Co-activation of the M. transversus auris with eye movements (Wilson's oculo-auricular phenomenon) and with activity in other cranial nerves.

Extreme lateral gaze induces a perceptible backward movement of the upper part of the pinna (Wilson, 1908). In 29 subjects (15 normal controls and 14 patients with peripheral eye-muscle or facial paresis) electromyographic (EMG) investigation of the transverse auricular muscle with simultaneous electronystagmographic (ENG) recording of the various ocular movements was carried out. Tonic activity was detected in the transverse auricular muscle during extreme horizontal eye movements, but was detected in only a few subjects during convergent or vertical movement of the eyes, or in the primary position. Investigation of the other cranial nerves revealed that EMG activity of the transverse auricular muscle is also occasionally present during chewing, coughing, swallowing, straining, inspiration, and vestibular stimulation.