Ulnar neuropathy "at the wrist" is really in the hand. Guyon's canal is between the pisiform and hamate bones. It's close to the wrist, though.

The numbers in this image are the Zones where injuries can take place, and they each create a unique clinical picture. #tweetorial
1/6 Let's count down from Zone 4. The superficial terminal branch, for practical purposes, is purely sensory, supplying the palmar aspect of the digits 4-5.

FYI: The dorsal ulnar cutaneous nerve (not shown) comes off in the forearm, supplies the backs of these fingers.
2/6

Saw another patient with sensory neuronopathy who had been misdiagnosed with functional neurological disorder.

What is sensory neuronopathy, and why do we keep missing it? A #tweetorial.
1/ First order of business. Neuronopathy is not the same as neuropathy. There’s a NO right in the middle of it.

That helps you remember the answer to the question: Is this just numb feet in a patient with diabetes?
2/

🧷🔥The Sensory Exam.🧊👈

Some neurologists just skip it. Compared to other parts of the exam, it's mired in subjectivity.

And slow! you could spend 10 minutes doing it and learn nothing.

But it can still be valuable, especially when done EFFICIENTLY. #tweetorial #neurology In this🧵, we're talking about examining a patient who does NOT have a sensory deficit as their chief complaint.

The screening sensory exam in this situation should focus on things people might not bring up in the history. What on earth could that be?

I administered the Montreal Cognitive Assessment (MoCA) to the image-generating AI program DALL-E this morning. Thing really went off the rails.

Let's see how it did. 🧵 "Do trails starting with 1-A-2-B etc."

Okay, that's not what we meant, but I see the confusion. 0 points.

What do inkblots and puppies hugging teach us about the way the long tracts are organized in the spinal cord? Everything.

Behold, our favorite tracts in the cervical cord.

A = fibers to/from the arm
T = fibers to/from the trunk
L = fibers to/from the leg

#tweetorial
1/7 Now let's just look at the arm fibers. For all three tracts, they are right up against the grey matter.

Want a #mnemonic to help you remember that?
2/7

Not pointing fingers, but I think some of us are misusing the word "bulbar."

The Bulb is the archaic term for the medulla. So bulbar weakness refers only to muscles supplied by cranial nerves 9-12.

Let's play a game called "Is THIS bulbar weakness?"
1/🧵 Is THIS Bulbar Weakness?

Yes.

(The picture's not upside down... you're upside down.)

A lateral medullary stroke damages the nucleus ambiguus of CN X, leading to dysphagia, dysarthria, and dysphonia.
2/🧵

Today's @UMICHNeuroRes Localization Rounds case.

A patient has sudden onset of:
▶️R facial weakness, upper and lower🫤
▶️Impaired adduction of the R eye with spared convergence
▶️R hypertropia that is present in all direction of gaze

Where is the lesion?
#tweetorial
1/ Let’s start with the face.

Upper and lower face = a lesion of the Facial Nerve (CN7.)

CN7 lesions are usually outside the brainstem, right? But remember that this pattern can also be seen with lesions affecting the nucleus or the course of the CN7 in the brainstem.
2/

In my first and only basic science research experience, I was complicit in scientific fraud.

There was no fabrication of data, per se. No doctoring of images. It was subtle experimental misconduct, and certainly an anomaly in the scientific community. I assumed.)
1/🧵 I had a 4-week summer research position when I was in college. The project had something to do with Na/K channels in pulmonary epithelial cells.

Honestly, I didn’t really understand it then, so I certainly wouldn’t be able to explain it now.
2/🧵

If you blow on someone’s foot and the toe goes🆙, that’s the London Sign. Sure, you could use a descriptive name, but I invented the maneuver, so I’m naming it after me. Everyone cool with that?
An irreverent/irrelevant #tweetorial on the rise & fall of neurologic eponyms. 1/ So do you say Guillain-Barre syndrome or AIDP?
Broca’s or expressive aphasia?
Kennedy’s disease or SBMA?
Devic’s disease or NMO?
Wilson’s disease or hepatolenticular degeneration?
2/

"What do you see when you're walking HOME from church?"

She was an older woman with a right MCA syndrome, and I will never forget what she said when my attending asked her that question.

Not a full #tweetorial, just some mind-blowing examples of neglect for neuronerds. 1/🧵 She was admitted on Saturday morning, and she was upset when she realized she would miss church. She only lived two blocks from the church, and walked there every Sunday. She hadn't missed a Sunday sermon in decades. 2/🧵

1/
We often check SPEP and/or immunofixation in patients with neuropathy. Why bother, and what should I do with the results?
Welcome to Paraproteinemic Neuropathy: A #tweetorial for neurologists who order tests they have no business interpreting. 2/
For starters, let's clear the air about terminology. These are all synonyms:
- Paraproteinemia
- Monoclonal gammopathy
- M-protein
- M component
They all mean identical plasma cells are overproducing identical copies of the same immunoglobulin or immunoglobulin fragments.

1/9
Just read the 2021 EAN/PNS diagnostic criteria for CIDP. It's an updated version of the 2010 version, and it's great! It clarifies lots of things and makes practical recs… and one that I think is problematic. Let’s unpack. Part #tweetorial, part rant. tinyurl.com/h7jppwzk 2/9
They use 2 diagnostic categories: CIDP and Possible CIDP. (In the 2010 version, we had Probable CIDP and Definite CIDP, but these have now been rolled into one category: CIDP.)
Both new categories rely heavily on NCS criteria.

BTW, it includes Sensory NCS criteria. Love it!

It gives my great pleasure to announce the release of THE PLEXUS, a new strategy card game about peripheral nervous system localization.

Folks, this may be our only hope to #endplexusphobia!

Click here ➡️theplexusgame.com

And open the 🧵for more surprises.
1/5 It’s a 2-3 player game that takes about 20 minutes🕓 to play. And here's the kicker: It's actually fun, and you don’t need to be be a master of brachial plexus anatomy to enjoy it. (In fact, my middle school-age son beat me the first time he played.😯)
2/5

"A bag with feet."

That's what the patient said he saw when we showed him the cookie jar picture. He was an older man who had been brought to the ED after being found driving his car around a field.

Here is what I think he was seeing:

#neurotwitter #tweetorial #MedEd He was unable to focus on the whole picture at once.

This is a striking example of simultagnosia, which in his case was related to bilateral parieto-occipital strokes (Balint's syndrome.)

1/11
Time for a #tweetorial on one of my favorite topics: Wrist Drop. @AANMember @NMatch2022 #neurology #futureneurologist #neurotwitter #neurotwitternetwork @AANEMorg #meded @KoriPoRodri

The first thing you should think of when you see a patient with weak wrist extension is… 2/11
This. Compression of the radial nerve at spiral groove. And usually, we think of it as being caused by...

1/6. This chart shows you everything you need to know about localizing foot drop. But let’s make it even simpler. If dorsiflexion is weak, there is one muscle that really matters: the tibialis posterior, which does ankle INVERSION. Let’s unpack that with a cool mnemonic. 2/6 Common things are common, and most of the time, a foot drop is caused by either:
- A common peroneal neuropathy at the fibular head or
- An L5 radiculopathy.