Spinocerebellar ataxias (SCAs) are a genetically heterogeneous group of autosomal dominantly inherited progressive neurodegenerative disorders (1). They are relatively rare and primarily affect adults, with a global estimated prevalence of <5.6 cases per 100,000 people, and an average of 3 cases per 100,000. Currently, more than 40 subtypes are known (2), with is spinocerebellar ataxia type 3 (SCA3) being the most common (3). The core symptoms of SCAs include gait ataxia, oculomotor disturbances, and dysarthria (4, 5). Currently, patients with SCA can be diagnosed through characteristic genetic testing (6).

Consistent with other neurodegenerative diseases, the clinical evaluation scale score is the most widely used outcome measure in clinical studies of SCA. Ataxia scales were mainly developed to quantify the impact of a known disease on each patient, enabling comparisons with other patients who have the same disorder (7). Among these scales, the Scale for the Assessment and Rating of Ataxia (SARA) and the Cooperative Ataxia Rating Scale (ICARS) are currently the most widely used and effective indices because of their sensitivity to changes and effortless operation (8). However, both SARA and ICARS have certain limitations. They have floor and ceiling effects, making them not very effective when the symptoms are either very mild or very severe. Above all, these scoring scales are inherently subjective (9) and often need to be supplemented with more reliable evaluation indicators.

At present, the use of magnetic resonance imaging (MRI) technology to explore the pathogenesis and potential biomarkers of SCA is gaining increasing attention (10). Structural or functional abnormalities of the brain tissue can be observed by different MRI techniques, including morphometric magnetic resonance imaging (MMRI), diffusion tensor imaging (DTI), blood oxygen level-dependent functional MRI (BOLD fMRI), and magnetic resonance spectroscopy (MRS) (11). Many related studies have revealed that there is a strong correlation between the MRI and scale results for SCA diagnosis and follow-up (12–14). However, there is a lack of summary and evaluation of the literature characteristics, research directions, and research hotspots related to the use of MRI in clinical cases of SCAs.

Bibliometrics is a quantitative statistical analysis tool that measures the influence and impact of research articles (15), and it is largely dependent on visualizing processing tools such as CiteSpace (16, 17). CiteSpace is a software package known to be a visual analytical tool for identifying the landscape, pattern, and emerging trends in a field of research or any knowledge domain based on selected literature databases, such as Web of Science (WoS) and Scopus (18, 19).

In this study, we conducted a bibliometric analysis of scientific articles published between 2009 and 2025 that focus on the use of MRI to study SCA. This analysis aims to outline the current research landscape, future research trends, and hotspots in this field.

To the best of our knowledge, this research marks the first instance in which we have used CiteSpace software to conduct a bibliometrics analysis of original research articles and reviews related to the use of MRI in SCA. This analysis spans from January 2009 to March 2023, utilizing data from the Web of Science database. Bibliometric analyses have become a powerful tool for summarizing the current state of knowledge of a certain research topic (27) as they present visual maps to display the current research overview more intuitively, and, to some extent, indicate future development trends. After excluding studies that did not meet the inclusion criteria, we selected 197 papers with 420 authors from 317 institutions in 44 countries for analysis. We used CiteSpace software to perform a comprehensive analysis of countries, research institutions, journals, authors, publications, and keywords to summarize the research overview of SCAs related to MR technologies and predict potential research hotspots in this field.

We observed that the number of publications exhibits an increasing trend of volatility over time (Figure 2). This indicates that the application of MR technology in SCA research is growing and becoming increasingly widespread. Several factors contribute to this trend: (1) Despite being a group of rare diseases, the increasing global population has made rare diseases, including SCAs, a public health priority, necessitating focused research attention (28); (2) Advances in MRI technology have expanded non-invasive detection possibilities, enabling more comprehensive evaluation of the microstructure and function of the brain in SCA patients; (3) Understanding the specific characteristics of SCAs, such as neuroradiology, can provide valuable auxiliary information in the diagnostic process (29). The annual growth of publications related to the application of MRI in SCAs is attributable to the outstanding contributions made by countries, institutions, journals, and researchers in this field.

