Marc Marcus

Science and honor / Radiology resident with a death wish

[Dear Son. @DearS_o_n]

Dear son, read this carefully,

[Lea Alhilali, MD @teachplaygrub]

Anyone can see the bright spot on diffusion—what sets you apart is if you can tell them why it’s there!

Can you tell a stroke’s etiology from its appearance on MRI?

Main stroke types:

Artery to artery embolism
—Vulnerable plaque ruptures & causes clot formation
—Occludes the artery & distal blood flow
—Makes a wedge shape

Distal hypoperfusion:
—At the border zones
—Remember borderzones almost look like a fancy letter H for Hypoperfusion = two vertical lines (ant, internal watershed) that have curls at each end (ant & post external watersheds)

Vasculitis
—Inflammation ofvessel wall
—Idiopathic, autoimmune, or infectious
—Remember: Vascu-LIGHT-us = tons of little regions LIGHT up on DWI
—Remember Vascu-LITE-us = usually in LITE vessels or small vessel territories

Impingement on perforators:
—Large vessel plaque covers opening of small perforator in its wall
—Perforators affect the Ps = pons, putamen (lenticulostriate)

Small vessel dz
—Many different pathologies that cause occlusion of small, unnamed vessels
—Remember: Small & subcortical both start w/—tend to be subcortical

Cardioembolic
—Emboli from heart stasis or vegetations
—Remember: Emboli & everywhere both start w/E = emboli go everywhere

So now you know how different etiologies have different distributions on MRI.

Remember, catching a stroke on DWI isn’t the end of your job—it’s the beginning!

[Raj Shamani @rajshamani]

The price of ambition is loneliness and being misunderstood.

[Ryan Holiday @RyanHoliday]

"All cruelty springs from weakness." — Seneca

[Orange Book 🍊📖 @orangebook]

People who know how to stay calm during the worst situations are just people who have already seen much worse, and learned that life continues nevertheless.

[Mastery Literature @MasteryQuot]

Masters have experienced endless criticisms of their work, doubts about their progress, and setbacks along the way.

[Carl Jung Archive @QuoteJung]

“The best way to find yourself is to lose yourself in the service of others.” - Carl Jung

[48 Laws Of Power Bot @48_quotes]

Never be distracted by people’s glamorous portraits of themselves and their lives; search and dig for what really imprisons them.

Once you find that, you have the magical key that will put great power in your hands.

[48 Laws Of Power Bot @48_quotes]

To gain power, you must be a source of pleasure for those around you — and pleasure comes from playing to people’s fantasies.

[Library Path @LibraryPath]

15 Deep Lines That Will Make You Think:

1.

[Randazzle Enriquez @Randazzle]

That’s a powerful lesson. True discipline isn’t about controlling others—it’s about holding yourself to a higher standard. Marcus Aurelius knew that greatness comes from being relentless with your own growth while giving grace to those around you. Be strict with yourself, but leave room for others to grow at their own pace. That’s real strength.

[Ryan Holiday @RyanHoliday]

Be strict only with yourself. It was said that the true majesty of Marcus Aurelius was that his exactingness was directed only at himself: "Tolerant with others," he reminded himself, "strict with yourself.

[48 Laws Of Power Bot @48_quotes]

Change is slow and, gradual.

It requires hard work, a bit of luck, a fair amount of self-sacrifice, and a lot of patience.

[Lea Alhilali, MD @teachplaygrub]

Can you get the diagnosis when it comes to carotid stenosis?

Having some confusion about the strokes you see w/ICA occlusion?

Why are there so many different patterns of infarcts w/ICA occlusion/stenosis?

There are 5 main infarct patterns—and they reflect the different types of disruption to flow you get w/carotid disease: artery to artery emboli, embolic shower, & hypoperfusion

Here’s what you see:
1.  Territorial infarction w/cortical or subcortical involvement
--From artery-to-artery or distal embolism.
--More than one occlusion indicates more proximal arterial dz

2.  Subcortical infarction
--When ICA, MCA, & ACA perforating deep arteries are occluded
--Can be from MCA occlusion w/good collaterals or emboli directly to deep perforating arteries

3. Combined territorial & smaller cortical and/or subcortical infarcts
--From partial embolism fragmentation or emboli shower of various sizes

4. Multiple small infarcts in the distal territories of the MCA & ACA
--If in more than one arterial territory, it’s suggestive of cardio-embolism
--If single arterial territory, it’s from a parent artery steno-occlusive lesion

5. Watershed infarctions.
Two types:
--External border-zone (located between the cortical territories of ACA, MCA, & PCA)
--Internal borderzone (between the deep & superficial networks of MCA & ACA)
--Traditionally thought from low-flow, but emboli are often a cause
--Hemodynamic mechanism may be more important in internal borderzone infarcts & embolism in external borderzone infarcts

[Marc Marcus @Spidermarc_]

"Find people who know the technique. Stay close to them and observe their skill. Use this opportunity to learn their craft. Let envy be the trait of those who choose the comfort of a fragile ego over the pursuit of excellence."

[Lea Alhilali, MD @teachplaygrub]

Have MULTIPLE questions about MULTIPLE sclerosis?

Having trouble seeing neuromyelitis optica?

In a fog about MOG?

Here’s the cheat sheet you NEED to distinguish the demyelinating diseases!

Demyelinating diseases predominantly involve the optic nerves, brain, & spine.

Three main chronic demyelinating diseases:
🔸Multiple sclerosis (most common)
🔸Neuromyelitis optica (NMO)
🔸Myelin oligodendrocyte glycoprotein (MOG) antibody associated disease or MOGAD

Each has its own features in the optic nerve, brain, & spine. Here’s how to remember them!

▶️MS
🔸Optic nerve:
MS only has 2 letters, so MS involvement of the optic nerve tends to be short segment
🔸Brain:
Letter M makes the shape of the perivascular distribution of lesions along the ventricles (Dawson’s fingers)
Letter S makes the shape of the subcortical U fiber involvement
🔸Spine:
MS is only 2 letters, so lesions are usually less than 2 vertebral bodies in length

▶️NMO
🔸Optic nerve:
NMO is a longer abbreviation, three letters, so longer involvement
NMO can stand for Near My Occiput. Occiput is posterior, so more posterior nerve involvement
🔸Brain:
NMO can stand for Near My Ocean. What is your brain’s ocean? The ventricles. NMO lesions are all periventricular
🔸Spine:
NMO is 3 letters, so lesions usually more than 3 vertebral bodies in length

▶️MOGAD
🔸Optic Nerve:
Remember MO’ GAD-olinium. So things that cause more regions of enhancement. MOGAD lesions are commonly bilateral & long segment & enhancement can extend perineural
🔸Brain:
Remember LO’ GAD. MOGAD typically involves the lower areas of the brain
🔸Spine:
Remember MO’ PLAID. MOGAD can give a plaid-like H shape in the cord from predominantly gray matter involvement

Hopefully, this cheat sheet will help you remember how to distinguish the demyelinating diseases! It ain’t lyin’ about diseases of myelin!

[Marc Marcus @Spidermarc_]

Strength does not come from physical capacity but from an indominable will.