibility and readership of U.S.-based studies. As a result, neurosurgical research from the U.S. continues to appear frequently in high-impact journals and garners widespread attention from the global scientific community.9

However, it is interesting to observe that the dominance of the United States in neurosurgical research has diminished somewhat in recent years, with an increasing number of highly cited papers now originating from Europe and Asia. This shift reflects the growing contribution of these regions to the global scientific community. Particularly noteworthy is the 'democratization' of the top 100 most-cited papers during the most recent decade, with a broader diversity of countries represented. This suggests a significant expansion of international influence in the field. One likely explanation for this trend is the substantial increase in multicenter studies, which have played a pivotal role in fostering international collaboration and the globalization of knowledge within neurosurgery. These collaborative efforts often bring together researchers from diverse geographical and institutional backgrounds, pooling expertise and resources to address complex scientific questions more effectively. Additionally, the growing interest in and investment in scientific research across the globe—particularly in Europe and Asia—has contributed to these changes. Countries that were traditionally underrepresented in neurosurgical research are now making significant strides in both the quality and quantity of their scientific output. This growing international participation not only enriches the field by incorporating a wider range of perspectives and approaches but also highlights the increasing recognition of the importance of neurosurgical research worldwide. These developments warrant continued observation, as they may signal lasting shifts in the global landscape of neurosurgical research and influence.10,11

Although cerebrovascular neurosurgery has historically been overrepresented as the most frequently referenced topic among the 100 most-cited articles,5 the past two decades have seen a notable shift in this trend. Neuro-oncology has now emerged as the subspecialty with the greatest number of top-cited publications. One possible reason for this change is that earlier neuro-oncology research was often focused on laboratory-based studies, which tended to be published in basic science or non-neurosurgical journals. These studies, while important, were not as commonly cited within neurosurgical circles. In contrast, recent neuro-oncology research has increasingly concentrated on clinical applications, particularly the management of high-grade gliomas and surgical approaches aimed at maximizing tumor resection. These topics are directly relevant to neurosurgical practice and are therefore more likely to be published in neurosurgical journals. This shift in focus has likely contributed to the rise in high-impact neuro-oncology publications within neurosurgical literature, as clinicians seek to address the complex challenges posed by brain tumors and improve patient outcomes. Moreover, the growing interest in advanced surgical techniques, intraoperative imaging, and the integration of molecular genetics in neuro-oncology has further fueled the production of highly cited papers. These developments have not only advanced the field of neuro-oncology but also made it a central focus of modern neurosurgical research, leading to a greater representation of neuro-oncology in the top 100 cited articles. This trend reflects a broader evolution in neurosurgery, where subspecialties with high clinical relevance and rapidly advancing technologies, such as neuro-oncology, are increasingly at the forefront of academic discourse."

The spine subspecialty now ranks second in the top 100 most-cited publications of the recent decade, a remarkable rise considering that spine-related research was largely anecdotal before the 1980s. Over the past few decades, there has been a substantial increase in neurosurgical interest in spine studies, with several spine-related articles now among the most frequently cited in the field. This growing focus reflects the increasing recognition of the spine as a critical area of neurosurgical practice, accounting for a significant portion of clinical work in both academic and private settings. One factor contributing to this trend is the rise of private funding agencies, which have likely provided additional resources for spine research. These agencies have played a pivotal role in supporting the development of new technologies and innovative surgical techniques for spine care, such as minimally invasive procedures, spinal instrumentation, and motion-preserving surgeries. The influx of private funding has allowed for larger-scale studies and more robust clinical trials, helping spine research to grow both in volume and quality. Additionally, the increasing prevalence of degenerative spinal diseases, trauma, and spinal deformities in aging populations worldwide has further driven the demand for advancements in spine surgery. This has led to a surge in high-impact research, aimed at improving patient outcomes, reducing complications, and enhancing recovery times. As a result, spine-related studies have not only gained more visibility in neurosurgical journals but have also become a central focus of neurosurgical practice. The continued growth in this subspecialty indicates a positive trend for the future of neurosurgical research, with spine surgery poised to remain a major contributor to the field’s evolving landscape.12,13

Trauma ranked third in the top 100 most-cited publications, with the subspecialties of head trauma and spinal cord injury drawing significant interest in scientific journals over the years. Historically, trauma research has been a critical area of focus, given its profound impact on neurosurgical practice and the high incidence of traumatic brain and spinal injuries globally. However, in the most recent decade, the popularity of trauma-related research appears to have declined, with fewer top-cited articles emerging compared to previous years. One reason for this shift may be the increasing specialization of trauma research, with much of the work now focusing on basic sciences, such as neuroprotection, neuroregeneration, and molecular pathways related to injury and recovery. As a result, many of these studies are being published in journals dedicated to basic science or specific subspecialties, rather than in general neurosurgical journals. This trend reflects a broader shift toward more niche, highly specialized research in trauma, where clinical studies may no longer dominate the field as they once did. In addition, advances in acute trauma care, improved imaging techniques, and standardized protocols may have contributed to a perceived plateau in major breakthroughs in trauma management, leading researchers to explore more focused, underlying biological mechanisms of injury and recovery. While trauma remains a crucial aspect of neurosurgery, the evolving direction of research suggests that the field is becoming more interdisciplinary, with collaboration between neurosurgeons, neuroscientists, and rehabilitation experts playing an increasing role. This transition may help drive future innovations, even if it results in fewer high-impact clinical trauma papers in the immediate term.14,15

