2022/10/26 by Andrew J. Martin
Medicine · #Facial Nerve Paralysis Treatment and Research #Trigeminal Neuralgia and Treatments #Botulinum Toxin and Related Neurological Disorders
paper · doi:10.1212/wnl.0000000000201484
A 52-year-old man complained of right eye closure whenever eating. He had experienced a right-sided Bell's palsy approximately before 12 months. An examination showed unilateral eye closure on jaw opening or lateral jaw movements, related to active contraction of the entire orbicularis oculi muscle, in addition to ipsilateral hemifacial spasm (Video 1). Marin-Amat syndrome is an acquired synkinesis occurring most frequently after Bell's palsy and is the opposite of the more common Marcus Gunn phenomenon, in which there is eyelid retraction on jaw opening or horizontal movement. It is sometimes erroneously termed an “inverse” Marcus Gunn, although this is a congenital condition in which there is inhibition, and resulting ptosis, of the levator palpebrae muscle on mouth opening, rather than the active contraction of orbicularis oculi seen in Marin-Amat syndrome. Botulinum toxin to the orbicularis oculi muscle, otherwise generally ineffective in the Marcus Gunn phenomenon, can therefore be therapeutic.