Post-COVID Guillain-Barré Syndrome: A Comparative Analysis of Two Review Studies

Abstract

Letter To the Editor | With interest we read the review article by Aladawi et al. discussing the current status of Guillain-Barré syndrome (GBS) associated with SARS-CoV-2 infection.[1] The authors concluded that acute inflammatory demyelinating polyneuropathy (AIDP) is the most common subtype of post-COVID GBS and that peripheral facial palsy is a frequent accompanying manifestation.[1] The review is clinically relevant, but several methodological and interpretational issues deserve discussion. A major concern is that the findings are not entirely novel. In a previous review, 220 patients with post-COVID GBS had already been collected during the period January to December 2020.[2] Reported subtypes included AIDP, AMAN, AMSAN, Miller-Fisher syndrome, polyneuritis cranialis, and the pharyngo-cervico-brachial variant.[2] Intravenous immunoglobulins represented the most common therapy, 41 patients required mechanical ventilation, and 12 patients died.[2] These findings are highly similar to those reported by Aladawi et al.[1] Surprisingly, however, the previous review was insufficiently discussed despite substantial overlap between the cited studies in both reviews. Another limitation concerns the discrepancy between the methods and results sections. According to the methods, the literature search extended from 26 August 2020 to 7 February 2021.[1] However, numerous studies published before August 2020 were included, while only a few studies from 2021 were considered. The rationale behind these unusual search dates should be clarified, or alternatively the methodology should state that the search actually started earlier. Furthermore, the methods do not mention that only case reports were included. Although the number of articles summarized in both reviews is nearly identical, the number of included patients differs markedly (220 versus 99).[1,2] This discrepancy appears to result from exclusion of cohort studies and larger case series, including studies by Foresti, Paterson, Filosto, and Keddie.[2] Since these studies were published within the stated search period and included clinically relevant data, the rationale for excluding them should be clearly explained. Exclusion of larger cohorts may substantially influence epidemiological interpretation, disease severity estimates, and outcome analysis. Including only case reports may also increase publication bias, as unusual or severe cases are more likely to be reported individually. The citation “Sandeep” appears incorrect because the actual first author is “Rana.” Such inaccuracies, although seemingly minor, reduce scientific precision and may create confusion for readers attempting to verify the original source. Careful correction of citation details and reference accuracy is essential to maintain the reliability and academic quality of a systematic review. Overall, the review has several methodological limitations that challenge the interpretation of its findings. Clarification regarding the search strategy, inclusion and exclusion criteria, and the substantial overlap with the previously published review would strengthen the scientific validity of the study. In particular, the authors should explain why nearly identical tables were obtained despite different search periods and why several cohort studies were omitted from the analysis. Addressing these issues would improve transparency, reproducibility, and the overall impact of the review while further contributing to the ongoing discussion regarding neurological complications of COVID-19.