Unilateral facial palsy with hemiplegia and positive anti-GT1a antibody: a case report and literature review.

Background: Guillain-Barré syndrome (GBS) is an autoimmune-mediated disorder characterized by an acute onset of symmetrical flaccid limb weakness. However, cases of persistent unilateral limb weakness and facial palsy with anti-GT1a antibody positivity have been rarely reported. Here, we describe this case to highlight its clinical importance. Case: A 60-year-old man presented with right shoulder and upper back pain, followed by right-sided limb weakness, peripheral facial paralysis, distal sensory impairment, and dyspnea. Symptoms were preceded by upper respiratory infection. Cerebrospinal fluid showed albuminocytological dissociation. Electromyography reported peripheral nerve damage in the extremities. Serum anti-GT1a IgG was positive. After a five-day course of intravenous immunoglobulin, he showed marked recovery in motor, sensory, and respiratory function. At six-month follow-up, his symptoms except dyspnea basically returned to normal. Conclusion: This case suggests a potential distinct GBS phenotype featuring unilateral limb weakness, unilateral facial palsy, and anti-GT1a antibody positivity, with a good response to IVIG. These findings expand the clinical spectrum of GBS and emphasize recognizing unilateral presentations to prevent misdiagnosis.