SPINE Congenital Flashcards
Scoliosis: definition
Lateral curvature of the spine in coronal view > 10 degree of Cobb angle.
Scoliosis Etiology
Idiopathic 80%
Secondary 20%
Scoliosis: sub-classification of idiopathic scoliosis
Infantile.
Juvenile.
Adolescent/adult
Scoliosis: classification of secondary scoliosis
-Neuromuscular: resulting from neurologic or myopathic anomalies (e.g. cerebral palsy, muscular dystrophy)
-Congenital: due to vertebral abnormality (VACTERL) or not (Marfan, NF, Ehler Danlos, osteogeneis imperfecta, dwarfism
-Tumor (e.g. osteoid osteoma, osteoblastoma)
-Trauma, infection, post surgical, degenerative
Scoliosis: clinical presentation
Asymptomatic in idiopathic cases.
Painful: underlying causes (e.g. tumor, trauma)
Scoliosis: associations
-Vertebral bodies near the apex are wedged.
-Other alignment anomalies such as kyphosis and rotational deformity.
-Sponlylolysis.
-Chiari 1 malformation, syrinx, tethered spinal cord, congenital bony abnormality, or tumor.
Scoliosis; complications
respiratory difficulty
Scoliosis; prognosis and treatment
Idiopathic: asymptomatic, non progressive.
-infantile, juvenile: tend to progress.
Treatment:
-observation
-Bracing
-surgical fusion if >40 degrees.
Scoliosis: Dx
-Standing PA long spine plain film.
Preferably weight bearing.
-Lateral bending films: assess structural or non-structural.
-Measurement of Cobb’s angle.
-CT/MR to assess underlying abnormalities, preoperative planning.
Scoliosis: shape and diagnosis
S-shaped: idiopathic, congenital, syndromic.
C-shaped: neuromuscular, Sheuermann syndrome, NF, congenital, syndromic
Short-curve: trauma, tumor, infection, radiation.
Neuromuscular scoliosis: definition
lateral curvature of the spine in coronal view secondary to neurological or myopathic disease.
Neuromuscular scoliosis: etiology
Neurogenic cause: cerebral palsy, spinal cord tumor, syringomyelia, traumatic paralysis, myelomeningocele, hereditary sensorimotor neuropathy
Myopathic cause: Duchenne muscular dystrophy, spinal muscular atrophy, Friedeich ataxia, artrogryposis
Neuromuscular scoliosis: clinical presentation
-Presence of clinical background; 20% associated with cerebral palsy
-Rapidly progressive scoliosis.
-Onsent in infancy or childhood.
Neuromuscular scoliosis: associations
Syryngomyelia,
Dysraphism,
tethered cord,
lordosis.
Neuromuscular scoliosis: complications
Respiratory difficulty.
Neuromuscular scoliosis: dx morphology
Single, long curve thoracolumbar scoliosis. Unbalanced.
TL kyposis common.
Normal vertebral morphology (+/- vertebral wedging)
Osteopenia
Neuromuscular scoliosis: Dx method
Xray PA standing long spine plain film.
MR of entire spine to exclude spinal cord or osseous abnormality.
Scheuermann Kyphosis: definition
Juvenile kyphosis secondary to multiple Schmorl’s nodes associated with anterior vertebral body wedging and endplate irregularity.
Scheuermann Kyphosis: Clinical presentation
Adolescent: 15+/- yo
Pain , worsening with physical activity
Kyphosis
Neurologic symptoms secondary to disc herniations.
Scheuermann Kyphosis: pathophysiology
Unknown.
Association with physical activity.
Genetic: familiar tendency.
Wedge appearance: growth delayed of the anterior portion.
Undulation of endplates: disc invaginations.
Limbus vertebrae: when disc material protrudes through growth plate of ring apophysis.
Scheuermann Kyphosis: associations
limbus vertebrae
lordosis of cervical and lumbar segments.
15% scoliosis.
Disc herniations.
Scheuermann Kyphosis: morphology
-Wedge-shaped thoracic vertebrae with irregular endplates
- ≥ 3 contiguous vertebrae, each showing ≥ 5° of kyphosis
-Undulation of endplates secondary to extensive disc invaginations
-Disc spaces narrowed with greatest narrowing anteriorly
-Well-defined Schmorl nodes
-Location:
-75% thoracic
-20-25: thoracolumbar
-<5% lumbar only
-rarely cervica.
-Thoracolumbar involvement: loss of normal lumbar lordosis, functionally significant
Scheuermann Kyphosis: diagnosis
Clue: Schmorl nodes without anterior wedging are not indicative of Scheuermann disease
CT: bone: endplate abnormalities more apparent.
MR: T1: Schmorl nodes, disc herniation with low signal intensity
± discogenic sclerosis
T2: Disc degeneration seen in 50%
Schmorl nodes may be low or high signal intensity
± bone marrow edema adjacent to Schmorl nodes
disc herniations.
Bone density: normal.
