Using internet search engines (such as Google search) in systematic literature reviews is increasingly becoming a ubiquitous part of search methodology. In order to integrate the vast quantity of available knowledge, literature mostly focuses on systematic reviews, considered to be principal sources of scientific evidence at all practical levels. Any possible individual methodological flaws present in these systematic reviews have the potential to become systemic. This particular bias, that could be referred to as (re)search bubble effect, is introduced because of inherent, personalized nature of internet search engines that tailors results according to derived user preferences based on unreproducible criteria. In other words, internet search engines adjust their user’s beliefs and attitudes, leading to the creation of a personalized (re)search bubble, including entries that have not been subjected to rigorous peer review process. The internet search engine algorithms are in a state of constant flux, producing differing results at any given moment, even if the query remains identical. There are many more subtle ways of introducing unwanted variations and synonyms of search queries that are used autonomously, detached from user insight and intent. Even the most well-known and respected systematic literature reviews do not seem immune to the negative implications of the search bubble effect, affecting reproducibility. Although immensely useful and justified by the need for encompassing the entirety of knowledge, the practice of including internet search engines in systematic literature reviews is fundamentally irreconcilable with recent emphasis on scientific reproducibility and rigor, having a profound impact on the discussion of the limits of scientific epistemology. Scientific research that is not reproducible, may still be called science, but represents one that should be avoided. Our recommendation is to use internet search engines as an additional literature source, primarily in order to validate initial search strategies centered on bibliographic databases.

Background. COVID-19 is a disease caused by a new strain of coronavirus (SARS-COVID-19). The WHO first learned about this new virus on December 31, 2019, following a report on a group of cases of viral pneumonia in Wuhan, Peoples Republic of China, and declared a pandemic in March 2020. The disease was an almost complete unknown at the outset, but knowledge of its pathophysiology, clinical picture, and treatment options grew and developed rapidly. Objective. Dizziness is a very common symptom that patients report in routine clinical practice and one of the significant clinical manifestations of COVID-19. This short report investigated a possible connection between COVID-19 and benign paroxysmal positional vertigo (BPPV). Methods. We present two cases of benign paroxysmal positional vertigo (BPPV), which developed within two weeks of SARS-COVID-19 infection, manifesting with mild disease severity in early November 2020. Results. In both cases, the disease manifested by severe, short-lived attacks of vertigo, objective-circular type, with accompanying nausea and vomiting. The symptoms occurred when lying in bed and turning to the right and assuming an upright position. The diagnosis of posterior semicircular canal BPPV (PC-BPPV) was made based on a subjectively and objectively positive right-sided DixHallpike test. Conclusions. The pathophysiology of post-COVID BPPV is probably similar to that of other viral infections, with some of its specificities such as inducing hypercoagulation and microthrombus formation, which can cause significant circulatory disorders possibly affecting its pathogenesis.

Background: Pregnancy-induced rhinitis (PIR) is a form of chronic non-allergic rhinitis not present before pregnancy that manifests itself during pregnancy with complete resolution of symptoms after delivery. Objective: The objective of this ambidirectional longitudinal cohort study is to evaluate the prevalence of PIR and to investigate the appearance and character of its symptoms, and its impact on the quality of life. Methodology: Six hundred eighty-one (681) women were recruited in the study. They completed questionnaires about nasal symptoms a day after delivery and each woman with nasal symptoms was interviewed 30 days later and data on symptom duration and quality were recorded. Results: The prevalence of PIR was 31.86% (N = 217), 47.14% (N = 321) women had no nasal symptoms and 21% (N = 143) of participants had prior sinonasal disease. The clinical presentation of pregnancy rhinitis included nasal obstruction as the most common symptom, followed by rhinorrhea, postnasal secretion, nose itching, sneezing, and hyposmia. The median duration of PIR was 4 months with their complete resolution of symptoms between 2th and 16th day after delivery in the majority of respondents. PIR was diagnosed significantly more often if the women carried a female child. PIR affected their quality of life during pregnancy in 53,9% women (N = 117), with an average VAS score of 8. It seems that pregnancy may affect the course of previously present sinonasal disease (allergic rhinitis, chronic rhinosinusitis, nonallergic rhinitis, or non-infectious rhinitis prior to the pregnancy). Conclusions: PIR is a common clinical entity with a wide range of symptoms with a direct impact on the quality of life in pregnancy. We propose a new definition of pregnancy-induced rhinitis.