0:01

Although we will have a separate lecture

0:03

on congenital spinal lesions,

0:06

I did want to close the discussion on the extradural

0:10

congenital anomalies with a discussion about

0:13

myeloceles and myelomeningoceles, et cetera.

0:18

The myelomeningocele is the classic lesion that is

0:21

associated with the arnold chiari malformation.

0:25

These are now being addressed intrauterine with

0:28

treatment for the skull base abnormality associated

0:32

with the arnold chiari malformation.

0:35

This is an open dysraphic state in which one can

0:39

see the CSF space directly at endoscopy

0:43

when you do the intrauterine therapy.

0:47

These patients are found by elevated Alpha-Fetoprotein

0:51

in the amniotic fluid, or they may be found because of

0:56

some screening ultrasound at the

0:59

time of the 20 week gestation.

1:03

Here, for example,

1:05

is an ultrasound which is demonstrating

1:08

the widening between the pedicles.

1:11

We're actually looking coronally here, and we see

1:13

widening between the pedicles in the area

1:16

where the myelomeningocele resides.

1:19

And on the more sagittal off limit parasagittal scan, you

1:24

see the cyst protruding outside of the spinal canal

1:28

and that of a myelomeningocele.

1:31

Here is a baby which was born with a huge cyst

1:38

that communicates with the spinal canal.

1:40

So we are just seeing portions of the lumbosacral

1:45

junction. So to orient you, this is obviously the baby's brain.

1:50

Here is the thoracic column and we're just off midline,

1:53

but we're coming to the lumbosacral junction and we have

1:57

this communication through a spinal dysraphism

2:00

to a huge cyst which is the myelomeningocele.

2:07

And this communicates with the intraspinal compartment.

2:10

And again, this is most commonly associated with an Arnold Chiari

2:15

hindbrain malformation with descent of the cerebellar

2:19

tonsils and portions of the cerebellum in association

2:22

with what typically is hydrocephalus.

2:25

This is another patient with an extradural cystic

2:28

lesion, in this case protruding anteriorly.

2:32

So this is our anterior pelvic spinal meningocele, and

2:37

this may be associated with abnormal development

2:39

of the lower sacrum and coccyx.

2:42

We have to be careful in looking at these cystic lesions

2:45

because remember that one of the tumors that can

2:48

affect the sacrum is the sacrococcygeal teratoma.

2:52

Sacrococcygeal teratomas have cystic portions, but

2:56

they often have in association fatty components,

3:00

as well as soft tissue components in this mixed

3:03

germ cell tumor. This particular case,

3:06

all we're seeing are the cystic components. And therefore,

3:09

this was an anterior sacral meningocele.

3:12

Here is a child that has a spina bifida, and yet

3:17

this was not an open spina bifida. For that,

3:20

I mean that the skin surface,

3:22

you weren't able to see the abnormality

3:24

at the skin surface.

3:25

The skin was covered over this lesion.

3:28

And that's typical of a lipomyelocele.

3:31

So this is a patient who has spinal dysraphism, with an

3:36

open spine here. You have cord tethering downward.

3:40

You have a fat containing lesion seen on the T1

3:43

weighted scan, and yet the skin is covered over this lesion,

3:47

and this is herniation predominantly of the spinal cord.

3:52

So therefore a myelocele more than fluid, which

3:56

would be dark on this T1-weighted scan.

3:58

So as I said,

3:59

myelomeningoceles are associated with Arnold Chiari

4:02

malformation Type II, or typically

4:04

Arnold Chiari malformation greater than 90%.

4:08

You may also see patients who have diastematomyelia,

4:11

which we'll talk about shortly.

4:13

They may show a syrinx in the spinal cord because of the

4:16

herniation of the tonsils inferiorly leading to high

4:20

pressure in the spinal canal, which is decompressed into

4:23

the central canal as a hydromyelic cavity

4:27

and scoliosis in 60% to 70%.

4:30

I also described your lipomyelomeningocele, that's

4:34

not associated with Arnold Chiari malformation.

4:37

It is a covered deficit and this is one that, again, one

4:42

will see on T1-weighted scan as

4:44

brightened signal intensity.

4:45

A myelocystocele is local dilatation of the central

4:49

canal. This may be associated with cloacal exstrophy.

4:53

And then we'll also talk about dorsal dermal sinus

4:56

tracts, which I demonstrated previously,

4:58

which may be associated with epidermal or dermoid cyst

5:02

in the intradural extramedullary location in 30% to 50%.

5:07

We've seen this case before.

5:09

It shows the fat containing lesion associated with the

5:13

spinal dysraphism, as well as the tethered spinal cord

5:18

as a lipomyelocele, large lipoma associated with it.