Bone scan: normal or increased activity
Failure of vertebral formation: examples
Hemivertebra, butterfly vertebra.
Failure of vertebral formation: physiopath
Failure of chondrification and ossification (day 40-60):
-Total aplasia: Both chondral centers fail to develop early in development
-Lateral hemivertebra: 1 chondral center does not develop; ossification center subsequently fails to develop on that side
-Sagittal cleft (butterfly) vertebra: Separate ossification centers form (but fail to unite) in each paired paramedian chondrification center
-Coronal cleft vertebra: Formation and persistence of separate ventral and dorsal ossification centers
-Posterior hemivertebra: Later failure at ossification stage
Genetics: abnormal PAX1 gene expression.
Failure of vertebral formation:
Epidemio
Clinical presentation
M=F
Usually diagnosed in infancy/childhood.
Isolated or part of a syndrome.
Increased risk with parental consanguinity.
Asymptomatic.
Diagnosed during scoliosis evaluation.
Association (neural deficit, limb or visceral abnormalities)
Failure of vertebral formation: Associations
Other developmental vertebral abnormalities:
- Partial duplication (supernumerary hemivertebra)
-Segmentation failure (block vertebra, posterior element dysraphism, pediculate bar, neural arch fusion)
-Dysraphism, split notochord syndromes (Diastematomyelia), syrinx, tethered cord/fatty filum, congenital tumor
-Syndromes: Klippel Feil, VACTERL, Gorlin, OEIS, Gorlin, gastroschisis, mucopolisacaridosis
- Visceral abnormalities; 61% of congenital scoliosis patients
Tracheoesophageal fistula common association (part of VACTERL)
Failure of vertebral formation: Dx
-Xray weight bearing. Best modality for “counting” vertebral levels, determining presence and severity of scoliosis
-CT: improves dx of ± posterior element dysraphism, fusion anomalies
-MR: Best modality.
Normal marrow and disc signal intensity.
T2: helps with ± lipoma, tethered cord, diastematomyelia, spinal cord compression
Vertebral segmental failure: definition
Vertebral column malformations (block vertebra, neural arch fusion, pediculate bar) resulting from deranged embryologic development → failure of normal segmentation
Vertebral segmental failure: clinical presentation and epidemiology
(Similar to failure of vertebral formation)
M=F
Severe cases in infancy/ mild cases in adulthood.
Either asymptomatic or scoliosis (accounts for 18%)
Part of a syndrome.
Block vertebra:
Failure of ≥ 2 vertebral somites to segment
* Combined vertebrae may be normal height, short, or tall
* Disc space frequently rudimentary or absent
* Frequent association with hemivertebra/absent vertebra above or below block level, posterior element fusion
Posterior arch anomaly:
* Failure to unite in midline → dysraphism (± unilateral pedicle aplasia/hypoplasia)
* Unfused spinous processes; L5, S1 > C1 > C7 > T1 > lower thoracic spine
* Multiple level posterior fusion → congenital vertebral bar
Bertolotti syndrome?
-Back Pain
-Enlargement of Transverse process.
-Unilateral or bilateral
-Most caudal lumbar vertebrae
-Articulation or
fusion with sacrum or ilium
Open Spina Bifida: Definitions of MMC and MC
Myelomeningocele (MMC): Open (lacking skin covering) spinal dysraphism in which neural placode (exposed flattened end of elongated spinal cord) protrudes beyond skin surface dorsal to spinal canal
MC: Open spinal dysraphism with neural placode flush with skin surface
Open Spina Bifida: epidemio, clinical presentation
Slight FEMALE predominance.
Most commonly due to folate insufficiency. Other causes: antiepileptic medication, obesity.
Clinically:
-Visible defect
-Neurological deficit: ~80% bowel, bowel dysfunction, lower limb
Open Spina Bifida: physiopath
Failure of closure of neural tube at 3rd week of gestation (caudal neuro pore should have closed at day 27-28)
Multifactorial:
- Folate deficiency, abnormal folate absorption
-In utero exposure to teratogens
Genetics:
-PAX 3 abnormal expression
-Methylenetetrahydrofolate reductase (MTHFR) mutation
Open Spina Bifida: Complications
- ~85% hydrocephalus
90% Chiari II: requireing CSF diversion. - ~85% hydrocephalus
90% Chiari II - Cord re-tethering (clinical diagnosis)
- Shunt malfunction
- Other: syringohydromyelia ~50%, arachnoid cyst, dermoid/epidermoid, dural ring constriction, brainstem compression, myelopathy, cord ischaemia.
Open Spina Bifida: Associations
-Aneuploidies: T13, T 18
-Kyphoscoliosis (neuromuscular type)
-Other malformations: ~50% syrongomyelia, ~46% splic cord malformation, diastomatomyelia, arachnoid cyst, tethering cord, vertebral segmentation, dorsal dermal sinus, caudal agenesis
Open Spina Bifida: Morphology, diagnosis
-Spinal dysraphic defect (parallel orientation of unfused lamina/spinous process)
-Elongation of spinal cord
-Neural placode inserting on back of thecal sac.
