Dear Andrea,

Some of the earliest measurements of MCA branch pressures obtained in mammals was published in 1967:(http://onlinelibrary.wiley.com/doi/10.1113/jphysiol.1967.sp008261/epdf).  The authors found that the mean MCA branch pressure was about 89-90% of that of the femoral artery pressure. A much more recent study (http://www.ncbi.nlm.nih.gov/pubmed/25366620) provides some excellent data obtained via direct measurements made in patients undergoing cerebral aneurysm embolization.

I hope you find this helpful!

Warm Regards,

Eric

Intracranial ICA have 10 mm LOWER than extracranial ICA...as in the article quoted.

IN THIS BIOMECHANCAL MODEL, BASILAR ARTERY seems to have a tiny bit higher arterial pressure than MCA http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3545010/figure/F5/

and the YOUNG'S modulus of arterial walls are here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3545010/figure/F5/

EDITTED

Actually, Chandramouli, it was the other way around- intracranial MAP of the ICA was about 10mmHg LOWER than extracranial ICA, with the differenced ascribed to the influence of intracranial pressure.

Thank you for the interesting suggestions.

I know that these data are really difficult to obtain.

Although obtained in different mammals, all the works agreed that mean arterial pressure inside the skull is lower than outside the skull.

Unfortunately, I am still missing some data about pressure profile.

Maximum systolic pressure in the skull can be higher even if mean pressure is lower in respect to some value outside the skull.

Indeed, pulse pressure amplification can enhance (especially) maximum values while viscous dissipation (that are expected to grow largely when diameter decrease) can reduce mean pressure level.

If someone has further information about invasive arterial pressure in the cerebral circulation I would be grateful.

Andrea

Hi Andrea,

If you want to know the arterial pressure of the cerebral circulation, you first have to go from brachial to central blood pressure, which is lower than brachial blood pressure especially in younger subjects and in male subjects.

For assessing central blood pressure you might start from a radial tonometric signal and use a so-called transfer function.

The better approach however is to perform a carotid tonometry and to scale this signal with brachial blood pressures. Mean and diastolic blood pressures do not change over the arterial tree, but systolic blood pressure increases from proximal to distal (pressure amplification). 

Best regards,

Thierry

Hi Andrea,

Excellent recommendation from Thierry Gillebert. Totally agree with the use of central pressures, mainly if they are retrieved with a carotid sensor (tonometry), calibrated with mean and diastolic brachial blood pressures.

Pereira T, Maldonado J, Coutinho R, Cardoso E, Laranjeiro M, Andrade I, Conde

J. Invasive validation of the Complior Analyse in the assessment of central

artery pressure curves: a methodological study. Blood Press Monit. 2014

Oct;19(5):280-7. doi: 10.1097/MBP.0000000000000058. PubMed PMID: 24892879.

All the best,

Telmo

Thank you to all for the further clarifications.

I expected that cerebral pressure would be closer to its central counterpart than to brachial values. Still, I do not have any information about the changes of pressure pulse generated by moving from central to cerebral sector. Indeed, both pulse pressure amplification and viscous losses should impact pressure pulse along this path, but I do not know which is the most impacting factor, and how the resulting pressure waveform is.

In this respect, any literature data seems to be apport strong evidence, probably because of  the difficulties in reliably measuring cerebral (and aortic) arterial pressure.

Best regards,

Andrea

http://cvphysiology.com/Blood%20Flow/BF004.htm

various other factors play a role in this pressure flow resistance equation.

A group of investigators in Iowa, including Don Heistad, Frank Faraci, and Gary Baumbach measured blood pressures in MCA and its smaller branches in animals since the 80s. They are still doing that in smaller MCA branches (the pial arterioles) using servo-null system in open cranial window in anesthetized mice. Here is an example of their earlier study in dogs:

http://www.ncbi.nlm.nih.gov/pubmed/1615550

Search their names to get more. Hope this helps.

Thank you to all for the good informations!

Andrea

Dear Andrea

Did you have any luck finding those values in the end?

Best regards

Grzegorz