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8 Neck and Thyroid Gland
8.1 Applied Anatomy and Physiology
The neck supports the head, allows it to move, and connects it to the trunk. It consists of an osteomuscular part, which is adapted to the upright human posture. The visceral part of the neck accommodates the upper respiratory and digestive tracts: the larynx, which functions as a sphincter and as the voice organ; the thyroid gland; the carotid sheath and its contents on either side; and the cervical lymphatic system.
The upper border of the neck courses along the inferior border of the mandible, through the apex of the mastoid process to the external occipital protuberance. For clinical and surgical reasons, the suprahyoid triangle is regarded as part of the neck. Inferiorly, the neck ends in a plane formed by the suprasternal notch, the clavicle, and the spinous process of the seventh cervical vertebra. Laterally, the borders of the trapezius muscle form the boundary with the posterior part of the neck ( ▶ Fig. 8.1a). The external shape of the neck depends on factors determined by constitution and sex. In men, the larynx is angular and forms the laryngeal prominence (or Adam’s apple), and the sternocleidomastoid muscle is well developed. In women, the structures are more slender and less prominent.
Fig. 8.1 (a, b) Regions and important triangles in the neck. 1, Submandibular triangle; 2, submental triangle; 3 and 3a, carotid triangle; 3b, infrahyoid triangle; 4, lateral cervical triangle, divided into (4a) posterior cervical triangle and (4b) omoclavicular triangle; 5, lesser supraclavicular fossa; 6, hyoid bone; 7, anterior belly of the digastric muscle; 8, sternocleidomastoid muscle; 9, posterior cervical region with the trapezius muscle. (a) Most of the regions are defined by muscles visible or palpable below the skin. (b) Right lateral view.
The sternocleidomastoid muscles and the borders of the trapezius muscle on each side, the hyoid bone, the laminae of the thyroid cartilage, and the cricoid cartilage contribute to the profile and are usually visible and palpable.
An enlarged thyroid gland (goiter) and tumor masses are typically visible and palpable (see ▶ p. 465).
8.1.1 Basic Anatomy
8.1.1.1 Regions
For clinical purposes, the sternocleidomastoid muscle divides the neck into two regions:
The median region of the neck, inferior to the hyoid, has (a) the superior carotid triangle ( ▶ Fig. 8.1b and ▶ Fig. 8.2), which is clinically important, with boundaries formed by the anterior borders of the sternocleidomastoid muscle, the superior belly of the omohyoid muscle, and the posterior belly of the digastric; and (b) the small inferior carotid triangle, the boundaries of which are the anterior border of the sternocleidomastoid muscle, the medial edge of the omohyoid muscle, and the root of the neck (sternocleidomastoid region). The suprahyoid triangle ( ▶ Fig. 8.1a) is divided into the submandibular triangle and the submental triangle.
Fig. 8.2 Superior carotid triangle. 1, Sternocleidomastoid muscle; 2, posterior belly of the digastric muscle; 3, superior belly of the omohyoid muscle; 4, common carotid artery; 5, internal jugular vein; 6, deep cervical lymph node; 6a, lymph node in the jugulofacial venous angle; 7, vagus nerve; 8, hypoglossal nerve; 9, superior laryngeal neurovascular bundle; 10, ansa cervicalis; 11, lower pole of the parotid; 12, submandibular gland; 13, facial artery and vein; 14, hyoid bone.
The lateral region of the neck is divided into two triangles by the inferior belly of the omohyoid muscle. The omohyoid muscle originates from the superior border of the scapula, crosses the internal jugular vein with a flat tendon, and continues as a superior belly to insert into the inferior surface of the hyoid ( ▶ Fig. 8.1b). The lower of these is the omoclavicular triangle, with boundaries formed by the omohyoid muscle, the clavicle, and the internal jugular vein. It corresponds to the supraclavicular fossa, which is often visible. The upper triangle is the posterior cervical triangle ( ▶ Fig. 8.1a).
8.1.1.2 Cervical Fascia
The cervical muscles, viscera, and carotid sheath ( ▶ Fig. 8.3) are enclosed in a fascia which is partly tight, partly loose, and partly incomplete.
Fig. 8.3 Fascial envelopes. Cross-section at the level of the fifth cervical vertebra. Muscle fascia can be divided into: A, superficial cervical fascia; B, pretracheal lamina or middle cervical fascia; and C, prevertebral fascia or deep cervical fascia. D, Cervical visceral fascia; E, carotid sheath.
The superficial cervical fascia lies beneath the platysma, encloses the sternocleidomastoid and trapezius muscles, inserts into the hyoid bone, and extends superiorly to the border of the mandible and inferiorly to the superior border of the sternum and the clavicle.
The medial cervical fascia is a multilocular system enclosing the entire cervical viscera—the thyroid gland, esophagus, trachea, pharynx, vessels, and nerves. It stretches between the two omohyoid muscles, the hyoid, the clavicle, the upper part of the sternum, and the scapula.
The deep cervical fascia forms a tight tube around the deep cervical muscles arising from the spinous processes of the bodies of the cervical spine. The prevertebral layer is part of the fascial system, running continuously from the base of the skull to the inferior end of the spinal column.
The deep cervical fascia is divided into the alar fascia (alar: resembling a wing) and a prevertebral part lying directly on bone. The prevertebral fascial space is thus divided into two to form the “danger space” ( ▶ Fig. 8.4). Infection can spread directly within it into the posterior mediastinum.
Fig. 8.4 Cervical interfascial spaces. 1, Superficial cervical fascia; 2, middle cervical fascia; 3, deep cervical fascia; 4, alar layer of the prevertebral fascia; 5, “danger space”; 6, hyoid bone; 7, thyroid cartilage; 8, cricoid cartilage.
The contents of the carotid sheath—the common carotid artery, external and internal carotid artery, internal jugular vein, vagus nerve, and sympathetic plexus—have their own relatively thick fascial envelope, consisting of parts of all three layers of the cervical fascia.
The interfascial spaces are extremely important functionally and clinically. They can change in shape and move relative to each other, adapting to head movements, vascular pulsation, chewing, swallowing, and respiration.
Note: The space between the superficial and middle cervical fascia is closed inferiorly as a sac due to their common insertion to the sternum and clavicle, thus preventing spread of infection inferiorly. In contrast, the space between the middle and deep cervical fascia communicates freely with the mediastinum ( ▶ Fig. 8.4). This allows infection and abscesses to track downward and allows infection secondary to esophageal injuries or surgical emphysema to spread.
8.1.1.3 Neck Spaces
The neck spaces are potential spaces determined by the anatomy of the cervical fascial layers, and are relevant for understanding the site and spread of deep neck space infection. The deep spaces of the neck can be divided into spaces that involve the entire length of the neck (including the retropharyngeal space, the “danger” space, and the prevertebral space); those that are limited to the area above the hyoid bone (the submandibular, sublingual, and parapharyngeal spaces); and the space limited to the area below the hyoid bone (the anterior visceral space).
The anterior visceral space ( ▶ Fig. 8.4) lies in the anterior aspect of the neck, is enclosed by the visceral layer, and completely surrounds the trachea, esophagus, and thyroid gland. It extends from the thyroid cartilage to the level of the fourth thoracic vertebra in the superior mediastinum.
