Sternocleidomastoid Muscle

Via the sternocleidomastoid muscle, and owing to the continuity of the infrahyoid muscles with the digastric muscle (posterior belly) and stylohyoid muscle, dysfunction of the clavicle and sternum causes a restriction of the temporal os, resulting in a CMD.

From: Cranial Osteopathy (2nd Edition) , 2004

Cervix Autopsy

David East. Eibling , in Operative Otolaryngology: Caput and Neck Surgery (Second Edition), 2008

Sternocleidomastoid Muscle

The SCM runs obliquely from anteroinferior to posterosuperior, inserting on the mastoid tip. Information technology tin can be readily differentiated from the platysma muscle past the direction of its fibers. It is crossed in an inferior-to-posterior direction by the GA nervus and the external jugular vein, which prevarication immediately deep to the platysma. If these structures are left on the surface of the SCM during flap elevation, the SCM assists in developing the fascial envelope in modified and selective neck dissections (Fig. 78-5). The posterior border of the SCM represents the posterior edge of nodal levels II through IV and the anterior border of level V (Fig. 78-half dozen). As the cervical contributions to the GA nerve get out the cervical plexus and sweep around the posterior edge of the SCM, they artificially separate levels IV and V, identifying the posterior limit of the selective neck dissection.

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Peripheral Nerve Surgical Procedures for Cervical Dystonia

Takaomi Taira , in Nerves and Nervus Injuries, 2015

Denervation of the Sternocleidomastoid Musculus

The sternocleidomastoid muscle is generally considered to take nerve supply from the accessory nerve. However, the innervation design to the SCM is not then simple and it as well receives fibers from the C2 and C3 anterior branches, as studied past Caliot et al. ( Caliot, Bousquet, Midy, & Cabanie, 1989; Caliot, Cabanié, Bousquet, & Midy, 1984). According to their report, at that place are three main types of variations of innervation pattern to the SCM (Figure 28.13). The classical "anastomotic" blazon of innervation (also referred to as Maubrac's type of innervation) was the most frequent, although present in only half of all cases. Because there are fibers arising from the loftier cervical (C2, 3) nerves to the SCM, abnormal contractions may even so remain even after intradural section of the eleventh nerve trunk. Therefore, denervation of the SCM should be carried out at the peripheral expanse where fibers of both the eleventh nerve and the cervical plexus enter the SCM.

Figure 28.thirteen. Variation of innervation design to the sternocleidomastoid muscle.

In the original Bertrand's technique, the peripheral main body of the eleventh nervus is completely exposed by sectioning the SCM with a large peel incision along the direction of the eleventh nervus. This makes it easier to place all the motor nerves going to the SCM. For corrective reasons, nosotros utilize a pocket-sized (2-iii   cm) skin incision forth the posterior edge of the SCM. The heart of the incision comes to a bespeak where the posterior border of the SCM crosses a line fatigued between the lower border of the earlobe and neck-shoulder bending. This betoken should be marked before introduction of anesthesia when the patient is still in a supine position. After skin incision, the groovy auricular nerve coming up from the posterior border of the SCM is identified. This point is chosen an auricular bespeak and is a nice landmark, because the main body of the eleventh nerve runs nether this point. With a fine monopolar stimulation (1-five   Five, 5   Hz, 0.ii-0.five   ms), the location of the eleventh nerve body is roughly confirmed by strong contractions of the trapezius musculus. Dissection should be carried out until the eleventh nerve torso is identified. One time the nervus is constitute, we dissect the surrounding tissue distally and proximally to betrayal the nerve trunk completely. We may partially cut the SCM itself. An operative microscope is essential to observe fine branches to the SCM and to preserve the eleventh master trunk. The great auricular nerve should as well exist preserved, otherwise the patient may suffer dysesthetic sensation in the earlobe. In most textbooks of anatomy, the eleventh nerve trunk is described as running behind the SCM, simply in my experience, the nerve pierces a role of the SCM in most cases. Dissection of the eleventh nerve should be carried out proximally, where the fat tissue behind the SCM appears. There are usually three to 4 branches from the principal torso to the SCM. These branches should exist checked with electric stimulation. When cutting the branches to the SCM, intendance should exist taken not to damage the main body with a electric current spread of bipolar coagulation. We stimulate the tissue forth the posterior border of the SCM to confirm that there are no more than nerve supplies to the SCM.

