The entity of Chiari Malformation: Literature overview and presentation of the 50 most cited relevant papers.
Authors: Panagopoulos Dimitrios , Strantzalis Georgios , Gavra Maro , Efstathios Boviatsis , Korfias Stefanos , Karydakis Ploutarchos 
Published: June 2022

Chiari malformations comprise a group of disorders, which share in common inherent anatomical abnormalities that involve the region of the brain stem and cerebellum, eventually coexisting with entities such as hydrocephalus, spina bifida, syringomyelia and tethered cord syndrome.In the mean-time, from the original description of this syndrome, several researchers have focused on an effort to elucidate the pathogenesis of Chiari malformation from a point of view that it is a primary neural anomaly. The aim of the current review is to investigate the time course of our knowledge regarding Chiari malformation, which has expanded significant in the past decades. As new insight has occurred regarding the pathophysiology and natural history of Chiari I malformation (CIM), in association with the widespread availability of MRI,the treatment modalities and algorithm for this patient population has been substantially evolved.Our purpose is to present a review of CIM and its most significant associated comorbidities,comment on techniques for surgical intervention and their expected outcomes. There is a bulk of literature reviews centered on Chiari malformations· in this context, we attempted a literature review, including a discussion centered onthe historical background, anatomical forms, pathophysiology, clinical presentation, relationships with other diseases and diagnostic procedures for these abnormalities. Moreover, a bibliographic search was performed, using Thomson Reuters web of Science and Pubmed databases, in order to identify the most noteworthy papers about Chiari Syndrome. The following parameters were recorded: article titles, number of total citations and citations per year, authors’ names, authors’ h-index, institution and country where the research took place, year of publication, the journal of publication and journal’s impact factor. In addition, we reviewed the journals’ Impact Factor and SCImago Journal Rank (SJR). To obtain all those parameters, besides Web of sciences, we utilized Scopus, SCimago Journal and Country rankings, and In Cites Journal Citation Reports. Our search resulted in 9.972 articles, published from 1855 until now (March2022). All articles are in English. The 50 most cited papers are presented in Table S1. All of them combined have been cited 8.999 times, in 3.262 different articles, with an average citation per item of 179.98. We have attempted to present a thorough overview of this group of disorders, as well as to trace the evolution of our knowledge regarding the anatomical abnormalities associated with this condition, imaging and treatment gold standards and future perspectives. The real pathophysiology, embryological background and natural history of CM have still not been entirely elucidated. This is in concordance with the fact that new suggestions have been submitted for the management of this malformation and more sophisticated imaging techniques have been introduced, in order to investigate in more details, the diagnosis. However, a lot of controversies remain, mainly centered on the optimum strategy which should be selected for selection of the appropriate surgical candidates and most efficacious treatment protocols, in order to obtain efficient decompression of the cranio-cervical junction.