The number of articles published on CSF increased throughout the study period, which is normal, as most bibliometric analyses on other diseases also reveal an upward trend in the number of publications [3, 13, 10]. The most significant aspect to point out is the predominance of case reports (approx. 35%), which show similar values as for other surgical areas, such as maxillofacial surgery (31%) . Individually, case reports are insufficient grounds on which to base treatment decisions, but when they are considered together and adequately codified and integrated into structured information systems, they can provide early insight toward characterizing rare diseases, as they allow physicians to compare cases and check diagnoses .
At a journal level, this study shows the important multidisciplinary approach in the area, as the three most prominent publications are journals of otorhinolaryngology, surgery, and clinical neurology. The multidisciplinary approach of the science is a scientific reality that has been associated with greater advances in knowledge, translation of results, and impact of research [4, 6].
The USA was the predominant country in research production, followed by various European countries (UK, Germany, France and Italy) and Japan. This situation is also apparent in the otolaryngology field [3, 17, 18], neurosurgery [2, 15, 16], as in other health sciences [3, 10]. The top countries did not include any from Africa, while the only Latin American country was Brazil. The top-contributing Asian countries (in addition to Japan) were India, China, and South Korea, while Turkey ranked eighth. A combination of factors can explain these observations. First of all, the USA emerges as the main point of reference in CSF, reflecting its global leadership in all scientific research spheres. Furthermore, the need to have a surgical structure to produce research in this field would favor the most developed countries to a greater extent [3, 7, 18].
The level of international collaboration was very low (6.21%), which highlights the need to develop surgical structures that favor the promotion of research in countries with less scientific development and implement strategies that favor multidisciplinary collaboration .
With regard to the MeSH terms, CSF rhinorrhea was the main branch, while surgery and postoperative complications were the most important sub-topics. Relevant topics related to managing patients with CSF were otorhinolaryngology and clinical neurology . Research also focused on identifying risk factors and assessing different treatments and their outcomes, as shown by the terms related to etiology (“Skull Fracture” of “Skull Base”), diagnosis (especially via “Tomography, X-Ray Computed” or “Magnetic Resonance Imaging”), treatment (“Treatment Outcome” or “Endoscopy”), and complications (meningitis).
There is difference in the patient profile of research in CSF rhinorrhea and CSF otorrhea, with the former area concentrating on older patients (“Adult” or “Middle Age”). Spontaneous CSF rhinorrhea is associated with increased intracranial pressure and considered a manifestation of idiopathic intracranial hypertension in middle-aged people, whereas secondary CSF rhinorrhea is associated with trauma in the same age group . On the other hand, CSF otorrhea research focused on the “Infant,” “Child, Preschool,” “Child” and “Adolescent” age groups, reflecting the fact that CSF otorrhea can be primary and in most of cases is secondary to pediatric skull base fractures . Thus, even though CSF rhinorrhea and CSF otorrhea are included under the same umbrella MeSH term, the profile of research is quite different in these sub-fields.
The main limitation of this study was that we did not analyze citations, with a focus on the journals with the highest impact and dissemination at an international level; this perspective would be necessary to reach a truly comprehensive view of research in the field.  Likewise, other aspects could also be considered, such as co-authorship networks or gender disparities in scholarly productivity [6, 18]