We unremarkably practise not denervate the trapezius muscle, because weakness of this muscle results in marked disabilities such as difficulty in raising the arm and shoulder joint problems. However, there are some patients in whom aberrant contraction of the trapezius musculus is a major symptom of CD. Krauss et al. (1999) reported a technique for performing fractional sectioning and myectomy of the trapezius muscle. They used comatose-awake-asleep anesthesia that allowed intraoperative control of the sectioning procedure to avoid causing postoperative weakness of arm elevation above the horizontal plane. This technique tin can be used every bit an adjunct to other peripheral surgical procedures in patients with marked laterocollis and dystonic peak and anteversion of the shoulder.

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Pare Structure and Surgical Beefcake

June K Robinson Md , E Ratcliffe AndersonJr Doc , in Surgery of the Skin, 2005

Sternocleidomastoid muscle

The sternocleidomastoid muscle originates from the sternum and clavicle and extends in a posterior diagonal fashion to insert onto the ipsilateral mastoid process and lateral portion of the occipital ridge. The muscles piece of work together to flex the neck and piece of work individually to turn the cervix and elevate the chin. With the caput rotated away from the observer, the sternocleidomastoid muscle becomes a prominent surface landmark that divides the neck into the anterior and posterior triangles. The musculus and the mastoid process are of import landmarks used to identify the spinal accessory nerve at its most exposed location in the posterior triangle (Fig. 1.21)

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Breast Wall

In Imaging Beefcake: Chest, Abdomen, Pelvis (2d Edition), 2017

Coronal MR, Normal Breast Wall

Sternocleidomastoid muscle

Deltoid muscle

Serratus inductive musculus

Sternohyoid muscle

Clavicle

Pectoralis major muscle

Pectoralis minor musculus

External oblique abdominal muscle

First of vi coronal T1-weighted MR images demonstrates normal chest wall structures (shown from anterior to posterior). This 1st section is through the medial clavicles.

Subclavian vein

Clavicle

Subclavius muscle

Anterior scalene muscle

Deltoid muscle

External oblique abdominal musculus

Serratus anterior musculus

Coronal T1 MR through the level of the subclavian veins is shown.

Subclavian artery

Posterior scalene musculus

Anterior attribute of brachial plexus

Pectoralis major musculus

Pectoralis pocket-sized musculus

Serratus inductive muscle

External oblique abdominal muscle

Coronal T1 MR through the level of the subclavian arteries and inductive aspect of the brachial plexus is shown.

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Head and Neck Cancer

Michael J. Wolfe , Keith Wilson , in Essentials of Surgical Oncology, 2007

Selective Cervix Dissections

The sternocleidomastoid muscle, the spinal accessory nerve, and the internal jugular veins are always preserved. The supraomohyoid cervix dissection requires the autopsy of level I. The fascia is taken off of the inductive edge of the SCM, around to the deep aspect of the muscle, to the posterior edge. The CN11 is located anteriorly and followed to the skull base. Great care is needed to avert damaging the CN11 equally it exits the posterior SCM. The muscle is retracted posteriorly. The omohyoid is located and the fascia is removed, but the muscle is preserved.

At the junction of the omohyoid and the SCM, a autopsy plane is created downward to the deep layer of the deep cervical fascia. The phrenic nerve is one time over again avoided. This airplane is then brought superiorly. As it is made, the contents of levels II through IV are retracted anteriorly. Avert pulling the contents of level 5 into the surgical aeroplane; this makes the dissection more than difficult and puts CN11 in danger. The cervical nerve roots are preserved. The specimen is removed from the IJ in the same manner as it is in the MRND types 2 and 3.

Knowing how to approach each level of the cervix in a autopsy will let for other selective neck dissection procedures. If level I is to be left, every bit information technology is in the lateral neck autopsy and the posterolateral neck dissection, the inductive edge of level II is the posterior abdomen of the digastric muscle. The assortment of SNDs was adult to decrease the morbidity of the neck autopsy. As such, efforts should be fabricated to preserve muscles, nerves, and claret vessels that should not be role of the specimen.

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The Cervical Spine and Cervicothoracic Junction

John W. High german , ... Joseph T. Alexander , in Spine Surgery (Third Edition), 2005

Triangles of the Neck

The sternocleidomastoid musculus divides the neck into two large triangles: inductive and posterior, which are respectively subdivided into iv and two triangles each. Knowledge of these triangles includes a definition of the borders and the contents of each triangle ( Figure 22.i).

