Imaging in Acute Imaging in Acute TorticollisTorticollisDivision of NeuroradiologyDepartment of Radiology

University of North Carolina at Chapel Hill

Overview of This PresentationOverview of This Presentation

I. IntroductionII. Imaging algorithm for acute torticollisIII. Causes of torticollis

A. TraumaB. Infection/InflammationC. NeoplasmD. Other/Idiopathic

IV. Atlantoaxial rotatory fixationV. Selected references

At the Conclusion of this Exhibit At the Conclusion of this Exhibit One Should Be Able To:One Should Be Able To:

• Define torticollis• Describe an algorithm for imaging patients

presenting with torticollis• List several potential causes of torticollis

and describe their typical imaging features• Discuss the concept of atlanto-axial

rotatory fixation and its diagnosis

Introduction: What is Torticollis?Introduction: What is Torticollis?• Derived from the

Latin tortus (twisted) + collis (neck or collar)

• Torticollis is defined as abnormal twisting of the neck which causes the head to be held in a rotated or tilted position.

Introduction: Clinical Aspects of Introduction: Clinical Aspects of Acute TorticollisAcute Torticollis

• Torticollis refers to a symptom rather than a distinct disease process

• It can be caused by a wide variety of conditions (over 80 causes have been described) which range from relatively innocuous to life-threatening

• May be congenital or acquired• Occurs more frequently in children than in adults• The right side is affected in 75% of patients

Introduction: Chronic Sequelae of Introduction: Chronic Sequelae of TorticollisTorticollis

• Physical– Positional plagiocephaly– Facial deformities– Cervical spine degeneration– Radiculopathies and myelopathies

• Psychiatric– Major depression– Agoraphobia– Substance abuse– OCD

Imaging of Patients with TorticollisImaging of Patients with Torticollis

• Choice of imaging studies depends on age and if history of trauma is present.

• In newborn infants with congenital muscular torticollis, ultrasound is preferred and often diagnostic.

• In older children and adults with post trauma torticollis, CT of neck/cervical spine is needed to exclude fracture or malalignment. If CT is positive, MRI and MRA of the neck should be considered to evaluate for associated cord, ligamentous, or arterial injuries.

• In older children and adults presenting with torticollis without trauma, neck/cervical spine CT is the initial imaging study; if negative, then brain and cervical spine MRI is performed to exclude a CNS cause of torticollis.

Imaging Algorithm for Acute TorticollisImaging Algorithm for Acute Torticollis

Patient withtorticollis

Newborn infant Older child oradult

Trauma No traumaUltrasound

CT neck and/orcervical spineNegative Positive

StopCT or MRI of neck

CT neck and/or cervical spine

Negative Positive NegativePositive

Stop MRI C-SpineMRA neck

MRI C-spineMRI brainStop

Causes of TorticollisCauses of Torticollis

Traumatic Causes of TorticollisTraumatic Causes of Torticollis• Muscular

– Fibromatosis colli– Muscle spasm following trauma

• Skeletal– Unilateral interfacetal dislocation (UID)– Occipital condyle fractures– Atlanto-axial rotatory fixation (? truly traumatic)

• CNS related– Subarachnoid hemorrhage– Spinal epidural hematoma

Traumatic Causes of Torticollis: Traumatic Causes of Torticollis: Fibromatosis ColliFibromatosis Colli

• Rare form of infantile fibromatosis affecting sternocleidomastoid muscle (SCM)

• Accounts for >80% of childhood cases of torticollis

• Due to traumatic delivery or possibly abnormal head position in utero

• Infants usually appear normal at birth, torticollis develops in the 2-3rd weeks of life

• More common in males and in right side• Sonographic findings are typical

Traumatic Causes of Torticollis: Traumatic Causes of Torticollis: Fibromatosis ColliFibromatosis Colli

Longitudinal US views of the right (top) and left (bottom) SCMs in an infant with torticollis. The right SCM is enlarged and of heterogeneous echotexture. The left SCM is normal. There are mildly enlarged lymph nodes posterior to the left SCM

Traumatic Causes of Torticollis: Traumatic Causes of Torticollis: Fibromatosis ColliFibromatosis Colli

Axial contrast CT in an infant with fibromatosis colli. The right SCM is enlarged and has faint central

enhancement (arrowhead).