-MMC or MC sac outside of skin level.
-Location: Lumbosacral ~45%
Thoracolumbar 30%
Lumbar 20%
Cervical 2%
Dx: MR best tool.
LipoMMC/ Lipomyelocele: definition
Closed spinal dysraphysm.
Presence of placode-lipoma interface (elongated spinal cord attaches to lipomatous tissue that is continuous with dorsal subcutaneous fat)
LMC: interface located within spinal canal
LMMC: interface protrution
LipoMMC/ Lipomyelocele:
clinical presentation and epidemio
Dx in infancy.
Soft mass covered by skin above buttocks.
60% neurologically normal, 88% will develop.
LipoMMC/ Lipomyelocele:
physiopath
Premature dysjunction of neural tube from ectoderm. This allows the mesenchyme to become part of neural fold, preventing the neural tube to close.
The mesenchyme is later induced into fat tissue.
LipoMMC/ Lipomyelocele:
Associations
~10% anorectal and genitourinary malformations (bifid uterus, duplicated vagina, renal agenesis)
~25% syringohydromyelia
<10% split cord malformation
40 other vertebral segmental abnormalities (25% sacral hypoplasia/agenesis.
OEIS, Klippel Feil, caudal agenesis.
LipoMMC/ Lipomyelocele:
morphology
Elongated spinal cord attached dorsally to lipomatous tissue, which is in continuity with dorsal subcutaneous fat, through osseus spinal dysraphic defect.
Does not move dependently/ventrally in prone position
Most commonly lumbosacral.
Spina bifida:
definition, classification
Incomplete closure of posterior bony elements of the spine.
No dural or neural abnormality.
2 forms: open (80%) or closed SB.
Spina bifida: physiopathology
failure of normal development neural tube (segmentation anomaly)
Multifactorial: genetic (PAX 1) and environmental.
Spina bifida:
associations
Associations can occur up to 40%.
-Aneuploidy: T18, T13, triploidy
-Syndromes: VACTERL, Klippel-feil, Aicardi
-Anatomic associations: Chiari II, hydrocephalus, limb anomalies (rocker bottom feet, talipes), neuroenteric cyst.
Spina bifida: morphology classification
- Six types:
Neurocentral synchondrosis
Retrosomatic/pedicular cleft
Spondylolysis (pars interarticularis defect)
Retroisthmic cleft
Paraspinal cleft (spina bifida occulta)
Spinosus cleft (spina bifida occulta)
Entity. Definition. Clinical presentation. Path. Associations
Lateral meningocele.
Meningeal dysplasia which causes meningeal protrusion (dural +arachnoid) through lateral exit neural foraminas into intercostal/extradural space.
Causes secondary osseous remodelation/scalloping.
Genetically: NOTCH 3 mutation.
Associations: strong NF 1 (85%)
W/ connective tissue anomaly: Marfan, Ehlers Danlos
Classically 4-5th dacade.
If isolated: asymptomatic
More frequently part of a syndrome.
If large: nonspecific motor or sensory symptoms (cord/nerve root compression) Rarely respiratory issues.
Lateral meningocele:
Morphology, diagnosis
CSF-filled sac that protrudes laterally through exit neural foramina into intercostal/extrapleural space.
Contiguous with neural foramen.
Same density/intensity to CSF.
Thoracic > lumbar
Right > left
If bilateral: think of syndrome (NF 1, Marfan, Ehlers Danlos)
Best clue: MRI (which replaced myelogram)
US: for paediatric screening.
No post con enhancement.
Entity. Definition. Path
Anterior Sacral Meningocele.
Mostly sporadic.
Meningeal herniation anteiorly into the pelvis through focal erosion or hypogenesis of sacral/coccygeal vertebral segments.
Complex (with neural tissue, familial or currarino triad syndrome AD Ch7) or Simple (marfan, NF1)
Path: classified as caudal cell mass anomaly.
Anterior sacral meningocele:
associations
Currarino Triad: Anorectal anomalies,
+ Caudal regression syndrome,
+ Epidermoid/dermoid tumor or other tethering lesion
When simple: Marfan, NF1
When complex: familial type, part of curarino triad.
Anterior Sacral Meningocele:
Morphology, diagnosis
Presacral cyst.
Contiguous with thecal sac through.
Anterior osseous erosion/dysgenesis. Foraminal widening. Scalloping of anterior wall (scimitar sacrum) +/- scoliosis.
Uni or multiloculated cyst. Usually no neural tissue.
Located at sacrum/coccys.
+/- lipoma/dermoid, cord tethering.
Absence of Ca+
No contrast enhancement
MR best. identify and characterize.
Us for infant screening.
Etiology. Definition. Presentation
Rare abnormality.
F > M
Presents at birth with large skin-covered back mass
Usually neurological intact but the lesion progresses and so develops lower limb neurosensory deficit.
