Perimesencephalic?

[sallym25]

Sorry folks.

I have seen so many posts lately containing this word. I have tried looking it up, but, It's just too technical for me. Does anyone have a plain english, understandable translation for it?

Sally x

[Sandi K]

Hi Sally!

Non aneurysm SAH (NASAH) and perimesencephalic are the same thing. I can't remember the true definition, I broke the word down one day but my tired brain can't remember what I came up with. It means I had a brain bleed with no aneurysm and no known cause.

Sandi K.

[sallym25]

Thanks Sandi,

I knew the NASAH bit, but didn't realise 'perimesencephalic' was such a general term. How does it differ from "angiogram negative" then? Sorry for my ignorance. I do wonder sometimes if my ignorance contributes to my lack of acceptance for my own situation. ( am not aware of having any angiograms, lumbar punctures, MRI's or MRA's. ) Can I help it?... I'm unique!

[Sandi K]

I don't know how they differ but I wonder if it has something to do with UK, US, and Canada using different terms for the same thing?

Angiogram negative, does that mean nothing was found during the angiogram?

I've found lots of US sites where they call any type of brain bleed a stroke. It's all very confusing. My neuro said I definitely did not have a stroke. But there are websites that call NASAHs a stroke.

Perhaps it just depends on where you live ?

[garyolly]

The CT finding that defines perimesencephalic NASAH (PM-NASAH) is blood isolated to the perimesencephalic cisterns anterior to the brainstem;

[Sandi K]

Thanks Gary!

[Surfer34]

Sorry folks.

I have seen so many posts lately containing this word. I have tried looking it up, but, It's just too technical for me. Does anyone have a plain english, understandable translation.

Perimesencephalic is basically an area of the brain.

PERI means "around or surrouding"

Mesencephalon is basically the midbrain or middle of the brain ( towards the bottom)

For most people in this section of the forum its going to be used in the context of the area of their brain that their subarachnoid hemorrhage (bleed) was located.

For people who have had a spontaneous SAH there is a group of patients who dont have an identifiable source of bleeding. These patients are called "angiogram negative" because radiological imaging (CT scans, cerebral angiograms, DSA) cant locate where the blood came from although the imaging can pinpoint where the blood from the bleed has settled.

Among this group of angio negative patients is a a subset of two groups. One group is called "diffuse" NASAH and the other is "perimesencephalic" NASAH. Both groups are "non aneurysmal" subarachnoid hemorrhage but are differentiated by the pattern of distribution of their blood on their initial non contrast CT scan.

A "perimesencephalic" pattern will basically be centered around the midbrain while a "diffuse" pattern will be spread out over more area and not as consentrated around the midbrain.

Side note : to make matters more confusing, the term and diagnosis of perimesencephalic is NOT exclusive to non aneurysmal SAH. In about 5% of cases with a perimesecephalic pattern of bleeding it is caused by an aneurysm. Only after you have had at least one cerebral angiogram (preferbaly two) can the "non aneurysm" label be applied.

Edited February 19, 2011 by Surfer34

[Surfer34]

I don't know how they differ but I wonder if it has something to do with UK, US, and Canada using different terms for the same thing?

Angiogram negative, does that mean nothing was found during the angiogram?

I've found lots of US sites where they call any type of brain bleed a stroke. It's all very confusing. My neuro said I definitely did not have a stroke. But there are websites that call NASAHs a stroke.

Perhaps it just depends on where you live ?

The termnology is the same throughout the world.

Angiogram negative does mean that no source of bleeding was found on imaging.

From everything I have been told and read a spontaneous SAH is in fact a stroke. It is a rare form of stroke and not the common kind. I believe SAH make up about 10% of all strokes.

I'm not sure why your doctor would have said you didnt have a stroke.

[Sandi K]

well done Surfer!

so i must be angiogram negative then because they couldn't find the source of the bleed. my letter says it was perimesencephalic so now I know what that means. weird about the stroke comment from my neurologist isn't it. I've read that he's an excellent neurosurgeon but a rotten communicator... i would have to agree with that. i didn't need surgery so have to assume that his surgery skills are better than his communicating skills!!!