Traumatic Causes of Torticollis: Traumatic Causes of Torticollis: Unilateral Interfacetal DislocationUnilateral Interfacetal Dislocation

Axial CT image and a saggital reformatted imagedemonstrate right facet dislocation (arrows).

Traumatic Causes of Torticollis: Traumatic Causes of Torticollis: Occipital Condyle FractureOccipital Condyle Fracture

Axial and coronal reformatted CT images show a right occipital condyle fracture (type III) in a patient presenting

with acute torticollis after trauma.

Occipital Condyle FracturesOccipital Condyle Fractures

• Classified into 3 types by Anderson and MontesanoI Axial loading fracture limited to the

occipital condyle without displacement intoforamen magnum

II Fracture of basiocciput extending into occipital condyle

III Small fragment arising from medial surface of condyle avulsed by an intact

alar ligament and distracted towards dens

Infectious and Inflammatory Infectious and Inflammatory Causes of TorticollisCauses of Torticollis

• CNS related– Meningitis

• Head and Neck related– Upper respiratory infections– Otitis media– Mastoiditis/Bezold’s abscess– Cervical adenitis– Retropharyngeal abscess

• Spine related– Vertebral osteomyelitis and/or discitis– Epidural abscess– Rheumatoid arthritis

Infectious Causes of Torticollis: Infectious Causes of Torticollis: Mastoiditis/Bezold’s AbscessMastoiditis/Bezold’s Abscess

Unenhanced (right) and enhanced (left) axial CT images in a patient with acute torticollis and right ear pain demonstrate coalescing mastoiditis eroding medial

surface of mastoid (arrow). Inferior to this is an abscess involving the right SCM (arrowhead).

Bezold’s Abscess

• Rare complication of suppurative mastoiditis occuring when infection erodes the mastoid tip into the neck, forming an abscess

• May cause spasm of the SCM, resulting in torticollis

• Abscess may spread down the plane of the sternocleidomastoid muscle into the lower neck

• Also associated with cholesteatomas

Infectious Causes of Torticollis: Infectious Causes of Torticollis: Suppurative AdenitisSuppurative Adenitis

Enhanced axial fat suppressed T1 MR image demonstrates a necrotic retropharyngeal lymph node (arrowhead) in a child with suppurative adenitis presenting as acute torticollis.

Infectious Causes of Torticollis: Infectious Causes of Torticollis: Discitis and OsteomyelitisDiscitis and Osteomyelitis

T1 post-GdT2

Inflammatory Causes of Torticollis: Inflammatory Causes of Torticollis: Rheumatoid ArthritisRheumatoid Arthritis

Unenhanced sagittal T1 MR in a patient with rheumatoid arthritis and torticollis. There is pannus destroying the dens and compressing the lower brainstem and medulla.

Neoplastic Causes of TorticollisNeoplastic Causes of Torticollis

• CNS tumors– Spinal cord or brainstem tumors– Posterior fossa tumors and cysts– Vestibular schwannoma– Metastases

• Bone tumors– Vertebral eosinophilic granuloma– Osteoid osteoma/osteoblastoma– Metastases (spine or skull base)

Neoplastic Causes of Torticollis: Neoplastic Causes of Torticollis: Spinal Cord TumorSpinal Cord Tumor

Sagittal enhanced T1 MRI of the cervical spine demonstrates an enhancing, expansile ganglioglioma in a 10- year-old female presenting with acute torticollis.

Neoplastic Causes of Torticollis: Neoplastic Causes of Torticollis: Skull Base TumorSkull Base Tumor

Axial enhanced T1 MRI in an adult with acute torticollis demonstrates a metastasis from renal cell carcinoma (arrowheads) involving the left

occipital condyle.

