No Disclosures
Congenital Spine
Nicholas S. Pierson, MD
University of Utah Neuroradiology
4th Intensive Interactive
Brain and Spine Imaging Conference
3/26/2015
Objectives
• Introduce key embryologic factors in
congenital spinal lesion development
• Case based review of representative
congenital spinal lesions
• Utilize a clinical-radiologic framework to
categorize lesions through case based
review
• Introduce key concepts of specific entities
including useful imaging modalities,
clinical history, and differentials
Disjunction
Primary Neurulation
• Primary
Neurulation
• Neural plate
folds and fuses
to form the
neural tube
• Disjunction- the
separation of
neuroectoderm
from ectoderm to
form the neural
tube.
Secondary Neurulation
• Secondary
Neurulation
Premature disjunction
Nondisjunction
Barkovich, A. J. & Raybaud, C. Pediatric Neuroimaging. (Wolters Kluwer Health, 2012). Figure 9.2
• Development of
neural structures
caudal to the
posterior
neuropore
• Connects to the
neural tube
formed by primary
neurulation
Barkovich, A. J. & Raybaud, C. Pediatric Neuroimaging. (Wolters Kluwer Health, 2012). Figure 9.3
Secondary Neurulation
• Secondary
Neurulation
Case 1
• Abnormal 18 week screening ultrasound
• Referral with follow up ultrasound
• Subsequent fetal MRI for further
characterization
• Becomes the
caudal portion of
the conus, filum,
ventriculus
terminalis
Barkovich, A. J. & Raybaud, C. Pediatric Neuroimaging. (Wolters Kluwer Health, 2012). Figure 9.3
Obstetric US
Fetal MRI
Sag T2
Long
Postnatal MRI
Sag T2
Ax T2
Trans
Ax T2
Myelomeningocele
Companion Case 1a
Companion Case 1a
Sag T2
Ax T2
Myelocele (myeloschisis)
Companion Case 1b
Open Spinal Dysraphism
• Meyeloceles and
Myelomeningocele
• Sequela of
nondisjunction
• Link with maternal
folate deficiency
• Rarely imaged
postnatal
• Repaired within 48h
Open Spinal Dysraphism
• Post operative
neurologic deficit should
be stable
• Change would be an
indication for MRI
Ax T2
Sag T2
• Post operative
complication
• Associated occult lesion
OSD Repair
Framework Part 1
1. Open Spinal Dysraphism
• Myelocele
– Hemimyelocele in the setting of diastematomyelia
• Myelomeningocele
– Hemimyelomeningocele in the setting of diastematomyelia
Case 2
• Infant with low back soft tissue mass
• Hairy tuft
DDX
•
•
•
•
Meningocele
Lipomyelocele
Lipomyelomeningocele
Terminal Lipoma
Ax T2
• Myelomeningocele
• Myelocele
Sag T2
Lipomyelomeningocele
• Neural placode inserts
into fatty mass
• Mass contiguous with
subcutaneous
• Expansion of
arachnoid space
• Displacement of
placode beyond the
spinal canal
• Sequela of premature
disjunction
• Inner aspect of the
neural tube induces
mesenchyme to fat
• Spinal cord always
tethered to fatty mass
• Fatty mass may be
large or nearly
imperceptible
Companion Case 2a
Sag T2
Lipomyelomeningocele
Ax T2
Lipomyelocele
Lipomyelocele
• Sequela of premature
disjunction
• Neural placode fat
interface within the
spinal canal
• Fat herniates through
spina bifida defect
• Analog to myelocele
• Always tethered
Companion Case 2b
Sag T1
Sag T2
Terminal Lipoma
Companion Case 2c
Sag T2
Terminal Lipoma
• Caudal most analog of
lipomyelocele
• Often presents with
fatty filum and
radiographic tethering
• Primary or secondary
neurlation?
• Not intradural,
associated with sacral
defect
Companion Case 2c
Sag T2
Axial T2
Dorsal Meningocele
Dorsal Meningocele
• Presents as palpable
mass or incidental
• Usually neurologically
intact
• Cord may be tethered at
the defect neck
• By definition does not
contain neural elements
• Debated embryology
Dorsal Meningocele
• Communicates with SA
space and may change
with valsalva
• Neck may be very small
• Surgery may be
warranted to close dural
defect.
• Exclude neural elements
by US/MRI
Framework Part 2
1. Open Spinal Dysraphism
2. Closed Spinal Dysraphism (With Mass)
•
•
•
•
Case 3
• Lower extremity weakness in a child
• No cutaneous stigmata or mass
Meningocele
Lipomyelocele
Lipomyelomeningocele
Myelocystocele (not included)
DDX
Ax T2
Sag T1
• Lipoma
• Filar fibrolipoma
• Dermoid/epidermoid
Ax T1
Sag T1 FS +C
Intradural Lipoma
• Intradural, intimately
involved with the cord
• Follows fat on all
modalities and
sequences
• Focal premature
disjunction
• Dura and posterior
elements induced
Companion Case 3a
Sag T1
Sag T1
Extensive intradural lipoma
Companion Case 3b
Ax T1
Sag T1
Ax T2
Fibrolipoma of the Filum
Companion Case 3c
Filum Fibrolipoma
• Often an incidental finding
• Hypodense, hyperintense
• If symptomatic or >2mm
thick consider lipoma
• 4-6% of population
• Anomaly of secondary
neurulation, caudal cell mass
• May be difficult to see on
sagittal imaging, axial T1?
