The Egyptian Journal of Radiology and Nuclear Medicine (2014) 45, 105–108

Egyptian Society of Radiology and Nuclear Medicine

The Egyptian Journal of Radiology andNuclearMedicine

www.elsevier.com/locate/ejrnmwww.sciencedirect.com

ORIGINAL ARTICLE

Role of three-dimensional multidetector

computerized tomography in diagnosis

of Eagle’s syndrome

* Corresponding author. Address: 81 Mohy El-Deen Abdel-Hameed,

Nasr City, Cairo, Egypt. Tel.: +20 1272964223/222877807.

E-mail addresses: ahmedfathyalasmar@yahoo.com (A.F.Abdel-Ghany),

drnohaosman@yahoo.com (N.M. Osman).

Peer review under responsibility of Egyptian Society of Radiology and

Nuclear Medicine.

Production and hosting by Elsevier

0378-603X � 2014 Production and hosting by Elsevier B.V. on behalf of Egyptian Society of Radiology and Nuclear Medicine.

http://dx.doi.org/10.1016/j.ejrnm.2013.12.004

Ahmed Fathy Abdel-Ghany *, Noha Mohamed Osman

Radiodiagnosis Department, Faculty of Medicine, Ain Shams University, Cairo, Egypt

Received 21 August 2013; accepted 5 December 2013Available online 31 December 2013

KEYWORDS

Eagle’s syndrome;

Styloid process;

Three-dimensional MDCT

Abstract Objective: To confirm the diagnosis of Eagle’s syndrome by three-dimensional MDCT

among patients with clinical suspicion of the disease.

Materials and methods: Non-contrast MDCT neck scans of 18 patients of clinical prediagnosis of

Eagle’s syndrome and 6 control subjects over 9 months period were reviewed for styloid process

lengths and medial angulations using conventional and three-dimensional images.

Results: Our study included 18 patients and 6 controls. The means of styloid process lengths and

medial angulations were 2.6� and 69.4�, 2.2 cm and 73� respectively. Statistical significance was

found (P < 0.05) between the medial angulations of SP of patients and controls rather than

between the lengths. MDCT revealed that 10 out of 18 patients had elongated styloid processes,

6 were bilateral, and 4 were unilateral 3 of them were right sided. Mean length of elongated styloid

processes was 4.4 cm (range from 3.3 to 5.4 cm), 4.5 cm in males and 4.2 cm in females. Three out of

18 patients had narrowed bilateral medial styloid process angulation, two of whom were bilateral

and one case was unilateral with additional styloid process elongation.

Conclusion: MDCT with three-dimensional reconstructions is valuable in diagnosing Eagle’s syn-

drome by virtue of determining styloid process length and medial angulation, thus confirming clin-

ical suspicion and aiding proper management.� 2014 Production and hosting by Elsevier B.V. on behalf of Egyptian Society of Radiology and Nuclear

Medicine.

1. Introduction

The stylohyoid complex (SHC), a bone–ligament complex, is

derived from the second pharyngeal arch (Reichert’s cartilage).It consists embryologically of four parts: the tympanohyal por-tion, which fuses to the petrous temporal bone to form thebase of the SP, the stylohyal portion, which forms the main

body of the SP and the ceratohyal portion, which becomesthe stylohyoid ligament and the hypohyal portion, forming

106 A.F. Abdel-Ghany, N.M. Osman

the lesser horn of the hyoid bone and representing the junctionbetween the SHL and the hyoid bone (1).

