Ch 6 Spine Pathology Flashcards
List 2 normal spine variants?
Filar cyst + ventriculus terminalis
Main difference b/w a filar cyst + ventriculus terminalis?
Filar: inferior to conus
Ventriculus: within conus
What is a filar cyst?
Anechoic structure within filum terminale, just inferior to conus medullaris
What is ventriculus terminalis?
-Widening of the distal central canal, located within conus
-Typically resolves within first few months of life
Another name for ventriculus terminalis?
5th ventricle or persistent terminal ventricle
What is spinal dysraphism + what causes it?
Broad group of spinal abnormalities due to improper fusion of the neural tube during fetal development
Where are spinal dysraphism defects m/c located?
Lower spine
When is the neural tube finished developing?
8th week gestation
The neural tube is formed by the closure of the ___?
Neural plate
Should a normal neural plate completely fuse?
Yes! Or else dysraphism occurs
Differentiate b/w open + closed spinal dysraphism?
Open:
-aka spina bifida aperta
-no skin covering sac
-neural tissue communicates with outside via defect
Closed: (harder to see)
-aka spina bifida occulta
-skin covered abnormality
Differentiate b/w a meningocele, myelomeningocele + myelocele?
Meningocele:
-protrusion of meninges w/o neural tissue
-closed defect
Myelomeningocele:
-protrusion of meninges + neural tissue
-bulge above skin
-open defect
Myelocele:
-exposed neural tissue flush with skin surface + has no skin or meninges covering spinal cord
-open defect
(myelo = neural tissue, meningo = meninges)
List the 2 types of open spinal dysraphism?
Myelocele + myelomeningocele (visible on outside of skin)
Myeloceles + myelomeningoceles are herniation’s through a defect in the ___ mater?
Dura
What is the m/c open spinal dysraphism?
Myelomeningocele
With open spinal dysraphism, the spinal cord is ___ at the level of the abnormality?
Tethered
List 3 complications of open spinal dysraphism?
-Decreased lower limb function to paralysis
-Bladder + bowel dysfunction
-Hydrocephalus
(similar complications to closed spinal dysraphism)
___ occurs due to an enlarged subarachnoid space?
Myelomeningocele
SF’s of open spinal dysraphism?
-Loss of normal conus
-Fluid filled sac
-Mass continuous with spinal canal
Closed spinal dysraphism is present with skin-covered ___ or ___?
Subcutaneous mass or various skin markers
List 2 subcutaneous masses associated with closed spinal dysraphism?
Lipomyelocele/lipomyelomeningocele + myelocystocele
List the m/c skin marker associated with closed spinal dysraphism?
Sacral dimples
Closed spinal dysraphism anomalies are associated with a ___?
Tethered cord
Tethered cord is a type of ___?
Closed spinal dysraphism
What is a tethered cord?
Low lying cord with a thickened filum terminale
What happens as the spinal column grows + tethering occurs?
Causes stretching of spinal cord + limits its movement
Tethered cord is almost always associated with ___ anomalies?
Dysraphic spinal
Tethered cord symptoms are similar to OSD/CSD but may present earlier or later on?
Later on - as the child grows the spinal cord gets pulled tight, causing neurological symptoms
What 5 anomalies are highly suspicious for a spinal abnormality?
-Hair tufts
-Vascular malformations
-Deep dimples
-Skin tags
-Deep clefts
(especially in lumbar region)
Tethered cord has a high association with ___ syndrome?
VACTERL
4 main SF’s of a tethered cord?
-Conus is at or below L3
-Decreased movement of filum terminale + nerve roots (cauda equina)
-Filum terminale will be thick (>2mm) or fatty
-Conus looks abnormally elongated + lack normal tapering
What is diastomyelia?
-Longitudinal split of the spinal cord into 2 hemicords (usually reunites to form single distal cord)
-Aka split cord malformation
Where does diastomyelia m/c occur?
In thoracolumbar region
Tethered cord, scoliosis, clubfoot, vertebral anomalies + dilation of the central canal is associated with ___?
Diastomyelia
Diastomyelia is diagnosed in what plane?
TRV (b/c 2 hemicords will be seen in this plane)
What is a dorsal dermal sinus?
-Thin epithelial lined tract that courses from skin towards spinal canal
-Focal disruption of fusion of spinal canal
Dorsal dermal sinuses m/c occur where?
In lumbosacral region
Dorsal dermal sinuses clinically appear as deep midline ___?
Dimples/pits
What is the main SF of a dorsal dermal sinus?
Midline tract from spinal cord to skin (m/c in area of a skin marker/abnormality)
___ is the m/c reason an infant is referred for a spinal u/s?
Sacral dimple (located <2.5mm from anus)
Sacral dimples can be associated with a ___ sinus?
Pilonidal sinus (this has no connection to the normal spine)
What is a spinal lipoma?
Collections of encapsulated fat/connective tissue with a definite connection to the spinal cord
(accounts for 20-50% of closed spinal defects)
Name the 3 types of spinal lipomas?
-Lipomyelocele/lipomyelomeningocele (m/c)
-Intradural lipoma
-Lipomas of filum terminale
What is the m/c spinal lipoma?
Lipomyelocele/lipomyelomeningocele
What is a lipomyelocele/lipomyelomeningocele?
-Skin covered echogenic fatty back mass that distorts + tethers the spinal cord
-M/c in lumbar region
How do intradural lipomas + lipomas of the filum terminale differ from lipomyeloceles/lipomyelomeningoceles?
They do not have an associated subcutaneous mass
What is an intradural lipoma?
Mass within spinal cord that is completely confined by the dura
What is a lipoma of the filum terminale?
-Small echogenic fatty mass in filum
-Filum thickens (>2mm)
What is a terminal myelocystocele?
-Skin covered cystic lumbar mass protruding through a dysraphic defect
-Abnormal dilatation of the terminal ventricle that communicates with the central spinal cord
What is a block vertebrae?
When 2 adjacent vertebral bodies fail to separate
What is a hemivertebrae?
Congenital lack of formation of one half of a vertebral body
What is a butterfly vertebrae?
Cleft/failure of fusion of the lateral halves of the vertebral body
What is the m/c type of germ cell tumour occuring in the neonatal period?
Sacrococcygeal teratoma
What is a sacrococcygeal teratoma?
Benign sacral mass (risk of malignancy)
Birth trauma is m/c assessed with what imaging modality?
MRI
___ is performed on infants with sepsis to obtain CSF for culture?
Lumbar punctures
How does the appearance of hematomas vary with age?
Initially: echogenic
Later on: anechoic as it resolves
Filum terminale is considered thick beyond what value?
2mm
How does a myelocele differ from a myelomeningocele?
Myelocele is flushed to skin with no meninges/skin covering it
