Ganglioside Antibodies as Formidable Neurologic Mimickers: A Case Report of Dual Anti-GQ1b and Asialo-GM1 Antibody Syndrome.

The neurologic manifestations of anti-GQ1b antibody syndrome continue to expand and include a spectrum of immune-mediated neuropathies such as Miller Fisher syndrome, Bickerstaff brainstem encephalitis, and optic neuropathy. Asialo-GM1 antibodies are associated with motor or sensorimotor neuropathies, particularly multifocal motor neuropathy. Reports describing concurrent seropositivity for anti-GQ1b and asialo-GM1 antibodies presenting with unilateral facial weakness and limb symptoms remain scarce. A 55-year-old woman with chronic back pain initially presented to an outside facility with new-onset left lower motor neuron facial palsy accompanied by paresthesia and extremity weakness. Neuro-axis MRI demonstrated moderate-to-severe multilevel spinal and neuroforaminal stenosis. She was discharged with prednisone and acyclovir for presumed idiopathic Bell's palsy. Shortly thereafter, she presented to our institution with worsening symptoms. Examination revealed diminished strength, hypoesthesia, and decreased reflexes with a persistent left lower motor neuron cranial nerve VII palsy. The remainder of the cranial nerve examination was normal, and there was no ophthalmoplegia or ataxia. Lumbar puncture demonstrated albuminocytologic dissociation. A ganglioside antibody panel was positive for anti-GQ1b and asialo-GM1 antibodies. This case highlights an unusual presentation of concurrent anti-GQ1b and asialo-GM1 antibody positivity manifesting as unilateral facial palsy and limb weakness initially attributed to Bell's Palsy. Recognition of ganglioside antibody syndromes as potential mimickers of Bell's palsy is essential to ensure prompt diagnosis and treatment, thereby reducing the risk of neurological morbidity.