Post

How to get URL link on X (Twitter) App

On the Twitter thread, click on or icon on the bottom
Click again on or Share Via icon
Click on Copy Link to Tweet
Paste it above and click "Unroll Thread"!
More info at Twitter Help

Rachel Gottlieb-Smith, MD, MHPE

Feb 3, 2022 • 12 tweets • 7 min read • Read on X

1/12
How does botulinum neurotoxin (BoNT) work to improve chronic migraine? 🤔

⚡️ Spoiler: it's probably not what you think!

A 🧵 about BoNT & #migraine

#MedTwitter #NeuroTwitter #tweetorial

2/
Let's start with a definition: what makes a migraine "chronic?"

◾️ Headache occurs at least 1⃣5⃣ days per month
◾️ Of which at least 8⃣ have features of migraine headache
◾️ For 3⃣ months or more

From: Int'l Classification of Headache Disorders ichd-3.org/1-migraine/1-3…

3/
And a bit of history: botulinum neurotoxin (BoNT) came to be studied for chronic migraine after anecdotes suggested that BoNT injections to treat wrinkles also helped with headaches!

4/
Two randomized controlled trials called PREEMPT (Phase 3 REsearch Evaluating Migraine Prophylaxis Therapy) showed that a form of BoNT - onabotulinumtoxinA (onabotA) - worked for the treatment of chronic migraine in adults

pubmed.ncbi.nlm.nih.gov/20647170/
pubmed.ncbi.nlm.nih.gov/20647171/

5/
PREEMPT pooled results:

◾️ Headache days/28 days actually 🔻 for both placebo & onabotA groups
◾️ But 🔻 more for onabotA group: at week 24, -8.4 for onabotA versus -6.6 for placebo

pubmed.ncbi.nlm.nih.gov/20487038/

6/
"Standard" PREEMPT protocol:
◾️ 7 head & neck muscles
◾️ 31 injections
◾️ 155 units
◾️ Every 12 weeks

➡️ Could also use "follow-the-pain" approach & inject up to 40 more units

pubmed.ncbi.nlm.nih.gov/20958294/

7/
So back to the ❓: how does it work?

BoNT acts on peripheral nerves by ✂️ SNARE proteins, which are needed for membrane fusion ➡️ 🚫 neurotransmitter release

pubmed.ncbi.nlm.nih.gov/25882077/

8/
We mostly think about its effect at the neuromuscular junction (NMJ): 🚫 acetylcholine ➡️ paralysis

📒 For a discussion of how BoNT works at the NMJ when we *don't* want it to, check out this 🧵 on infant botulism:

https://twitter.com/RGottliebSmith/status/1487474908301041673?s=20&t=98ROJ67tn62-36_EjmdFkQ

9/
But actually: BoNT also acts on sensory neurons! And that's how it's thought to work to treat chronic migraine, a sensory disease

10/
Through its actions on sensory neurons, BoNT blocks release of glutamate, substance P & calcitonin gene-related peptide (CGRP) -- neurotransmitters all involved in pain signaling

pubmed.ncbi.nlm.nih.gov/32602955/

11/
& the injection sites per the PREEMPT protocol closely match the sensory innervation of the face, scalp, and cervical region

For a more detailed review:
pubmed.ncbi.nlm.nih.gov/32602955/

@ahsheadache

12/
So in summary, for BoNT & chronic migraine:
🔑 Mechanism thought to be sensory, not motor!

⚠️: 🚫 medical advice, & onabotA is not currently FDA approved for chronic migraine in children (used off label)

For great resources on #migraine treatment:
@ahsheadache @amfmigraine

• • •

Missing some Tweet in this thread? You can try to force a refresh

This Thread may be Removed Anytime!

Twitter may remove this content at anytime! Save it as PDF for later use!

More from @RGottliebSmith

Rachel Gottlieb-Smith, MD, MHPE

@RGottliebSmith

Jul 8, 2022

1/🧵
Ever look at an #EEG & wonder what the 🧠 squiggles mean?

This #twEEGtorial is for you

#MedTwitter #NeuroTwitter #EEGTwitter #Tweetorial

2/
Let’s start with some background:

💡 #EEG = electroencephalogram
💡 What an EEG does: records electrical activity in the 🧠

3/
You might then 🤔: how does the 🧠 create ⚡️?

A bit of neuroscience: 🧠 cells called neurons generate ⚡️ through the flow of charged ions (sodium & potassium) across their membranes

An EEG on the scalp can't detect the ⚡️ of a single neuron, but can when neurons are in sync

Read 16 tweets

Rachel Gottlieb-Smith, MD, MHPE

@RGottliebSmith

May 21, 2022

1/
The only good thing to come of finding this on my leg last week: I learned enough to write a #tweetorial about it

A 🧵/twitter PSA about what to do if a tick comes for you – & what neuro presentations you can see w/ tick-borne illnesses

#MedTwitter #NeuroTwitter #IDTwitter

2/
After time outside in a non-wooded area, I found this on my leg. I didn’t realize what it was, so I grabbed it & flung it off... only to then find a very active, crawling tick on my counter. 😱

So after freaking out for a moment (or 2), I had to figure out what to do with it.

