Deep Neck Spaces Anatomy and Infections

Dr/Ahmed BahnassyAssistant professor of radiology

Qassim University

Deep Neck Spaces

Anatomy of the Cervical Fascia

Anatomy of the Deep Neck Spaces

Relevance to neck infections

Cervical Fascia Superficial Layer

Deep Layer Superficial Middle Deep

Cervical Fascia

Superficial Layer Platysma Muscles of Facial

Expression

Cervical Fascia Superficial Layer of the

Deep Cervical Fascia (rule of two’s)

Muscles Sternocleidomastoid Trapezius

Glands Submandibular Parotid

Spaces Posterior Triangle Suprasternal space of

Burns

Cervical Fascia

Middle Layer of the Deep Cervical Fascia

Muscular Division Infrahyoid Strap

Muscles Visceral Division

Pharynx, Larynx, Esophagus, Trachea, Thyroid

Buccopharyngeal Fascia

Cervical Fascia

Deep Layer of Deep Cervical Fascia Alar Layer

Posterior to visceral layer of middle fascia

Anterior to prevertebral layer

Prevertebral Layer Vertebral bodies Deep muscles of the

neck

Cervical Fascia

Carotid Sheath Formed by all three

layers of deep fascia Contains carotid

artery, internal jugular vein, and vagus nerve

“Lincoln’s Highway”

Deep Neck Spaces

Described in relation to the hyoid Entire length of

the neck Suprahyoid Infrahyoid

Deep Neck Spaces Entire Length of Neck:

Superficial Space Surrounds platysma Contains areolar tissue,

nodes, nerves and vessels Involved with cellulitis

and superficial abscesses

Deep Neck Spaces Entire Length of

Neck: 1.Retropharyngeal Space Posterior to pharynx

and esophagus Anterior to alar layer

of deep fascia Extends from skull

base to T1-T2

Deep Neck Spaces

Entire Length of Neck: 2.Danger Space

Anterior border is alar layer of deep fascia

Posterior border is prevertebral layer

Extends from skull base to diaphragm and is so named because it contains loose areolar tissue and offers little resistance to the spread of infection.

Deep Neck Spaces

Entire Length of Neck: 3.Prevertebral Space

Anterior border is prevertebral fascia

Posterior border is vertebral bodies,ALL and deep neck muscles

Extends along entire length of vertebral column. Infection in this space tends to stay somewhat localized due to the dense fibrous attachments between the fascia and the deep muscles.

Deep Neck Spaces Entire Length of Neck:

4.Visceral Vascular Space Carotid Sheath Like the prevertebral space the

visceral vascular space is quite compact, contains little areolar tissue and is resistant to the spread of infection. It is termed the “Lincolin’s highway” of the neck . It extends from the base of skull into the mediastinum and because it receives contributions from all three layers of deep fascia it can become secondarily involved by infection in any other deep neck space by direct spread.

Deep Neck Spaces Suprahyoid:

1.Submandibular Space Anterior/Lateral—

mandible Superior—mucosa Inferior—superficial layer

of deep fascia Posterior/Inferior--hyoid

Deep Neck Spaces Suprahyoid: Submandibular

Space comprises Sublingual Space

Areolar tissue Hypoglossal and lingual nerves Sublingual gland Wharton’s duct

Submylohyoid Space Anterior bellies of digastrics Submandibular gland (These two subdivisions freely

communicate around the posterior border of the mylohyoid. )

Deep Neck Spaces

Suprahyoid: 2.Parapharyngeal Space (pharyngomaxillary space )

Superior—skull base-petrous portion of temporal bone vs. sphenoid

Inferior—hyoid Anterior—ptyergomandibular

raphe Posterior—prevertebral fascia Medial—buccopharyngeal fascia Lateral—superficial layer of deep

fascia,medial pterygoid and parotid .

The parapharyngeal space communicates with submandibular , retropharyngeal, parotid and masticator spaces with important implications in spread of infection .