The retropharyngeal space is the potential space that exists between the posterior aspect of the visceral layer and the alar division of the deep layer. It extends from the base of the skull to the level of the first or second thoracic vertebrae. It contains two lateral chains of lymph nodes separated by a midline raphe. The danger space lies between the alar and prevertebral layers of the deep cervical fascia. It extends from the base of the skull to the posterior mediastinum at the level of the diaphragm and is limited laterally by its fusion with the prevertebral layer and the vertebral transverse process. The prevertebral space lies between the vertebral bodies and the prevertebral layer of the deep cervical fascia. It extends from the base of the skull to the level of the coccyx.
The parapharyngeal space can be compared with an inverted cone, with its base lying superiorly at the base of the skull and its apex inferiorly at the hyoid bone. It is divided into a prestyloid and a poststyloid component. Its medial border is formed by the lateral pharyngeal wall, and its lateral border is the superficial layer of the deep cervical fascia overlying the mandible, the parotid gland, and the internal pterygoid.
The submandibular space is divided by the mylohyoid muscle into the sublingual space above and the submental space below. These two spaces communicate freely around the posterior edge of the mylohyoid muscle. The entire space is bounded by the mandible anteriorly and laterally. The hyoid bone limits its inferior aspect and the intrinsic muscles of the base of tongue from its posterior border. The sublingual space contains the sublingual gland, the hypoglossal nerve, and Wharton duct. The submandibular space contains the submandibular gland.
The sublingual space encloses the sublingual gland and is a site for abscesses of the floor of the mouth (see also ▶ Fig. 3.1, ▶ p. 254).
The submental space is between the mylohyoid muscle and platysma. It is typically involved in Ludwig angina, together with the submandibular and sublingual spaces (see ▶ p. 285).
The parotid space encloses the parotid gland and the preauricular lymph nodes.
Note: These boundaries are defined by individual anatomic structures and do not necessarily contain nonspecific and specific inflammations, primary tumors of the cervical organs, lymph-node metastases, and primary and malignant lymphomas.
8.1.1.4 Vascular Anatomy
The common carotid artery is the main artery of the neck. On the right side, it rises from the brachiocephalic trunk and on the left from the aortic arch. Superiorly, it runs lateral to the trachea and larynx, without giving off any branches, to reach the level of the upper border of the thyroid cartilage, where it divides into the external and internal carotid artery.
The external carotid artery is the anterior branch of the common carotid artery. It runs superiorly in the carotid triangle, where it gives off branches, and runs beneath the posterior belly of the digastric muscle and the stylohyoid muscle. It crosses the retromandibular fossa and then courses in front of the external ear to reach the temporal region, where it divides into its final branches.
There are eight branches of the external carotid artery: the superior thyroid; lingual; facial; ascending pharyngeal; occipital; posterior auricular; internal maxillary, which gives off the middle meningeal artery; and the superficial temporal arteries ( ▶ Fig. 8.5).
Fig. 8.5 The carotid artery and its branches. 1, Common carotid artery; 2, internal carotid artery; 3, external carotid artery; 4, superior thyroid artery; 5, lingual artery; 6, facial artery; 7, internal maxillary artery; 8, middle meningeal artery; 9, superficial temporal artery; 10, posterior auricular artery; 11, occipital artery; 12, posterior branch of occipital artery; 13, ascending pharyngeal artery; 14, subclavian artery; 15, vertebral artery; 16, meningeal anastomoses; 17, carotid siphon; 18, ophthalmic artery; 19, angular artery.
The internal carotid artery is the posterior branch of the common carotid artery. It supplies the brain and the eyes, and initially runs (as does the external carotid artery) in the carotid triangle before coursing deeper in the retromandibular fossa and through the carotid canal into the skull.
The lower part of the neck receives its important arterial supply from branches of the thyrocervical trunk: the suprascapular, inferior thyroid, and ascending and superficial cervical arteries ( ▶ Fig. 8.6).
Fig. 8.6 The subclavian artery and its branches. The subclavian artery divides into different arteries, which supply the base of the neck and the upper thoracic aperture. 1, Brachiocephalic trunk; 2, thyrocervical trunk; 3, transverse cervical artery; 4, inferior thyroid artery; 5, ascending cervical artery; 6, suprascapular artery; 7, common carotid artery; 8, left subclavian artery; 9, internal thoracic artery; 10, vertebral artery; 11, transverse foramen; 12, basilar artery.
The carotid sinus is located in the adventitia of the carotid bulb where the common carotid bifurcates into external and internal branches. It contains baroreceptors/pressor receptors for blood-pressure regulation and is supplied by the carotid sinus nerve (Hering nerve) from the glossopharyngeal cranial nerve IX.
The carotid body is a small structure measuring up to 5 mm in size. It lies in the adventitia of the medial wall of the bifurcation and has chemoreceptor properties that control respiration, blood pressure, and heart rate, depending on the blood’s O2 and CO2 levels and pH. It is also supplied by the carotid sinus nerve (CN IX). It may undergo neoplastic change as a chemodectoma/carotid body tumor (see ▶ pp. 99–100; ▶ 449).
The vertebral artery arises from the subclavian artery in the root of the neck but does not participate in the blood supply to the soft tissue of the neck. The right and left vertebral arteries join intracranially to form the basilar artery. It gives off branches for the meninges and the cervical medulla and supplies the circle of Willis. The vertebral arteries transport ≈30% of the cerebral blood supply.
The internal jugular veins, together with their main tributaries, i.e., the anterior and external jugular veins, provide the main venous drainage for the head. The vertebral veins and the venous plexus in the cervical spinal canal normally carry ≈30% of the cerebral venous drainage. When one or both internal jugular veins are ligated, the vertebral venous plexuses can restore an adequate level of cerebral venous drainage ( ▶ Fig. 8.7) within a few days.
Fig. 8.7 (a, b) Cervical venous system. 1, Internal jugular vein; 2, external jugular vein; 3, anterior jugular vein; 4, vertebral veins; 4a, venous plexus in the cervical vertebral canal; 5, subclavian vein; 6, brachiocephalic vein; 7, superior vena cava. a, Cervical medulla; b, arachnoid; c, dura; d, epidural space with venous plexus and fat; e, periosteal tube; f, vertebral body. I, Greater jugulosubclavian venous angle; II, lesser jugulofacial venous angle.
A central venous catheter can be introduced via the internal jugular vein or the subclavian vein. Indications include total parenteral nutrition, drug administration, and measurement of central venous pressure. The position of the catheter should be confirmed on radiography before an infusion is started.
Note: The greater jugulosubclavian venous angle is situated posterior to the sternoclavicular joint at the root of the neck, and lateral and superior to it lie the supraclavicular or prescalene lymph nodes. The lesser jugulofacial venous angle is formed by the opening of the facial vein into the internal jugular vein. There is also a collection of important lymph nodes at this point ( ▶ Fig. 8.7).
Circulatory disorders of the internal carotid artery: These may cause little or no symptoms, provided there is adequate collateral circulation via the circle of Willis or from the external carotid artery: first, via the facial, angular, and ophthalmic arteries to the carotid siphon (ophthalmic collaterals; A in ▶ Fig. 8.8a); or second, via the occipital, meningeal, and vertebral arteries (occipital anastomosis; B in ▶ Fig. 8.8a).
