Name:
Insular gliomas and tractographic visualization of the connectome
Description:
Insular gliomas and tractographic visualization of the connectome
Thumbnail URL:
https://cadmoremediastorage.blob.core.windows.net/e67c9c68-07cc-401b-b0e1-cf0b3a539c6b/videoscrubberimages/Scrubber_528.jpg
Duration:
T00H10M25S
Embed URL:
https://stream.cadmore.media/player/e67c9c68-07cc-401b-b0e1-cf0b3a539c6b
Content URL:
https://cadmoreoriginalmedia.blob.core.windows.net/e67c9c68-07cc-401b-b0e1-cf0b3a539c6b/21-194.mp4?sv=2019-02-02&sr=c&sig=NkySG5lu0mqxHuaqH1U0sgM9xPmHxIa23odbbpY9ZDk%3D&st=2025-03-27T13%3A42%3A40Z&se=2025-03-27T15%3A47%3A40Z&sp=r
Upload Date:
2021-12-06T00:00:00.0000000
Transcript:
Language: EN.
Segment:0 .
[MUSIC PLAYING]
SPEAKER: In this video, we demonstrate the use of connectomics and tractographic visualization using artificial intelligence to help improve the resection of an insular glioma. So reviewing the anatomy of the large scale brain networks. First we'll start with the default mode network. The default mode network, or DMN, is an anterior cingulate, posterior cingulate, and lateral parietal network. You can see that the two medial components, the anterior cingulate and posterior cingulate components, are connected via the cingulum bundle, with the lateral parietal component being an isolated island, at least relative to these networks.
SPEAKER: The default mode network does a variety of functions that are critical to cognition and emotional regulation, most notably, episodic memory, theory of mind, and imaginative thinking. The anatomy of the salience network is shown here. This is a middle cingulate and anterior insular network. You can see that the two components are connected via the frontal aslant tract. And the frontal aslant tract is named because it runs aslant to the overall anterior to posterior white matter of this part of the brain.
SPEAKER: If you look at the middle cingulate component, it's important to note that in addition to the areas that are in the Brodmann area 32 complex, you can see in the upper left, there's an area called SCEF, which stands for supplemental and cingulate eye field. This area is better thought of as a key component of both the salience network and the supplementary motor area. Importantly, a good portion of the supplementary motor area is, in fact, subcomponents of the default mode network and salience network.
SPEAKER: Finally, the central executive network is best thought of as the opposite network to the DMN. So where the DMN is handling internal mental processes, the central executive network is handling active thinking and active processes. It has a four-component aspect with a thin portion of the superior longitudinal fasciculus connecting these areas.
SPEAKER: And this is comprised of the frontal polar region, as seen on the left in the upper left image; an area called 8C, which is one of the most highly connected portions of the human cerebrum; area PFm, which is in the supramarginal gyrus; and area TE1m, which is in the temporal lobe in the middle temporal gyrus. Now these networks, the central executive network and the default mode network, are generally not firing at the same time.
SPEAKER: But the salience network mitigates a switch that switches between the internal and external mental world networks, or the DMN and CEN. And this highlights the role of the salience network in decision-making and decision-action activation. More importantly, by understanding the interplay of these axes, we can begin to grasp a better understanding of how to avoid complications when working around these networks.
SPEAKER: In this particular case, both the central executive network and salience network have components that are around the insula, and thus are at risk from this operation. Patient is a 39-year-old woman who presented with a very complex history that initially was somatostatin disorder and depression, but later on developed a seizure and a sensory disturbance. The depression is actually relevant in this case, as we'll show in a bit.
SPEAKER: She eventually was found to have this low-grade glioma, which is centered mostly in the left insula, the superior temporal gyrus operculum, and the temporal stem. The particular question we had in this case were multifold. As you can see in this image in the Quicktome software, the most common concern that people have is ultimately the corticospinal tract.