All the studies show that it shouldn't happen to us again. I don't get that. Why not? Wouldn't you think that if it happened once it could happen again? And if it's a type of stroke, wouldn't you think that you are prone to more strokes? It's not sitting with me well. For a bit I was satisfied with this info but right now I'm not. If it happened once why wouldn't it happen again.

Sandi K.

[Surfer34]

Sandi - It appears angiogram negative SAH are a controversial and not well understood area of neurology and medicine.

I have read endless studys and debates on perimesencephalic bleeds and their lack of rebleeding and why it is so.

There is no agreement by medical experts on what causes the bleeds and they cant explain why there is a lack of rebleeding among the perimesencephalic group.

It seems that most doctors think the source of bleeding is a vein or capillary and not an artery like in most aneurysms. Its also believed that there is a drainage problem in perimesencephalic patients that can cause momentary back pressure against what should normally be low pressure veins, thus causing a burst.

If you read up on it you'll get some very interesting theories.

** your comment about neurosurgons being rotten communicators is SPOT ON !!! haha

when i was in the hospital my neurosurgon talked to me for about 12 seconds combined. when I asked what happened he said "your fine".

my follow up neurosurgon wasnt any better. i noticed they seemed to get very offended when you ask them questions and they dont want to bother with answering them

thats why i went on my quest for second, third and 4th opinions. most of what i learned though i learned from published studies on the internet.

Edited February 19, 2011 by Surfer34

[debstir]

Thanks Surfer34 for all this detail, much appreciated! I'm still awaiting the paperwork from my hospital stay, will be interested in what it says. What I *remember* them telling me was that no aneurisms were found, they couldn't find the source of the bleed, and it was at the base of the brainstem.

Deb

[RB-R]

Deb that is what they said to me and my paperwork doest'nt say much more. Put all your questions down on paper to ask on your next appt.

Take care Rhiann x

[ericy]

This article really helped me: http://www.uptodate.com/contents/perimesencephalic-nonaneurysmal-subarachnoid-hemorrhage

[MaryB]

I don't know how they differ but I wonder if it has something to do with UK, US, and Canada using different terms for the same thing?

Angiogram negative, does that mean nothing was found during the angiogram?

I've found lots of US sites where they call any type of brain bleed a stroke. It's all very confusing. My neuro said I definitely did not have a stroke. But there are websites that call NASAHs a stroke.

Perhaps it just depends on where you live ? My neurosurgeon uses both words he calls my Intracerebral Hemorrhage a stroke but not my Subarachnoid. I am in Indiana, USA. It is so hard to understand any of it - I want to know and understand but "shut down" when it gets overwhelming. I have a list a mile long to ask when I go in and I never ask most of it. I just get to the point of it is what it is. My husband kept a diary of my hospital time which was nice but I need to be spoken to like someone with brain damage when you explain this confusing diagnoses. A few weeks ago I had an MRI with and w/o contrast and they saw a small tumor - I was like " Are you kidding me?" "How about that Penn State Coach?" This is not my normal reaction to things but I also in my mind am not worryign about anything I cannot change or control. So I was ok so we check THAT out in 3 months as well to see if it grows.

[MaryB]

I don't know how they differ but I wonder if it has something to do with UK, US, and Canada using different terms for the same thing?

Angiogram negative, does that mean nothing was found during the angiogram?

I've found lots of US sites where they call any type of brain bleed a stroke. It's all very confusing. My neuro said I definitely did not have a stroke. But there are websites that call NASAHs a stroke.

Perhaps it just depends on where you live ? My neurosurgeon uses both words he calls my Intracerebral Hemorrhage a stroke but not my Subarachnoid. I am in Indiana, USA. It is so hard to understand any of it - I want to know and understand but "shut down" when it gets overwhelming. I have a list a mile long to ask when I go in and I never ask most of it. I just get to the point of it is what it is. My husband kept a diary of my hospital time which was nice but I need to be spoken to like someone with brain damage when you explain this confusing diagnoses. A few weeks ago I had an MRI with and w/o contrast and they saw a small tumor - I was like " Are you kidding me?" "How about that Penn State Coach?" This is not my normal reaction to things but I also in my mind am not worryign about anything I cannot change or control. So I was ok so we check THAT out in 3 months as well to see if it grows.

ps I am more afraid of a

repeat angiogram than anything else.