Terminal myelocystocele:
Path, associations, complications
Results from abnormal secondary neurulation of caudal cell mass
Associated to other caudal cell mass abnormalities: Cloacal exstrophy, imperforate anus, omphalocele, pelvic deformities, equinovarus, ambiguous hypoplastic genitalia, and renal abnormalities
Syndromic association:
OEIS (omphalocele, bladder extrophy, imperforated anus, sacral agenesis)
Caudal regresion syndrome.
Complications:
Chiari I, Chiari II, hydroephalus, vertebral segmentation abnormalities.
Terminal myelocystocele:
Morphology, diagnosis
Triad:
-Closed sacral/coccyx dysraphysm
-Arachnoid lined meningocele contiguous with spinal subarachnoid space
-Low lying hydromyelic tethered cord in the meningocele, expands into large terminal cyst.
MR best imaging tool to make diagnosis and find associatins and complications.
Entity. Definition. Clinical presentation.
Dorsal dermal sinus.
Closed spinal dysraphism. Midline/paramidline subcutaneous sinus tract (lined by stratified squamous epithelium) extending from skin surface (above the intergluteal cleft) toward deep layer (may end in subcutaneous tissues, fascia/muscle, vertebrae, epidural space, subarachnoid space, or even intramedullary within spinal cord)
Presentation:
-Asymptomatic.
-Infection meningocele, abscess.
-Neurologic defect.
Dorsal dermal sinus:
path, association, complication
Path: Closed spinal dysraphism due to incomplete disjunction of cutaneous & neural ectoderm at 3- to 8-weeks gestation.
When spinal cord is surrounded by mesenchyme & undergoes relative ascent with respect to spinal column, adherence remains & forms long, epithelium-lined tract.
Tract is lined by stratified squamous epithelium
Associations/complications:
-Cutaneous stigmata: Midline or paramidline dimple above gluteal cleft, hyperpigmented patch, capillary malformation/stain, hairy nevus
-Up to 40% can be seen with additional coexisting closed spinal dysraphism (e.g., lipomyelomeningocele, split cord malformation, tethered cord syndrome)
-(Epi-)dermoid cyst (~ 50%)
-Tethered cord, intradural lipoma, split cord malformation
-Infection: meningitis, abscess
Dorsal dermal sinus:
Morphology, diagnosis
Morphology: Linear, midline/paramidline, sagittal T1-hypointense tract in subcutaneous tissues
-Terminates anywhere from subcutaneous tissues (blind ending) to spine (epidural, intradural/intrathecal, or even intramedullary)
-Course varies from short to long: extraspinal or intraspinal (>50%, May terminate in subarachnoid space, conus medullaris, filum terminale, nerve root, fibrous nodule on cord surface, or (epi-)dermoid cyst)
± (epi-)dermoid cysts along tract (~ 50%)
± tethered cord with low-lying conus medullaris, intradural lipoma, or split cord malformation
-Intraspinal extension may be occult on imaging (necessitating operative exploration of dura)
-Located anywhere along neuraxis; most common location ~ 70% is lumbosacral region above intergluteal cleft, 25% occipital.
Dx: MR imaging best demonstrates constellation of abnormalities
T1 and T2: hypointense tract. Dorsal dural tenting may indicate point of dural penetration
Contrast for concern of infection/inflammation or evalution of emangiom extent.
US: for initial screening in infants< 6months
Etiology, Definition, clinical presentation
Tethered spinal cord.
Abnormally low position (below L2)& restricted mobility of conus medullaris and thickened filum terminale >2mm, in concert with characteristic symptoms
-Symptoms appear during rapid growth period (4-8yo, adolescents growth spurt)
-Cutaneous stigmata present in ~50% (Hairy patch, hemangioma, skin tag, atypical dimple)
-Lower extremity motor weakness and sensory dysfunction (weakness, spasticity. Abnormal gait, reflexes, bladder dysfunction)
-Scoliosis (20%), vertebral segmentation abnormalities, dysraphysm.
-Pain (secondary to degenerative chanes)
Tethered spinal cord:
path, association, complication
Incomplete retrogressive differentiation with failure of terminal cord involution or failure of filum terminale to lengthen
Associations:
-55% with thickened filum terminale >2mm
-25% syringohydromyelia or myelomalacia
-VACTERL
-Open, closed spinal dysraphism
-Scoliosis, vertebral segmentation abnormality.
-23% Fibrolipoma
-3% filar cyst
Complication:
Progressive, irreversible neurologic impairment
Tethered spinal cord:
Morphology, diagnosis
Best clue: Low-lying conus medullaris: below L2-L3 disc level
-May appear taut or directly attached to dorsal thecal sac
Lack of conus motion with CSF pulsations
Lack of dependent ventral shift of conus when prone
-May have thickened filum terminale 55% (>2mm at L5-S1)
± fatty infiltration or lipomatous mass 25%
± bony/soft tissue dysraphism
± hyperintense dilation of lumbar/conus central canal secondary to syringohydromyelia or myelomalacia 25%
-US to screen infants < 6 months (cutaneous stigmata present in ~50%, or systemic anomalies)
-MR to define underlying anomalies for surgical planning in symptomatic patients
Entinty. Definition. Clinical presentation and origin
Epidermoid cyst.
