Letter to the Editor: Anti-SARS-CoV-2 Vaccination-Related Polyradiculitis Requires Early Diagnosis and Treatment to Improve the Outcome

Letter to the Editor,

With interest we read the article by Duong-Quy et al. on a 22-year-old, previously healthy male who developed flaccid quadriparesis with lower limb predominance 14 days after the first anti-SARS-CoV-2 vaccination with the CoronaVac (Vero Cell) vaccine [1]. Guillain–Barré syndrome (GBS) was suspected upon admission, and the patient was treated with oxygen, intravenous glucocorticoids, antibiotics, and enoxaparin [1]. Although further diagnostic work-up confirmed the diagnosis GBS and additionally revealed a SARS-CoV-2 infection, the patient was consecutively treated with only cefadroxil, levofloxacin, and dexamethasone [1]. Under this regimen, GBS worsened and the patient developed facial palsy, chewing difficulties, dysphagia, and acute respiratory distress syndrome (ARDS) requiring mechanical ventilation [1]. Not earlier than after initiation of plasma exchange on hospital day 11 did the patient improve and could be extubated and weaned by hospital day 28 [1]. The study is excellent, but has limitations that are a cause for concern and should be discussed. This article is based on previously conducted studies and does not contain any new studies with human participants or animals performed by any of the authors.

A limitation of the study is that no nerve conduction studies (NCSs) were done. NCSs are critical to classify the subtype of GBS. NCSs allow differentiating between a lesion of the axon (axonal damage) and a lesion of the myelin sheath (demyelinating lesion). According to this differentiation, the main subtypes of GBS are acute inflammatory demyelinating polyneuropathy (AIDP), acute motor axonal neuropathy (AMAN), and acute motor and sensory axonal neuropathy (AMSAN). Knowing the GBS subtype is critical, as the response to treatment, prognosis, and outcome may vary significantly between these entities.

There is no mention according to which criteria GBS was diagnosed. The most widely applied diagnostic criteria for GBS are the Brighton criteria [2]. The Brighton criteria rely on the clinical assessment, NCSs, and cerebrospinal fluid (CSF). GBS is present with diagnostic certainty level 1 if there is symmetric flaccid limb weakness, lack or absence of deep tendon reflexes, a monophasic course, absence of CSF pleocytosis, elevated CSF protein, NCSs consistent with a subtype of GBS, and lack of alternative diagnoses [3].

Another limitation of the study is that the patient did not undergo cerebral imaging. Because GBS can be complicated by brainstem encephalitis (Bickerstaff encephalitis) [4], it is critical to know whether “poor response to verbal stimuli”, dysphagia, and chewing difficulty were due to affection of the central or peripheral nervous system (CNS, PNS).

The patient was described to respond poorly to verbal stimuli [1]. We should know whether this was classified as aphasia or dysarthria and whether it was due to impaired consciousness, disorientation, cognitive impairment, tiredness, depression, affection of the CNS, or involvement of the lower cranial nerves in GBS.

We should also know why no appropriate diagnostic work-up and treatment for GBS was initiated on hospital day 1, although the diagnosis GBS was suspected upon clinical assessment already on admission. Steroids given on hospital day 2 are ineffective for GBS. Despite further evidence for the diagnosis GBS on hospital day 3 [1], only cefadroxil, levofloxacin, and dexamethasone were given. Not earlier than on hospital day 11 was plasma exchange begun. Delay of adequate treatment can worsen GBS and can worsen the prognosis, as in the index patient. Therefore, it cannot be ruled out that worsening of GBS during the early course of the disease was due to delayed GBS treatment and not due to the infection with SARS-CoV-2.

Overall, the intriguing study has limitations that cast doubt on the results and their interpretation. Addressing these issues would strengthen the conclusions and could improve the status of the study. Suspicion of GBS requires immediate diagnostic work-up and early adequate treatment not to delay recovery and satisfactory outcome.