The SP is a cylindrical bony outgrowth located in front of the

stylomastoid foramen and it extends from the temporal boneoutward. The SP is positioned between the internal carotid ar-tery (ICA) and external carotid artery (ECA) and positioned

posterolateral to the tonsillar fossa.Medial to the SP is the inter-nal jugular vein along with cranial nerves VII, IX, X, XI andXII. The SP tip is close to the ECA laterally, while medially,

the SP tip is close to the ICA with sympathetic chain (2,3).Eagle’s syndrome refers to an elongated, increased in thick-

ness or angulated ossified stylohyoid complex which can pro-ject into the tonsillar fossa and irritate the surrounding

anatomical structures in the neck (4). Because of its strategicposition, any abnormality of the SHC may lead to non-specificclinical symptoms including pharyngeal pain localized to the

tonsillar fossa, dysphagia, referred otalgia, foreign body sensa-tion in the throat and temporary voice changes. These symp-toms can be confused with a wide variety of facial

neuralgias, temporomandibular, oral and dental diseases (5).Eagle’s syndrome was first described by Eagle in (6). He

identified two subtypes of the syndrome, the classic Eagle’s

syndrome; unilateral pharyngeal pain, aggravated by swallow-ing and frequently reverberating in the ear, and the carotid orvascular syndrome and is attributed to impingement of theinternal carotid artery, extracranially by the styloid process.

This can cause a compression when turning the head or in dis-section of the carotid artery resulting in a transient ischemicaccident or stroke (7).

Symptoms of Eagle’s syndrome rely on the length, widthand angulation of the styloid process (8). Styloid process elon-gation (SPE) can be assumed if either the SP or the adjacent

stylohyoid ligament ossification shows an overall length in ex-cess of 30 mm (9). Langlais et al. (10) have classified the styloidprocess elongation into three morphological types; elongated –

the styloid process and the stylohyoid ligament appear like acontinuous structure, this is the commonest type (8); pseudoar-ticulated – the process seems to be joined to the stylomandib-ular or stylohyoid ligament by means of a single pseudo-joint

and segmented – the styloid process and ligaments consist ofseveral mineralized segments.

Medial angulation of SP should not be less than 65� (11).

Clinical suspicion of Eagle’s syndrome is made through palpa-tion of the ESP in the tonsillar fossa which is normally not feltand confirmation can be done by radiographical imaging,

more commonly; a panoramic radiography (PR) is used todetermine SPE, however, PRs are not capable of displayingthe orientation and dimensions of the styloid process. On theother hand, multidetector computed tomography (MDCT)

provides a reliable visualization of these features (12).In this study, we aimed to confirm the diagnosis of Eagle’s

syndrome by three-dimensional multidetector computed

tomography (3D MDCT) among a series of patients referredwith clinical suspicion of the disease.

2. Materials and methods

2.1. Patients

This retrospective study was done between July 2011 andNovember 2012 among Egyptian population, it included 18

patients (12 males and 6 females; mean age 46.7, range: 32–65 years) which were referred for non contrast MDCT neckby the Ear, Nose and Throat consultant on bases of clinical

suspicion of Eagle’s syndrome. Twelve of our patients com-plained of odynophagia, 2 patients had odynophagia accom-panied by otalgia, while 4 patients had the complaint of

foreign body sensation in the throat.Six control individuals (4 males and 2 females, mean age

51 years; range 35–62 years) were included in the study within

the same period; they were referred for CT neck as a part ofassessment of obstructive sleep apnea and had no relevant clin-ical history suggestive of Eagle’s syndrome.

2.2. MDCT scanning

MDCT neck scans were done in Misr Radiology Center,Cairo, Egypt. In all cases, CT neck scans were performed with-

out intravenous contrast injection with 16- section multidetec-tor row CT scanner (Bright Speed; GE medical systems,Milwaukee, USA) using standard parameters of 0.75 mm col-

limation and 0.5 mm slice thickness, **kV 120; mAs 360; heli-cal pitch 0.562:1 and rotation time 0.8 s.

2.3. Image reconstruction and analysis

In both patients and control individuals of the study, the styloidprocesses were reviewed in axial conventional images then wetransferred the original raw data to the workstation (ADW4.0

GE Medical Systems, USA) where three dimensional (3D)images were reconstructed by using volume rendering (VR)and surface shaded display (SSD) techniques. The length and

medial angulation of SP were measured through the 3D images.The styloid process length is measured between the point atwhich the SP attaches to the temporal bone and the end of the

SP (ossification in the stylohyoid ligament attached to the SPwas added to the length). The medial angulation of the styloidprocess is measured between the line crosses from the bases of

both SP and the longitudinal axis of its trunk.

