Schwannoma of the Zygomatic Branch of the Facial Nerve

The Presence of a Zygomatic Nerve Plexus in a Cadaveric Specimen Without a Zygomatic Branch of the Facial Nerve

The extratemporal course of the facial nerve distributes in facial mimic muscles in a complex pattern. The traditional depictions of five main branches without anastomoses are not common. Davis classification remains the gold standard in the classification of facial nerve branching patterns. During a routine dissection of an 74-year-old male cadaveric specimen, we detected a very rare anatomical variation. The zygomatic branch of the facial nerve was totally absent. The temporofacial division of the main trunk was bifurcated to a temporal and a buccal branch. The anterior temporal and posterior buccal branches formed a plexus to supply the orbicularis oculi muscle. This unique variability highlights the complexity of the extratemporal facial nerve course. Retrograde facial nerve dissection requires deep knowledge of every anatomical variation of the facial nerve course to avoid an iatrogenic injury.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-023-03601-y.

Lyme neuroborreliosis as a cause of sudden sensorineural hearing loss and facial palsy

We present a case of sudden sensorineural hearing loss and rapidly progressive facial palsy in a female patient in her 40s with no, apparently, notable past medical or surgical history. Investigations revealed a positive serology for B. burgdoferi and the MRI allowed us to identify suggestive signs of Lyme meningitis with multiple cranial nerve involvement. After diagnosis, the patient was treated with intravenous ceftriaxone with a full recovery of sensorineural deafness and facial palsy. This case report highlights the importance of collecting a complete medical history in all cases of facial palsy and sudden hearing loss while presenting an infrequent clinical presentation of early disseminated Lyme disease with neuroborreliosis.