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This is a CT scan of a 17-year-old boy with seizures.

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And we can see multiple areas of cortical

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and juxtacortical calcification here.

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Left superior frontal gyrus near the vertex.

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Right superior frontal gyrus near the vertex.

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The right parietal lobe.

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The right inferior frontal gyrus.

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The left frontal pole.

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Right frontal pole.

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So, multiple areas.

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We're also seeing some

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areas of mineralization along the lateral margin

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of the body, the lateral ventricles.

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Here's a tiny area of mineralization.

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These are additional subependymal nodules

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that are calcified.

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So, this patient has tuberous sclerosis complex.

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MRI confirms,

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we can see these subependymal nodules.

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Here's one.

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Some of them can be very subtle.

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Fortunately, we're not seeing any large ones

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near the Foramen of Monroe

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to suggest SEGA or suggest any signs of impending

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impingement of the Foramen of Monroe.

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FLAIR MRI shows multiple areas

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of cortical dysplasia

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throughout both cerebral hemispheres.

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There are multiple in the right,

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the left cerebral hemispheres, which,

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when looking closely,

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have the morphology of a focal cortical

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dysplasia, type 2B.

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And the problem is,

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how do you do epilepsy surgery in a patient with

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at least 10-20 different areas of dysplasia?

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Any one of them,

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or possibly more than one,

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could be causing the seizure.

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Well, that's where multimodality imaging comes in.

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Everything from

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ictal interictal spec imaging,

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EEG, magnetoencephalography.

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But then,

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this image here is actually performed.

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We can see these little areas of hypointense signal.

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They look like little circles overlying parts of the brain.

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And we can see these little areas in the

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interhemispheric fissure. These are electrodes.

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These are electrodes that we

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can see on this radiograph.

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Lateral and a frontal radiograph overlie

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the suspected areas of seizure onset.

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What does this allow?

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This allows them to record an EEG,

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not from the skin surface where the electrical

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abnormality has to go through the dura,

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the meninges,

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the skull and the skin.

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But it's immediately on the surface,

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so these areas can allow detection of seizure

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onset to within a centimeter.

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That level of detail allows us to scrutinize the

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imaging to find areas where the seizures might be

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coming from and come up with a plan to figure out

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what to resect. This patient underwent

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a resection of the left frontal pole.

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You can see the resection goes pretty much to the

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margin of the frontal horn of the

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If we go up now,

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there's another focal resection that was here.

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There was a very active area of seizure onset

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right here. Why resect just that?

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Not everything in between? Well,

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this is the central sulcus.

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So this is approximately where you would

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expect motor for the right leg.

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This is where you'd expect

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motor for the right hand.

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And this area here is called supplementary motor

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area. It is not primary motor cortex,

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but it is involved in motor coordination.

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As much of that as possible that can be spared is

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good. Now, supplementary motor area injuries,

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whether resection or otherwise,

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usually do not result in any

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permanent loss of function.

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It may require some physical therapy

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to regain coordination and things,

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but there was no need from an epilepsy control

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standpoint to resect this parenchyma in between.

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So,

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working together with the epileptologists

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and the neurosurgeons,

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we were able to figure out which electrodes were

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related to the seizure onset,

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allowing resection of the frontal pole and a

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resection of this very focal area of the left

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superior frontal gyrus near the vertex and spare

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the periorlandic cortex for primary motor function

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and spare portions of supplementary motor area.

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These electrodes are placed in the operating room.

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We use image guidance to help determine where to

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place the electrodes once they're in place.

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As you can see,

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they put the skull back on and

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they recover the patient.

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The patient can get an MRI as well

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as plain film or even CAT scan,

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and to be able to determine where

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these electrodes are.

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The patient is then monitored in the intensive

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care unit for several days,

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waiting for a seizure to happen.

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So it doesn't have to just be occurred

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during the operating room time.

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The patient can be in the intensive care unit,

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but under close observation.

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And when they seize these electrodes,

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we can pick up the source of the seizure.

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Then, after several days of monitoring,

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the patient can return to the operating

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room to remove these electrodes.

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These are called grid electrodes.

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When they remove them,

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if there's an appropriate candidate,

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they can also perform the resection.

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So this results in the ability to do awake

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monitoring of a patient for

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a prolonged period of time

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in the intensive care unit,

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which is safer than performing prolonged

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monitoring in the operating.