2/Temporal lobe can be divided centrally & peripherally. Centrally is the hippocampus. It’s a very old part of the brain & is relatively well preserved going all the way back to rats. Its main function is memory—getting both rats & us through mazes—including the maze of life
3/Peripherally is the neocortex. Although rats also have neocortex, theirs is much different structurally than humans.
So I like to think of neocortex as providing the newer (neo) functions of the temporal lobes seen in humans: speech, language, visual processing/social cues
4/So let’s start w/the oldest part of the temporal lobe, the hippocampus, and we will move clockwise from there.
5/Next to the hippocampus is the parahippocampal gyrus. I remember this b/c the hippocampus is the oldest part of the temporal lobe & older folks love to go in pairs. So this is the PAIR-ahippocampal gyrus—it pairs w/the old hippocampus
6/Next to the parahippocampal gyrus is the fusiform gyrus. I remember this b/c this gyrus bridges (some might say FUSES) the older, allocortex part of the temporal lobe (hippocampus/parahippocampal) w/the newer, neocortical structures. Fusiform gyrus is the neocortical bridge
7/Fusiform gyrus bridges the older temporal lobe w/the new lateral temporal neocortex.
I think the lateral neocortex looks like a parfait—w/the superior, middle, & inferior temporal gyri layered on top of the fusiform gyrus. Heschl’s transverse gyrus forms the strawberry on top
8/You can remember that the fusiform gyrus is at the bottom of this parfait b/c fusiform means elongated—and the stem of a parfait glass is elongated—almost fusiform!
9/You can remember that Heschl’s gyrus is the fruit on top b/c Heschl sounds like Bushel, and fruit to put on top comes in Bushels!
10/You can also see this parfait in the coronal plane, although it is a little tilted!
11/Last temporal lobe structure is the temporal stem. It is the white matter connecting the gyri of the temporal lobe to the rest of the brain. I remember this b/c I think the temporal lobe looks like an upside-down cauliflower—& the STEM of that cauliflower is the temporal STEM
12/So now you can remember the anatomy of the temporal lobe:
An old couple
A bridge fusing them to the next generation
A delicious parfait
All connected by a cauliflower stem.
I hope this new anatomy knowledge will be anything but temporary!
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1/Having trouble remembering what you should look for in vascular dementia on imaging?
Almost everyone worked up for dementia has infarcts. Which ones are important?
Here’s a thread on the key findings in vascular dementia!
2/Vascular cognitive impairment, or its most serious form, vascular dementia, used to be called multi-infarct dementia.
It was thought dementia directly resulted from brain volume loss from infarcts, w/the thought that 50-100cc of infarcted related volume loss caused dementia
3/But that’s now outdated. We now know vascular dementia results from diverse pathologies that all share a common vascular origin.
It’s possible to lose little volume from infarct & still result in dementia.
So if infarcts are common—which contribute to vascular dementia?
1/ I always say, "Anyone can see the bright spot on diffusion images—what sets you apart is if you can tell them why it’s there!”
If you don't why a stroke happened, you can't prevent the next one!
Can YOU tell a stroke’s etiology from an MRI?
Here’s a thread to show you how!
2/First a review of the vascular territories.
I think the vascular territories look a butterfly—w/the ACA as the head/body, PCA as the butt/tail, and MCA territories spreading out like a butterfly wings.
3/Of course, it’s more complicated than that.
Medially, there are also small vessel territories—the lenticulostriates & anterior choroidal.
I think they look like little legs, coming out from between the ACA body & PCA tail.