The borders of the posterior or dorsal triangle are the dorsal edge of the sternocleidomastoid muscle, the ventral border of the trapezius muscle, and the middle third of the clavicle. The deep cervical fascia covers the dorsal cervical triangle, thus forming its roof. The floor of the dorsal cervical triangle is formed by the scalenus posterior, scalenus medius, levator scapulae, and splenius capitis muscles, also as the lateral extension of the prevertebral fascia that overlies these muscles. The dorsal belly of the omohyoid musculus partitions the dorsal cervical triangle into a large rostral occipital triangle named for the occipital artery exiting at its apex and a small caudal subclavian triangle named for the subclavian artery, which lies deep to it.

The spinal accompaniment nervus leaves the deep surface of the sternocleidomastoid muscle to enter the dorsal triangle of the neck, which information technology crosses to innervate the trapezius muscle. The two important structures establish in the dorsal cervical triangle, which ascend above the spinal accompaniment nerve, are the occipital artery and the lesser occipital nervus. The occipital artery leaves the dorsal cervical triangle at its apex where the sternocleidomastoid and trapezius muscles approach one some other on the superior nuchal line. This avenue then ascends to supply the dorsal scalp. The lesser occipital nerve ascends along the dorsal surface of the sternocleidomastoid muscle before ramifying into several superficial branches that supply the scalp dorsal to the ear.

Caudal to the spinal accompaniment nerve are many important anatomic structures. The external jugular vein, which is formed by the confluence of the posterior auricular and the posterior division of the retromandibular vein at the bending of the mandible, courses over the sternocleidomastoid musculus obliquely to enter the dorsal cervical triangle caudally, en route to joining the subclavian vein approximately ii cm to a higher place the clavicle. three 2 branches of the thyrocervical trunk cantankerous the dorsal cervical triangle. The suprascapular artery runs rostral to the clavicle earlier passing deep to the clavicle to supply the periscapular muscles. The transverse cervical artery lies 2 to 3 cm rostral to the clavicle and too runs laterally beyond the dorsal cervical triangle to supply the periscapular muscles.

Three superficial nerves too exit the dorsal triangle beneath the spinal accessory nerve. In all cases, these fretfulness ascend from the cervical plexus, which is formed by the ventral rami of the rostral four cervical spinal fretfulness. The plexus lies inside the lateral neurovascular conduction pathways located betwixt the internal jugular vein and the sternocleidomastoid musculus. The superficial nerves then arise along the middle portion of the dorsal border of the sternocleidomastoid musculus to supply the skin of the neck and scalp between the mastoid process and the inion. The smashing auricular nerve crosses the sternocleidomastoid muscle and ascends toward the parotid gland, branching into dorsal and ventral rami that supply the skin in an area stretching from the angle of the mandible to the mastoid process and the skin of the neck. The transverse cervical nervus also crosses the sternocleidomastoid muscle to supply the pare overlying the ventral cervical triangle. The supraclavicular fretfulness arise from a single trunk that trifurcates into lateral, intermediate, and medial branches that innervate the pare of the neck, ventral chest, ventral shoulder, sternoclavicular joint, and acromioclavicular articulation. The phrenic nerve arises, in part, from the cervical plexus and, in part, from the brachial plexus. The brachial nervus arises about the scalenus anterior muscle, where it crosses ventromedially and deep to the transverse cervical and suprascapular arteries and the prevertebral fascia, to descend through the superior thoracic aperture nearly the origin of the internal mammary artery. The upper, center, and lower trunks of the brachial plexus prevarication deep to the floor of the posterior cervical triangle. They emerge between the scalenus medius and scalenus inductive muscles and cross deep to the transverse cervical and suprascapular arteries to descend nether the clavicle to enter the axilla.

The borders of the inductive or ventral cervical triangle are the ventral edge of the sternocleidomastoid muscle, the junior border of the mandible, and the midline of the cervix. The ventral cervical triangle may be subdivided into four smaller triangles: submental, submandibular, carotid, and muscular.

