Why do peripheral nerve blocks work for migraine? Let’s explore.

#neurology #migraine #headache #neuroX #FOAMed #medschool #MedEd #medicine

https://twitter.com/isaaclamb01/status/2031744809505804622

Migraine headache is complicated. While older, simplistic models focused on vasodilation and meningeal pain via the trigeminal nerve, we now recognize a complex cascade of pain which centers around the trigeminovascular system.

Source: DOI 10.3389/fnmol.2024.1355281

We’d like to think that our medicines are perfectly effective, but the reality is that sometimes bad outcomes like recurrent stroke still happen despite optimal medical therapy. What should we do next?
#neurology #cardiology #MedEd #medschool #FOAMed #stroke #neuroX A middle-aged woman w/ nonvalvular afib on apixaban presents to neurology clinic. Months prior, she had a CRAO causing monocular vision loss. Workup showed additional acute, silent embolic infarcts in the anterior and posterior circulation, confirming embolic etiology.

INPATIENT STROKE WORKUP
Pt 4: Other

We’ve done the other three, so let’s wrap up our tour of the TOAST stroke criteria with a grab bag of etiologies, including such diverse causes as dissection, endocarditis, and vasculitis.

#neurology #neuroX #MedEd #FOAMed There are too many subtypes to mention in one post, but we will touch briefly on the most common. These are all comparatively rare, but collectively not uncommon.

INPATIENT STROKE WORKUP

Part 2: Small Vessel Disease (SVD)
If there’s large artery (atherosclerosis), then you know there must be a small vessel disease! The vessels may be small, but the deficits are not. Neither are they rare: they account for about 25% of ischemic strokes. As before, we will be following the TOAST framework. While the trial itself bears little significance today, the framework it used to categorize strokes is a very helpful cognitive tool and has been repeatedly used in subsequent research.

Brainstem anatomy is notoriously tricky, but it’s made 10x easier by the Rule of 4s! Whether you are a medical student or studying for neurology boards, this powerful mnemonic will take you far!

#neurology #FOAMed #MedEd #neuroX #MedSchool #tweetorial

🧵⬇️ This is a revamp of a topic I did several years ago, newly expanded. Original credit for the Rule of 4s goes to Peter Gates.

Idiopathic intracranial hypertension (IIH)

This relatively common disorder is an important secondary cause of headache and can cause permanent vision loss. Let’s dive into the presentation, work up, and diagnosis together!

#neurology #FOAMed #MedEd #neurotwitter #tweetorial IIH is a syndrome characterized by CSF hypertension which is not due to obstruction or other mass-occupying lesion.

The prevalence is about 1 in 100,000 in the general population, but it’s 20 times more common in the highest risk population, obese women < 45.

NEUROLOGICAL APPROACH TO DIZZINESS

Dizziness is one of the most common reasons for a neurology consult. The murky waters of the vestibular system are scary to us mere mortals. But having a framework provides a map to sail these choppy seas!

Thread below: The first step, we’ve all been told, is to find out what a patient means by dizzy:
⁃Vertigo
⁃Presyncope
⁃Imbalance
⁃Other
When it comes to acute dizziness, we neurologists tend to care most about vertigo.

FIRST TIME SEIZURE

Anyone who spends time on an inpatient neurology service knows this is one of our top 5 consults/admits. This thread will break down the workup and the decision of who needs to be on antiseizure medication (ASM).

#neurology #FOAMed #neurotwitter The first step: was it really a seizure?

Common mimics of seizures:
- Syncope (esp convulsive syncope)
- PNES/functional seizures
- Behavioral staring spells (esp in kids)
- Stroke/TIA
- Movement disorder

What is Romberg’s sign and how should it be used?

I often see this sign misused to suggest a cerebellar ataxia. But it’s the exact opposite - the test exists to point AWAY from central cause!

Explanation below ⬇️ HISTORY
Moritz Heinrich Romberg was a pioneering German neurologist who’s focused on one of the most important diseases of the time: syphilis. Without effective treatments, syphilis could cause tabes dorsalis, a degenerative disease of the spinal dorsal columns.

INPATIENT STROKE WORKUP
Pt 3: Cardioembolic strokes

In a cardioembolic stroke, a blood clot starts in or passes through the heart but ends up in the brain. It’s managed differently than the other two types we’ve covered. Let’s jump in!
#neurotwitter #neurology #MedEd #FOAMed

https://twitter.com/isaaclamb01/status/1732156075929940240

PATHOPHYSIOLOGY

Cardioembolic strokes are generally caused by the other two corners of Virchow’s triad: stasis (eg afib) and hypercoagulability (eg paradoxical embolus from a DVT). Overactivity of secondary coagulation results in a thrombus which can embolize.

INPATIENT WORKUP OF STROKE
Pt 2: Small vessel disease

If there’s large vessel (atherosclerosis), you know there must be a small vessel category. Join me as we work through another major category of stroke!

#neurology #MedEd #FOAMed #neurotwitter #tweetorial

https://twitter.com/isaaclamb01/status/1731364492825465296

As before, we will be following the TOAST framework. While the trial itself bears little significance today, the framework it used to categorize strokes is a very helpful cognitive tool and has been repeatedly used in subsequent research.

INPATIENT WORKUP OF STROKE

To many, stroke admissions are not very exciting: it’s formulaic with the same tests ordered every time. But if you understand the reason behind the tests, it becomes much more interesting! Let’s explore together.

#neurology #meded #stroke #FOAMed Back in the 1990s, there was a study called the TOAST trial that categorized strokes by mechanism. That framework is very helpful to this day and I’ll be using it here.

This thread will focus on the most common cause: large artery atherosclerosis (LAA)

I'm a collector, a neurology nerd, and a history fan by nature. The result of all of those is that I now own every major type of #neurology reflex hammer, and I've done the work for you to rank them.

Check out my reasoning below.

#neurotwitter #medtwitter Tromner (S)
It's simultaneously the Cadillac and the Toyota Camry of reflex hammers. Most (American) neurologists carry one for a simple reason: it's the best. Best length, best weight, pointed tip for Babinski sign... There's really nothing negative to say.

PSA: don't withhold a QT prolonging drug just because the computer calculated a QTc above 450-460 ms. The computer correction is usually (>50% by the study below) very inaccurate. And it only takes 15 seconds to do it right (or at least better).

PMID: 27317349
#MedEd #tweetorial Background: QT intervals change depending on HR. To compare them, one can correct for HR using many different formulas:
- Bazett
- Hodges
- Fridericia
- Framingham
- Rautaharju

There are a lot of jargon words in #neurology. As a student, I felt particularly confused by the words clonus, myoclonus, and asterixis, so I made this #tweetorial for learners who feel like I did.
#MedTwitter #MedEd #medicalschool #neurotwitter Clonus is RHYTHMIC involuntary muscle contractions. It's caused by lesions to the pyramidal tract (ie UMN). It's likely due to exquisitely hyperreflexic muscle stretch reflexes - basically the muscle contraction triggers itself to keep firing in a feedback loop.

Learning brainstem #neuroanatomy would be nearly impossible without the rule of 4s. I'm going to pass this along for anyone trying to learn #neurology, as this might be the single most powerful mnemonic I know of.

I present to you, The Rule of 4s: a #MedEd #tweetorial

(1/10) 4 cranial nerves per brainstem level
- Midbrain: 1-4
- Pons: 5-8
- Medulla: 9-12

* CNs 1 and 11 do not connect with the brainstem
* CN5 enters in the pons, but has nuclei at all three levels

(2/10)