Fig. 8.8 (a) Collateral circulation in insufficiency of the internal carotid artery. A, Ophthalmic collateral; B, occipital anastomoses. 1, Common carotid artery; 2, internal carotid artery with stenosis; 3, external carotid artery; 4, facial artery; 5, ophthalmic artery; 6, carotid siphon; 7, vertebral artery; 8, occipital artery; 9, meningeal anastomoses. (b) Bypass circulation in subclavian steal syndrome. 1, Aortic arch; 2, common carotid artery; 3, occluded subclavian artery (black); 4, internal carotid artery; 5, external carotid artery; 6, occipital anastomoses (see also a); 7, vertebral artery; 8, branches of the thyrocervical trunk.
Acute occlusion of this arterial system and its collaterals causes hemiplegia and unilateral sensory deficits. If the occlusion develops slowly (as in arteriosclerosis, for example), ischemic cerebral attacks initially occur, followed by generalized cerebral insufficiency.
Prior to surgery for head and neck carcinoma with cervical metastases (N3), it is important to test the capacity of the cerebral collateral reserve before proceeding with resection of the internal carotid artery.
Vertebrobasilar insufficiency: One of the sites of predilection for stenosis of the vertebral artery is the segment between its origin from the subclavian artery and its entry into the canal in the transverse process of the sixth cervical vertebra. Stenosis at this site causes temporary, recurrent, or prolonged attacks of dizziness, drop attacks, hearing disorders, disorders of vision, and sudden syncope. Chronic vertebral arterial deficiency may present with the medulla oblongata or Wallenberg syndrome.
Lateral medullary syndrome (Wallenberg syndrome): The syndrome, also known as posterior inferior cerebellar artery (PICA) syndrome, is a neurological injury due to ischemia caused by occlusion of the intracranial branches of the vertebral artery or the PICA. Acute-onset symptoms include dysphagia, hoarseness, nausea and vomiting, vertigo, facial pain, loss of facial sensation, ataxia and Horner syndrome, and uncontrollable hiccups. The usual cause is a brainstem stroke.
Subclavian steal syndrome: The resulting cerebral circulatory disorders are due to occlusion of the subclavian artery between its origin in the aorta and the origin of the vertebral artery. Vascular anomalies, trauma, and arteriosclerosis cause a reverse flow in the vertebral artery in favor of the arterial supply to the ipsilateral arm and the thyrocervical trunk at the expense of cerebral circulation ( ▶ Fig. 8.8b).
8.1.1.5 Cervical Lymphatic System
Approximately 300 lymph nodes can be found in the human neck. The cervical lymphatic system is a component of the reticuloendothelial or reticulohistiocytic system. Portals to this system include the lymphoepithelial organs of the nasopharynx and oropharynx (see ▶ p. 259).
Note: Up to the age of ≈8 or 10 years, hyperplasia of the cervical lymph nodes in the drainage area of the nasopharynx or oropharynx, due to reactive swelling of the tonsils, often results from the close connection between the lymphoepithelial and reticuloendothelial systems. Newly developed lymphadenopathy always requires investigation at any age.
Lymph channels lead from tributary tissue areas to regional lymph nodes or groups. The lymph nodes in the neck are incorporated into a network of lymph capillaries and lymph vessels, which drain on both sides into the large lower deep cervical lymph nodes, from which the lymph finally flows back into the venous system ( ▶ Fig. 8.9).
Fig. 8.9 Classification of cervical lymph nodes. The neck is divided into six three-dimensional levels containing lymph-node groups. The superficial border is formed by the superficial cervical fascia below the platysma muscle. The deep plane is formed by the prevertebral fascia and the cervical visceral fascia (see ( ▶ Fig. 8.3). I, Submental and submandibular groups; II, upper jugular group; III, middle jugular group; IV, lower jugular group; V, posterior triangle group; VI, anterior compartment group.
On the left side, the thoracic duct usually ends in a delta-shaped network. On the right side, the right lymphatic duct sinks into a cervical lymph trunk, 1 to 2 cm long, in the respective jugulosubclavian angle. These cervical lymph trunks receive afferents on both sides from the cranial area via the jugular trunks, from the axilla via the subclavian trunks, and from the thoracic area via the bronchomediastinal trunks.
The main drainage of the intrathoracic lymph is to the right jugulosubclavian angle, with the exception of the lymph of the left upper lobe of the lung. Lymph from the lower half of the body reaches the left jugulosubclavian angle via the thoracic duct. Lymph from the left superior lung segments also flows into the venous system via the left jugulosubclavian trunk (A2 in ▶ Fig. 8.10).
Fig. 8.10 Central lymph spaces of the body at the base of the neck on both sides and their efferents from the cranial lymph nodes, cervical lymph nodes; thoracic (mediastinal and tracheobronchial) lymph nodes; abdominal lymph nodes (mesenteric, lumbar, inguinal, and iliac nodes); and inferior lymph nodes. A1, Right central lymphatic space; A2, left central lymphatic space with the opening of the thoracic duct. 1, Thoracic duct.
Note: The lymph-node groups in both jugulosubclavian angles, the supraclavicular lymph nodes, are the last stations for lymph drainage from the entire body ( ▶ Fig. 8.10).
The chains of lymph nodes around the major veins of the neck, especially the internal jugular vein, are embryologically determined. The lymph-node groups of greatest clinical importance lie between the middle and deep cervical fascia. Horizontal and vertical chains anastomose in the carotid triangle. They can be palpated below the angle of the jaw and can be demonstrated surgically in the jugulofacial venous angle in the carotid triangle (see A1 and A2 in ▶ Fig. 8.10).
8.1.1.6 Nerves
The motor, sensory, and autonomic nerve supply of the neck is complex.
Motor supply of the cervical musculature and the diaphragm ( ▶ Fig. 8.11):
Fig. 8.11 Motor nerves in the neck. 1, Hypoglossal nerve; 2, ansa cervicalis superior radix; 3, ansa cervicalis inferior radix; 4, minor occipital nerve; 5, great auricular nerve; 6, transverse cervical nerve; 7, supraclavicular nerves; 8, to the brachial plexus.
The accessory (or spinal accessory) nerve supplies the sternocleidomastoid and trapezius muscles.
The hypoglossal nerve supplies the tongue.
The ansa cervicalis, which originates from the cervical plexus, supplies the infrahyoid muscles.
Branches of cranial nerves V, VII, and XII innervate the suprahyoid musculature of the floor of the mouth. Although the thyrohyoid muscle is infrahyoid, it is also supplied by CN XII.
The phrenic nerve, arising from C 3 to C 5, runs inferiorly over the scalenus anterior muscle to supply the diaphragm.
Sensory nerve supply of the external neck: This arises from the cervical plexus, C 1 to C 4, and consists of the great auricular nerve, the greater and lesser occipital nerves, the transverse nerve of the neck, the supraclavicular nerves, and the dorsal rami over the nape.
Erb’s point describes the convergence of the anterior branches at the midpoint of the posterior border of the sternocleidomastoid muscle. Infiltration at the Erb’s point produces local anesthesia in the lateral part of the neck ( ▶ Fig. 8.12).
Fig. 8.12 Sensory nerves in the neck. 1, Occipital nerve; 2, great auricular nerve; 3, transverse cervical nerve; 4, supraclavicular nerves.
Note: The nerves of the cervical plexus, especially the great auricular nerve, may be used as grafts for reconstruction of the facial or hypoglossal nerves.
