Transcranial ultrasound stimulation in neuromodulation: a bibliometric analysis from 2004 to 2024

Abstract

Background: Transcranial ultrasound stimulation (TUS) is a non-invasive neuromodulation technique with promising clinical potential. Its therapeutic efficacy and safety are significantly influenced by stimulation parameters. However, the global research hotspots and future research trends of TUS application in the field of rehabilitation are unclear. This study analyzes the status of TUS research. Understand the annual publication trends, international and institutional cooperation pattern and influential authors and journals and keyword hotspot.

Methods: A comprehensive literature search was conducted on the Web of Science core database using TUS-related subject headings until 27 December 2024. Two researchers independently screened articles based on pre-determined inclusion and exclusion criteria. Software packages such as CiteSpace and VOSviewer were used to visualize the results.

Results: A total of 577 literatures were included. The results show that the annual publication volume shows an increasing trend, reaching a peak in 2024. The United States, China and Germany dominated the number of publications, with the largest number of institutions being Harvard University, the University of Toronto and Brigham and Women's Hospital. Brain stimulation is the journal with the most articles and citations. Research hotspots include transcranial magnetic stimulation, noninvasive brain stimulation, Parkinson's disease, and Alzheimer's disease.

Conclusion: A bibliometric analysis of the literature shows that research interest in transcranial ultrasound stimulation is growing rapidly, with annual publications growing exponentially since 2013 and receiving increasing attention from researchers. The findings suggest that TUS is currently used primarily in neurological diseases, particularly in the study of Parkinson's disease and Alzheimer's disease. At the same time, it is found that an emerging international cooperation model with the partnership between the United States, China and Germany as the core has gradually taken shape. Although preclinical studies have shown promising neuromodulator effects, the current study suggests that TUS needs to undergo further multicenter clinical validation. These findings provide evidence to guide future research priorities for non-invasive neuromodulation.

Keywords: bibliometric analysis; neuromodulation; non-invasive brain stimulation; physiotherapy; transcranial ultrasound stimulation.

Figure 1

Selection process and reasons for exclusion.

Figure 2

Annual publication volume from 2004 to 2024.

Figure 3

The top 10 productive countries of the topic.

Figure 4

Top 30 countries chord diagram of collaboration strength.

Figure 5

Network visualization of institutions. In the diagram, a circle represents an item, and each item corresponds to a label. The more important an item is, the larger its label and circle will be. Different colors indicate different clusters.

Figure 6

Overlay visualization of institutions (2004–2024). In the diagram, collaboration network of top 30 institutions, node size reflecting publication volume, edge thickness indicating collaboration strength, and color gradients representing temporal activity (yellow = recent, purple = earlier).

Figure 7

Dual-map overlay of article citations. The left chart shows the distribution of cited journals, classified by subject areas. The right figure depicts the distribution of cited journals. Similarly, they are classified by discipline. Wavy curves depict the citation links. Their colors are determined by their source star clusters. The communication and connection among the groups of cited journals indicate.

Figure 8

Top 25 references with the strongest citation bursts.

Figure 9

Co-occurrence network visualization of keywords. In the diagram, a circle represents an item, and each item corresponds to a label. The more important an item is, the larger its label and circle will be. Figure presents a network visualization of keywords, where nodes of different colors represent keywords clustered into distinct thematic groups, and node size corresponds to their frequency of occurrence.

Figure 10

Co-occurrence overlay visualization of keywords in VOSviewer. Figure displays an overlay visualization of keywords, with nodes colored in yellow denoting recently emerging keywords, reflecting contemporary research trends, while purple nodes represent earlier keywords, highlighting foundational themes.

Figure 11

Co-occurrence density visualization of keywords in VOSviewer. Figure provides a density visualization of keywords in the form of a heatmap, where warmer colors indicate regions of higher keyword density, illustrating areas of concentrated research activity.

Figure 12

High-frequency keywords cluster map. The figure shows the keyword clustering analysis of the included Chinese literature. Each color represents a cluster, and the size of the category affects the ranking.

Figure 13

Top 25 keywords with the strongest citation burst.