1/Understanding cervical radiculopathy is a pain in the neck! But knowing the distributions can help your search
A #tweetorial to help you remember cervical radicular pain distributions
2/First, a rule of thumb—or rather a rule of elbow! You have 10 fingers. If you divide that in half, you get 5.
If you divide your arm in half, that's at the elbow, you'll also get 5--C5 that is! C5 radiates to the elbow. So if it radiates below this, it's > C5 & above is < C5
3/So let’s start with C2. C2 predominantly radiates along the dorsal aspect of the scalp, as it supplies the greater occipital nerve. I remember this bc the number 2 has a swan like neck that mimics the contour of the back of the head and its distribution
4/Next is C3. C3 starts radiating right around the ear and circles around to the front of the neck, as it is a contributor to the great auricular nerve and anterior cutaneous nerve of the neck. I remember how it starts bc the number 3 looks like those big grandpa ears.
5/C4 radiates along the suprclavicular fossa, as it helps innervate the supraclavicular nerve, and goes towards the deltoid. I remember this because the triangular part of the number 4 looks the bulging deltoids that you always see on TV, but never in real life
6/I remember C5 using that general rule that half of the number of fingers (5) equals halfway down the arm (elbow). C5 radiates towards the elbow.
7/C6 radiates to the thumb. I remember this because when you count to 6, you use up all the fingers on one hand and then end on the thumb of the next hand. So you end on a thumb when you count to 6 and C6 radiates to the thumb
8/We only have two cervical nerves left (C7, C8) for the 4 fingers left. So we will just use every other finger. So starting with C6 at the thumb—skip a finger gets you to the middle finger, that’s C7, skip the next finger gets you to the pinky, and that’s C8!
9/Now you know where in the c-spine to look when a patient has pain radiating from the neck—but remember there are subtleties to this & these are general guidelines to help you.
Hopefully, remembering cervical radicular pain distributions will no longer be a pain in the neck!
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1/Do radiologists sound like they are speaking a different language when they talk about MRI?
T1 shortening what? T2 prolongation who?
Here’s a translation w/an introductory thread to MRI.
2/Let’s start w/T1—it is #1 after all! T1 is for anatomy
Since it’s anatomic, brain structures will reflect the same color as real life
So gray matter is gray on T1 & white matter is white on T1
So if you see an image where gray is gray & white is white—you know it’s a T1
3/T1 is also for contrast
Contrast material helps us to see masses
Contrast can’t get into normal brain & spine bc of the blood brain barrier—but masses don’t have a blood brain barrier, so when you give contrast, masses will take it up & light up, making them easier to see.
1/Does your ability to remember temporal lobe anatomy seem, well, temporary?
Or are you feeling temporally challenged when it comes to this complex region?
Here’s a thread to help you remember the structures of the temporal lobe!
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
@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)