1/Mass shootings are a great tragedy. Commentators often casually link them w/mental illness. But are there neuro imaging findings to correlate w/their behavior?
A nonpolitical đź§µabout what we can see in brains of mass killers #neuroscience#MedTwitter#NeuroTwitter#GunViolence
2/The first mass killer was Charles Whitman, the bell tower shooter in 1966. He complained of headaches before the shooting & a glioblastoma was found in his frontal lobe, leading people to believe that structural abnormalities may lead to this behavior.
3/Unfortunately, this theory did not hold. No other mass killer has had a structural lesion like a tumor. It is often difficult to draw conclusions since much of the brain tissue in these killers is often destroyed by either self or non self inflicted wounds to the head at death
4/Despite this, autopsy in Las Vegas shooter Stephen Paddock showed ⬆️ corpora amylacea, a cellular debris product seen in aging, in his frontal lobe(impulse control) & hippocampus (memory). However, he had no neurodegeneration
4/Also, b/c of the small number of mass killings relative to general homicides, it is difficult to draw sweeping conclusions. Therefore, people have tried to look for differences in brains of people who commit homicide vs those who commit other violent offenses to look for clues
5/Studies have found decreased gray matter (neurons) in the frontal and temporal regions in those who commit homicide compared to other violent offenders, the same regions of accelerated aging changes in the Las Vegas shooter.
6/Unfortunately, however, there is no smoking gun on imaging that can alert us to the people who may commit these heinous acts or help us to understand why they committed them. They will, sadly, remain a tragic mystery.
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@TheAJNR 2/Perfusion imaging is based on one principle: When you inject CT or MR intravenous contrast, the contrast flows w/blood & so contrast can be a surrogate marker for blood.
This is key, b/c we can track contrast—it changes CT density or MR signal so we can see where it goes.
@TheAJNR 3/So if we can track how contrast gets to the tissue (by changes in CT density or MR signal), then we can approximate how BLOOD is getting to the tissue.
And how much blood is getting to the tissue is what perfusion imaging is all about.
1/Do you get a Broca’s aphasia trying remember the location of Broca's area?
Does trying to remember inferior frontal gyrus anatomy leave you speechless?
Don't be at a loss for words when it comes to Broca's area
Here’s a 🧵to help you remember the anatomy of this key region!
2/Anatomy of the inferior frontal gyrus (IFG) is best seen on the sagittal images, where it looks like the McDonald’s arches.
So, to find this area on MR, I open the sagittal images & scroll until I see the arches. When it comes to this method of finding the IFG, i’m lovin it.
3/Inferior frontal gyrus also looks like a sideways 3, if you prefer. This 3 is helpful bc the inferior frontal gyrus has 3 parts—called pars
Brain MRI anatomy is best understood in terms of both form & function.
Here’s a short thread to help you to remember important functional brain anatomy--so you truly can clinically correlate!
2/Let’s start at the top. At the vertex is the superior frontal gyrus. This is easy to remember, bc it’s at the top—and being at the top is superior. It’s like the superior king at the top of the vertex.
3/It is also easy to recognize on imaging. It looks like a big thumb pointing straight up out of the brain. I always look for that thumbs up when I am looking for the superior frontal gyrus (SFG)
If the patient is symptomatic & the greatest stenosis from the plaque is >70% of the diameter of normal distal lumen, patient will likely benefit from carotid endarterectomy
But that doesn’t mean the remaining patients are just fine!
3/Yes, carotid plaques resulting in high-grade stenosis are high risk
But assuming that stenosis is the only mechanism by which a carotid plaque is high risk is like assuming that the only way to kill someone is by strangulation.