Deep Neck Spaces Suprahyoid: Parapharyngeal

Space comprises: Prestyloid

Medial—tonsillar fossa Lateral—medial pterygoid Contains fat, connective tissue,

nodes Poststyloid

Carotid sheath Cranial nerves IX, X, XII The stylopharyngeal aponeurosis

of Zuckerkandel is formed by the intersection of the alar, buccopharyngeal and stylomuscular fascia and acts as a barrier to the spread of infection from the prestyloid compartment to the poststyloid compartment.

Relations to other spaces

Normal anatomy of parapharyngeal space. BS = buccal space, ICA = internal carotid artery, IJV = internal jugular vein, MS = masticator space, PMS = pharyngeal mucosal space, PPS = parapharyngeal space, PS = parotid space, PVS = prevertebral space, RPS = retropharyngeal space, SMS = submandibular space, T = torus tubarius. Axial schematic at nasopharynx level shows that parapharyngeal space is divided into prestyloid and poststyloid compartments by tensor-vascular-styloid fascia connecting tensor veli palatini muscle with styloid process.

Deep Neck Spaces Suprahyoid: Peritonsillar Space

Medial—capsule of palatine tonsil

Lateral—superior pharyngeal constrictor

Superior—anterior tonsil pillar Inferior—posterior tonsil pillar. This space contains loose

areolar tissue, primarily in the area adjacent to the soft palate, which explains why the majority of peritonsillar abscesses will localize to the superior pole of the tonsil.

Deep Neck Spaces Suprahyoid:3.Masticator and

Temporal Spaces Formed by the superficial layer

of deep cervical fascia and contains.

Masseter and pterygoids Temporalis. The masticator space is in direct

communication with the temporal space superiorly deep to the zygoma. The temporal space has as its lateral boundary the superficial layer of deep fascia and its medial boundary the periosteum of the temporal bone. It is subdivided into superficial and deep spaces by the body of the temporalis muscle. This space contains the internal maxillary artery and the mandibular nerve.

Deep Neck Spaces Suprahyoid:4. Parotid Space

Formed by superficial layer of deep fascia and dense septa from capsule into gland.

In addition to the parotid gland, this space contains the parotid lymph nodes, the facial nerve and posterior facial vein.

The fascial envelope is deficient on the supero-medial surface of the gland, facilitating direct communication between this space and the parapharyngeal space.

Deep Neck Spaces Infrahyoid: Anterior

Visceral Space Formed by middle layer of

deep fascia Contains thyroid, trachea,

esophagus. This potential space runs from the thyroid cartilage into the anterior superior mediastinum to the arch of the aorta. Below the level of the thyroid gland this space communicates laterally with the retropharyngeal space .

Relevance to Deep Neck

Space Infections

Pathophysiology

Deep neck space infections can arise from a multitude of causes., as follows:

1. Spread of infection can be from the oral cavity, face, or superficial neck to the deep neck space via the lymphatic system.

2. Lymphadenopathy may lead to suppuration and finally focal abscess formation.

3. Infection can spread among the deep neck spaces by the paths of communication between spaces.

4. Direct infection may occur by penetrating trauma.

Spread of infection Tonsillitis may lead to peritonsillar abscess. If not treated

successfully, peritonsillar abscess may spread to the lateral pharyngeal space. From thereto the posterior pharyngeal and prevertebral spaces and into the chest. Mediastinitis and empyema may ensue.

Alternatively, infection may spread from the lateral pharyngeal space to the contents of the carotid sheath, leading to internal jugular vein thrombosis, subacute bacterial endocarditis, pulmonary emboli, carotid artery thrombosis cerebrovascular insufficiency, Horner syndrome ,or may cause even airway obstruction .

Retropharyngeal Abscess 50% occur in patients 6-12 months of age 96% occur before 6 years of age

Retropharyngeal phlegmon. Axial CT section through the lower nasopharynx shows a well-marginated lucent area in the retropharyngeal/parapharyngeal space with an enhancing

wall and surrounding edema

Pediatrics Cause—suppurative

process in lymph nodes Nose, adenoids,

nasopharynx, sinuses

Adults Cause—trauma,

instrumentation, extension from adjoining deep neck space

Danger Space Cause—extension from retropharyngeal,

prevertebral or parapharyngeal space Can extend to mediastinum .

