Protocols and assessment procedures in fiberoptic endoscopic evaluation of swallowing: an updated systematic review

•Assessments of neurological populations do not demonstrate standardization in swallowing videoendoscopy.•Need for standardization of VED protocols for patient diagnosis and management.•None of the studies used the same protocol.•The quality of the studies varied widely mainly in their methodologies and protocols. Neurological alterations can generate swallowing disorders and fiberoptic endoscopic evaluation of swallowing is one of the tests performed for its diagnosis, as well as assistance in dysphagia management. To identify and describe a fiberoptic endoscopic evaluation of swallowing standardized protocol for the neurological adult population and its stages. Systematic review registered on the PROSPERO platform (CRD42018069428), carried out on the websites: MEDLINE, Cochrane Library and Scielo; published between 2009 and 2020. Randomized clinical trials, cross-sectional, and longitudinal studies were included. Two independent judges evaluated the study design and extracted the data from the selected studies. Doubts regarding inclusion or not of the studies were evaluated by a third judge. Scientific articles included were those with adult neurological remained patients with outcomes: (1) diagnosis of swallowing disorder (2) change in sensitivity in laryngeal region (3) penetration of food offered (4) aspiration of food offered. 3724 articles were initially selected, after personalized search for patients with neurological alterations 101 studies remained. In the end, 21 qualitative studies from 2009 to 2020 remained in the systematic review and they were described in detail and compared. Seven articles used protocols of the institutions in which the research took place and four mentioned using the same protocol. The reliable reproducibility of the protocols is feasible only in three of the articles, even presenting different protocols. There is no standard or validated protocol to assess the swallowing function of adults with neurological diseases.