Vagal nerve system—mixed nerves: This system consists of the vagus nerve (CN X), glossopharyngeal nerve (CN IX), and the cranial root of the accessory nerve (CN XI). These nerves leave the base of the skull through the jugular foramen and have motor, sensory, and parasympathetic functions in the neck, especially for the pharynx and the larynx. The superior ganglion of the vagus nerve lies at the base of the skull, and the inferior ganglion at the level of the hyoid bone (for functions of the vagal nerve system, ▶ Table 8.1 ).
Motor | Larynx: The recurrent laryngeal nerve curves around the subclavian artery on the right side and the aortic arch on the left side. The paired nerves then run superiorly between the trachea and the esophagus on each side. The recurrent nerves supply all the laryngeal muscles, with the exception of the cricothyroid muscle (see also ▶ Fig. 4.14 and ▶ Fig. 8.26) |
Pharynx: Motor vagal impulses reach the pharyngeal musculature via the glossopharyngeal nerve | |
Sensory | In the neck, these nerve branches are responsible for sensory supply to the base of the tongue, epiglottis, and larynx. The tracheal and bronchial branches of the vagus are involved in the reflex control of respiration. Sensory impulses from the posterior meatal wall and the tympanic membrane run in the auricular branch of the vagus |
Parasympathetic | Secretory parasympathetic fibers run from the neck to the organs of the thorax and abdomen |
Secretory regulation of the parotid gland is controlled via the glossopharyngeal nerve (see also ▶ p. 261) | |
Sympathetic chain | The cervical part of the sympathetic trunk lies in front of the prevertebral fascia and the transverse processes of the cervical spine. The sympathetic trunk supplies the heart, blood vessels, glands, smooth muscular organs, and accessory glands of the skin |
The superior cervical ganglion and the inconstant middle cervical ganglion arise from several segments | |
The inferior cervical ganglion, with the upper thoracic ganglia, forms the stellate ganglion. It lies between the transverse process of the seventh cervical vertebra and the head of the first rib. Postganglionic fibers from the superior ganglion run to the carotid, middle ear, salivary and lacrimal glands, and the ciliary ganglion via cranial nerves IX, X, and XI and the upper three cervical nerves |
The cranial sympathetic nerve supply: The sympathetic nervous system is dominant during physical and mental stress. It innervates all of the smooth muscles, the various glands of the body, and the striated muscle of the heart, triggering increase in blood pressure and heart rate, dilation of the pupils, and sweating, in addition to many other somatic reactions.
The cell bodies of the preganglionic neuron are located in the lateral horn of the spinal cord. The nerve fibers leave the spinal cord through the anterior root, and via a communicating branch reach the sympathetic trunk. This consists of several ganglia and nerve fibers and extends from the neck to the sacrum along each side of the vertebral column.
The sympathetic nerve fibers supplying the glands (e.g., salivary glands) and smooth muscle of the head (e.g., vessel walls, piloerector muscles, pupilloconstrictor muscle) leave the spinal cord as preganglionic fibers in the first thoracic nerve (T 1) and travel by way of the white communicating branches to the cervical portion of the sympathetic trunk. This contains three sympathetic ganglia: the inferior, middle, and superior cervical ganglia. The inferior cervical ganglions fuse with the first thoracic ganglion of the sympathetic trunk to form the stellate (radiating star-shaped) ganglion. Postganglionic neurons leave the spinal cord in the first thoracic segment and ascend and enter the sympathetic trunk at the highest sympathetic ganglion in the neck (the superior cervical ganglion). The postganglionic axons reach their effector organs with efferent fibers for the oculomotor, facial, glossopharyngeal, and vagus nerves by winding around arteries on their way to supplying the innervated structures. In this way, the neurons reach and supply the glands and smooth muscles together with the arteries. There are also afferent sympathetic fibers in the facial, glossopharyngeal, and vagus nerves.
Note: Stimulation of the superior cervical ganglion (fright response) produces dilation of the pupil and widening of the palpebral cleft, exophthalmos, sweating, and an increase in vascular tone. Blockage of the stellate ganglion by drugs or tumor leads to the opposite reaction (i.e., apparent enophthalmos, miosis, anisoconia (unequal pupils), apparent anhidrosis, and partial ptosis [Horner syndrome]).
8.1.2 Basic Physiology
Coughing: Afferent impulses running in the vagus nerve cause reflex deepening of inspiration, followed by glottic closure. The glottis opens suddenly, with an explosive escape of compressed air after contraction of the expiratory thoracic muscles. High air speeds are obtained during coughing attacks, which can eject mucus, crusts, and foreign bodies (see ▶ pp. 347, ▶ 393, ▶ 404).
Straining: The thoracic and abdominal muscles are strongly contracted with voluntary closure of the glottis. The trunk becomes a mechanically fixed unit, so that the hip and shoulder muscles can respond with a coordinated brief and maximum effort (e.g., when lifting objects or bringing the body into the upright position).
In the Valsalva maneuver (see ▶ p. 27), the thoracoabdominal muscle pump develops high-compression pressure on the vascular system with an extrathoracic increase in venous pressure, producing protrusion of the veins of the head and neck and a decrease in arterial pressure due to obstruction of venous return to the heart. The patient may faint.
8.2 Methods of Investigation
8.2.1 Specific History
The following typical symptoms are reported when the patient’s history is taken:
Pain: This can be characterized as constant pain, pain during swallowing, during pressure or palpation, or during neck movement.
Signs of local inflammation: The skin above the suspect area is red and warm or swollen, often in combination with local or diffuse pain.
Restricted movement of the cervical vertebrae: The head and neck show restricted active and passive mobility in the anterior and posterior, and also lateral, directions.
Globus feeling: This includes a foreign-body sensation, a feeling of pressure in the neck area, and a pulsing sensation.
Swelling: The swelling can be characterized by its consistency (hard, smooth, mobile, fixed) and extent (circumscribed, diffuse).
8.2.2 Inspection of the Neck Region
Inspection is oriented to the neck structures that contribute to the profile. This includes examination of the color of the overlying skin and of any lesions (e.g., rubor, vascular signs, venous congestion, pigmentation) as well as fistulous openings, swellings, or indurations (lymphadenopathy, tumor, abscess). The position and mobility of the head are examined, with observation for spasm of the neck muscles (e.g., in inflammatory processes) or functional disorders of the cervical spine.
8.2.3 Palpation
Palpation is carried out either from the front or behind, and both sides are palpated and compared. The head should be tilted slightly forward to relax the soft tissues. Palpable abnormalities mostly affect the thyroid gland, lymph nodes, salivary glands, tumors, cysts, and abscesses ( ▶ Table 8.2 ).
Thyroid swelling Lymphadenopathy
|
Median and lateral cervical cysts Inflammation and tumors of the submandibular gland and the cervical part of the parotid gland Deep inflammation or abscess |
Lipoma Hemangioma, lymphangioma, cystic hygroma |
Carotid body tumor |
Characteristic palpable findings in the neck are tumor, rubor, pain, resistance, fluctuations, pulsations, and indurations.
The evaluation and description note the shape, size, and mobility of the lymph nodes.
Auscultation and palpation are performed for suspected vascular anomalies (carotid body tumors, vascular aneurysms, carotid artery stenosis).
