Post-COVID vaccination Guillain-Barre syndrome.

Abstract

We read with interest the article by Berrim et al. about four patients with Guillain–Barré syndrome (GBS) after a SARS-CoV-2 vaccination.1 All four patients had developed acute demyelinating polyneuropathy (AIDP) 7–30 days after vaccination.1 All four benefited significantly from the administration of intravenous immunoglobulins (IVIG).1 The study is appealing but raises concerns that warrant further discussion. A limitation of the study is that SARS-CoV-2 infection was not ruled out in each patient.1 There is no mention that the polymerase chain reaction (PCR) test for SARS-CoV-2 was negative in patient 1. Not only SARS-CoV-2 vaccinations but also SARS-CoV-2 infections can be complicated by GBS.2 We disagree with the notion that autonomic involvement in GBS manifests only as bladder dysfunction.1 Autonomic involvement in GBS can also manifest as photophobia, drooling, sicca syndrome, postural, orthostatic tachycardia syndrome (POTS), palpitations, gastroparesis, vomiting, diarrhoea, constipation, erectile dysfunction, reduced lubrication, urinary hesitancy, incontinence or hyperhidrosis. We therefore should be informed how extensively patient 1 was evaluated for autonomic involvement. The administration of a contrast agent is absolutely necessary to document thickening or enhancement of the spinal roots. However, there is no mention of whether magnetic resonance imaging (MRI) of the cerebrum or spinal cord was done with or without contrast medium in patient 1. We should know if dysphonia in patient 3 was due to involvement of the cranial nerves IX or X, due to brainstem encephalitis (Bickerstaff encephalitis [BBE]) or due to cerebellitis. BBE, cerebellitis and lower cranial nerve involvement have been reported as a complication of SARS-CoV-2 vaccination.3-5 The patient relapsed 8 weeks after onset.1 We should know if chronic inflammatory demyelinating polyneuropathy (CIDP) was being considered and if the patient met the diagnostic criteria for CIDP.5 The authors mix up electroneurography with electromyography (EMG). EMG is the examination of the skeletal muscles with needle or surface electrodes. Electroneurography, also known as nerve conduction studies (NCSs), investigates the peripheral nerves. What was obviously applied in the index study is NCS but not EMG. We disagree with the statement ‘The diagnosis of GBS is often made clinically, but lumbar puncture and EMG studies can help to substantiate the diagnosis’.1 For level 1 evidence according to the Brighton criteria, axonal or demyelinating lesions on NCSs and CSF cell count <50/mL cells are mandatory for establishing the diagnosis.6 We disagree that GBS associated with SARS-CoV-2 vaccination is rare.1 SARS-CoV-2 vaccination-associated GBS has been reported in at least 400 patients worldwide,7 and it can be speculated that many more cases occurred without being reported in the literature. We disagree with the idea that acute, disseminated encephalomyelitis (ADEM) is a differential diagnosis of GBS.1 ADEM is a central nervous system (CNS) disorder and demyelination affects the CNS but not the PNS. A patient cannot have flaccid quadriparesis and lower limb weakness at the same time, as patient 4.1 This contradiction should be clarified. Overall, the study carries obvious limitations that require re-evaluation and discussion. Clarifying these weaknesses would strengthen the conclusions and could improve the study. The author declares no competing interest.