Doubled omohyoid muscle in human: a case report and literature review

Diagnostic value of high-frequency ultrasound in omohyoid muscle syndrome

PURPOSE

To investigate the diagnostic value of high-frequency ultrasound in omohyoid muscle syndrome.

MATERIAL AND METHODS

A retrospective analysis of 11 patients diagnosed with omohyoid muscle syndrome was carried out, and the characteristics of high-frequency ultrasound images were summarized.

RESULTS

Ultrasonography of the omohyoid muscle showed a narrow band of hypoechoic muscle bundle. The ultrasonographic manifestation of omohyoid muscle syndrome showed a thickening of the omohyoid muscle on the affected side. The omohyoid muscle on the affected side bulged forward during swallowing and lifted the overlying sternocleidomastoid muscle. The difference between the thickness of the omohyoid muscle intermediate tendon on the affected side and the healthy side at rest was statistically significant (t = 58.23, P < 0.001). The difference between the thickness of the affected omohyoid muscle intermediate tendon at rest and during swallowing was statistically significant (t = 14.57, P < 0.001). There was no statistically significant difference between the thickness of the omohyoid muscle intermediate tendon on the healthy side at rest and during swallowing (t = 0.56, P > 0.05).

CONCLUSION

High-frequency ultrasound is the preferred imaging method in the diagnosis of omohyoid muscle syndrome.

Sternohyoid muscle syndrome

OBJECTIVES

Patients presenting with neck mass are challenging for many otolaryngologists. If a mass on the lower lateral neck exists with swallowing and disappears after swallowing, it has been diagnosed as an omohyoid syndrome in most literature. The mechanism of sternohyoid syndrome has not been proven or investigated before. We investigated sternohyoid syndrome, commonly misdiagnosed as an omohyoid syndrome.

METHODS AND PATIENTS

Two patients were investigated. Outpatient photography, computed tomography and operating findings were reviewed. We found that the sternohyoid muscle was inserted at an abnormal site, the midportion of the clavicle. There was no abnormality of other muscles. We also reviewed all literature that previously diagnosed this condition as an omohyoid syndrome.

RESULTS

There was no literature about sternohyoid syndrome. We found that the abnormal muscle is a sternohyoid muscle and not omohyoid muscle. The color of the left sternohyoid muscle was dark red, and the fascia covering the muscle was denuded. The muscle had lost elasticity and moved abnormally.

CONCLUSION

Our patients did not have omohyoid syndrome. The symptoms of omohyoid syndrome are the same as sternohyoid syndrome but the problematic muscle is different. This is the first known report diagnosing sternohyoid syndrome, and should be a consideration in the diagnosis of a lateral neck mass.