We observed that research on this rare disease is gradually deepening in countries such as the United States, China, Italy, Germany, and Brazil (Figure 3). Notably, the United States and Germany have emerged as significant contributors to this research field, with their publication volumes and centrality ranking among the highest globally. This finding reflects the European and American efforts at establishing large-scale SCA cohorts within their borders. The accomplishment is attributed to sufficient funding, robust research institutions, and outstanding researchers, placing them at the forefront of international research. In developing countries like China and Brazil, research efforts are notably focused on Fujian Medical University, Central South University, and Campinas State University. The focus of these two countries in this field may be linked to their large populations (30). Notably, China and Brazil exhibit lower centrality than their European counterparts. This observation may be attributed to the relatively recent development in the biopharmaceutical field, given their status as developing countries (31). Furthermore, institutions and authors in Brazil and China currently lack international communication. Possible factors contributing to this phenomenon encompass linguistic and cultural disparities, divergences in research methodologies within academic systems, restricted avenues for information acquisition and dissemination, and the absence of collaborative mechanisms and platforms. Comprehending these potential causes can facilitate the identification of strategies to strengthen bilateral relations. Due to the lack of multivariate cooperation, the MRI equipment and techniques commonly used in different countries may differ. Therefore, the technology used in the United States, Germany, China, Italy, Brazil, and other countries will dominate the analysis. To foster future research, increased collaboration with scholars from the United States and Europe is essential. Multilateral cooperation via global and regional networks, including the GlobalSCA, EuroSCA, and the Pan-American Genetic Ataxia Network, is essential for advancing and expanding this research.

It is important to highlight that the 10 most cited journals do not exhibit a high BC value, which indicates node centrality within the network. A low BC value signifies that these publications play a limited mediating role in the academic network, implying a reduced capacity to connect disparate sub-networks. Consequently, the primary contribution of these papers lies in their extensive citation rather than functioning as pivotal bridges for academic communication. This finding underscores the critical importance of enhancing communication and collaboration.

The author with the highest number of citations is Dr. Thomas Klockether (Figure 7) from the University of Bonn (Germany). He is the author of an SCA review that has been cited 29 times (1). Dr. Klockether has made outstanding contributions to this field, and his article is considered groundbreaking in SCA research.

Analysis of cited references serves as a valuable tool to reflect the knowledge foundation and identify the mainstream direction of the field. The results of our citation analysis (Table 3) indicate that the primary research focus is on utilizing MRI to investigate changes in the brain microstructure of SCA patients, aiming to optimize the diagnosis, prediction, and treatment of SCA diseases based on these findings. MRI stands as one of the most widely utilized technologies for studying SCAs. Among the research methods, structural MRI (sMRI) is particularly effective in evaluating and monitoring macroscopic morphological changes in the brains of SCAs patients (32). It quantifies the degree and pattern of atrophy in the affected areas of SCA patients (33). Voxel-based morphometry (VBM) is widely used in SCA research (34, 35) and involves a voxel-wise comparison of the local concentration of gray matter between two groups of subjects (36). Diffusion MRI is another commonly used technique to study SCAs, which provides a new perspective for quantifying microstructural damage to cerebellar structures (37). As diffusion MRI (dMRI) is a true quantitative imaging technique, its indicators can serve as potential imaging biomarkers, allowing for early detection of pathological changes and tracking and predicting subtle changes in subsequent examinations and clinical trials (38). Functional MRI (fMRI) is a relatively new imaging technique, and research using it as a keyword began in 2015. Despite its initial emergence, scholars researching SCAs have paid less attention to fMRI since 2019. This trend may indicate a shift in focus within the academic community, influenced by the increasing maturity of the technology and awareness of its limitations (39). Moreover, fMRI demands higher image quality but poses a challenge, as many patients with SCA exhibit poor cooperation during examination; however, fMRI is starting to gain traction again in 2021, likely due to improvements in the state of the art. Overall, MRI remains the best-studied surrogate biomarker candidate for polyglutamine expansion SCAs (40). In recent years, scholars have achieved significant results using various MRI research methods mentioned above, and our keyword analysis further indicates that this area is set to become one of the future research hotspots. The development of multiple MRI techniques has introduced novel research avenues for SCAs. Integrating MRI imaging with multi-omics analysis can enhance our understanding of SCAs and offer a promising approach to refining diagnostic methods and therapeutic strategies. Furthermore, the emerging role of artificial intelligence (AI) in follow-up studies may significantly influence the future trajectory of this field.