Other Causes of Torticollis• Dystonic syndromes (idiopathic spasmodic torticollis)• Chiari 1 malformation• Syringomyelia• Neuroleptic drug reactions• Congenital vertebral anomalies (e.g. – congenital

scoliosis, cervical segmentation anomalies, Klippel-Feil syndrome)

• Hemifacial microsomia• Oculomotor nerve palsies/Strabismus• Gastroesophageal reflux (Sandifer’s syndrome)• Vascular abnormalities (craniocervical AV fistula;

congenital hypoplasia of the internal carotid artery)• Pseudotumor cerebri

Other Causes of Torticollis: Other Causes of Torticollis: Chiari I MalformationChiari I Malformation

Unenhanced midsagittal T1 weighted MR image shows significant downward displacement of peg-shaped cerebellar tonsils (arrowhead) through foramen magnum (type I Chiari malformation).

Other Causes of Torticollis: Other Causes of Torticollis: Chiari I Malformation with a SyrinxChiari I Malformation with a Syrinx

Unenhanced sagittal T1 weighted image demonstrates a large, expansile, multiseptated cyst in the cervical cord of a patient with a Chiari I malformation and torticollis.

Chiari I MalformationChiari I Malformation• Defined as greater than 5 mm of displacement of

triangular-shaped cerebellar tonsils below the foramen magnum

• Believed to be due to an abnormality of expression of spinal segmentation genes that lead to varying degrees of hypoplasia of the skull base

• Unclear if torticollis is due to associated skeletal abnormalities or due to compression of brainstem and lower cranial nerves

• Torticollis may be caused by syringohydromyelia even in absence of a Chiari malformation

Other Causes of Torticollis: Other Causes of Torticollis: Klippel-Feil SyndromeKlippel-Feil Syndrome

Lateral radiograph of the cervical spine shows hypoplasia and fusion of lower cervical vertebrae in a patient with Klippel-Feil syndrome and torticollis

Klippel-Feil SyndromeKlippel-Feil Syndrome• Heterogeneous group of conditions unified by presence

of congenital synostosis of some or all cervical vertebrae• Classic triad described by Klippel and Feil consisting of

short neck, low posterior hairline, and limited range of motion of neck (seen in <50% of patients)

• Commonly associated abnormalities include congenital scoliosis, rib abnormalities, deafness, genitourinary abnormalities, Sprengel’s deformity, and cardiac abnormalities

• Along with congenital scoliosis, accounts for nearly 1/3 of nonmuscular causes of torticollis in children

• Cervical anomalies are well characterized by CT

Idiopathic Spasmodic TorticollisIdiopathic Spasmodic Torticollis(IST)(IST)

• Also referred to as cervical dystonia• Nontraumatic, acquired form of torticollis

presenting as spasms or jerks of SCMs• Females more commonly affected by 4.5:1• Typically occurs in adults over age 30• Diagnosis requires exclusion of other potential

causes of torticollis and that symptoms be present for at least 6 months

• Conventional neuroimaging studies usually negative

Idiopathic Spasmodic TorticollisIdiopathic Spasmodic Torticollis(IST)(IST)

• Although pathophysiology of IST is not understood, the interstitial nucleus in the brainstem has been implicated as a probable site of abnormality

• IST may be due to abnormalities of the basal ganglia, vestibular systems, or spinal accessory nerves

• Proton MR spectroscopy in IST patients may demonstrate diminished n-acetyl-aspartate (NAA) levels in basal ganglia when compared with normal controls

Proton MR Spectroscopy inProton MR Spectroscopy inIdiopathic Spasmodic TorticollisIdiopathic Spasmodic Torticollis

Long echo time proton MRS at level of left basal ganglia (left) demonstrates low level of n-acetyl-

aspartate relative to normal right basal ganglia (right).

Atlanto-axial Rotatory FixationAtlanto-axial Rotatory Fixation• Atlanto-axial rotatory fixation (AARF) is a

controversial entity - Is it the result of or the cause of torticollis?

