Guillain Barre Syndrome as a Complication of COVID-19: Letter to the Editor

We read with interest the Letter to the Editor in response to our systematic review entitled “Guillain Barre Syndrome as a Complication of COVID-19: A Systematic Review” which was published on May 5, 2021.¹ When compared with another review article by Finsterer et al.,² which was published on May 4, 2021, the authors of the letter made a few observations about our systematic search and techniques.

The letter noted that our article has similar conclusions to the review published by Finsterer et al.² The article published by Finsterer et al.² reviews 220 patients diagnosed with SARS-CoV2-related Guillain–Barrie syndrome (GBS) and concluded that GBS after COVID-19 is likely due to a postinfectious mechanism, and that it is associated with a worse outcome compared to non-COVID-related GBS. The article also concluded that the prevalence of GBS has most likely increased after the pandemic started. In terms of the patients’ demographics, clinical presentation, GBS subtypes, treatment and outcomes, the article provides patients’ age range of 8–94 years and a latency period of 10–90 days. As for clinical and electrophysiologic variants, the article classifies GBS subtypes and to acute inflammatory demyelinating polyneuropathy (AIDP), acute motor axonal neuropathy (AMAN), acute motor and sensory axonal neuropathy (AMSAN), Miller Fisher syndrome (MFS), polyneuritis cranialis (PNC), pharyngeal, cervical, and brachial (PCB) variant, and Bickerstaff encephalitis (BFE) in which AIDP was noted to be the most common variant. In terms of the clinical outcomes, the study classifies clinical outcomes in those patients into three categories: partial recovery, complete recovery and death.

In our study, we agree that we have similar conclusions including increased incidence of COVID-related GBS in males and AIDP being the most common electrophysiologic variant. However, our study still has some other important conclusions including providing the median values for both age and latency period, instead of providing ranges. In addition, our study classified the GBS cases either as clinical variants (classical sensorimotor GBS, paraparetic GBS, MFS, PCB, bilateral facial palsy with paranesthesia, BFE, pure motor GBS, pure sensory GBS) or as electrophysiologic variants (AIDP, AMAN, AMSAN) in which the most common clinical GBS variant was the classical sensorimotor subtype with frequent involvement of the facial nerve. We have stratified the disease outcomes differently as we categorize the clinical outcomes into (intensive care unit admission, mechanical ventilation, death).

Additionally, the letter raises inquiries about our search methods as there were similarities between the included cases in our study and the cases in the article by Finsterer et al.² The letter also questions why the article by Finsterer et al.² was not included in our paper while it was published prior to our review. Moreover, the letter points out that our review included a smaller number of cases. After reviewing both articles, it was noted that the article by Finsterer et al.² was accessible online 1 day prior to the publication date of our article which can explain why it could not be included in our review. We have also noted that Finsterer et al.’s² literature search included different keywords compared with ours (“neuropathy,” “Guillain Barre syndrome,” “polyradiculitis,” “AIDP,” “AMAN,” “AMSAN,” “Miller-Fisher syndrome,” “PNC,” and “BFE,” in combination with “SARS-CoV-2,” “COVID-19”, and “coronavirus”). Furthermore, the literature search in that article included different languages (English, French, Spanish, Italian, and German).² On the other hand, our search was limited to English and Spanish languages. These two factors can explain why the articles that the author highlighted in his letter were not visible in our search, including the cohort studies mentioned in the letter.

The letter also mentions that our article included studies published prior to our search period. We would like to clarify that in our article, we started searching the literature on August 26, 2020, which signifies the date when we started our literature search. This date does not signify that the articles included in our review were not published prior to August 26, 2020. Finally, as for the citation in Table 1, we agree that the author’s last name is not “Sandeep” as we mentioned in our table. However, on the journal website, the authors’ names are listed in a way that the author’s last name is listed first, followed by a comma, and then the author’s first name, which might have caused some confusion for us while we were working on the table. However, this does not affect the accessibility to the paper cited in our table, and the reference was already cited correctly.