2.4. Statistical analysis

Student’s t-test was used for comparison between two indepen-

dent groups; the patients and control group to determine thesignificant difference between the mean lengths and medialangulations of styloid processes. The probability of error (P-

value) of <0.05 was considered to be statistically significant.IBM SPSS statistics (V. 21.0, IBM Corp., USA, 2012) wasused for data analysis.

3. Results

Our study was carried out with a total of 18 patients: 12 (67%)

males and 6 (33%) females mean age was 46.7 (age rangesfrom 32 to 65 years), another 6 control individuals were in-cluded, 4 males and 2 females, mean age was 51 years.

Interpreting the lengths of styloid processes of patients in3D images of the CT neck scans, it was found that the meanvalue for lengths of styloid processes among patient series(36 styloid processes) was 2.6 cm. Regarding the 6 control indi-

viduals, 2.2 cm (range 1.4–3.6 cm) was the mean length of SPs(12 styloid processes), 2.4 cm was the mean of the right side

Role of three-dimensional multidetector computerized tomography 107

and 2.6 cm of the left side. There was no statistical significancebetween lengths of SP of patients and that of control subjects(P = 0.25, p> 0.05).

Ten patients out of 18 (55.6%) (6 males and 4 females) hadESP (a total of 16 ESPs), 6 (60%) of whom had bilateral ESP(Fig. 1), 3 (30%) were unilateral right sided and 1 (10%) pa-

tient was‘ unilateral left sided. Elongated styloid processes ran-ged from 3.3 to 5.4 cm, mean was 4.4 cm, and mean length ofelongated right styloid processes was 4.37 cm while 4.36 cm for

the elongated left ones. The mean value of lengths of ESP inmales (4.5 cm) was higher than that in females (4.2 cm).

The mean medial angulation of SP in the 18 patients of thestudy (36 medial angulations) was 69.4�, 69� for the right side

(range 56–79.2�) and 70� for the left side (range 57.3–80.7�).The mean medial angulation among control subjects (12 med-ial angulations) was 74.2�, 73� for the right side (range 68.4–

80�) and 76� for the left side (range 71–84.5�). There was sta-tistical significance between the medial angulations of SP ofpatients and that of control subjects (P = 0.02, P < 0.05).

Three out of 18 patients of the study had narrowed medialstyloid process angulations, 2 of whom had bilateral narrow-ing of the angle, the values of medial angulations were 56�,57.3� (Fig. 2) and 57�, 62� in the two patients respectively,while the remaining one had unilateral right sided narrow med-ial angulation (52.4�) in addition to ESP.

4. Discussion

The reported length of styloid process reaches up to 30 mm.Elongated styloid process accounts approximately to 4–7%

of the population, 4% only are symptomatic (13).Styloid process elongation could be an incidental finding in

some asymptomatic individuals (14). Abnormal angulation

rather than elongation of the styloid process may be responsi-ble for the irritation of a number of structures coursingthrough the parapharyngeal space (12).

Several imaging modalities are capable of detecting ESPsuch as plain radiographs, panoramic radiographs and com-puted tomography. Radiographic imaging is liable for super-

imposition of anatomical structures so computedtomography is more useful as it eliminates these drawbacksand it provides 2D images in variable planes and 3D-CTimages from which we can get all the information about the

styloid length, angulation and anatomical relations (14).Treatment of Eagle’s syndrome is either conservative or

surgical, but the conservative treatment is short lived (15).

Fig. 1 Male patient, 47 years old, complained of odynophagia, 3D S

processes.