Spinocerebellar ataxias have multiple subtypes, with the most common ones being SCA1, SCA2, SCA3, SCA6, and SCA7. These subtypes collectively account for approximately 70% of dominant SCA cases (41, 42). Among them, SCA3 is the most common subtype globally (43). Correspondingly, keyword analysis also confirms that SCA3 is currently the most extensively studied subtype in this research field. SCA3 is also the most common subtype in countries such as the United States, China, and Germany (44). Notably, these countries also demonstrate high publication volumes in related research articles. In addition, keyword analysis reveals that SCA2, a subtype with a higher proportion in Italy and Spain, has also garnered considerable attention (45).

Previous neuropathological studies have shown that SCA patients exhibit varying degrees of neuronal loss in several brain regions, such as the cerebellum, brainstem, spinal cord, cerebral cortex, and basal ganglia (43, 46). The brainstem and cerebellum are the earliest, most common, and most significant regions of change in SCA patients (47–49). Correspondingly, keyword analysis shows that both regions have received considerable attention in research, and that the brainstem is the most extensively studied brain region. Due to the physiological and anatomical characteristics of the brainstem structure, fMRI and sMRI have been hindered in brainstem research for many years (50). However, advancements in imaging technology have enabled more accurate and faster brainstem imaging (51). The cerebellum, a brain region that accounts for 80% of neurons in the entire brain, has been proven to play an important role in a wide range of cognitive behaviors. New imaging techniques will be able to quantify the microstructure of the cerebellum, observe the unique tissue environment of the lobules, describe more complex cerebellar subregions, evaluate the functional status of the cerebellum, and provide a more detailed description of the occurrence and development of diseases (52).

The analysis of Burst keywords depicted that there has been a significant increase in the frequency of “feature” appearing as a keyword in recent years. This observation suggests that using MRI data as a feature to explore biomarkers of SCAs may become one of the hotspots of future research. The selection of optimal biological biomarkers can enhance the effectiveness of MRI technology in monitoring disease progression, predicting treatment efficacy, and other aspects (53).

Bibliometric analysis has certain limitations that warrant consideration. First, as bibliometric analysis is fundamentally a quantitative approach, the relationship between quantitative metrics and qualitative outcomes often remains ambiguous. Consequently, qualitative conclusions drawn from bibliometric analyses may be subject to bias. For example, relying exclusively on publication counts as an evaluation criterion may overestimate institutions engaged in frequent yet small-scale research while underestimating those producing fewer but more comprehensive studies focused on large-scale populations. Second, bibliometric research can provide only short-term projections regarding research fields. Therefore, scholars should exercise caution when making ambitious claims about research fields or their long-term implications.

This bibliometric analysis provides evidence for the research hotspots and frontiers in the application of MRI in SCA diseases. Our results showed that Europe, the United States, China, and Brazil have made notable and outstanding contributions to the field. With the advancement in MRI technology, sMRI and dMRI have gained widespread application in SCA research. In contrast, fMRI, a relatively new technology, still offers significant research opportunities. SCA3 has received the most attention because it affects the largest number of patients. The brainstem and cerebellum are the most extensively studied brain regions. Additionally, future research can strategically focus on exploring the application of MRI as a biomarker in SCAs.