Dear Editor/Reader

We were delighted to receive a letter [1] regarding the interests and limitations of the case report that we recently published in the Pulmonary Therapy journal [2]. In this case report, a 22-year old man with no significant past medical history developed quadriparesis with predominance in the lower limbs 2 weeks after his first dose of the coronavirus disease 2019 (COVID-19) inactivated vaccine (Vero Cell) [2]. The patient had no fever, cough, or other respiratory symptoms prior to admission. The reverse transcription polymerase chain reaction (RT-PCR) test result for COVID-19 was negative prior to vaccination, at admission, and 2 days later. This patient was diagnosed with Guillain–Barré syndrome (GBS) on the basis of clinical symptoms, and cerebrospinal fluid (CSF) analysis revealed albuminocytologic dissociation.

However, as a result of disease progression and concomitant COVID-19 infection during hospitalization, the patient was transferred to the intensive care unit (ICU) and treated with mechanical ventilation, antibiotics to prevent nosocomial infection, intravenous corticosteroids, anticoagulation, and therapeutic plasma exchange (TPE) with 5% albumin replacement. Fortunately, the patient was weaned off the ventilator on day 28, discharged on day 42, and made a complete recovery 6 months later without any neurological sequelae [2]. The outcome of the reported patient was excellent considering the high mortality and morbidity of patients with severe and complicated COVID-19 during the fourth wave of the pandemic in 2021 in Vietnam. But this case report still has some disputable issues, as mentioned in a recent letter-to-the editor, written by Finsterer [1].

Firstly, as mentioned in this letter, the main limitation of this case report was related to the lack of nerve conduction studies (NCSs). We completely agree with the letter’s author that NCSs are critical to classifying the subtype of GBS because it helps to differentiate between axonal damage and demyelinating lesions and to categorize GBS subtypes: acute, inflammatory demyelinating polyneuropathy (AIDP), acute, motor, axonal neuropathy (AMAN), or acute, motor and sensory, axonal neuropathy (AMSAN) [1]. We also assume that knowing the GBS subtype is critical for predicting treatment responsiveness and disease prognosis. Unfortunately, in our case report, NCSs could not be performed as the patient contracted COVID-19 during his initial hospitalization in the Department of Neurology and had to be transferred to the ICU of the COVID-19 hospital (Phu Chanh—Binh Duong General Hospital). In fact, the lack of NCSs was due to the shortage of healthcare resources available at that time since a majority of healthcare workers and physicians were mobilized for the care of patients with COVID-19 in the ICU and frontline field hospitals. On top of this, more than 60% of them contracted COVID-19 and thus were collectively isolated in COVID-19 facilities. This case report was also written at the peak of the fourth wave of the COVID-19 pandemic in Binh Duong province—an area in Vietnam with the second-highest number of COVID-19 infections and deaths after Ho Chi Minh city.

Secondly, although the Brighton criteria [3] used for the diagnosis of GBS are widely applied by neurologists as commented by the letter’s author, in our GBS case report, the diagnosis of GBS due to Vero Cell relied on clinical assessment during which symmetric flaccid limb weakness and lack of deep tendon reflexes, associated with the absence of CSF pleocytosis and elevation of CSF protein were noted [4]. Additionally, as with both this case report and our previously published report, the diagnosis of GBS could be consolidated by the elimination of alternative diagnoses [5]. In our case report, differential diagnoses such as compressive myelopathy, transverse myelitis, acute myelitis, or GBS due to other causes were excluded by a multidisciplinary specialist staff on the basis of laboratory testing and MRI (magnetic resonance imaging) [2]. Therefore, all the relevant comments presented in this letter to editor are very useful for strengthening the diagnosis of GBS in clinical practice [1].

Thirdly, as remarked by the letter’s author [1] who would like to know about the patient’s cerebral imaging to make sure that other motor deficits such as poor response to verbal stimuli, dysphagia, and chewing difficulty could not be due to brainstem encephalitis (Bickerstaff encephalitis) complicated by GBS [6]. In our case report, the patient was described to respond poorly to verbal stimuli because he exhibited peripheral motor deficit and that was not related to aphasia or dysarthria or due to impaired consciousness or cognition [2].

Finally, as mentioned above, we would like to emphasize again that during the fourth wave of the COVID-19 pandemic in Vietnam, optimal treatment of GBS for the patient in this case report was delayed because of a lack of healthcare resources upon his admission into the Department of Neurology. TPE was only performed when the patient’s health status critically worsened, and the patient developed respiratory distress due to concomitant COVID-19 infection. TPE was not the conventional treatment for patients with GBS in this local hospital prior to the COVID-19 pandemic. Hence, we completely agree with the letter’s author that the delay of adequate treatment might worsen GBS symptoms and prognosis. However, we are unable to determine whether the poor progression of GBS during the early course of the disease was due to delayed treatment or concomitant SARS-CoV-2 infection. This notion has been discussed in our case report and has been considered as one of its limitations [2].

In conclusion, we would like to thank the letter’s author again for mentioning the strengths and limitations of our recently published case report as this current discussion may help clinicians to improve diagnosis and treatment approaches for patients with GBS. As demonstrated in previous reports [7,8,9], in the context of the COVID-19 pandemic in 2021, it might be difficult to determine the ideal conditions for the management of severe and critical patients. Thus, constructive discussions between readers and editors are crucial for providing new insights into issues related to the COVID-19 pandemic and for helping physicians to strengthen their knowledge about COVID-19 and other related issues.