• True atlanto-axial subluxation or dislocation is rare

• 75-80% of reported cases occur in children• Compression of spinal cord may occur if there is

anterior or posterior displacement• Vertebral artery kinking or stretching may occur

and cause posterior circulation ischemic symptoms

Atlanto-axial Rotatory FixationAtlanto-axial Rotatory Fixation• Frequently, there is an antecedent history of

trauma or upper respiratory infection• “Grisel’s syndrome” = non-traumatic atlanto-axial

subluxation secondary to ligamentous laxity and inflammation following infection or surgery in the head and neck region

• It has been postulated that swollen capsular and synovial tissues and muscle spasm prevent reduction early on and that ligament and capsular contractures develop later, ultimately causing fixation

Types of Atlanto-axial Rotatory Types of Atlanto-axial Rotatory Fixation (Fielding classification)Fixation (Fielding classification)

Type 1 Rotatory fixation w/o anterior displacement of atlas (intact transverse and alar ligaments) – most common type

Type 2 Rotatory fixation with 3-5 mm of anterior displacement of atlas (implies deficiency of transverse ligament)

Type 3 Rotatory fixation with >5 mm of anterior displacement of atlas (implies deficiency of both transverse and alar ligaments)

Type 4 Rotatory fixation with posterior displacement of atlas (implies deficiency of odontoid process)

Types of Atlanto-axial Rotatory Types of Atlanto-axial Rotatory Fixation (Fielding classification)Fixation (Fielding classification)

From Lustrin ES, Karakas SP, Ortiz AO, et al. Pediatric cervical spine: Normal anatomy, variants, and trauma. Radiographics 2003; 23:539-60. (Used with permission)

Radiographic Diagnosis of Atlanto-Radiographic Diagnosis of Atlanto-axial Rotatory Fixationaxial Rotatory Fixation

• CT is essential for imaging of AARF• When rotation is accompanied by anterior or

posterior displacement (Fielding types 2-4), CT is diagnostic

• Type 1 rotatory fixation appears identical to other causes of torticollis when patients are imaged at rest– Thus, patients with suspected type 1 AARF should be

scanned at rest and with maximal voluntary contralateral head rotatation

– CT in patients with AARF shows little or no change in position of atlas with respect to axis

Type 1 Atlanto-axial Rotatory Type 1 Atlanto-axial Rotatory FixationFixation

Axial CT image with head rotated to left shows widened space between dens and right C1 lateral mass which

persists with rotation of head to right (arrowheads) compatible with AARF. The atlanto-dental interval is

normal making this a type 1 AARF.

Selected ReferencesSelected ReferencesAnderson PA, Montesano PX. Morphology and treatment of occipital condyle

fractures. Spine 1988; 13:731-6.Ballock RT, Song KM. The prevalence of nonmuscular causes of torticollis in

children. J Pediatr Orthop 1996; 16:500-4.Castillo M, Albernaz VS, Mukherji SK, Smith MM, et al. Imaging of Bezold’s

abscess. AJR Am J Roentgenol 1998; 171:1491-5.Federico F, Lucivero V, Simone IL, Defazio G, et al. Proton MR spectroscopy

in idiopathic spasmodic torticollis. Neuroradiology 2001; 43:532-6.Fielding JW, Hawkins RJ. Atlanto-axial rotatory fixation (fixed rotatory

subluxation of the atlanto-axial joint). J Bone Joint Surg Am 1977; 59:37-44.Kraus R, Han BK, Babcock DS, Oestreich AE. Sonography of neck masses in

children. AJR Am J Roentgenol 1986; 146:609-13.Roche CJ, O’Malley M, Dorgan JC, Carty HM. A Pictorial Review of Atlanto-

axial Rotatory Fixation: Key points for the radiologist. Radiographics 2001; 56:947-58.

Tracy MR, Dormans JP, Kusumi K. Klippel-Feil Syndrome: Clinical features and current understanding of etiology. Clin Orthop Relat Res 2004; 424:183-90.