Research paper Electrophysiology of Guillain-Barré syndrome in Bangladesh: A prospective study of 312 patients Badrul Islam a,⇑ , Zhahirul Islam a , Hubert P. Endtz b , Israt Jahan a , Bart C. Jacobs c,d , Quazi D. Mohammad e , Hessel Franssen f a Laboratory Sciences and Services Division, icddr,b, Dhaka, Bangladesh b Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, the Netherlands c Department of Immunology, Erasmus University Medical Center, Rotterdam, the Netherlands d Department of Neurology, Erasmus University Medical Center, Rotterdam, the Netherlands e National Institute of Neurosciences and Hospital, Dhaka, Bangladesh f Department of Neuromuscular Disorders, Utrecht Brain Center, the Netherlands article info Article history: Received 16 November 2020 Received in revised form 24 February 2021 Accepted 28 March 2021 Available online 22 April 2021 Keywords: Guillain-Barré syndrome Criteria Conduction block Demyelination Axon loss Anti-GM1 antibody abstract Objective: To describe the electrophysiological features in relation to clinical and serological findings of Guillain-Barré syndrome (GBS) in the national neuroscience hospital in Bangladesh. This is one of the few studies that investigated GBS patients using standardized electrophysiology in low-income countries. Methods: In a prospective and observational study, we investigated 312 GBS patients by standardized clinical, serological and electrophysiological methods. Unilateral motor and sensory nerve conduction studies (NCS) were performed within two weeks of onset of weakness. Follow up NCS were performed in 189 patients and classified according to eight sets of established GBS criteria. Serology included assess- ment of anti-GM1 antibodies and anti-campylobacter jejuni lipo-oligosaccharide (LOS) antibodies. Results: Depending on the criteria used, 44–59% patients had axonal GBS with anti-GM1 antibodies being present in 55–58% and 9–42% patients had demyelinating GBS with anti-GM1 antibodies being present in 7–35%. Conduction block (CB) with demyelinative slowing in the same nerve segment was found in 24% (74/312) patients, and CB without demyelinative slowing in the same nerve segment was found in 18% (56/312) patients, of whom anti-GM1 antibodies were found in 27% and 57% patients respectively. Follow-up NCS showed a change in GBS classification in 11–26% of patients, mainly from demyelinating to axonal GBS. Conclusions: The predominant subtype of GBS in Bangladesh is axonal but demyelinating GBS also occurs with classification being strongly dependent on the applied criteria. Significance: The present study demonstrates the importance of reaching international agreement on GBS criteria that should be based on the best evidence. Ó 2021 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). 1. Introduction Guillain-Barré syndrome (GBS) manifests with symmetrical muscle weakness with or without sensory symptoms and signs, putatively resulting from immune-mediated nerve damage. Nerve electrophysiological evidence of axon or myelin damage may have important association with the immunological status of the patient, specially the anti-ganglioside antibodies in the patient’s serum (Albers et al., 1985; Cornblath, 1990; Hadden et al., 1998; Ho et al., 1995; Meulstee et al., 1995; Rajabally et al., 2015; Uncini et al., 2017; Van den Bergh et al., 2004). Classification into demyelinating and axonal forms is, however, ambiguous since cut-off values for slowing consistent with demyelination differ between proposed criteria sets, requirements differ between crite- ria sets, and conduction block was shown to represent demyelina- tion as well as axolemmal dysfunction (Uncini and Kuwabara, 2015; Uncini et al., 2013). Nevertheless, it is recognized that the two most prevalent subtypes are acute inflammatory demyelinat- ing polyneuropathy (AIDP) for Europe and the USA and acute motor axonal neuropathy (AMAN) for Northern China and Japan (Doets et al., 2018). Previous studies have reported that preceding infections with Campylobacter jejuni (C. jejuni) which induce anti- bodies to its lipo-oligosaccharides (LOS) and which subsequently https://doi.org/10.1016/j.cnp.2021.03.007 2467-981X/Ó 2021 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). ⇑ Corresponding author at: Laboratory Sciences and Services Division (LSSD), International Center for Diarrheal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh. E-mail address: badrul.islam@icddrb.org (B. Islam). Clinical Neurophysiology Practice 6 (2021) 155–163 Contents lists available at ScienceDirect Clinical Neurophysiology Practice journal homepage: www.elsevier.com/locate/cnp