The submental triangle is bounded by the hyoid trunk and laterally past the ventral bellies of the right and left digastric muscles. This triangle has, as its floor, the two mylohyoid muscles that connect to each other in the midline past forming a median raphe. Within this triangle lie the submental lymph nodes that drain the ventral natural language, the floor of the oral cavity, the middle portion of the lower lip and the skin of the chin, and several pocket-size veins that ultimately converge to form the anterior jugular vein.

The boundaries of the submandibular triangle are the inductive and posterior bellies of the digastric musculus and the inferior border of the mandible. The flooring of the submandibular triangle is formed by the mylohyoid, hyoglossus, and middle constrictor muscles. The submandibular gland fills a significant portion of this triangle, and its duct passes parallel to the tongue to open into the rima oris. The hypoglossal nerve besides passes into this triangle along with the nerve to the mylohyoid muscle, a co-operative of the junior alveolar nerve, and portions of the facial artery and vein.

The carotid triangle is divisional by the ventral border of the sternocleidomastoid muscle, the rostral edge of the rostral belly of the omohyoid muscle, and the caudal border of the dorsal abdomen of the digastric muscle. Within the carotid triangle lie the bifurcation of the common carotid avenue, the internal jugular vein laterally, the vagus nerve dorsally, and the ansa cervicalis (Figure 22.1B ).

The muscular triangle is bounded past the median plane of the neck, the caudal edge of the rostral belly of the omohyoid muscle, and the medial border of the sternocleidomastoid muscle. Within this triangle lie the infrahyoid muscles and neck viscera.

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Neurological Emergencies

Steven W. Salyer PA‐C , ... Ralph Terpolilli , in Essential Emergency Medicine, 2007

Cranial Nerve Eleven (Spinous Accessory)

The sternocleidomastoid (SCM) and trapezius muscles, which aid in stabilization and movement of the cervical spine and shoulders, receive their innervation from the eleventh cranial nerve (the spinous accessory nervus). This nerve actually originates in the upper cervical spine merely ascends into the attic before descending dorsum to its muscular connections, thereby making either cervical or intracranial sites locations for lesions that might result in weakness. Testing involves the patient shrugging his or her shoulders while the clinician looks for symmetrical move and endeavor. The patient's upper extremities should be otherwise relaxed. Then, this position should be maintained as a moderate amount of downwards pressure level is practical over the shoulders to test for subtle loss in muscle strength. Adjacent, with the patient's head in a level, neutral position, the clinician should have him or her rotate the head to either shoulder while the clinician places gentle resistance to the opposite side of the face up. The examiner should observe for the more than pronounced advent of the sternocleidomastoid muscle on both sides with this maneuver and should class muscular strength on the usual objective scale (i.eastward., 0–5).

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Head, confront and neck pain

Torsten Liem DO Osteopath GOsC (GB) , in Cranial Osteopathy (2d Edition), 2004

Crusade:

Normally, trauma etc. Increased tone in these muscles may exert compression on the cervical nerves. For example, spasm of the trapezius or semispinalis capitis can bring pressure to bear on the greater occipital nervus.

In particular, spasm of the longissimus capitis at its attachment to the mastoid process may exert traction inferiorly and medially. By drawing the temporal bone toward the occiput, it produces pinch at the occipitomastoid suture and narrowing at the jugular foramen.

In most cases this condition remains unrecognized and asymptomatic. It is only in response to trigger factors such every bit physical or psychological overexertion, stress, fatigue, cold etc. that there may be a further increase in musculus tension, with consequently reduced venous drainage in the cranium. The premenstrual phase in women may also human activity equally a trigger gene. Thus, an increase in intracranial CSF volume, intensifying intracranial congestion, has been recorded during the premenstrual phase.

Reduced perfusion in the cerebral arteries may result from venous congestion and this is responsible in the terminal analysis for minimal yet significant cognitive hypoxia. Headaches may ultimately be triggered by boosted factors (alcohol, phenylalanine in chocolate, sodium glutamate, vino or cheese etc.) that exercise not increase muscle tone but cause vasodilatation. The increased supply of blood leads to raised intracranial pressure with subsequent headache.

b)

Sternocleidomastoid muscle: (this passes obliquely across the occipitomastoid suture): increased tone in the sternocleidomastoid or trapezius muscles may adversely affect venous return and the nerve structures at the jugular foramen.

c)

Muscles at the cranial base: longus capitis, rectus capitis anterior, superior constrictor muscle of the pharynx.

d)

Increased muscle tone in the occipitofrontalis musculus, especially its frontal belly, may give ascension to headache.

east)

Masticatory muscles: masseter, temporalis, lateral pterygoid muscles etc. Increased musculus tone in the temporalis musculus may compress the squamous suture or, in the event of unilateral spasm, fix the frontal bone to ane side.

