1/Wish that your knowledge of autoimmune encephalitis was automatic?
Do you feel in limbo when it comes to the causes of limbic encephalitis?
Do you know the patterns of autoimmune encephalitis?
Here’s a thread with some hints to help you figure it all out!
2/Two pearls: (1) Most common pattern is limbic encephalitis (2) Small cell can cause any autoimmune pattern.
You can also remember the causes by the demographic:
🔸Young man: testicular
🔸Older: Small cell
🔸Woman with psychiatric symptoms: breast
3/Limbic encephalitis is the most common pattern
But it has many, many different causes
Remember--limbic involvement is shaped like a question mark!
So for limbic encephalitis, the cause remains a question bc the differential is so broad
Must question & clinically correlate!
4/Some other patterns to remember:
Multifocal = small cell and neuroendocrine
Remember:
🔸Small cell gives you mets everywhere = small encephalitis everywhere
🔸Neuroendocrine can arise from different places all over your body = encephalitis different places all over your brain
5/Central/Deep gray = malignant thymoma
Remember:
Thymus is located central and deep in your chest, so its pattern is central and deep!
6/Frontal = ovarian teratoma
Remember:
Ovaries are situated on the uterus right where the frontal lobes are situated on the brain!
7/Brainstem = testicular
Remember:
Brainstem hangs down from the cerebrum like the testicles
Hopefully, these hints will help you, so that the next time you see autoimmune encephalitis, you can be on autopilot!
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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.