3/
Memories from med school flashed into my head of what you’re SUPPOSED to do:

1⃣ Remove tick w/ tweezers
2⃣ Grab close to skin & pull tick off without twisting so it doesn’t break apart
3⃣ Disinfect

Since I had already accidentally messed up 1⃣ & 2⃣, I started w/ 3⃣

Read 17 tweets

Rachel Gottlieb-Smith, MD, MHPE

@RGottliebSmith

Apr 15, 2022

1/🧵
What’s going on in the 🧠 that causes motion sickness – and what’s the link with #migraine?

A #tweetorial about motion sickness, the importance of matching, and why serotonin matters

#MedTwitter #NeuroTwitter

2/
First, let’s review some structures of the vestibular system that help us sense body movement:

1⃣ Semicircular canals = angular acceleration
2⃣ Otoliths (utricle & saccule) = linear acceleration & head tilt

📷: cell.com/current-biolog…

3/
The 🧠 combines this vestibular input with visual 👀 & proprioceptive input to assess motion

➡️ This is where the importance of matching comes in

...So what happens when the inputs don't match?

Read 10 tweets

Rachel Gottlieb-Smith, MD, MHPE

@RGottliebSmith

Feb 13, 2022

1/
#MedTwitter: ever learn a mnemonic that you can’t remember 5 minutes later? 🙋‍♀️

What makes a mnemonic useful (or not)?

A 🧵 about the good – and the bad – of mnemonics

#MedEd #NeuroTwitter #Tweetorial

2/
First, some background:

Mnemonic = relating to memory

Mnemonic devices/techniques (often called mnemonics for short) = memory aids or strategies that help with recall

Goal: transition info from working memory to long-term memory (and then be able to retrieve it later!)

3/
Let’s review 3 mnemonic techniques:

1⃣ Method of loci AKA “memory palace”
▪️ Type of imagery mnemonic
▪️ Info mentally placed at important landmarks along an imagined path ➡️ recall by re-tracing the route
▪️ Vivid images are helpful

Image from pubmed.ncbi.nlm.nih.gov/33613393/

Read 11 tweets

Rachel Gottlieb-Smith, MD, MHPE

@RGottliebSmith

Jan 22, 2022

1/
What's the best strategy for effective - and time efficient - teaching in clinic?

A 🧵 for 4⃣ teaching strategies when 🕗 is limited (& how they might be used in #neurology)

#MedEd #NeuroTwitter

pubmed.ncbi.nlm.nih.gov/18276715/
pubmed.ncbi.nlm.nih.gov/29383053/

2/
1⃣ One-minute preceptor (initially called: 5-step microskills)
pubmed.ncbi.nlm.nih.gov/1496899/

5 steps & examples 👇

Pros:
✅ Assess learner's knowledge
✅ 👍 & constructive feedback "built in"
✅ Clinical reasoning
✅ Good for novice learners

Cons:
⛔️ "1 min" is a bit unrealistic

3/
2⃣ SNAPPS
pubmed.ncbi.nlm.nih.gov/14507619/

Pros:
✅ Very learner-driven
✅ Aligns well w/ traditional presentation model
✅ Clinical reasoning

Cons:
⛔️ May not work as well for novice learners

Read 7 tweets

Rachel Gottlieb-Smith, MD, MHPE

@RGottliebSmith

Jan 13, 2022

@MedTweetorials

1/🧵
What's your favorite anti-seizure medication (ASM)?

If you said levetiracetam (LEV), you're not alone.

Why do so many #neurologists ♥️ LEV? A #tweetorial.

#MedStudentTwitter #NeuroTwitter #MedTwitter @MedTweetorials

2/
What's so good about LEV? First, some #pharmacology:

✅ Fast PO absorption
✅ 1:1 PO:IV 💉
✅ Few med interactions
✅ Can load for status epilepticus

pubmed.ncbi.nlm.nih.gov/31029217/

3/
And lots of clinical uses:

1⃣ Focal and generalized seizures
2⃣ From 👶 to 🧓
3⃣ Often used in 🤰 (category C): pubmed.ncbi.nlm.nih.gov/28472982/
4⃣ Good for status epilepticus (60 mg/kg, up to 4500 mg) - similar efficacy to phenytoin & valproic acid:
pubmed.ncbi.nlm.nih.gov/32203691/