A Case Report of Guillain-Barré Syndrome Presenting as Facial Diplegia: A Deviation From the Classical Ascending Paralysis

Guillain-Barré syndrome (GBS) is an immune-mediated inflammatory disorder affecting the peripheral nerves, typically presenting with ascending paralysis and areflexia in the lower limbs, but can also have other variable presentations. Such variable presentations can rarely include an isolated involvement of the facial nerve as the initial presenting feature. We explore a case of a 53-year-old male patient who initially came with bilateral lower motor neuron facial nerve palsy, preliminarily diagnosed as inflammatory Bell's palsy. However, the patient later re-presented with further neurological deficits involving the lower limbs, prompting further investigations that subsequently led to the diagnosis of GBS. This case highlights the importance of having a high index of suspicion for GBS when evaluating patients presenting solely with bilateral lower motor neuron facial nerve palsy, as GBS can rarely present in such a manner. While Bell's palsy remains a common cause of facial palsy, bilateral involvement is unusual and should prompt evaluation for secondary causes such as GBS.