Berry Aneurysms & associated inheritable diseases

[shaman06]

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Alright, SDN newbie here with my first post. Any help would be appreciated!

I'm noticing a conflict with the proposed mechanisms of berry aneurysm formation, particularly between RR Goljan Path and FirstAid.

FirstAid (2010, pg 401) states that Berry Aneurysms are associated with ADPKD, Ehlers-Danlos, and Marfan's Syndrome, with other risk factors of advanced age, HTN, smoking, and race. The argument I have always heard here is that the inherited disorders have defects in collagen or elastin synthesis (which increase the risk of Berry Aneurysms), which until recently I've been 'drinking the koolaid' on.

However, the aneurysms are likely to form at junctions of the cerebral vessels and communicating arteries - sites where no internal elastic lamina or smooth muscle is present - which would contradict what FirstAid is saying.

Goljan says that the inherited diseases (such as ADPKD) are more likely to have Berry Aneurysms simply because of Hypertension. He also lists under Ehlers-Danlos an increasing risk of Aortic Dissection, which I can buy since this is a defect in elastic arteries (thus, Marfans & Ehlers dissection risk); however, I have not heard anywhere that Ehlers-Danlos nor Marfans would predispose to HTN.

Maybe I'm diving way deeper into these diseases than I need to for Step 1, but they are high-yield diseases and I absolutely shouldn't miss a point on them, so I thought I'd try and get this figured out!

Thanks!

 

[21CentSouldier]

Alright, SDN newbie here with my first post. Any help would be appreciated!

I'm noticing a conflict with the proposed mechanisms of berry aneurysm formation, particularly between RR Goljan Path and FirstAid.

FirstAid (2010, pg 401) states that Berry Aneurysms are associated with ADPKD, Ehlers-Danlos, and Marfan's Syndrome, with other risk factors of advanced age, HTN, smoking, and race. The argument I have always heard here is that the inherited disorders have defects in collagen or elastin synthesis (which increase the risk of Berry Aneurysms), which until recently I've been 'drinking the koolaid' on.

However, the aneurysms are likely to form at junctions of the cerebral vessels and communicating arteries - sites where no internal elastic lamina or smooth muscle is present - which would contradict what FirstAid is saying.

Goljan says that the inherited diseases (such as ADPKD) are more likely to have Berry Aneurysms simply because of Hypertension. He also lists under Ehlers-Danlos an increasing risk of Aortic Dissection, which I can buy since this is a defect in elastic arteries (thus, Marfans & Ehlers dissection risk); however, I have not heard anywhere that Ehlers-Danlos nor Marfans would predispose to HTN.

Maybe I'm diving way deeper into these diseases than I need to for Step 1, but they are high-yield diseases and I absolutely shouldn't miss a point on them, so I thought I'd try and get this figured out!

Thanks!

Right, my guess is that it's a 2ndary insult resulting from primary cardiovascular issues, ie, lower cardiac outputs with compensatory mechanisms to increase blood pressure eventually leading to higher blood pressures and thus hypertension. Couple it with RAA activation and you could potentially be increasing the amount of blood being driving through the Circle of Willis.

If you recall too that ADPKD is associated also with hypertension which could lead to increased hemodynamic stress on the vessel walls.

However, this is all my conjecture.

Definitely some interesting points you've brought to light; thanks for bringing it up.

 

[shaman06]

Right, my guess is that it's a 2ndary insult resulting from primary cardiovascular issues, ie, lower cardiac outputs with compensatory mechanisms to increase blood pressure eventually leading to higher blood pressures and thus hypertension. Couple it with RAA activation and you could potentially be increasing the amount of blood being driving through the Circle of Willis.

If you recall too that ADPKD is associated also with hypertension which could lead to increased hemodynamic stress on the vessel walls.

However, this is all my conjecture.

Definitely some interesting points you've brought to light; thanks for bringing it up.

Thanks for the response. I like that argument, especially with the ADPKD, but it doesn't seem to explain (in my mind at least) the Ehlers-Danlos and Marfan connections to Berry Aneurysms, still. hmmmm. . .

 

[norealname]

I'll just make a simple comment, not sure if it is as deep as your thought process so far, but here goes.
* In APKD, patients have predisposition to early-onset hypertension --> berry aneurysms because of increased stress at the bifurcations in circle of Willis for relatively long periods of time
* In Marfan's and ED, the arterial walls are weak in general because of decreased connective tissue strength --> increased susceptibility to berry aneurysm formation because of that weakness.

These arguments works for me, makes things simple and clean.