Background: Patients with the omohyoid syndrome present with a transient lower neck swelling during swallowing. The mechanism of functional derangement has been hypothesized previously but never proven. Our aim is to show how this can be demonstrated real-time.
Method and patients: Five patients were studied. Serial photography, clinical videography, real-time ultrasonography, and simulated cine mode computed tomography were used. Findings were compared with the normal side. The literature was reviewed.
Results: Very little literature experience is available. The swelling appears when the throat ascends and subsides with its descent in unison with omohyoid prominence. The sternomastoid is passively tented up by an abnormal underlying omohyoid. This latter appears to have lost its restriction to bowstring by the retaining deep cervical fascia.
Conclusion: The described approach allowed for definite proof of the pathogenetic mechanism, provided a means of diagnosis, and suggested further insight into the management of these patients.