Lymph nodes—palpation technique: It is advisable to palpate the individual lymph-node groups bimanually in sequence ( ▶ Fig. 8.13), recording their topographic sites, number, shape, and size. The consistency of the nodes, which may be soft, elastic, fluctuant, firm, or hard, should also be recorded. Other important characteristics are pulsation and mobility. In addition, the neck muscles, shoulder, and thyroid gland should also be evaluated.
Fig. 8.13 Systematic palpation of the cervical lymph nodes. Palpation starts with the submental (1) and submandibular (2) groups, followed by the mandibular angle (3), then along the anterior border of the sternocleidomastoid muscle (4) to the supraclavicular group (5), and further along the accessory nerve to the nuchal group (6). The examination should be completed with palpation of the preauricular parotid group (7).
8.2.4 Diagnostic Imaging
8.2.4.1 Main Techniques
Two-dimensional B-mode ultrasound: This is regarded as the gold standard for detecting soft tissue lesions in the neck. Ultrasonography can provide useful information helping to identify specific lesions on the basis of morphological ultrasound criteria.
Note: Ultrasound is not able to distinguish positively between benign and malignant tissue structures.
Computed tomography (CT): Multiplanar spiral CT scan images, with or without contrast, provide detailed views of anatomical structures, differentiating between vascular lesions, inflammatory and tumor-based tissue structures (especially in the lymph nodes), cysts, and destructive cervical mass lesions.
Magnetic resonance imaging (MRI): This provides excellent discrimination of soft tissue, with differentiation between neoplastic, and inflammatory lesions. Intravenous gadolinium is used to enhance tumors and vascular structures, but renal function should be assessed prior to injection.
Positron emission tomography CT (PET-CT): This is a specific imaging modality that demonstrates increased metabolic activity in neoplastic tissue after the injection of fluorodeoxyglucose (FDG).
Conventional plain radiography of the neck: In the anteroposterior and lateral projections, conventional plain radiography provides an overview of bony structures (cervical spine), cartilaginous structures (larynx), soft tissue swellings (prevertebral), cysts, emphysema, foci of tuberculous calcification, sialoliths, radiopaque foreign bodies, and phleboliths. With the advent of scanning imaging modalities, the indications for plain radiographs have declined.
8.2.4.2 Special Techniques
Plain radiographs of the cervical spine (four views): These show the morphological basis of functional disorders. In clinical practice, plain radiographs of the cervical spine have largely been supplanted by MRI neck.
Digital subtraction angiography (DSA): This method can detect pathological changes in the vascular structures of the neck, such as stenosis, aneurysm, glomus tumor, or carotid body.
Doppler/Duplex ultrasound: This is used to assess blood flow in the extracranial vessels (common carotid, external, and internal carotid artery, subclavian and vertebral artery).
Lymphoscintigraphy: This is a method for intraoperative verification of a sentinel lymph node in the head and neck region, as a criterion for selective lymph-node biopsy or neck dissection.
8.2.5 Biopsy
Fine needle aspiration (FNA): This method allows sampling of solid tissue masses for cytologic analysis and should usually be performed under ultrasound guidance. The procedure requires considerable experience in cytomorphological evaluation of the sample material.
Core biopsy: Tissue aspiration for histologic evaluation. Only positive results can be used to establish a diagnosis.
Open biopsy: Excision of isolated lymph nodes or wedge excision of a solid tumor mass (incision biopsy) is the most reliable method for histological assessment. However, caution must be applied in patients with head and neck tumors as biopsy of a malignant neck node, particularly squamous cell carcinoma (SCC), will seriously affect the outcome, subsequent management, and prognosis.
8.3 Clinical Aspects of the Neck Region
8.3.1 Inflammatory Diseases of the Neck
8.3.1.1 Soft Tissue Infection
Superficial infections affecting the skin and its appendages have to be distinguished from deep infections affecting the viscera. Superficial infections are usually primary infections of the skin and its appendages, often caused by Staphylococci spp. Inflammations of the cervical visceral spaces are usually secondary to necrosis or inflammation of the regional lymph nodes, with or without suppuration, or extend from internal organs such as the airway and the esophagus. The infection is caused by mixed flora of staphylococci, streptococci, gram-negative organisms, or tuberculous bacilli.
8.3.1.2 Superficial Infections
Furuncles or carbuncles: A furuncle or boil is an abscess of a hair follicle, typically caused by Staphylococcus aureus. A carbuncle is a cluster of furuncles that interconnect beneath the skin. Furuncles are predisposed in diabetics and patients with immunosuppression or alcoholism. Furuncles will normally burst and discharge spontaneously but resolution can be hastened by lancing under sterile condition. Carbuncles are more likely to require incision and drainage. Concomitant antibiotic therapy may be indicated if there is associated cellulitis.
Infected sebaceous cysts and subcutaneous dermoids may mimic a cervical abscess. They are excised completely after a course of antibiotics to suppress local inflammation.
8.3.1.3 Abscesses
Clinical features: The clinical picture is determined by the site of the inflammatory process and the affected fascial space. The parapharyngeal and submandibular spaces are most commonly involved. Collections of pus lying deep in the neck often cannot be palpated. The functions of the soft tissue of the neck are restricted, and deep swellings cause pain such as trismus, pain on swallowing, and muscle rigidity. Examination of the blood shows the typical signs of infection. Shivering, respiratory obstruction, or mediastinitis occur with bacteremia/septicemia or thrombophlebitis.
Pathogenesis: The cause is a soft tissue infection originating from the head, primary or secondary inflammation of the cervical lymph nodes, a purulent thyroid infection, and/or infected cysts. Descending specific otogenic abscesses (Bezold mastoiditis, see ▶ p. 73) are uncommon today.
Diagnosis: This is based on the history, clinical findings, special imaging studies, and microbiology.
Treatment: Deep neck space infections are treated by immediate intravenous antibiotics. Infection may present at a cellulitic stage prior to abscess formation, and may well resolve with medical treatment alone. A CT scan should be considered to determine the presence, site, and size of an abscess. An abscess is likely to require incision and drainage.
8.3.1.4 Mediastinitis
Clinical features: These include severe malaise, fever, retrosternal or intrascapular pain, cutaneous emphysema (gas formation), and venous congestion.
Pathogenesis: The visceral space in the neck is not closed off from the superior mediastinum (see pp. 426–428) so that an inflammation in the former may spread into the area of the latter. Perforation of the hypopharynx or esophagus during diagnostic endoscopy, removal of a foreign body or pharyngeal pouch surgery, is particularly likely to track into the upper mediastinum.
Diagnosis: This is based on the history, clinical findings, chest radiographs—if necessary, with contrast films using a watery medium to demonstrate the perforation—and CT neck and chest. Blood culture should be considered.
Treatment: Treatment includes immediate intravenous antibiotics. Collections of pus in the neck or mediastinum should be drained.
Technique of surgical drainage: An incision is made along the anterior border of the sternocleidomastoid muscle, and blunt dissection is carried down to the esophagus. The sternocleidomastoid muscle and thyroid gland are separated by retractors, and a finger is directed along the esophagus into the posterosuperior mediastinum. A drain is introduced once the abscess has been opened.
The anterior mediastinum is entered through a horizontal incision above the suprasternal notch. The anterior wall of the trachea is exposed and a finger is used to open the upper mediastinum. A drain is introduced.