SPEAKER: In this case, as usual within gliomas, this is mostly medial to the tumor. That's important to note that if you exit the superior deep boundary of an insular glioma, you can hit it. Interestingly, when we look at the IFOF segmentation, and we've included the normal IFOF for comparison, you can see that the inferior fronto-occipital fasciculus is missing on the side of the tumor.
SPEAKER: When we look at the objects regarding the salience network, which include the frontal aslant tract, as well as the nodes of the salience network seen here in this three- dimensional image, you'll note that the salience network has been pushed upward by the tumor and distorted. Given its role in depression, as well as being aware of your interoceptive sensations, this makes a likely cause of her symptoms.
SPEAKER: Now what we're trying to determine with the language system, of course, is how far back can we cut the superior temporal gyrus safely. And as you can see, that the majority of this tumor is safe, but the cut on the superior temporal gyrus has to be posteriorly angled. You can see here on the sagittal cut that, again, we have a fairly clear angle into the tumor. Now you can see here in the intraoperative setting we have the temporal lobe.
SPEAKER: And what we're first going to start off is making a cut from anterior to posterior, to begin to work inside this keyhole craniotomy. You can see we can utilize the image guidance with the Quicktome outputs to visualize these networks. And this allows us to first cut and remove the majority of the temporal pole underneath the bone flap with the cut that safely works along the STG to expose the insula.
SPEAKER: Now notice that we, again, have respected the anterior boundary of the temporal portion of the language system, as seen in this combined shot of the image guidance with the Quicktome output and the brain tumor. You can see that now we've identified the temporal stem. And you can see that where the image guidance is helpful here is making that cut in an angle that preserves the connectivity of language system.
SPEAKER: The insular resection is mostly an anatomic resection, as we know that the IFOF, as well as the salience network, are not located in the parenchyma around this tumor. And again we define windows, remove the circumflex arteries to begin debulking the insula, with the goal of making the insula plane aligned with the hippocampus and amygdala. Once we've done that, we begin seeing the characteristic appearance of the basal ganglia, which we know is our deep boundary.
SPEAKER: Again at this point we're attempting to work posteriorly along the superior temporal operculum. And you can see this tumor, as seen at about 5 o'clock on this diagram, is tucked underneath the language system. We know that we cannot work more posteriorly. We must work underneath that overlying cleft, because otherwise we'd be violating the language system. And this makes this angle so much more difficult, but ultimately it was necessary to achieve a good speech outcome for this patient.
SPEAKER: And as you see, we're taking a steep posterior angle, identifying the posterior insula vessels, and then using this to safely debulk the superior temporal gyrus component under the language system. Now if the Quicktome output had told us that we could remove some overlying cortex, this of course would have made this somewhat simpler. We're now working on the superior boundary.
SPEAKER: You can see portions of the lenticulostriate arteries and basal ganglia. And, again, you can see the angle that we did to safely enter this very difficult portion of the insula through this transopercular approach. You can also see, as we saw in the preoperative images, the close proximity to the corticospinal tract. While image guidance is helpful for identifying basal ganglia tissue, another helpful guidepost to know how deep you can go is when you begin finding the white speckles, you're in the basal ganglia.
SPEAKER: Now the superior part of the insula is the most dangerous part, and not only because it's a difficult angle. As you can see, we've changed the angle of the microscope, and we're working between this Y-shaped vessel that we often see in the superior division of the MCA. But we also know that portions of the salience network and the corticospinal tract are at risk from the preoperative planning.
SPEAKER: So you can see these, are highlighted in blue and red, the blue being motor, and the red being language. And this shows the exact position of the face motor fibers, which are visualizable with constrained spherical deconvolution tractography, which is crossing fiber tractography. So as you can see, an excellent resection of this tumor was performed.
SPEAKER: And ultimately the patient had an excellent speech outcome, with a gross-total resection of this complex lesion. Ultimately, what connectomics provided here was a detailed map of the language system, including cortical regions, which helped us define the safe boundaries and angles of resection and entry into the insula opercular region.
Form Title Download
Form Title Bookmark
Form Title Share
Form Title Cite
