Deep neck spaces are potential spaces located between layers of cervical fascia. Infections can spread between these spaces through direct extension or lymphatic drainage. Common sites of infection include the retropharyngeal space, parapharyngeal space, submandibular space, and peritonsillar space. Odontogenic infections are a frequent cause of submandibular space infections, while tonsillitis can lead to peritonsillar abscesses. Understanding the anatomy of the neck spaces is important for diagnosing and properly treating neck infections.

1. Deep Neck
Spaces Anatomy
and Infections
Dr/Ahmed Bahnassy
Assistant professor of radiology
Qassim University

2. Deep Neck Spaces
 Anatomy of the Cervical Fascia
 Anatomy of the Deep Neck Spaces
 Relevance to neck infections

3.  Superficial
Layer
Cervical Fascia
 Deep Layer
 Superficial
 Middle
 Deep

4. Cervical Fascia
 Superficial Layer
 Platysma
 Muscles of Facial
Expression

5. 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

6. Cervical Fascia
 Middle Layer of the
Deep Cervical Fascia
 Muscular Division
 Infrahyoid Strap
Muscles
 Visceral Division
 Pharynx, Larynx,
Esophagus, Trachea,
Thyroid
 Buccopharyngeal
Fascia

7. 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

8. Cervical Fascia
 Carotid Sheath
 Formed by all three
layers of deep fascia
 Contains carotid
artery, internal
jugular vein, and
vagus nerve
 “Lincoln’s
Highway”

9. Deep Neck Spaces
 Described in
relation to the
hyoid
 Entire length of
the
neck
 Suprahyoid
 Infrahyoid

10. Deep Neck Spaces
 Entire Length of Neck:
Superficial Space
 Surrounds platysma
 Contains areolar tissue,
nodes, nerves and vessels
 Involved with cellulitis
and superficial abscesses

11. 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

12. 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.

13. 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.

14. 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.

15. Deep Neck Spaces
 Suprahyoid:
1.Submandibular Space
 Anterior/Lateral—
mandible
 Superior—mucosa
 Inferior—superficial layer
of deep fascia
 Posterior/Inferior--hyoid

16. 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. )

17. 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 .

18. 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.

19. 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.

20. 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.

21. 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.

22. 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.

23. 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 .

24. Relevance to
Deep Neck
Space Infections

25. 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.

26. 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 .

27.  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/parapharynge
al space with an enhancing
wall and surrounding edema

28.  Adults
 Pediatrics
 Cause—trauma,
 Cause—suppurative instrumentation,
process in lymph nodes extension from
 Nose, adenoids, adjoining deep neck
nasopharynx, sinuses
space

29.  Danger Space
 Cause—extension from retropharyngeal,
prevertebral or parapharyngeal space
 Can extend to mediastinum .

30.  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

31. Tuberculous abscess
in prevertebral space

32.  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

33.  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

34. 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.

35. 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.

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

37.  Parapharyngeal
Space
 Cause—infection
of pharynx, tonsil,
adenoids,
dentition, parotid,
mastoid,
suppurative
lymphadenitis,
extension from
other deep neck
spaces

38.  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.

39.  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

40.  Masticator
Temporal Space
 Swelling along
ramus of mandible  Parotid Space
 Cause—  Medial bulge
odontogenic, from of posterior
third molars lateral
pharyngeal
wall
 Cause—
parotitis,
sialolithiasis,
Sjogren’s
syndrome

41.  Right neck
abscess with
extension to
the
masticator
space

42.  Internal Jugular Vein Thrombosis
Complications
 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.

44. 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

45. 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

46. 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