The inverse Marcus Gunn phenomenon. An electromyographie contribution.

A patient with the inverse Marcus Gunn anomaly is presented. Electromyographic studies showed the salient fact that the closing of the involved eye on opposite motion of the lower jaw was not mediated by seventh nerve stimulation of the orbicularis oculi but by inhibition of the homolateral levator palpebrae superioris. As a consequence of this observation, a specific and effective operation could be planned.