Overlap of Bickerstaff Encephalitis and Pharyngeal-Cervical-Brachial Variant of Guillain-Barré Syndrome Following COVID-19 Infection

A 36-year-old woman developed numbness in both fingers and unsteadiness around 10 days after COVID-19 infection. She was admitted to our hospital after experiencing drowsiness, dysarthria, and gait disturbance within three days. On admission, her vital signs were stable, with no signs of infection. Neurological examination revealed disturbances in consciousness, ophthalmoplegia, ataxia, pharyngeal and cervical muscle weakness, and sensory abnormalities predominantly affecting the upper extremities. Brain MRI and CSF examination revealed no abnormalities, whereas the median nerve somatosensory evoked potential indicated an intracranial conduction abnormality. Based on these findings, brainstem encephalitis of non-infectious origin was suspected, and IVIg and high-dose IV methylprednisolone therapies were initiated. Subsequent serological testing revealed the presence of serum anti-GQ1b and anti-GT1a IgG antibodies, confirming the diagnosis of Bickerstaff brainstem encephalitis (BBE) and pharyngeal-cervical-brachial variant of Guillain-Barré syndrome following COVID-19 infection. The patient responded well to immunotherapy, with rapid improvement in neurological symptoms. By day 20, the patient was able to walk independently, although mild ataxia persisted. On day 24, she was transferred to another hospital for rehabilitation. This case highlights the overlap of the BBE and PCB variants as neurological complications following COVID-19 infection. The presence of anti-ganglioside antibodies, specifically anti-GQ1b and anti-GT1a, plays a crucial role in diagnosis, even when triggered by COVID-19. Early recognition and prompt immunotherapy may contribute to a favorable prognosis.