Selective Peripheral Denervation of the Sternocleidomastoid and the Posterior Cervical Group Muscles for Cases with Spasmodic Torticollis

Abstract

Selective peripheral denervation for the sternocleidomastoid and the posterior cervical group muscles were performed, according to the method reported by Bertrand, with satisfactory results in two cases with idiopathic spasmodic torticollis. For denervation of the sternocleidomastoid, the skin incision extended from the base of the ear to the junction of the horizontal and the vertical portion of the trapezius muscle. The peripheral accessory nerves were identified at the lower portion of the incision and their proximal parts were exposed until they gave off branches to the sternocleidmastoid. All identified branches innervating the sternocleidomastoid were coagulated and severed and the muscle itself was also sectioned totally. In order to denervate the muscles of the posterior cervical group, the extradural section of the roots of C1 and C2 combined with coagulation and section of the posterior primary divisions (rami) of C3, 4, 5 and 6 was performed with posterior midline skin incision. Bertrand named this procedure ramisectomy to differentiate it from the classical intrathecal rhizotomy (Foerster-Dandy's method). The first case had spasmodic torticollis of rotation to the left side with a retrocollic component which had been intractable to different kinds of treatment for nine years. By peripheral denervation of the right sternocleidmastoid and the bilateral posterior cervical group, the patient became free from any abnormal involuntary movements. The effects continued without restriction of neck movement during the follow up period of one and a half years, though obvious atrophy of the denervated muscles was observed. The second case had rotaional torticollis to the right side. By denervation of the left sternocleidomastoid and the right posterior cervical group, the symptoms improved significantly, but some residual abnormal movements were detected postoperatively. At the second operation, further denervation was sundertaken and satisfactory results were obtained. This method is very effective for spasmodic torticollis which is intractable to other kinds of treatment.