[Bickerstaff's brainstem encephalitis with one-and-a-half syndrome]

Area of Science:

• Neurology
• Immunology

Background:

• Bickerstaff's brainstem encephalitis (BBE) is a rare neurological disorder.
• It is characterized by ophthalmoplegia, ataxia, and altered consciousness.

Observation:

• A 50-year-old woman presented with semicoma, external ophthalmoplegia, and hyporeflexia.
• She exhibited extensor plantar responses and developed one-and-a-half syndrome, indicating pontine tegmentum involvement.

Findings:

• High titers of anti-GQ1b IgG antibodies were detected in her serum.
• Auditory brainstem response confirmed a brainstem lesion, despite normal MRI and CSF.
• Complete symptom resolution occurred after steroid pulse therapy.

Implications:

• This case suggests a potential role for anti-GQ1b IgG antibodies in both intramedullary and extramedullary lesions in BBE.
• It highlights the importance of antibody testing in diagnosing and managing BBE.
• Further research is warranted to elucidate the precise pathogenic mechanisms.