Actinomycosis is an uncommon condition that typically present with a slow growing painless mass adjacent to the mandible. If left untreated, the mass becomes fibrotic and chronic fistulas appear. Local lymph nodes may enlarge and occasionally metastatic abscesses appear in distant sites. The usual cause is Actinomyces israelii, a gram-positive nonsporing organism, which is a common oral commensal. Treatment usually includes excision of the mass and a long-term antibiotic such as penicillin for 6 months.
8.3.2 Inflammatory Cervical Lymphadenopathy
8.3.2.1 Acute Cervical Lymphadenitis
Clinical features: Patients present with acute-onset, painful, tender cervical lymphadenopathy. The site of the lymphadenitis is dependent on the primary site of the infection. A careful topographic search for the source of infection within the head and neck region is essential.
Occasionally, presentation may be subacute, with induration and decreasing or fluctuating tenderness. Abscess formation may point and burst, causing to spontaneous discharge.
Primary infection arising in patients with human immunodeficiency virus (HIV) typically has an incubation period of 1 to 3 weeks followed by an “acute” stage marked by flulike symptoms, an itchy skin rash, and generalized lymphadenitis.
Pathogenesis: Children up to the age of 10 years are prone to acute cervical lymphadenitis, usually due to nasopharyngeal infection. The most frequent cause is streptococcal infection but other potential causes include viruses (rubella, cytomegalovirus, Epstein-Barr, HIV) and mycobacterial infection.
The second frequency peak occurs in adults between 50 and 70 years of age. It is important to exclude malignancy in older patients presenting with acute cervical lymphadenitis.
Note: Enlarged cervical lymph nodes may still persist even though the primary focus of infection has resolved.
Diagnosis: Large infected/inflamed cervical nodes are likely to be painful and tender. Necrotic nodes may be fluctuant. The source of infection should be sought. Malignancy and immunosuppression should be excluded. If there is any element of doubt, an ultrasound scan and/or MRI neck or CT scan with contrast should be requested, prior to surgical intervention. Lymph-node incision, drainage, and biopsy may be indicated once malignancy is excluded.
Differential diagnosis: This includes metastatic carcinoma, Hodgkin and non-Hodgkin lymphoma, inflamed thyroglossal duct cyst, infected branchial cyst, tuberculous lymphadenopathy, toxoplasmosis, and acquired immune deficiency syndrome (AIDS).
Treatment: Broad-spectrum antibiotics are administered, escalated to intravenous therapy according to the clinical presentation. A group of inflamed enlarged lymph nodes may coalesce to form a “phlegmon,” which will often respond to intravenous antibiotics. Lymphadenitis that has already progressed to form an abscess requires incision and drainage. Pus should be sent for culture and sensitivity test and tissue submitted for histology. Simple aspiration of an abscess is unlikely to be successful.
Note: Acute cervical lymphadenitis normally resolves after treatment of the primary infection. Occasionally, induration of the lymph nodes persists. Caseation due to central necrosis within swollen lymph nodes is suspicious of tuberculosis: other potential causes include an infected branchial cyst, lymph-node tumors, the fluctuating lymphadenitis of cat-scratch fever, or tularemia. Lymph-node biopsy and histology may be diagnostic in such cases.
8.3.2.2 Chronic Cervical Lymphadenitis
Chronic cervical lymph-node enlargement that has been present for more than 4 weeks has to be distinguished from malignant diseases such as malignant lymphoma and cervical lymph-node metastasis.
A diagnostic protocol for cervical lymphadenopathy is mandatory, taking into consideration the presence of risk factors, the patient’s age, specific and nonspecific symptoms, and disease history.
Clinical examinations using palpation and B-mode ultrasound allow initial localization and measurement of the lymphadenopathy. Serological screening tests are helpful for differentiating specific lymphadenopathies. Surgical removal of the lymph node will provide the most accurate diagnosis, but must only be done after a full and thorough assessment of the respiratory tract to exclude a primary tumor.
8.3.2.3 Chronic Inflammatory Lymphadenopathy
Tuberculous Lymphadenopathy
Tuberculous lymphadenitis, previously termed scrofula, can be due to Mycobacterium tuberculosis or non-tuberculous mycobacteria (NTM)/mycobacteria other than tuberculosis (MOTT) such as Mycobacterium avium intracellulare, M. scofulaceum, M. haemophilum, or M. fortuitum.
While tuberculous lymphadenitis is uncommon, it should always be considered in adults with immunosuppression, particularly with HIV infection.
Non-tuberculous mycobacterial lymphadenitis is more likely to occur in young children.
Clinical features: Any group of lymph nodes in the cervical region may be affected; the disease is bilateral in 20% of patients. The upper jugular, supraclavicular, and nuchal lymph nodes are most often involved. Tuberculous lymphadenopathy is typically painless or only produces slight pain. The lesions may be solitary, multiple, small or large, firm or fluctuant. Fistulas or old retracted fistulous scars may be present in addition to acute reactivated lymph nodes, possibly with reddening of the skin and fluctuation ( ▶ Fig. 8.14).
Fig. 8.14 An inflamed cutaneous reaction and lymph-node swelling due to a tuberculous infection.
Pathogenesis: Tuberculosis lymphadenitis is mainly a secondary hematogenous infection, usually caused by human tuberculous mycobacteria; occasionally, it is due to atypical mycobacteria, particularly in children. Primary pharyngeal infection is now rare and generally occurs in patients with active pulmonary TB. The infection spreads from patients with active tuberculosis who may be apparently healthy and tuberculin-positive.
Note: Calcification of tuberculous lymph nodes is often considered to be an indication that they have healed, but this is incorrect. Tubercle bacilli can survive for decades in caseous and calcified centers of lymph nodes.
Diagnosis: Important points to elucidate from the patient’s history include country of origin, a family history of tuberculosis, and visits to endemic areas in Asia, Africa, and south-eastern Europe. Radiographic and CT images of the neck showing calcification of the lymph nodes are almost always pathognomonic. A positive tuberculin skin test in an immunocompetent adult in the absence of previous vaccination may be helpful, but false-positive/false-negative results do occur and the test may not be diagnostic. Chest radiography and tuberculosis serology (Interferon Gamma Release Assay [IGRA]) complete the diagnostic protocol.
The diagnosis is confirmed by the histology of the excised lymph nodes, identifying granuloma formation, caseation, and acid-fast/alcohol-fast staining bacilli. Microbiology is particularly important for atypical mycobacterial infection, but can take several weeks to obtain a result.
Differential diagnosis: Lymphoma should be excluded. Other possible diagnoses to consider include: acute cervical lymphadenitis, branchial cleft cyst, metastatic carcinoma, Hodgkin disease, sialadenitis, salivary tumor, neurinoma, nodular goiter, dermoid cysts, and sialadenitis secondary to a salivary stone.
Treatment: Tuberculous lymphadenitis is treated with antituberculous medication such as long-term combined quadruple drug therapy using isoniazid, rifampicin, pyrazinamide, and ethambutol. Antibiotic resistance to antituberculous drugs has been reported and management should be directed by an appropriate specialist expert in the field.
The management of non-tuberculous mycobacterial lymphadenitis is controversial and includes awaiting natural resolution, medical therapy, and surgical excision of the nodes. The balance of treatment includes prevention of scarring and long-term cosmesis.
Surgery: Surgery should be considered for:
Lymph nodes 2 cm or more in diameter that show no tendency to resolve.
Lymph nodes with calcification.
