Embolic stroke: hemorrhagic or ischemic?

[donkeyboy]

I use Golgan almost exclusively for path, but his explanation about embolic strokes makes no sense to me, are they ischemic or hemorrhagic? here's what he writes:


Embolic (hemorrhagic) stroke

​

1. Ischemic type of stroke due to embolization
2. Source of emboli
   • Most often originate from the left side of the heart
3. Produces a hemorrhagic infarction
   ​
   • (1) Most occur in the distribution of the MCA
   • (2) Vessel reperfusion after lysis of embolic material produces hemorrhage.

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[njbmd]

I use Golgan almost exclusively for path, but his explanation about embolic strokes makes no sense to me, are they ischemic or hemorrhagic? here's what he writes:


Embolic (hemorrhagic) stroke

​

1. Ischemic type of stroke due to embolization
2. Source of emboli
   • Most often originate from the left side of the heart
3. Produces a hemorrhagic infarction
   ​
   • (1) Most occur in the distribution of the MCA
   • (2) Vessel reperfusion after lysis of embolic material produces hemorrhage.

Likely a typo which is why review books are not good replacements for textbooks.

 

[ACSurgeon]

I use Golgan almost exclusively for path, but his explanation about embolic strokes makes no sense to me, are they ischemic or hemorrhagic? here's what he writes:



Embolic (hemorrhagic) stroke

1. Ischemic type of stroke due to embolization
2. Source of emboli
   • Most often originate from the left side of the heart
3. Produces a hemorrhagic infarction
   • (1) Most occur in the distribution of the MCA
   • (2) Vessel reperfusion after lysis of embolic material produces hemorrhage.

I think two points are worth noting:
1- the distinction of hemorrhagic vs. ischemic is often used as a histologic Dx (red= hemorrhagic, white= ischemic) AND in the acute setting, to determine if you want to use thrombolytic agents and anti-coagulate your patient (ischemic as in with an occlusion) vs. not (hemorrhagic as in a ruptured aneurysm). Imaging usually helps guide treatment.
2- As you described above, having one type of stroke does not preclude the existence or later-occurrence of the other. Since there is collateral circulation in the brain, many (most?) ischemic strokes become hemorrhagic at some point.

 

[Knicks]

Likely a typo which is why review books are not good replacements for textbooks.

Textbooks never have typos in them?

Cool.

 

[211519]

I use Golgan almost exclusively for path, but his explanation about embolic strokes makes no sense to me, are they ischemic or hemorrhagic? here's what he writes:



Embolic (hemorrhagic) stroke

1. Ischemic type of stroke due to embolization
2. Source of emboli
   • Most often originate from the left side of the heart
3. Produces a hemorrhagic infarction
   • (1) Most occur in the distribution of the MCA
   • (2) Vessel reperfusion after lysis of embolic material produces hemorrhage.

An embolic stroke is an ischemic stroke - classically. There are instances when a thrombus of varying origin can result in a bleed.

In the Goljan passage you are referring to, he means ischemic initially. Once the cells start suffering from ischemia, they release varying inflammatory mediators which enter the surrounding tissues and affect nearby cells. The purpose is the preservation of brain tissue, but the result is vasoconstriction, etc, which can then cause hemorrhage (microinfarcts). As a result, the embolic/ischemic stroke also causes hemorrhage.

One lovely tangent is Superior Sagittal Sinus Thrombosis, which causes ischemia and microinfarcts when dehydration (often via cholera) results in low blood volume, slow flow, accumulation of clots, and occasional vessel rupture.

 

[vicinihil]

So are embolic strokes ischemic or hemorrhagic? I was under the impression that THROMBOTIC strokes were ischemic while EMBOLIC strokes tend to be recanulated leading to a hemorrhagic stroke but I may have understood incorrectly. Thanks!

 

[illixir]

There are two categories: ischemic and hemorrhagic.

Embolic strokes are ischemic initially. They fall under the category of ischemic stroke. On gross, the infarcts are often hemorrhagic because after the period of ischemia there has been reperfusion because of cytokines/inflammatory infiltrate leading to resorption or recanalization as it is a smaller bit of material plugging the vessel. That process does not tend to occur as often in a thrombotic occlusion so those will not turn hemorrhagic. They are still both ischemic strokes.