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Complications of Pedicled Myocutaneous Flaps

Francisco J. Civantos , James L. Netterville , in Complications in Head and Neck Surgery (Second Edition), 2009

Sternocleidomastoid Muscle

The sternocleidomastoid musculus has been used with an overlying skin paddle for oral crenel and pharyngeal reconstruction. It is based either superiorly on the occipital and posterior auricular arteries or inferiorly on a co-operative of the thyrocervical trunk. Its main reward is its regional proximity to the areas beingness reconstructed. It provides a non–pilus-bearing skin isle, and the donor site is airtight primarily. However, the blood supply to the skin paddle is tenuous, with partial skin loss in more than 50% of cases. 56–59 Furthermore, if the blood supply to the flap has been interrupted during neck dissection, it cannot be used. The theoretic possibility of transplanting neck metastases is another business organization. The sternocleidomastoid provides fantabulous carotid coverage, only it is oft resected during neck autopsy, and it is therefore rarely used in head and neck oncologic surgery. It probably maintains some usefulness as a musculus flap in specific situations, but the skin island is poorly vascularized. Because at that place is another musculus—the platysma—betwixt the sternocleidomastoid and the overlying skin island, it is theoretically unlikely that the sternocleidomastoid perforators would be the major blood supply to this skin, and clinical experience has confirmed this.

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Differential Diagnosis

In Pediatric Clinical Advisor (Second Edition), 2007

Torticollis

Torticollis means "twisted neck." Head tilt is the predominant finding and ofttimes is accompanied by neck stiffness. Contraction or contracture of the muscles of the neck causes the head to be tilted to ane side. The head usually is tilted toward and the chin is rotated away from the affected side when the sternocleidomastoid (SCM) musculus is in spasm.

Congenital conditions

Muscular (SCM muscle hematoma with scarring, presumably from birth trauma)

Vertebral anomaly (hemivertebrae or other vertebral segmentation abnormalities)

Klippel‐Feil syndrome (decreased number and fusion of cervical vertebrae)

Intrauterine positional abnormality, perhaps leading to shortening of SCM muscle

Built nystagmus

Spasmus mutans (commonly manifests before half-dozen months with head bobbing, caput tilt, and nystagmus)

Infection

Retropharyngeal or, less commonly, peritonsillar cellulitis or abscess

Cervical adenopathy or adenitis

Vertebral osteomyelitis

Pneumonia (particularly upper lobe disease)

Tuberculosis

Ocular conditions

Cranial nerve (CN) palsies, especially CN IV (caput tilts to allay diplopia)

Nystagmus

Trauma

Neck muscle spasm acquired by primary musculus (SCM) injury or vertebral injury

Myositis or fibromyositis (inflammation or spasm of SCM from draft on cervix or wry neck)

C‐spine injury

Fracture

Subluxation

Dislocation

Dislocation and subluxation more than common with bony dysplasias (achondroplasia)

Ligamentous laxity (trisomy 21)

Clavicle fracture

Tumors

Posterior fossa tumor

Eosinophilic granuloma (may involve vertebrae)

Osteoid osteoma (nighttime pain, relieved past acetylsalicylic acid)

Intraspinal tumor

Movement disorders that may partially involve Torticollis

Dystonia

Dystonia musculorum deformans

Kernicterus

Wilson illness (hepatolenticular degeneration)

Dystonic reactions (oculogyric crunch)

Phenothiazines

Antidepressants

Chlorpromazine

Droperidol

Fluphenazine

Haloperidol

Thioridazine

Trifluoperazine

Selective serotonin reuptake inhibitors (rare)

Antiemetics

Prochlorperazine (Compazine)

Trimethobenzamide (Tigan)

Movement agents

Metoclopramide (Reglan)

Other medications

Sandifer syndrome (gastroesophageal reflux with dystonia‐like movements, presumably in response to discomfort of esophagitis, patient tries to reposition to relieve hurting, which leads to writhing movements)

Miscellaneous Causes

Juvenile arthritis

Fibrodysplasia ossificans progressiva

Ligamentous laxity

Poliomyelitis

Cognitive palsy

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