Cystic lesion containing squamous epithelium. *No skin appendages. *
Congenital 60%
M. Clinical presentation 3-5th decade. M > F
Asymptomatic.
If symptomatic, slowly progressive: lower limb motor and sensory issues, bowel bladder dysfunction.
Acquired 40%
Implantation of skin elements during spinal puncture, MMC surgery. Extramedullary, near vertebral interspace.
Epidermoid cyst:
Path, Associations, complications
Squamous epithelium with progressive desquamation and breakdown of keratin into the cyst.
Congenital: anomalus implantation of ectodermal cells during closure of neural tube 3-5GA.
Macro: white capsule, white material.
Associations: 20% dermal sinus, segmentation anomalies, diastematomyelia.
Rare closed spinal dysraphism.
Epidermoid cyst:
Morhphology, location dx.
Uni or multilobular.
40% intramedullary. 60% extramedullary.
Cauda equine 35%, lower thoracic 26% or, lumbar 22%
Acquired: cauda equina
Appears as simple cyst:
T1 (but brighter than CSF)
T2 ,
faint peripheral enhancement,
DWI restriction (keratin)
Entinty. Definition. Clinical presentation.
Dermal cyst.
Benign cystic lesion lined by squamous epithelium, also containing skin appnedages (follicles, sweat glands, sebaceous glands)
Congenital 60%
Present in childhood, <20yo. M=F.
Asymptomatic.
If symptomatic, slowly progressive: lower limb motor and sensory issues, bowel bladder dysfunction.
Rarely rupture= acute symptoms (acute chemical meningitis)
Infectious meningitis if associated with dermal sinus.
Acquired 40%: iatrogenic. LP.
Dermal cyst:
path, associations, complications
Result from inclusion of epithelial issue within the neural groove during embryonic development.
Macro: wall might be thickened with Ca+, containing yellowish material
Associations: 20% dermal sinus, segmentation anomalies, diastematomyelia
Rare closed spinal dysraphism.
Complication:
-cyst rupture (Acue chemical meningitis)multifocal T1 high signal areas (fat) are demonstrated within the subarachnoid space and/or ventricular system.)
-Infectious meningitis (if associated with dermal sinus)
Dermal Cyst:
Morphology, diagnosis
40% intramedullary. 60% extramedullary.
60% lumbar, 20% cauda equine.
(rarely thoracic or cervicaal)
Fat content + keratin
T1 hyper (fat or sebaceous gland) hypo (water)
T2: hyper
faint peripheral enhancement,
Less likely to DWI restriction.
Supresses with Fat suppression sequences.
Bony remodelling/errosion
Best tool: MR
Entity. Definition. Clinical presentaation.
Diastematomyelia.
Sagital division of spinal cord into 2 hemicords, each with 1 central cana. dorsal horn and ventral horn.
Presentation at childhood. Mainly F.
Indistinguishable from causes of tethered spinal cord.
Cutaneous stigmata indicate DSM level (> 50%); “fawn’s tail” hair patch most common
Other severe cases: progressive kyphoscoliosis, neurologic and MSK abnormalities.
Diastematomyelia,
Path, Associations, Complications
Path: Split notochord syndrome spectrum (with dorsal enteric fistula/sinus, and dorsal enteric cysts/diverticula).
Genetics: sporadic (rare familiar cases)
Associations:
85% Congenital spinal deformities
Congenital scoliosis (79%)
Tethered spinal cord (75%); thickened filum terminale (40-90%)
Syringohydromyelia (50%) 1 or both hemicords, usually above DSM
Intersegmental laminar fusion (60%);
Spinal dysraphism (myelocele/myelomeningocele 15-25%, hemimyelocele 15-20%)
Segmentation and fusion anomalies (SFA)
Chiari 2 malformations (15-20%)
Spinal lipoma (26%)
Dermoid cyst (13%)
20% Other split notochord syndromes(with dorsal enteric fistula/sinus, and dorsal enteric cysts/diverticula).
Complications:
Cord ischaemia,
Roots may adhere to dura: meningocele manqué
Diastematomyelia,
Morphology, types , Dx.
Morphology: Best clue: Fibrous or osseous spur splits spinal cord into 2 hemicords
Hemicords usually reunite above and below cleft
Hemicords can be symmetric (Each hemicord contains 1 central canal, dorsal horn/root, and 1 ventral horn/root surrounded by pial layer) or asymmetric (Division of anterior or posterior hemicord (“partial DSM”)
± fibrous or osseous spur = Type 1
± thickened filum, cord tethering.
Either 1 or 2 dural tubes.
Thoracolumbar cleft (85% between T9 and S1) > > upper thoracic, cervical clefts
Pang type I
Separate dural sac, arachnoid space surrounds each hemicord
Osseous/fibrous spur
More commonly symptomatic. More anomalies. Worse prognosis.
