0:01

This is a CT scan of the head in

0:03

a 16-year-old boy with seizures.

0:06

And we can see some calcified nodules along

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the lateral margin of the lateral ventricles.

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A tiny speck here on the superolateral margin

0:15

of the right lateral ventricle,

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and a slightly larger but still overall small

0:21

lesion on the lateral margin of the posterior

0:23

body of the left lateral ventricle.

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We see another tiny area of mineralization

0:29

adjacent to the right caudothalamic groove,

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which is the lateral margin of the anterior

0:35

body of the right lateral ventricle,

0:36

adjacent to the level of the foramen of Monroe.

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MRI confirms a diagnosis of tuberous sclerosis complex.

0:44

You can see areas of dysplasia

0:47

in both cerebral hemispheres.

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We can see here in the left,

0:54

approximately the junction of the left

0:56

parietal and occipital lobes.

0:58

You can see the left frontal lobe.

1:01

You can see the left temporal lobe.

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Here's the lesion in the left temporal lobe.

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It's in the left inferior temporal gyrus.

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Overall,

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there's a relatively mild tuber burden,

1:15

but this patient still had profound seizures

1:18

that were debilitating.

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Historically, it was said that tuberous sclerosis complex was

1:24

not a great candidate for epilepsy surgery.

1:28

Because you had multiple lesions,

1:30

you don't know which one to resect,

1:31

and you can't resect them all.

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Well,

1:34

that's where modern imaging and multimodality

1:37

evaluation can really help.

1:39

Working with the epileptologists,

1:41

these two images are from what's called Ciscom

1:45

subtraction SISCOM interictal SPECT imaging,

1:48

co-registered with MRI. What does that mean?

1:52

It means we give a nuclear medicine,

1:55

radio tracer that localizes to areas

1:59

of blood flow and metabolism.

2:01

It is an agent that can cross the blood

2:03

brain barrier, and you give it once.

2:07

When a patient is interictal,

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they haven't seized in a while.

2:11

And what generally happens is areas where

2:14

seizures originate between seizures have

2:17

slightly lower metabolism and slightly lower

2:20

blood flow than the rest of the brain.

2:23

Then what you try and do is you monitor

2:26

the patient with continuous EEG,

2:28

and you have a nuclear medicine technologist

2:30

sitting at the bedside,

2:32

ready to inject the tracer.

2:34

When the patient seizes,

2:36

they inject the medicine right away.

2:38

During a seizure,

2:40

the area of seizure onset is highly

2:42

metabolically active.

2:44

Because it's highly metabolically active,

2:47

it has a lot of blood flow.

2:49

The radio tracer then localizes to this area,

2:53

more so than areas of the brain.

2:56

Well, we now have it where, during a seizure,

2:59

ICTYL injection is slightly more blood

3:03

flow than the rest of the brain,

3:06

and the interictal has less blood flow.

3:09

Most of the rest of the brain should have

3:12

approximately similar blood flow in

3:14

the ICTYL and interictal states.

3:16

So with complex mathematics

3:19

and computer formulas,

3:21

it's possible to co-register the ictal and

3:23

interictal images and subtract them.

3:26

And you preferentially identify areas

3:29

where the seizures are coming from.

3:31

And this gives us a hint that possibly the

3:34

left temporal pole is an area where seizures

3:37

might be coming from if we remember this

3:40

patient had an area of dysplasia

3:42

in the left temporal lobe,

3:44

and we know that the seizures likely are

3:49

coming from there because this also

3:50

matches what the EEG says.

3:53

So now,

3:53

even though the patient has other

3:55

areas of cortical dysplasia,

3:57

we now have reasons to think that the left

3:59

temporal lobe is going to be the predominant

4:01

cause of the seizures.

4:02

So this patient underwent a

4:04

left temporal lobectomy.

4:05

The left temporal lobectomy allowed the left

4:09

temporal pole to be resected with, hopefully,

4:11

the site of seizure onset.

4:13

You can see here that

4:15

as we go inferiorly,

4:18

their resection went more further posteriorly.

4:22

Why is that helpful? Well,

4:24

we thought the temporal pole was where

4:25

the seizures were coming from,

4:27

and that was confirmed on intraoperative

4:29

electrocorticography.

4:31

But we felt that it was possible,

4:34

while we were there,

4:35

to get this area of dysplasia in that region,

4:38

which possibly was either the cause of the

4:41

seizures or there was a seizure

4:44

circuit where it was involved,

4:48

and therefore both were able to be resected.

4:51

Well, why not just take off everything?

4:53

Well,

4:54

the goal of this was to preserve as

4:57

much brain parenchyma as possible,

4:59

because we don't know if the patient,

5:01

years down the road,

5:02

may need a second resection somewhere else.

5:05

Additionally,

5:06

this is the left hemisphere in

5:08

a right-handed individual.

5:09

And this bump right here is the transverse

5:14

temporal gyrus, or Heschel's gyrus.

5:16

This is the region where,

5:20

in the left hemisphere,

5:21

you typically have receptive language.

5:23

And this patient,

5:26

functional MRI confirmed a left hemispheric

5:28

language lateralization.

5:29

So by performing the resection

5:33

at an angle like this,

5:34

they were able to avoid the language cortices.

5:38

So this patient has tuberous sclerosis complex.

5:42

And while there are several areas

5:44

of cortical dysplasia,

5:46

EEG confirmed with Ciscom ICTYL

5:49

interictal subtraction.

5:50

SPECT co-registered with MRI confirmed that

5:53

the left temporal was likely the culprit

5:57

with a multimodality workout.

6:00

Up in collaboration with the epileptologist.

6:02

It allowed a resection that

6:05

removed both the presumed site of seizure onset

6:09

and the adjacent

6:11

area of dysplasia,

6:12

which was likely either the

6:13

source or involved.

6:15

And the patient had improved seizure control.