Companion Case 4c
• Clubfoot
• Findings on ultrasound prompted
subsequent MRI
Companion Case 4c
Ax T2
Sag T2
Ax T1
Tight Filum/ Tethered Cord
Tight Filum
• Many lesions result in tethering of the cord
• Related to shortening and thickening of the
filum
• Likely a consequence of dysfunctional
caudal cell mass regression
• Presentation at birth may be as lower
extremity deformities or scoliosis
• Presentation during somatic growth:
weakness, urinary symptoms, abnormal gait
Tight Filum
• Neurosurgical untethering
• Neurological defect should remain stable
• Recurrence prompts concern for
retethering
Case 5
• Incidental spinal cord lesion
DDX
Ax T2
• Syrinx
• Cystic dilation of the terminal ventricle
• Cystic cord neoplasm
• Astrocytoma
• Ependymoma
• Hemangioblastoma
• Cord insult resulting in myelomalacia
Sag T2
Ax T1 +C
Cystic Dilation of Terminal Ventricle
• Focal expansion of
terminal ventricle
• Usually 2-4mm
• Focal expansion
localized to conus
• Difficult to distinguish
from syrinx
• Important to exclude
neoplasm with MRI
Cystic Dilation of Terminal Ventricle
• Typically incidental
• No treatment
• Option to follow with MRI
to document stability
• Some authors argue to
consider a normal variant
• Ependymal lined
• Symptomatic may be
fenestrated
Case 6
• Sinus tract on physical exam
• Asymptomatic
Sag STIR
Sag T1
Sag T2
Dorsal Dermal Sinus
• Focal nondisjunction
• Usually terminates at the
conus when lumbar
• +/- Tethering
• +/- Mass
Ax T2
Sag DTI
Sinus tract w/ epidermoid
• Dermoid/epidermoid
• Lipoma
• Arachnoiditis
• +/- Osseous defect
Companion Case 7a
Dorsal Dermal Sinus
• Delineation of tract
important for Sx planning
• As cord ascends pulls
tract with it
• Usually presents as
dimple
• If tethered, may present
with neurologic symptoms
Ax T2
Sag T2
Sinus tract w/ tethering
Companion Case 7b
Companion Case 7c
Ax T2
Sag T2
Ax T1
Ax T2
Ax T1
Sag T1
Tract w/ Appendage
Sacral/Coccygeal Dimple
Sacral/Coccygeal Dimple
Framework Part 3
• Low sacral dimple with
fibrous tract to bone
• Usually within the gluteal
cleft
• Usually worked up over
undue concern
• Becomes less
conspicuous with growth
• Limited imaging role
1. Open Spinal Dysraphism
2. Closed Spinal Dysraphism (With Mass)
3. Closed Spinal Dysraphism (No Mass)
•
•
•
•
•
Intradural Lipoma
Fibrolipoma
Tight filum terminale
Persistent terminal ventricle
Dermal sinus
Case 8
• Child with scoliosis
• Now with tethered cord symptoms
• Urinary irregularities
Ax T2
Cor T2
Ax CT
Diastematomyelia Type 1
Diastematomyelia
Diastematomyelia
• Split cord malformation
• Defect of notocord
development
• Indistinguishable from
other cord tethering
etiologies clinically
• High incidence of
cutaneous stigmata
• High incidence of
segmentation abnormality
• Type 1: two cords,
arachnoid space, and
thecal sac,
osseous/fibrous bar
• Type 2: two cords share
same arachnoid space and
thecal sac, no osseous bar
• Resection of bar,
untethering, correct
scoliosis
Postoperative
Companion Case 8a
Ax CT
Ax T2
Cor T2
Scout
Ax T2
Sag T2
Diastematomyelia Type 2
Case 9
• Anal atresia
• Abnormality on screening obstetric
ultrasound
Cor T2
Sag T2
SagT1
Ax T2
Caudal Regression
Caudal Regression Type 1
Caudal Regression
• Spectrum ranging from
complete absence to
coccygeal truncation
• Spectrum of neurologically
normal to severely impaired
• Associated w/ anal/rectal and
genital urinary abnormalities
• Infants of diabetic mothers
• Complex embryology
Companion Case 10a
• Type 1: Distal cord
hypoplasia/truncation,
severe sacral abnormality
• Type 2: Tethered cord, less
severe sacral abnormality,
may be tethered by mass
• Complex neurosurgical and
orthopedic management
Cor T2
Sag T2
Ax T2
Caudal Regression Type 2
Framework Part 4
1.
2.
3.
4.
Framework
Open Spinal Dysraphism
Closed Spinal Dysraphism (With Mass)
Closed Spinal Dysraphism (No Mass)
Closed Spinal Dysraphism (Complex
Dysraphic States)
•
•
•
•
•
Diastematomyelia
Caudal agenesis
Segmental spinal dysgenesis (not included)
Neurenteric cyst (not included)
Dorsal enteric fistula (not included)
Rufener, S., Ibrahim, M. & Parmar, H. A. Imaging of Congenital Spine and Spinal Cord Malformations.
Neuroimaging Clinics of North America 21, 659–676 (2011).
Conclusion
References
•
• Introduced key embryological factors in
lesion development
• Reviewed clinical-radiologic framework
for congenital spinal lesions
• Discussed specific disease entities
utilizing that framework
• Incited a sense of enthusiasm for this
interesting topic
•
•
•
•
•
•
•
•
Congenital Spine
Nicholas S. Pierson, MD
University of Utah Neuroradiology
4th Intensive Interactive
Brain and Spine Imaging Conference
3/26/2015
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