Pang type II
Single dural sac, arachnoid space
No osseous spur; ± adherent fibrous bands tether cord
Rarely symptoms (unless hydromyelia, tethering)
Dx:
US to screen infants with skin dimple or cutaneous marker
MR imaging most definitive for characterization
Bone CT ± myelography to optimally define spur anatomy for surgical planning
Congenital spinal malformation characterized by segmentation failure of ≥ 2 cervical vertebrae ± thoracic, lumbar segmentation failure.
DIAGNOSIS?
KLIPPEL FEIL SYNDROME.
Klippel Feil syndrome:
Clinical presentation, Path
2-3rd decade. Slight F.
Classic triad (~50%): Short neck, low posterior hairline, and limited cervical motion
3rd decade: symptoms of degenerative changes, cervical motion limitations.
Path: not universally accepted. Classified within abnormal segmentation.
Mostly sporadic.
Could be hereditary (AD or AR)
Klippel Feil:
Associations, complications.
Associations:
Scoliosis (usually congenital) ± kyphosis (60%)
Hemivertebrae, butterfly vertebrae, spina bifida (other segmental abnormalities)
Odontoid dysplasia, basilar impression, C1 assimilation, occipitocervical instability
Syringomyelia, diastematomyelia (20%), Chiari 1 malformation (8%), neurenteric cyst or dermoid (rare)
Cervicomedullary neuroschisis ± synkinesis (20%)
Sprengel deformity ± omovertebral bone (15-30%);
Other: Sensorineural hearing loss (30%), external ear anomalies, genitourinary tract abnormalities (35%), congenital heart disease (14%), upper extremity deformity, facial anomalies
Complications: ↑ risk of neurologic injury following minor trauma secondary to hypermobility of cervical segments.
Klippel Feil,
Morphology, Classificaton, Dx.
-Congenital cervical segmentation and fusion anomalies of > 2 levels
-Single or multilevel.
-C2-C3 (50%) > C5-C6 (33%) > craniovertebral junction (CVJ), upper thoracic spine
-Vertebral bodies usually smaller than normal
-Vertebral body narrowing (“wasp waist”) at fused rudimentary disc space ± **fusion of posterior elements
-Adjacent** disc spaces at mobile levels ± degenerative changes
-Spinal canal diameter usually normal (if enlargement, consider syringomyelia. If narrow, secondary to degenerative changes)
Types:
I (9%): Massive fusion of cervical, upper thoracic spine → severe neurologic impairment, frequent associated abnormalities
II (84%): Fusion of ≥ 1 cervical vertebral interspaces
III (7%): Fusions involve cervical and lower thoracic/lumbar vertebra
Dx:
Radiography to evaluate and follow instability (flex/extend), degenerative changes
MR to exclude cord compression, detect degenerative changes
Recommendation: Look for instability, progressive degenerative changes, cord/brainstem compression
Entity? Definition? Clinical presentatoin?
Basilar invagination.
Def: tip of the odontoid process projects above the foramen magnum.
Presentation: asymptomatic until 2nd to 3rd decade (weakness, neck pain, bowel and bladder disturbance and/or paresthesia)
Basilar invagination, Causes
Paget, RA and rickets, Osteogenesis imperfecta, osteomalacia, Klippel Feil
Achondroplasia, cleidocranial dysostosis, hyperparathyroidism, Fibrous dysplasia,
Basilar invagination, findings
Findings:
**30% **associated with neuraxis abnormality: Chiari, syringomyelia, hydrocephalus.
Often associated with platybasia (skull base flattening over 143 grades)
**Stenosis of foramen magnum and compression of medulla oblongata. **
Osteogenesis imperfecta:
clinical presentation, Cause
Mutation at type I collagen. Affects bones, skin and sclera.
Sporadic or AD.
Clinically:
Short statue
Kyphosis.
Blue sclera, deafness, brittle teeth, joint laxity, fragil thin skin, respiratory and cardiac abnormality.
Osteogenesis imperfecta:
Findings
- Osteopenia
- Cortical thining (reduced medullary trabeculae)
- Fractures at vertebra (codfish vertebra: cupping of superior and inferior vertebral body endplates)
- Long bones bowing and angulation.
- Zebra stripe sign (post medical treatment)
- Enlarged epiphyses
- Popcorn metaphyseal calcifications
- Medullary cavity filled with fat
- Other: basilar impression, otospongiosis, protrusion acetabulae, coxa vara.
Entity. Definition. Clinical presentation.
Osteopetrosis.
Uncommon. Heterogeneous group of hereditary disorder characterised by defective osteoclast functioning. Results in incrased bone density and sclerosis, distorted architecture.
Clinical presentation: (infantile, intermediate, adult)
Varies depending on age of presentation.
General: Fractures, pain, neurologic symptoms. Long bone more common
Infantile form, more advanced: Dense bones, marrow space obliteration, Growth disturbance
Delayed form: Thickened bone cortex, bone within bone appearance
Osteopetrosis:
Path, types
Mutation found in > 90%. Affects either ↓ number or ↓ functionality.
