2/Let’s start with L1. L1 radiates to the groin. I remember that b/c the number 1 is, well, um…phallic. So the phallic number 1 radiates to the groin.
3/Let’s skip to L3 for a second. I remember L3 is to the knee—easy, it rhymes!
4/Ok, back to L2. Two is the number between 1 and 3, so the distribution of L2 is between the distributions of L1 and L3—and between the groin and knee is the thigh. L2 radiates to the thigh. It’s not the catchiest way to remember it, but it works.
5/L4 radiates to the calf. I remember this bc the number 4 looks like the calf, with the top part of the 4 looking like a bulging gastroc & the bottom part of the four is the rest of the calf connecting to the ankle. Don’t we all wish we had bulging gastrocs like the number 4!
6/L5 radiates to the big toe. So I have the little rhyme “Five is to the big guy!” L5 is also foot drop. So I remember big guys are heavy, and heavy gravity = drop. If I hear the history “foot drop,” I never stop looking until I have traced out the entire L5 nerve root.
7/Finally, S1 radiates to the side of the foot. I remember this bc both S1 & Side start w/S.
So now you know where in the lumbar spine to look when a patient says the pain radiates down the leg & hopefully remembering the lumbar radicular distributions won’t cause you any pain!
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1/Have MULTIPLE questions about the new criteria for MULTIPLE sclerosis?
ECTRIMS 2024 just came out w/proposed new changes to the McDonald criteria for multiple sclerosis.
The changes are complex, but here is a thread w/the basics that you NEED to know!
2/The 2017 criteria were complex as well, but the basic theme was that they required dissemination in both time & space.
So you needed lesions in multiple locations and of multiple different ages.
3/Proposed new criteria bring a paradigm shift from relying on a combination of dissemination in both space in time, to relying on other factors that can replace dissemination in time
It also proposes that new imaging features specific to MS can be used in diagnosis as well
How back pain radiates can tell you where the lesion is—if you know where to look!
Do YOU know where to look?
Here’s how to remember the lumbar radicular pain distributions!
2/Why is it important to know the radicular pain distributions?
Most times patients have many POSSIBLE sources of pain--and when you are looking at an MRI, it's your job to decide which finding is the most LIKELY source of pain
These pain distributions can help you do that!
3/Let’s start with L1. L1 radiates to the groin.
I remember that b/c the number 1 is, well, um…phallic.
1/Hate it when one radiologist called the stenosis mild, the next one said moderate--but it was unchanged?!
How do you grade it?
Do you estimate? Measure? Guess???
Here’s a thread about a lumbar grading system that’s easy, reproducible & evidence-based!
2/Lumbar stenosis has always been controversial.
In 2012, they tried to survey spine experts to get a consensus as to what are the most important criteria for canal & foraminal stenosis.
And the consensus was…that there was no consensus
So what should you use to call it?
3/Well, you don’t want just gestalt it—that is a recipe for inconsistency & disagreement
But you don’t want to measure everything either—measurements are not only cumbersome, they introduce reader variability & absolute measurements don’t mean the same thing in every patient.