To raise awareness of challenging cases of upper and lower motor neuron (UMN/LMN) facial paralysis in different clinical settings.

Facial strength assessment appears to be a straight-forward exercise in neuroanatomic localization. Classical teaching holds that a LMN pattern of facial paralysis is reflected by simultaneous involvement of the upper and lower facial muscles, which is frequently seen in Bell's palsy. When the forehead is spared, it reflects an UMN pattern triggering a stroke alert. However, we have encountered several situations in which the clinical presentation was not as straightforward.

We present five clinical cases of facial paralysis with different pathology: an evolving LMN facial paralysis mimicking stroke; a brainstem stroke mimicking a Bell’s palsy; leptomeningeal carcinomatosis mimicking brainstem disease; Guillain-Barre with facial diplegia; familial facial paralysis with recurrent episodes.

A forehead sparing facial weakness was suspicious for stroke but was preceded by ipsilateral post-auricular pain pointing towards an inflammatory process. Advanced imaging showed no stroke; the facial weakness progressed to Bell's palsy over days. A complete seventh nerve paralysis accompanied by diplopia from an ipsilateral sixth nerve palsy was confirmed on imaging as an acute stroke at the facial colliculus, the locus of sixth and seventh cranial nerve approximation; this illustrates that diplopia with facial paralysis should prompt targeted imaging. UMN facial paralysis in the setting of cancer mimicked a stroke; advanced imaging revealed leptomeningeal carcinomatosis seeding the sixth and seventh nerve fascicles in the subarachnoid space. In Guillain-Barre syndrome, facial diplegia accompanies areflexia. A familial predisposition to facial paralysis may present with an acute LMN facial paralysis and a contralateral chronic facial synkinesis.

Facial paralysis has many faces and may be defined by the company it keeps. A thorough history, neurological examination, and targeted imaging are vital for an accurate diagnosis.