The two traditional surgical approaches are targeted to styloi-dectomy (removal of the elongated portion of the styloid pro-cess) through the intraoral approach (transpharyngeal) or the

extraoral approach (16).In our study, the mean age of patients was 46.7 years, Ya-

vuz et al. (18) and Kosar et al. (18) reported the mean ages of

their patients were 48.2 and 44.7 respectively.Our study also revealed that there was statistical signifi-

cance between the means of SP medial angulations between

patients and control groups, while, there was no statistical sig-nificance between the means of SP lengths between patientsand control groups. This might draw the attention to the clin-ical significance of narrow medial angulation of SP as an

important etiology for symptoms rather than the SP elonga-tion. This agrees with Okur et al. (24) who studied the SP med-ial angulations among symptomatic and asymptomatic

subjects and concluded that the medial angulations of SPmight be responsible for stylalgia complaints in patients ratherthan the lengths of SP.

The incidence of CT positive cases for ESP among clinicallysuspicious patients of our study was 55.6%. Male to female ra-tio was 3:2 with male gender predilection 60%. Our finding is

not fitting with Ilguy et al. (8) and Woolery (19) who found fe-male predominance of Eagle’s syndrome while it agrees withBozkir et al. (20) who stated that 63% of ESP patients weremales and with Ekici et al. (21) and Gozil et al. (22) who pre-

sumed ESP are more frequent in males. The mean value oflengths of ESP in males was higher than that in females inour study which coincides with Gozil et al. (22), Ekici et al.

(21) and Kosar et al. (18).In our study, ESP lengths ranged from 3.3 to 5.4 cm and the

mean was 4.4 cm, 60% of ESPs were bilateral, 30% were uni-

lateral right sided, and while 10% were unilateral left sided. Il-guy et al. (8), Bozkir et al. (20), Balcioglu et al. (23) and Kosaret al. (18) reported that bilaterality is mostly common. Bozkir

et al. (20) stated that the mean length of ESP was 5.3 cm. It hasbeen noted in our study that there is no significant variation inthe mean length of right styloid processes (4.37 cm) comparedto left ones (4.36 cm), this agrees with Yavus et al. (17) who re-

ported in their patient group ESP ranged from 3.5 to 8.0 cm,5.0 cm mean length for the right and 5.2 cm for the left. Kosaret al. (18) found the mean length of SP was 4.1 cm while it was

4.0 cm at the right, and 4.1 cm at the left side.Regarding the medial angulations of styloid processes in

our 18 patients of the study, we found that 3 patients had nar-

rowed styloid process medial angulation, 2 of whom werebilateral and the remaining unilateral right sided case had

SD CT oblique view shows elongated right (a) and left (b) styloid

Fig. 2 Female patient, 43 years old, complained of odynophagia and otalgia, 3D VR CT coronal plane shows narrow right (a) and left

(b) styloid process medial angulation (asterisks).

108 A.F. Abdel-Ghany, N.M. Osman

additional unilateral ESP at the same side. The mean medialangulation of styloid processes of those 3 patients was 69.2�,68� and 70� for the right and left sides respectively. This coin-cides with Kosar et al. (18) who reported the mean medialangulation in their symptomatic patients as 67.5�, 66� for the

right side and 69� for the left side.Bas�ekim et al. (11) found that SP lengths in asymptomatic

individuals varied between 1.6 and 5.5 cm (mean length

2.83 cm) and the mean medial angulation was 69.5�. Onbaset al. (25) reported mean length of SP was 2.68 cm and medialangulation of 72.2�, Ramadan et al. (4) reported 2.7 cm and

medial angle was 72�, while Yavus et al. (17) reported in theircontrol group 2.8 cm mean length for the right and 2.6 cm onthe left side.

In conclusion, MDCT with 3D reconstructions are valuable

in diagnosing Eagle’s syndrome by virtue of determining sty-loid process length and medial angulation, thus confirmingclinical suspicion and aiding proper management.

Conflict of interest

The authors have no conflict of interest to declare.

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