The Anatomical Basis Of The Improved Accessory Nerve Amputation Operation In Treating The Spasmodic Torticollis

Spasmodic Torticollis or ST is one of the most common diseases in limited musle tension obstacles, which refers to the uncontrollable neck muscle spasm or clonic convulsion caused by the abnormal central nervous impulses, thus the head and neck will be convulsively slanted and twisted to one side, and finally it will cause the hyperactivity and abnormal postures. Presently many schlors have considered Spasmodic Torticollis or ST as the extrapyramidal disease. The morbidity rate of Spasmodic Torticollis is one in twenty thousand, the incidence of the disease is related to gender and age, the incidence of female is usually1.5-1.9times higher than male. The50-60years age groups have the highest rates of Spasmodic Torticollis diagnoses, and70%-90%of the patients get the disease in their forties to seventies. The recovery progress of spasmodic torticollis is slow and only a few patients can self heal. At present, the cause of Spasmodic Torticollis is still not clear, so it is relatively difficult to choose the right drug to cure the disease. Now the anti-cholinergic medicines, dopaminergic and anti-dopaminergic medicines have been applied to the clinical treatment, but the effect was not satisfying. The application of A-type Botox injection break the deadlock of medical therapy in curing the Spasmodic Torticollis, the new method can temporarily relieve the ST symptoms by injecting A-type Botox to the major spasm neck musles, but the therapy also has its shortcomings, when repeatedly used in the long term, it will cause drug resistance and unwanted side effects. In recent years, the B-type Botox has been applied to the clinical treatment as well, which can treat the A-type Botox resistance patients, the short term effect is good, but the function mechanism of which is not clear and more further follow-up care should be done to observe the long term effect. Recently, with the clinical application of various surgical operations, such as the accessory nerves amputation operation, deep brain stimulation, microvascular decompression,selective peripheral nerve amputation and muscle exsection etc, they will bring hope to the treatment of Spasmodic Torticollis. Among all the operations mentioned above, the accessory nerves amputation operation is most widely used in curing the spasmodic torticollis, because the effect of which is good and the cure rate is high. However, the disadvantages of the operation are, the anatomical structure of the neck is complicated and the requirement in performing the operations is hard to meet. When or after the accessory nerves amputation operation, complications always happen because the operation sometimes will cause damage of the surrounding structures. In our follow-up visits of the patients who have the normal accessory nerves amputation operation, we found the following three cases are quite common among the patients.1. Damaging the great auricular nerve, which will cause the skin sensory disturbance of the great auricular nerve parts such as parotid gland, the lower part of masseter muscle,earlobe, auricle and mastoid;2. Causing the dysfunction of the trapezius muscles. After the accessory nerves were cut off, it will result in the "sloping shoulders".3. The relapse of Spasmodic Torticollis shortly after the accessory nerves amputation operation. Therefore, we will do the applied anatomy study on the adjacent structure of the accessory nerves, and redesign the surgical approaches and resection scope, so as to avoid the happening of the complications.Objective:To seek safe operation area and provide applied anatomy foundation for the improved accessory nerve amputation operation in treating the spasmodic torticollis, the researcher observed the anatomy structure of the accessory nerves, the great auricular nerve and the sternocleidomastoid muscle based on the study of the local neck structure.Method:Firstly, take15embalmed national adults head and neck samples and expose the cutaneous neck branches, the accessory nerves and the sternocleidomastoid muscle in proper sequence. Secondly, position the sternocleidomastoid muscle bulge as point A, the point that accessory nerves muscle penetrate the sternocleidomastoid muscle as point B and the great auricular nerve shallow point as point C, measure and write down the distance from point A to B and C respectively. Thirdly, dissociate and expose the sternocleidomastoid muscle, measure the breadth between the mandibular angle and the sternocleidomastoid muscle bulge, take down the distance from the great auricular nerve and the attachment intersection to the front edge of the sternocleidomastoid muscle. Lastly, ascertain the body surface projection of the great auricular nerve and the entry point of the accessory nerves of the sternocleidomastoid muscle, then do the simulation surgery based on the measuring results.Result:1、The data obtained are as the followings,1. The distance between the point that accessory nerves muscle penetrate the sternocleidomastoid muscle and the sternocleidomastoid muscle bulge is6.28±0.45cm;2. The distance between the sternocleidomastoid muscle bulge and the great auricular nerve shallow point is6.92±0.65cm;3.The distance between the entry point of the accessory nerves and the great auricular nerve shallow point is0.92±0.33cm;4. The breadth between the mandibular angle and the sternocleidomastoid muscle bulge is4.52±0.49cm;5.the distance from the great auricular nerve and the attachment intersection to the front edge of the sternocleidomastoid muscle is2.62±0.42cm.2、The trunk part of great auricular nerve mostly penetrate from the1/4mid-upper part of the stemocleidomastoid muscle posterior margin, then it slant upper front to the1/3part the mandibular angle and the stemocleidomastoid muscle bulge joint, the body surface projection of great auricular nerve is consistent with the connection between the sternocleidomastoid muscle posterior margin and the earlobe root.3、Body simulation surgery:Operate simulation surgery on five bodies based on the statistics measured above, make ten cuts on the area, the sternocleidomastoid muscle bulge and the accessory nerves were well exposed while the great auricular nerve was avoided being hurt.Conclusion:1、Make transverse incision on the entry point of the accessory nerves of sternocleidomastoid muscle bulge, the left part of the transverse incision was not made beyond the scope of the body surface projection of the great auricular nerve, so that it can protect the great auricular nerve well.2、ut part of the sternocleidomastoid muscle bulge on the entry point of the accessory nerves, which can not only damage the target organ that damage the ingrowth of accessory nerves but keep the nerve branches lead to the trapezius muscle.3、Measuring the anatomy position of the accessory nerves, the great auricular nerve and the sternocleidomastoid muscle bulge can provide anatomy foundation for the improved accessory nerve amputation operation in treating the spasmodic torticollis.