Fluctuant lymph nodes.
Fistulas.
Collar-stud abscess, involvement of the lymph nodes, soft tissue abscess, and involvement of the overlying skin.
Surgical treatment may include removal of specifically affected lymph nodes, affected soft tissues, and cervical skin. In many cases, particularly with collar-stud abscess, a selective neck dissection (see ▶ p. 462) with reconstruction of the skin defect may be necessary. Infections with atypical mycobacteria may require aggressive surgery with excision of all infected tissue, balanced against inducing a complication such as facial nerve paralysis.
Extensive excisional procedures for tuberculous lymphadenitis are associated with a high risk of complications and caution should be applied.
Tonsillectomy is no longer recommended as a means of eliminating a tuberculous primary focus.
Syphilis
See also ▶ p. 279.
Stage I, primary chancre: An indolent regional lymphadenopathy appears 1 to 2 weeks after the primary lesion on the lips, mouth, tonsils, or facial area.
Stage II: Multiple cervical lymphadenopathy may occur.
Stage III: Rarely causes lymphadenopathy.
Sarcoidosis (Boeck Disease)
Clinical features: Lymphadenopathy affects the mediastinal and supraclavicular nodes in 65% to 75% of cases and the peripheral nodes in 10% to 20%, and may include the retroperitoneal nodes. The eyes, lacrimal glands, and salivary glands are affected in 5% to 25% of cases. The skin is affected in 10% to 40% of cases with erythema nodosum or lupus pernio. The mucous membranes of the nose and sinuses, pharynx, larynx, trachea, mouth, and esophagus demonstrate pale-red granular areas.
Heerfordt syndrome is a rare but distinctive presentation that includes uveoparotitis and facial paralysis (see ▶ p. 487).
Pathogenesis: The cause of this condition remains unknown. Affected tissues display a noncaseating epithelioid cell granulomatous reaction, spreading in the reticulohistiocytic system.
Treatment: Systemic steroids are the mainstay of active sarcoidosis. Cytotoxic therapy and anti-tumor necrosis factor-α (anti-TNF-α) drugs are used in severe cases.
Cat-Scratch Disease
Clinical features: Cat-scratch disease typically occurs in children and young patients up to the age of 20 years. An erythematous primary focus occurs in the skin or oral mucosa. This is followed 1 to 5 weeks later by a regional painless, or almost painless, lymphadenopathy. There may be associated general malaise, aches, and pains.
Pathogenesis: Cat-scratch disease is a granulomatous condition caused by the Rickettsia Bartonella spp. Bartonella henselae, a small aerobic gram-negative coccobacillus, is the most common microorganism. In most cases, the infection follows a scratch or a bite from a cat, but dogs, rodents, and hedgehogs may also be carriers. The vector between cats is the cat flea. It is postulated that transmission to humans occurs by contamination of a scratch or mucosal surface with cat flea feces containing B. henselae.
Diagnosis: Most patients have had contact with cats, especially kittens. Blood serology is sensitive and specific, confirms the diagnosis, and excludes underlying malignancy. Polymerase chain reaction (PCR) RNA, if available, will also confirm the diagnosis.
Treatment: Cat-scratch disease typically resolves without treatment. The use of antibiotics is controversial, but rapid resolution is reported with azithromycin. Doxycycline is also effective.
Tularemia (Rabbit Fever/Deer Fly Fever)
Tularemia is caused by Francisella tularensis, named after the county of Tulare in California. The zoonosis is widespread in rodents, particularly in rabbits and hares. It is transmitted by ticks and other biting insects and contaminated drinking water.
It causes oral and skin ulcers, fever, malaise, headache, and lymphadenopathy. Lymph nodes may suppurate.
The diagnosis can be challenging, but investigations should include blood culture, and serology. Histological examination of affected nodes shows reticulocytic lymphadenitis with abscess formation. The treatment of choice is streptomycin, but alternatives include aminoglycosides and tetracyclines—a relapse rate of up to 50% has however been reported. The severity and type of lymphadenopathy determine the need for surgical treatment.
Toxoplasmosis
Signs and symptoms: Acquired toxoplasmosis causes an acute or subacute influenza-like illness with subfebrile temperatures for 6 to 8 weeks. An important clinical feature is lymphadenopathy affecting especially the nuchal, periauricular, jugulodigastric, supraclavicular, and rarely axillary and inguinal nodes. The chronic form affects adults and produces few characteristic symptoms, but may cause headache or chronic eye disease.
Infants with congenital toxoplasmosis can develop sensorineural hearing loss, microcephaly, chorioretinitis, and developmental delay. Early antiparasitic therapy can prevent sensorineural hearing loss. There is no evidence that screening pregnant women prevents maternal-fetal transmission.
Pathogenesis: Infection in humans is caused by Toxoplasma gondii, a protozoan which is transmitted by consumption of raw/undercooked beef, lamb, or pork, or ingestion of food contaminated with cysts from feline feces.
There is evidence of previous infection in a high proportion of the population, as antibodies are found in up to 70% of clinically healthy people. The great majority of postnatal infections proceed without causing characteristic clinical symptoms.
Diagnosis: The diagnosis is made from the clinical picture and serology. The full blood count shows lymphocytosis with atypical mononuclear cells.
Serological tests: Serology includes toxoplasma-specific antibodies and immunoglobulin levels. High titers of immunoglobulins G and M indicate an acute or chronic infection. The Sabin-Feldman dye test and the complement-binding reaction are rarely used nowadays.
Histological examination of lymph nodes usually reveals Piringer-Kuchinka syndrome—an epithelioid cell lymph-node reaction with no necrosis and argyrophilic granules in the protoplasm of the reticulum cells.
Differential diagnosis: The above serologic findings, particularly in combination with lymph-node biopsy, are very characteristic of toxoplasmosis.
Lymphadenopathy with similar lymphocytic changes in the blood picture also occurs in infectious lymphocytosis, rubella roseola infantum, and listeriosis. Similar findings occur in lymphadenopathy secondary to antiepileptic drugs (sodium channel blockers, γ-aminobutyric acid (GABA) receptor blockers, and carbamazepine); antitoxins; some antibiotics and serum injections; transplanted tissue drainage areas; infectious mononucleosis.
Treatment: The preferred regimen involves a combination of pyrimethamine and sulfonamides (sulfadiazine).
Lyme Disease
Lyme disease is a zoonosis, transmitted to humans by a spirochete from infected blacklegged tick bites. This is a multisystem disease with an incubation period of 1 to 4 weeks.
Signs and symptoms: Lyme disease can produce a wide range of symptoms, depending on the stage of infection:
Early signs and symptoms occur 3 to 30 days after a tick bite. The initial clinical features are erythema migrans at the bite site, with lymphadenitis and viral-like symptoms (fever, chills, headache, fatigue, muscle and joint aches). Erythema migrans occurs in approximately 70% to 80% of infected persons. It begins at the site of a tick bite after a delay of 3 to 30 days; it is rarely painful or itchy. A typical sign is a “bull’s-eye” appearance which may appear on any area of the body.
Later signs and symptoms occur weeks to months after tick bite. Variable organ involvement supervenes at 3 to 8 weeks. Ipsilateral or bilateral facial palsy develops in 60% of cases, especially in children. The late stage is dominated by neurologic symptoms such as meningopolyradiculitis (severe headaches and meningism). It can cause sensorineural hearing loss and laryngeal paralysis. Additional erythema migrans rashes are found on other areas of the body. Arthritis with knees and large joints swelling, and muscle and tendon pain can occur.