Prevertebral Space Back, shoulder, neck

pain made worse by

deglutition Dysphagia or

dyspnea Cause—Pott’s

abscess, trauma, osteomyelitis,

extension from retropharyngeal and

danger spaces

Tuberculous abscess in prevertebral space

Visceral Vascular Space Induration and tenderness over SCM Torticollis toward opposite side Spiking fevers, sepsis Cause—intravenous drug abuse, extension from

other deep neck spaces

Submandibular Space Anterior neck swelling,

floor of mouth edema Cause—70-85% have

odontogenic origin First molar and

anterior Second and third

molars Sialadenitis,

lymphadenitis, mandible fractures,etc.

Right submandibular gland infection with a stone

Which space is affected ? The apex of the first molar is above the

mylohyoid, so involvement of this tooth, or teeth anterior to this, will first involve the sublingual space. In contrast, the apices of the second and third molars are below the mylohyoid and infection here will first spread to the submylohyoid space. However, as previously mentioned, these spaces freely communicate around the posterior border of the mylohyoid, and both subspaces may be involved.

Ludwig’s angina

Tender, firm anterior neck edema without fluctuance

Contrast CT scan through the tongue and oral cavity demonstrates an enhancing inflammatory mass with abscess in the right tongue and oral cavity with extension into the parapharyngeal space and masticator space.

Ludwig's angina. Axial CT section through the tongue demonstrates diffuse enlargement of the tongue associated with low attenuation areas consistent with phlegmon.

Parapharyngeal Space Cause—infection

of pharynx, tonsil, adenoids, dentition, parotid, mastoid, suppurative lymphadenitis, extension from other deep neck spaces

Middle ear infections or mastoiditis may involve the parapharyngeal space after rupture of a Bezold’s abscess on the inner aspect of the mastoid tip along the digastric ridge.

. Bezold's abscess, upper left neck. A, Axial noncontrast CT section defines an ill-defined mass in the upper posterior left neck. B, Axial CT section (bone window setting) demonstrates lytic destruction in the lower left mastoid secondary to coalescent mastoiditis.

Peritonsillar Space Fever, malaise “Hot-potato” voice,

trismus. Cause—extension

from tonsillitis. These infections are uncommon in the pediatric population, but instead tend to effect post-pubescent individuals.

CT section demonstrates an enhancing mass in the right peritonsillar region with a low-attenuation area centrally consistent with an abscess cavity

Masticator Temporal Space Swelling along

ramus of mandible Cause—

odontogenic, from third molars

Parotid Space Medial bulge

of posterior lateral pharyngeal wall

Cause—parotitis, sialolithiasis, Sjogren’s syndrome

Right neck abscess with extension to the masticator space

Complications Internal Jugular Vein Thrombosis Lemierre’s syndrome F/C, prostration, swelling and pain

along SCM Bacteremia, septic embolization, dural

sinus thrombosis Pulmonary embolism

occurs in up to 5% of these patients. Patients that develop deep neck infection secondary to intravenous drug abuse.

Right jugular vein thrombosis. Axial CT section through the neck below the angle of the mandible demonstrates a low attenuation area with an enhancement wall in the right neck medial to the indistinct and enlarged sternocleidomastoid muscle.

Complications

Carotid Artery Rupture Mortality of 20-40% Sentinel bleeds from ear, nose, mouth Majority from internal carotid, less from external

carotid, and fewest from common carotid

Complications Mediastinitis

A- MDCT of the neck shows two large fluid collections containing gas in both the submandibular spaces (arrows).(B) At the level of the hyoid bone, a large fluid collection is seen in the visceral space (C) Large fluid collection in the visceral space (D) The fluid collection spreads to the anterior mediastinum (E) Sagittal multiplanar reformatted CT image shows spread of descending necrotizing mediastinitis

Special Consideration Recurrent Deep Neck

Space Infection THINK CONGENITAL

ABNORMALITY Nusbaum, et al: 12 cases of

recurrent deep neck infection Most Common: second branchial

cleft cyst Others: first, third, fourth branchial

cleft cysts, lymphangiomas, thyroglossal duct cysts, cervical thymic cyst

Infected right branchial cleft cyst. CT scan shows an oval-shaped lucent area in the right neck at the level of the upper thyroid cartilage