A purely hemorrhagic stroke occurs when the intial event is hemorrhage as in an intracerebral hemorrhage. Subarachnoid hemorrhage can fall under here as well.

 

[njbmd]

Textbooks never have typos in them?

Cool.

Not so much that they don't have typos but they do have more explanations than a review book which assumes that you have learned something to "review" in the first place.

 

[211519]

So are embolic strokes ischemic or hemorrhagic? I was under the impression that THROMBOTIC strokes were ischemic while EMBOLIC strokes tend to be recanulated leading to a hemorrhagic stroke but I may have understood incorrectly. Thanks!

When a thrombus or a part of a thrombus breaks off and moves to a new location, it is an embolus.

 

[turkeyjerky]

So are embolic strokes ischemic or hemorrhagic? I was under the impression that THROMBOTIC strokes were ischemic while EMBOLIC strokes tend to be recanulated leading to a hemorrhagic stroke but I may have understood incorrectly. Thanks!

No, you understand it perfectly. It's pretty clear that several posters don't understand the pathologic definition of a hemorrhagic stroke.

 

[jl lin]

An embolic stroke is an ischemic stroke - classically. There are instances when a thrombus of varying origin can result in a bleed.

In the Goljan passage you are referring to, he means ischemic initially. Once the cells start suffering from ischemia, they release varying inflammatory mediators which enter the surrounding tissues and affect nearby cells. The purpose is the preservation of brain tissue, but the result is vasoconstriction, etc, which can then cause hemorrhage (microinfarcts). As a result, the embolic/ischemic stroke also causes hemorrhage.

One lovely tangent is Superior Sagittal Sinus Thrombosis, which causes ischemia and microinfarcts when dehydration (often via cholera) results in low blood volume, slow flow, accumulation of clots, and occasional vessel rupture.

👍

 

[deuce924]

An embolic stroke is an ischemic stroke - classically. There are instances when a thrombus of varying origin can result in a bleed.

In the Goljan passage you are referring to, he means ischemic initially. Once the cells start suffering from ischemia, they release varying inflammatory mediators which enter the surrounding tissues and affect nearby cells. The purpose is the preservation of brain tissue, but the result is vasoconstriction, etc, which can then cause hemorrhage (microinfarcts). As a result, the embolic/ischemic stroke also causes hemorrhage.

One lovely tangent is Superior Sagittal Sinus Thrombosis, which causes ischemia and microinfarcts when dehydration (often via cholera) results in low blood volume, slow flow, accumulation of clots, and occasional vessel rupture.

This about sums it up....

 

[username456789]

So are embolic strokes ischemic or hemorrhagic? I was under the impression that THROMBOTIC strokes were ischemic while EMBOLIC strokes tend to be recanulated leading to a hemorrhagic stroke but I may have understood incorrectly. Thanks!

My impression (and I may be incorrect) was that embolic strokes initially are ischemic (like another poster stated). The event is the embolus "clogging up" a vessel distal to where it originated from (where it presumably caused no symptoms). However, these are often recannulated and thus become hemorrhagic/"red" infarcts, pathologically, as reperfusion and such takes its course.

Versus a a thrombotic stroke (or any other cause of vessel stenosis) which is also an ischemic stroke, but generally does not reperfuse (and thus no "hemorrhagic" designation).

 

[donkeyboy]

thx for the replies,

From what I gather from the responses: Embolic strokes are ischemic strokes, but can later lead to hemorrhage after recanalization and reperfusion

i checked robbins anyways, and I found that I was confusing hemorrhagic/ischemic strokes with hemorrhagic/ischemic infarcts which are actually categorized separately

Ischemic vs. hemorrhagic strokes are defined based on the initial event which causes tissue hypoxia. ie. ischemia--> hypoxia (ischemic stroke) vs. hemorrhage--> hypoxia (hemorrhagic stroke)

Ischemic vs. hemorrhagic infarcts as other have mentioned are for histologic diagnosis. ie. blood can flow into an area that had previously undergone an ischemic stroke, leading to a hemorrhagic infarct.