-AR: infantile type (malignant type)
Severe anemia, hepatosplenomegaly, recurrent infections,fractures, macrocephaly, progressive blindness > deafness, ± hydrocephalus, coxa vara
-AD type 1 (not true): enhanced osteoblast activity → high bone mass
Universal osteosclerosis but marked at cranial vault while spine is almost unaffected
-AD type 2: most common form. ~40% are asymptomatic. Osteosclerosis predominantly involves spine, pelvis, & skull base; mandibular osteomyelitis
-X linked recessive (very rare)
Macro: Dense, brittle bones with ↑ fracture risk. Micro: disorganized dense bones (not functional).
Osteopetrosis:
Morphology
General:
-Diffuse ↑ bone density (hyperostosis and sclerosis), **severe cortical thickening, loss of corticomedullary differentiation** with dense bone extending into medullary space.
Skull, brain, face: Macrocrania, frontal bossing
Thick, dense skull base &/or calvarium
cranial vault (Loss of diploic space)
Absent/underdeveloped paranasal sinuses.
Axial skeleton:
-Bone-within-bone appearance (vertebral, carpal. Idem inability to remodel bone)
-Rugger jersey or sandwich vertebrae (sclerotic endplates) vs diffuse sclerosis.
-“black bone”: infantile type: Complete absence of marrow due to replacement by dense bone
-Ribs & costochondral junctions: Widening
-Pelvis: Bone-in-bone appearance
Appendicular skeleton:
-Dense skeleton vs. radiolucent bands in metaphyses (Loss of corticomedullary definition)
-Undertubulation Erlenmeyer flask demormity of metaphyses (widening of bone shaft, mostly distal femur.) (inability to remodel bone: cortical bone is not resorbed and remains visible within larger (more adult)
-Coxa vara
± extramedullary hematopoiesis
Entity, Definition, Clinical presentation,
Epidemiology (maternal association)
Caudal regression syndrome.
Constellation of caudal developmental growth abnormalities and associated soft tissue anomalies raging from absent coccyx to lumbosacral agenesis
Clinical: In utero ~ adulthood. M=F.
Ranges from neurologically normal → severely impaired (mild foot disorders → complete lower extremity paralysis and distal leg atrophy, neurogenic bladder dysfunction, morotr and sensory deficit)
Association with diabetic mother.
Caudal regression syndrome:
Types?
2 main group:
-Group 1: More severe caudal dysgenesis with high-lying, club-shaped cord terminus (↓ number of anterior horn cells). Distal spinal cord hypoplasia, severe sacral osseous anomalies
-Group 2: Less severe dysgenesis with low-lying, tapered low lyingdistal cord elongation and tethered by tight filum, lipoma, lipomyelomeningocele, or terminal myelocystocele
Caudal regression syndrome,
associations
100% tethered cord and low conus.
65% thickened filum +/- dermoid/lipoma
~50% MMC
~20% other spinal anomalies (vertebral, diastematomyelia, terminal hydromyelia, lipoMMC, terminal myelocystocele, anterior sacral meningocele, terminal lipoma)
24% congenital heart defect, pulmonary hypoplasia
24% genitourinary abnormality (renal agenesis/ectopia, mullerian duct malformation, urinary bladder malformation)
Anorectal anomalies (particularly anal atresia)
Currarino triad: Partial sacral agenesis with intact 1st sacral vertebra, presacral mass, anorectal malformations
Association with VACTERL (10%), omphalocele, exstrophy bladder, imperforate anus, spinal anomalies (10%), and Currarino triad syndromic complexes
Orthopaedic: extreme case of fusion (sirenomelia)
Caudal regression syndrome,
Morphology, dx
Morphology:
Clue: Incomplete lumbosacral spine formation + Abnormal distal spinal cord
Spectrum: Partial or total. Unilateral or bilateral. Dysgenesis, hypogenesis lumbosacral joints.
Vertebral column terminates in thoracic spine
Caudal vertebral bodies often fused.
Severe osseous canal narrowing rostral to last intact vertebrae
Location: lumbosacral segment
± prominent nerve/dorsal root ganglion (DRG) enhancement
-Group 1: Distal spinal cord hypoplasia (wedge-shaped cord termination), severe sacral osseous anomalies. ± dilated central canal, conus CSF cyst
-Group 2: Tapered, low-lying, distal cord elongation with tethering, less severe sacral anomalies
Dx:
US for infant.
MR for further assessment, treatment planning. (lumbosacral deficiency, distal spinal cord morphology, and presence/absence of tethering/lipoma, hydromyelia, osseous spinal narrowing, etc)
Etiology, definition.Clinical presentation
Neuroenteric cyst.