Pathogenesis: The disease is caused by the spirochete Borrelia burgdorferi, transmitted mainly by the bite of the tick Ixodes ricinus (Central Europe), Ixodes scapularis (Eastern USA), Ixodes pacificus (Western USA), and Ixales persulcatus (Russia).
Diagnosis: Serological for specific antibodies, using ELISA (enzyme-linked immunosorbent assay) for IgG and IgM antibodies. There may be a delay before antibodies reach detectable levels, especially within 4 weeks of infection, and negative tests should be repeated after 4-6 weeks.
Differential diagnosis: Differentiation is required from spring-summer meningoencephalitis.
Treatment: The antibiotic treatment of choice is doxycycline (in adults), amoxicillin (in children), and ceftriaxone for 3 to 4 weeks. Alternative choices are cefuroxime and cefotaxime.
Prognosis: The prognosis is favorable with treatment.
8.4 Cervical Syndrome/Cervical Spine Syndrome
This term is a collective name for a multitude collection of diverse orthopaedic and neurological symptoms that are considered to emanate from the cervical spine.
Clinical features: The cervical spine syndrome is an imprecise term that is not really a syndrome. The term is frequently used in patients with pain in the region of the cervical spine, without specifying any causal factors.
Possible causes of pain include muscular strain caused by physical stress or incorrect posture. Protrusion or dislocation of an intervertebral disk, or arthrosis and inflammation of the facet joints can also cause this disorder. Blockage of a facet joint can cause localized pain, as well as sympathetic nervous system reactions. Clinical symptoms can also be caused by exaggerated motion in single segments of the cervical vertebrae, due to abrasion of stiffened neighboring segments.
Additional clinical symptoms often attributed to the cervical spine are otalgia and acute cochleovestibular disorders with hearing difficulties, tinnitus, and vertigo. Dysphonia of an undefined origin, chronic pharyngitis, and globus sensation are characteristic signs and symptoms in the pharyngeal and laryngeal sections of the neck area.
Other more complex syndromes accompanied by the cervical spine syndrome include acute torticollis, cervical fusion syndrome, and subclavian steal syndrome.
Diagnosis: The history provides preliminary, and often decisive, indications of disorders of the cervical spine. Inspection can identify soft tissue changes as indications of reflex secondary changes in the area of blocked facet joints. Palpation can detect trigger points, and an analysis of the quality of skin and muscle is carried out. An important examination method is testing the segmental movement of the cervical spine and cervicothoracic junction. This can identify any restricted movement of individual intervertebral joints. This examination method requires chiropractic experience for accurate assessment of alterations.
Treatment: Treatment should include neck mobilization and reduction of muscle spasm, as offered by a physiotherapist or chiropractor. Techniques to relax the muscles, passive mobilization of individual joints, stretching of muscles, manipulations, therapeutic use of local anesthesia, and relief of muscle spasm by botulinum toxin injections are generally effective. All of these can be supplemented with physical measures (application of warmth) and medications where deemed necessary (anti-inflammatory drugs, antirheumatics, muscle relaxants).
8.5 Neck Trauma
Neck trauma can be due to direct or indirect blunt injury and penetrating injury.
8.5.1 Injuries to the Cervical Spine
Indirect injuries are typically caused by road traffic accidents and sports injuries. They may be accompanied by other direct injuries to the head and neck area. Flexion-extension injuries are known to be associated with alteration in the senses of hearing and balance. There are three typical mechanisms of injury that usually occur during sports and road-traffic accidents:
Sprain injury (sprain means overstretching or tearing of ligaments).
Torsion injury, often combined with sprain.
Flexion-extension/acceleration/deceleration injury/whiplash injury.
Nausea and vomiting and cochleovestibular reactions (loss of hearing, tinnitus, vertigo) are symptomatic of these injuries. Disturbances of sensation and paralysis can also appear. Patients with suspected injury to the cervical spine should undergo imaging that includes plain radiographs of the neck, CT, and MRI. Possible injuries include fractures of C 1 (the atlas) or C 2 (the dens). Should there be any suspicion of a fracture and an unstable cervical spine, the neck should be immobilized until stability is confirmed by a CT scan.
The management of injuries to the cervical spine should be multidisciplinary and may include the intervention of otolaryngologists, orthopaedic surgeons, emergency surgeons, neurologists, and neurosurgeons.
8.5.2 Injuries to the Aerodigestive Tract
Injuries to the larynx are described on ▶ pp. 343–347, injuries to the trachea on ▶ pp. 393–394, and injuries to the esophagus on ▶ pp. 402–404.
Such injuries can arise from blunt or penetrating trauma as well as heat trauma during fires and inhalation. In all cases, the airway could be compromised. Depending on the force involved, blunt trauma to soft tissues leads to tissue swelling secondary to edema or hematoma, and to surgical emphysema if a defect occurs in the mucosal continuity of the subglottis, trachea, or hypopharynx.
The degree of injury is determined by the direction and varying degrees of force. Open injuries to the hypopharynx and esophagus generally and exploration and repair unless the defect is small. Diagnostic delay should be minimized. The decision to operate includes taking account of the type of injury and the readiness of theater availability.
Tracheal injury is uncommon and can be managed expectantly if relatively minor. Otherwise, securing the airway with intubation or tracheostomy is necessary, and tracheal repair may also be appropriate.
8.5.3 Vascular Injuries
The most significant vascular injuries include trauma to the common carotid artery or internal jugular vein. The danger associated with opening one of the major veins is air embolism. If the volume of air aspirated is more than 10 to 20 mL, the result is fatal. Emergency treatment of air embolism consists of immediate digital compression, flat body posture, and subsequent surgical repair.
Patients with carotid artery hemorrhage usually die at the time of injury due to hemorrhagic shock. Even with immediate digital compression and rapid surgical treatment, a high proportion of the survivors of open injuries to the common and internal carotid arteries have residual cerebral defects. Investigation is best done with helical CT angiography and, if available, color-flow duplex Doppler imaging.
Successful treatment depends on interdisciplinary management involving trauma surgeons, anesthesiologists, and vascular surgeons. The main debate centers around ligation versus vascular repair and reperfusion; the latter has been shown to give better results in patients with severe neurological damage with preoperative coma and ischemia that had been present for a only short period of time.
Vertebral artery injury has gained greater recognition due to the availability of angiography, and most injuries can be dealt with by selective arterial embolization.
8.6 Congenital Anomalies of the Neck
8.6.1 Thyroglossal Duct Cysts and Fistulas
Thyroglossal duct cysts are the most common congenital abnormality in the head and neck. They typically present with a midline swelling in children and young adults.
Clinical features: A thyroglossal duct cyst presents with a firm elastic swelling in the midline of the neck at the level of, above, or below the hyoid bone ( ▶ Fig. 8.15). The patient may have a globus sensation and a visible lump. Seventy-five percent are prehyoid and 25% are above or below the hyoid. Thyroglossal cysts can become infected if not removed, and can subsequently burst and form a fistula. If a fistula is present, its external opening is often inflamed.
Fig. 8.15 A thyroglossal duct cyst typically forms an elastic swelling in the midline of the neck at the level of the hyoid bone.
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