BACKGROUND

Guillain-Barré syndrome (GBS) is an acute type of polyradiculoneuropathy, that occurs following immune events such as infection and vaccination. Approximately 40%–70% of GBS cases develop following infection, and autoantibodies against glycolipids (mainly ganglioside antibodies) are detected in over 50% of cases. The cause is generally accepted to be an abnormality in the immune process.1 2 Recently, several reports of GBS associated with SARS-CoV-2 infection have emerged. However, as far as we have investigated, there are still no reports in Japan.3 However, in a review of 37 cases of SARS-CoV-2-infection-related GBS, less than half of the studies investigated antiganglioside antibodies.4 Furthermore, few reports have provided details related to the antiganglioside antibody investigated, and clear descriptions of the relevant tests are available only for anti-GM1, anti-GQ1b and anti-GD1b antibodies.5–14 Most reported cases (64.8%) of SARS-CoV-2-infection-associated GBS were of the acute inflammatory demyelinating polyneuropathy type. Acute motor and sensory axonal neuropathy and acute motor axonal neuropathy types were observed in 13.5% and 2.7% of cases.4 In the present report, we discuss a case of axonal-type GBS associated with SARS-CoV-2 infection, where the patient was tested for various antiganglioside antibodies. Furthermore, we review the cases of SARS-CoV-2-infection-related GBS reported to date, in order to provide insight into the clinical characteristics and pathological mechanisms underlying the disease. Our report also highlights the need for clinicians to remain cautious when attempting to diagnose SARS-CoV-2-infection-related GBS, and when using high-dose IV gamma globulin therapy in patients at risk of thrombosis.

Case presentation

A 54-year-old woman with a history of asthma was admitted to our hospital in May 2020 with reports of numbness and weakness in her extremities. Twenty days prior to the onset of neurological symptoms, she developed cough and fever; oropharyngeal reverse transcriptase PCR test results were positive for SARS-CoV-2. Although she had pneumonia on CT of the chest, oxygen was not needed. Therefore, we did not administer additional treatment, and continued budesonide, formoterol fumarate hydrate and montelukast sodium, that were originally being used to treat asthma. In addition, we used betamethasone only for the first 2 days to avoid the risk of exacerbation of asthma. Following approximately 2 weeks of treatment, PCR results were negative. However, at that time, she began to experience numbness in the lower extremities, that gradually spread to the upper extremities. Within the next week, she began to develop weakness in the extremities. Neurological examination revealed no findings suggestive of abnormalities in the central nervous system. Tendon reflexes in the upper extremities were normal, although they were absent in the lower extremities. The Medical Research Council Scale grade for muscle strength was 4/4 for proximal and 5/5 for distal muscles of the lower extremities, and 4/4 for proximal and 4/4 for distal muscles of the upper extremities; she was able to walk. Her modified Erasmus GBS Outcome Score (mEGOS) was 3/9, while her Hughes’ functional grade was 2. Superficial sensation was mildly impaired in the distal extremities, deep sensation was normal and she had no ataxia.

Investigations

Blood tests revealed normal blood glucose levels and no findings suggestive of collagen disease, thyroid disease or vitamin abnormalities. Cerebrospinal fluid (CSF) assessment at admission at approximately 3 weeks after onset revealed normal protein levels and cell counts. All tests for antiganglioside antibodies were negative. The ganglioside antigens used in the ELISA were GM1, GM2, GD1a, GD1b, GD3, GalNAc-GD1a, GT1a, GT1b, GQ1b and GA1 (asialo-GM1). Ganglioside complexes containing two of the above 10 antigens were also used as described in a previous study.15 CSF was not tested for SARS-CoV-2 PCR. On admission, the patient’s first electrophysiological examination was normal. However, the second examination performed 1 week later revealed decreases in compound muscle action potential (CMAP) amplitudes in the median, radial and tibial nerves compared with those obtained in the first examination (table 1). Since the patient had a history of asthma, we did not perform lumbar MRI using a contrast agent.

Differential diagnosis

This case fulfilled two of the required features for the diagnosis of GBS based on the criteria described by Asbury and Cornblath.16 In addition, several other clinical features strongly supported the diagnosis.

She had no systemic symptoms, multiorgan involvement or elevation of serological markers (eg, elevated sedimentation rate or rheumatoid factor) suggestive of vasculitis. Furthermore, she had no malignancy or history of exposure to heavy metals and other toxins.

Treatment

Although the patient was diagnosed with GBS, she was followed up without IV immunoglobulin therapy due to her mEGOS and functional grade.

Outcome and follow-up

Approximately 2 weeks later, her symptoms had begun to improve, and she was discharged home on day 18; normalisation of the Achilles tendon reflex was also observed. An electrophysiological examination performed 1 month later revealed improved CMAP amplitude in most nerves. Although her weakness had improved, she continued to experience numbness.