robbins says hemorrhagic infarcts are associated with embolic events, 'hemorrhage presumed secondary to reperfusion of damaged vessels via collaterals or dissolution of occlusive material.' golgan calls embolic strokes "ishemic type" which produce hemorrhagic infarcts. ie. both say that embolic strokes produce hemorrhagic infarcts, but it is only golgan who puts strokes into categories of ischemic vs. hemorrhagic, so if we're catergorizing, embolic strokes are ischemic type, but they produce hemorrhagic (red) infarcts

 

[turkeyjerky]

but it is only golgan who puts strokes into categories of ischemic vs. hemorrhagic, so if we're catergorizing, embolic strokes are ischemic type, but they produce hemorrhagic (red) infarcts

yes. goljan is noting the difference between hemorrhagic infarcts secondary to embolic events and intracerebral hemorrhages, which are possibly due to rupture of a charcot-bouchard aneurysm. this thread should serve as a good reminder on how horrible a term 'stroke' is.

 

[Droopy Snoopy]

One lovely tangent is Superior Sagittal Sinus Thrombosis, which causes ischemia and microinfarcts when dehydration (often via cholera) results in low blood volume, slow flow, accumulation of clots, and occasional vessel rupture.

Funny you mention that, SSS thrombosis been on both my Step II and III exams. Never seen it in practice though. Great post btw.

 

[typhoonegator]

Charcot Bouchard aneurysms are not conclusively linked to deep intracerebral hemorrhage in man. They are uncommon, and have no definitive association with ICH. There are numerous studies to support this.

Embolism (from fat, air, amniotic fluid, fibrin, cardiac valve, soft clot, etc.) leads to ischemia in the surrounding brain tissue. If not corrected quickly, this leads to an ischemic stroke. With recanalization, there is a chance of secondary hemorrhage into the ischemic bed. This is one of the reasons we don't use IV tPA after the first 3-4.5 hours, because you greatly increase the chance of secondary hemorrhage.

A thrombotic event in the brain usually takes the form of a lacunar stroke, another ischemic stroke subtype. This is characterized by lipohyalinosis of the deep small vessels, with eventual cessation of flow or microembolism from platelet aggregates.

Strokes that come from clots that form on other vessels, like carotid plaques or aortic atheroma are another form of embolic stroke, we refer to as artery-to-artery strokes, or atheroembolic strokes. This is to differentiate them from cardioembolic strokes, which tend to have a different (but overlapping) risk factor profile.

The colloquial terminology is imperfect. Hope this helps to clarify a bit.

By the way, venous sinus thrombosis leads to increased local perfusion pressure. In the short term, this causes decreased local perfusion and ischemia. Left untreated, the pressure can grow and lead to hemorrhage, massive cerebral edema, and increased ICP. It is dramatic and difficult to treat.

 

[jl lin]

Charcot Bouchard aneurysms are not conclusively linked to deep intracerebral hemorrhage in man. They are uncommon, and have no definitive association with ICH. There are numerous studies to support this.

Embolism (from fat, air, amniotic fluid, fibrin, cardiac valve, soft clot, etc.) leads to ischemia in the surrounding brain tissue. If not corrected quickly, this leads to an ischemic stroke. With recanalization, there is a chance of secondary hemorrhage into the ischemic bed. This is one of the reasons we don't use IV tPA after the first 3-4.5 hours, because you greatly increase the chance of secondary hemorrhage.

A thrombotic event in the brain usually takes the form of a lacunar stroke, another ischemic stroke subtype. This is characterized by lipohyalinosis of the deep small vessels, with eventual cessation of flow or microembolism from platelet aggregates.

Strokes that come from clots that form on other vessels, like carotid plaques or aortic atheroma are another form of embolic stroke, we refer to as artery-to-artery strokes, or atheroembolic strokes. This is to differentiate them from cardioembolic strokes, which tend to have a different (but overlapping) risk factor profile.

The colloquial terminology is imperfect. Hope this helps to clarify a bit.

By the way, venous sinus thrombosis leads to increased local perfusion pressure. In the short term, this causes decreased local perfusion and ischemia. Left untreated, the pressure can grow and lead to hemorrhage, massive cerebral edema, and increased ICP. It is dramatic and difficult to treat.

Excellent synopsis. . . very helpful. I'm using this as a basis for further study. Thank you.👍