[Sandi K]

Hi Mary, I remember the early days very well and it is all so overwhelming. It's like a different language. I knew nothing about brain bleeds and the Internet was confusing. BTG was very helpful in sorting things out and explaining it all. I finally got to a place where I could ask the right questions of the docs and sort through the information on the web. You will get there too. Welcome to BTG! Please go to the 'Introduce Yourself' threads and tell us about yourself. We would all love to get to know you better. The members here have been so wonderful and warm and helpful with me.

Sandi K. Xoxoox

[kpaggett]

Hey, I am a neurophysiologist and when my p-NASAH hit, it was all news to me!

What I do know:

perimesencephalon is to denote the area of the blood- near the pons or the midbrain.

subarachnoid is the layer the blood was in - not the actual brain, but the area just outside the brain-the subarachnoid space.

Hemorrhage is blood or bleeding.

so...a Perimesencephalic NA-SAH shows up as a specific pattern of blood. The subarachnoid blood is confined to the midbrain cisterns, with no intraventricular or intracerebral hemorrhage.

Is this a stoke? Not in a classical sense because there is no Grey or White matter involvement, but most general information classifies them together.

[Sandi K]

Kpagget, it's pretty cool to have a neurophysiologist on this site with us! I'm sorry you had to come looking for us cuz of the SAH but I'm glad you found us!

Sandi K.

[JellyB]

Morning all,

I was NASAH with no cause for the bleeding ever found.

So far as angiogram negative goes .....this was the category I fell into. This confused me slightly aswell but they explained that all it really means is that the angiogram results were normal (i.e. no aneuryisms or other abnormalities were found). This is 'Good News'.

In my case the bleeding was assumed to be via a vein (rather than an artery). Our bodies heal veins all the time from cuts etc. And this, I think, is why we have such a low chance of re-bleeding. It's because, hopefully, the body has done its magic and successfully repaired the damaged vein so it shouldn't be a problem again.

Hope this simple explanation helps.

Bye

[donnamarie]

Hi Sandi mine was classed as a stroke and my insurance paid out on the definition of stroke resulting in perament Damage. I get different information every time im at the doc/ consultant :devil:

[Karen]

As far as I know or from what I've read, a Stroke occurs when there is an interruption to the supply of blood to the brain, whether it be from a clot or a bleed. http://en.wikipedia.org/wiki/Stroke

[debbie b]

Sandi - It appears angiogram negative SAH are a controversial and not well understood area of neurology and medicine.

I have read endless studys and debates on perimesencephalic bleeds and their lack of rebleeding and why it is so.

There is no agreement by medical experts on what causes the bleeds and they cant explain why there is a lack of rebleeding among the perimesencephalic group.

It seems that most doctors think the source of bleeding is a vein or capillary and not an artery like in most aneurysms. Its also believed that there is a drainage problem in perimesencephalic patients that can cause momentary back pressure against what should normally be low pressure veins, thus causing a burst.

If you read up on it you'll get some very interesting theories.

** your comment about neurosurgons being rotten communicators is SPOT ON !!! haha

when i was in the hospital my neurosurgon talked to me for about 12 seconds combined. when I asked what happened he said "your fine".

my follow up neurosurgon wasnt any better. i noticed they seemed to get very offended when you ask them questions and they dont want to bother with answering them

thats why i went on my quest for second, third and 4th opinions. most of what i learned though i learned from published studies on the internet.

My neurosurgeon didn't even speak to me when i finally saw him, he spoke to my husband, I lost my temper and then the surgeon laughed and explained in plumbers language what happened with my leak and how he repaired the leak.

[Skippy]

Hi Debbie

You'll notice that Surfer 34 is no longer a member of BTG - his posts consisted purely of statistics and poor ones at that - his so called research was not wide spread and only resulted in scaring and worrying people on here - so please do not take anything posted by Surfer 34 as either gospel nor possible.

[MaryB]

FYI while googling "Perimesencephalic SAH Definition" just now I clicked on a link and it was Sandi answering Sallys questions on this thread! LOL, Oh yea, it means NASAH.

MaryB