Functional neurosurgery, despite fluctuating levels of interest over the years, has gained increased recognition in recent times due to significant technological advancements, such as deep brain stimulation and neuromodulation techniques. However, these innovations have not yet translated into a major influence on the most-cited articles in the broader field of neurosurgery.16 One possible explanation for this is the preference for publishing functional neurosurgery research in highly specialized subspecialty journals, which may limit its presence in general neurosurgical citation rankings. The niche focus of functional neurosurgery, despite its clinical importance, may also contribute to its underrepresentation in top-cited literature. Similarly, research on cerebrospinal fluid (CSF) dynamics and hydrocephalus is underrepresented among the top 100 most-cited articles. This may be attributed to the fact that much of the work in this area is concentrated in pediatric neurosurgery, where CSF-related issues, such as hydrocephalus, are a central part of the practice and research focus. As a result, many key studies in this field are published in journals specifically dedicated to pediatric neurosurgery, where they represent a significant portion of the surgical knowledge base. Additionally, the specialized nature of hydrocephalus research and the prevalence of this condition in pediatric populations likely contribute to its limited presence in top-cited neurosurgical articles that often encompass a broader scope of topics. Despite their underrepresentation in citation metrics, both functional neurosurgery and CSF dynamics remain critically important areas of study, with significant clinical implications. Their continued development, driven by technological innovations and specialized research, will likely play an essential role in the future of neurosurgical practice, even if their influence is not immediately reflected in general citation rankings.

Several limitations regarding our methodology should be acknowledged. First, our study focused exclusively on neurosurgical journals, meaning that highly cited investigations led by neurosurgeons but published in non-neurosurgical journals, such as general medical, oncology, or radiology journals, were not included. As a result, significant contributions to neurosurgery from interdisciplinary research might have been overlooked. Furthermore, our analysis only included journals with the highest impact factor within the neurosurgical field, potentially excluding influential journals that are dedicated to specific areas or subspecialties, such as functional neurosurgery, spine surgery, or pediatric neurosurgery. The emergence and development of specialized journals in niche fields of neurosurgery is likely to alter the landscape of top-cited articles in the coming years. As these subspecialty journals gain prominence, future top 100 rankings may shift, making it increasingly difficult to capture the full breadth of impactful research by focusing solely on high-impact, general neurosurgical journals. Evaluating these broader journals alone may no longer be sufficient to fully understand evolving research trends within the field of neurosurgery. Lastly, our citation analysis was limited to data from the Web of Science, excluding other important databases such as Google Scholar and Scopus. These platforms index a broader range of journals and articles, and their inclusion could reveal additional influential papers that were not captured in our study. As a result, some citations may have been missed, potentially affecting the accuracy of the rankings. Future research should consider incorporating multiple databases to provide a more comprehensive overview of the citation landscape in neurosurgery.

The timeframe selected for our investigation also presents a significant limitation concerning the number of citations each article has accumulated. This limitation affects both recent and older papers, though in different ways. For more recent articles, their lower citation counts may not accurately reflect their true impact, as they have had less time to accumulate citations. These newer publications may take several years before their full influence on the field is realized, potentially skewing their position in the current rankings. Conversely, older papers face their own challenges. While they had ample time to accrue citations, some may have been overlooked in more recent literature due to a phenomenon known as 'obliteration by incorporation.17 This concept, coined by historian Robert K. Merton, refers to the tendency for foundational ideas to become so widely accepted and integrated into common knowledge that they are no longer cited. As a result, despite having a lasting influence on the field, these seminal works may no longer appear frequently in citation databases, causing them to drop out of citation-based rankings. Therefore, the citation counts of both newer and older publications may not always correspond to their actual long-term impact on neurosurgery. Newer papers may rise in future rankings as their influence grows, while older studies may remain underrepresented, even if their concepts have been fundamental in shaping current practices. This temporal bias is a key limitation of any citation analysis and should be considered when interpreting our findings. Future studies could address this issue by incorporating more sophisticated metrics, such as citation trajectories or alternative indicators of long-term impact.

Finally, it is important for the reader to recognize the inherent limitations of using citation analysis as a measure of the impact or quality of journal articles. While citation counts can provide some insight into how widely a work is referenced within the academic community, they do not necessarily reflect the true significance, innovation, or practical relevance of the research. Many factors, such as the visibility of the journal, the size of the research community, and the trending nature of certain topics, can disproportionately influence citation metrics. As a result, the relationship between citation frequency and the actual scholarly or societal impact of an article or journal is still a matter of considerable debate within the academic world.18