Imaging%20in%20Acute%20Torticollis

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Imaging in Acute Torticollis
Division of Neuroradiology Department of
Radiology University of North Carolina at Chapel
Hill
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Overview of This Presentation

• Introduction
• Imaging algorithm for acute torticollis
• Causes of torticollis
• Trauma
• Infection/Inflammation
• Neoplasm
• Other/Idiopathic
• Atlantoaxial rotatory fixation
• Selected references

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At the Conclusion of this Exhibit 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

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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.

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Introduction Clinical Aspects of Acute
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

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Introduction Chronic Sequelae of Torticollis

• Physical
• Positional plagiocephaly
• Facial deformities
• Cervical spine degeneration
• Radiculopathies and myelopathies
• Psychiatric
• Major depression
• Agoraphobia
• Substance abuse
• OCD

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Imaging 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.

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Imaging Algorithm for Acute Torticollis
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Causes of Torticollis
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Traumatic 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

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Traumatic Causes of Torticollis Fibromatosis
Colli

• Rare form of infantile fibromatosis affecting
  sternocleidomastoid muscle (SCM)
• Accounts for gt80 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

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Traumatic Causes of Torticollis Fibromatosis
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

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Traumatic Causes of Torticollis Fibromatosis
Colli

• Axial contrast CT in an infant with fibromatosis
  colli. The right SCM is enlarged and has faint
  central enhancement (arrowhead).

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Traumatic Causes of Torticollis Unilateral
Interfacetal Dislocation

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

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Traumatic Causes of Torticollis Occipital
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.

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Occipital Condyle Fractures

• Classified into 3 types by Anderson and Montesano
• I Axial loading fracture limited to the
  occipital condyle without displacement
  into foramen 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

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Infectious and Inflammatory Causes of Torticollis

• CNS related
• Meningitis
• Head and Neck related
• Upper respiratory infections
• Otitis media
• Mastoiditis/Bezolds abscess
• Cervical adenitis
• Retropharyngeal abscess
• Spine related
• Vertebral osteomyelitis and/or discitis
• Epidural abscess
• Rheumatoid arthritis

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Infectious Causes of Torticollis
Mastoiditis/Bezolds 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).

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Bezolds 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

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Infectious Causes of Torticollis Suppurative
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.

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Infectious Causes of Torticollis Discitis and
Osteomyelitis

• T1 post-Gd

T2
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Inflammatory Causes of Torticollis Rheumatoid
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.

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Neoplastic 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)

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Neoplastic Causes of Torticollis Spinal 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.

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Neoplastic Causes of Torticollis Skull 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.

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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 (Sandifers syndrome)
• Vascular abnormalities (craniocervical AV
  fistula congenital hypoplasia of the internal
  carotid artery)
• Pseudotumor cerebri

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Other Causes of Torticollis Chiari 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).

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Other Causes of Torticollis Chiari 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.

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Chiari 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

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Other Causes of Torticollis Klippel-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

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Klippel-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 lt50
  of patients)
• Commonly associated abnormalities include
  congenital scoliosis, rib abnormalities,
  deafness, genitourinary abnormalities, Sprengels
  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

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Idiopathic Spasmodic Torticollis(IST)

• Also referred to as cervical dystonia
• Nontraumatic, acquired form of torticollis
  presenting as spasms or jerks of SCMs
• Females more commonly affected by 4.51
• 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

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Idiopathic Spasmodic Torticollis(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

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Proton MR Spectroscopy inIdiopathic 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).

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Atlanto-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

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Atlanto-axial Rotatory Fixation

• Frequently, there is an antecedent history of
  trauma or upper respiratory infection
• Grisels 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

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Types of Atlanto-axial Rotatory 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 gt5 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)

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Types of Atlanto-axial Rotatory Fixation
(Fielding classification)

• From Lustrin ES, Karakas SP, Ortiz AO, et al.
  Pediatric cervical spine Normal anatomy,
  variants, and trauma. Radiographics 2003
  23539-60. (Used with permission)

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Radiographic Diagnosis of Atlanto-axial 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

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Type 1 Atlanto-axial Rotatory Fixation

• 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.

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Selected References

• Anderson PA, Montesano PX. Morphology and
  treatment of occipital condyle fractures. Spine
  1988 13731-6.
• Ballock RT, Song KM. The prevalence of
  nonmuscular causes of torticollis in children. J
  Pediatr Orthop 1996 16500-4.
• Castillo M, Albernaz VS, Mukherji SK, Smith MM,
  et al. Imaging of Bezolds abscess. AJR Am J
  Roentgenol 1998 1711491-5.
• Federico F, Lucivero V, Simone IL, Defazio G, et
  al. Proton MR spectroscopy in idiopathic
  spasmodic torticollis. Neuroradiology 2001
  43532-6.
• Fielding JW, Hawkins RJ. Atlanto-axial rotatory
  fixation (fixed rotatory subluxation of the
  atlanto-axial joint). J Bone Joint Surg Am 1977
  5937-44.
• Kraus R, Han BK, Babcock DS, Oestreich AE.
  Sonography of neck masses in children. AJR Am J
  Roentgenol 1986 146609-13.
• Roche CJ, OMalley M, Dorgan JC, Carty HM. A
  Pictorial Review of Atlanto-axial Rotatory
  Fixation Key points for the radiologist.
  Radiographics 2001 56947-58.
• Tracy MR, Dormans JP, Kusumi K. Klippel-Feil
  Syndrome Clinical features and current
  understanding of etiology. Clin Orthop Relat Res
  2004 424183-90.