Cyst along neuraxis lined with mucin-secreting cuboidal or columnar epithelium resembling alimentary tract. Derived from displaced endodermal tissue
Clinical: Adolescent. Slight M
Some asymptomatic, but most show progressive neurologic deterioration, headaches
Usually present in adolescents;
Acute presentation rare, usually from infection → meningitis
Neuroenteric cyst,
Path, associations
Path:
-Caused by incomplete separation between primitive endoderm & ectoderm during 3rd embryonic week
-Enteric & spinal structures connected through persistent neurenteric canal (a.k.a. canal of Kovalevsky) (Normally, this cannal transiently connects amniotic cavity and yolk sac from 23-25 days)
Sporadic or syndromic (Klippel-Feil, VACTERL, OEIS)
Associations:
-Associated with vertebral anomalies, split cord malformation, lipoma, dermal sinus tract, & tethered spinal cord
-Malformations of gastrointestinal tract: Duplication, fistula, anal atresia
-Syndromic (Klippel-Feil, VACTERL, OEIS)
Neurogenic cyst,
Morphology, ds
Morphology:
Cyst along neuraxis ± vertebral segmentation anomalies ~50%
Usually intraspinal (~ 90%)
Most are intradural extramedullary ~90%
simple unilocular cysts (rarely multilocular)
Cyst similar to CSF of proteinaceous/hemorrhagic
Ventral > > dorsal to spinal cord
Mainly lower cervical or upper thoracic
Intracranial (~ 10-25%) (~90% posterior fossa)
Can be associated with other closed spinal dysraphisms
Mass effect on spinal cord, Enlarged spinal canal with widening of interpedicular distance.
Scoliosis
Dx: Tc-99m cyst uptake (gastric mucosa) confirms diagnosis
MR vertebral anomalies, cord compression, & cyst relationship to adjacent structures
Bone CT/3D CT to characterize osseous anomalies, surgical planning
Entity. Definition. Clinical presentation
Sacrococcygeal Teratoma
Most common tumor of the fetus or infant.
Germ cell tumor made up of various parenchymal cell types from > 1 germ layer (usually all 3). Potentially grows both internally & externally (with latter more common). Both benign (80%, mature) & malignant (17%) varieties.
F»_space; M
-Frequently diagnosed in utero.
-Most others: within furst few days of life (exophytic mass)
-Type IV: present in childhood w/ urinary retention, bowel isusues, scoliosis, etc.
-AD: Currarino triad: Presacral mass (usually anterior meningocele or SCT), anorectal malformation, sacral anomalies
Classification of sacrococcygeal teratoma.
Frequency of each.
Classification into 4 types:
Type I (47%): Primarily external in location
Type II (34%): Dumbbell shape, equal pelvic & external components
Type III (9%): Primarily located within abdomen/pelvis
Type IV (10%): Entirely internal, no external component
Sacrococcygeal teratoma:
Path. Assoc. Comp. Prog.
Path:
Failure in secondary neurulation (canalization and retrograsive differentiation)
-Arises from pluripotential cells at caudal tip of notochord (coccyx)
-Teratomas are made up of various parenchymal cell types from > 1 germ layer, usually all 3. May contain hair, teeth, cartilage, & fat, amongst other tissues
-Genetic: Mainly sporadic.
Curarino type is AD. There are familial tendency.
-Tumors can be mature or immature.
-17% malignant. Yolk sac tumor > embryonal Ca. Might require QT.
Associations:
10% other congenital anomalies: Primarily defects of hindgut & cloacal region, other midline defect (MMC, spina bifida)
Complications:
-Arteriovenous shunting in tumor → high-output cardiac failure
-Hydrops > 90% before birth, intratumoral haemorrhage, rupture, fetal demise.
Prognosis/Treatment:
Good prognosis with benign tumor and complete resection.
-~15% risk of recurrence (tumor spillage/incomplete resection)
Might require QT.
Sacrococcygeal teratoma
Morph. Dx.
Morphology:
Always with presacral components; exophytic extension more common than internal growth
Heterogeneous **mixed solid & cystic **masses
**Ca⁺⁺, fat, hemorrhage, cysts, various soft tissues **in mass
Solid components may show moderate to high vascularity
Classification into 4 types:
Type I (47%): Primarily external in location
Type II (34%): Dumbbell shape, equal pelvic & external components
Type III (9%): Primarily located within abdomen/pelvis
Type IV (10%): Entirely internal, no external component
-Malignancy: ↑ with age, type IV
Age at diagnosis. Subtype IV. Male. Necrosis/haemorrhage. Elevated α-fetoprotein.
-Genetic type: Currarino triad: Presacral mass (usually anterior meningocele or SCT), anorectal malformation, sacral anomalies
Dx: Best clue: Large, solid, cystic, or mixed mass with exophytic perineal/buttock component & relatively small presacral component. Ca²⁺, bone, fat, fluid levels, various soft tissues in mass.
-MR best for identifying intraspinal extension, surgical planning.
-Xray/CT: best for Ca+. Variable enhancement pattern post IV.
-US: most common prenatal modality.
-PET: often in evaluation of malignant recurrence
