Hi Kim,
I'm actually dealing with high blood pressure issues as we speak. My doctor recently changed my medication from Procardia to Dynacirc and Cozaar because Dynacirc is suppose to not only lower your pressure, but is also suppose to provide better blood flow to the brain area. Anyway, I returned to work last week, and my pressure got up to 164/117 with my pulse at 52 bpm! That scared the living daylights out of me!

I've also been experiencing headaches, but I'm thinking it's related to my elevated pressure. I'm not working again, so I'm monitoring my pressure this week to see if it goes back down. I'm now 4 months post-op, and although I know we're all different, I wonder what's wrong with me when I hear about others (i.e. itsme

) returning to work even sooner...
I too was told that it is better for my pressure to be slightly elevated than too low. If it's too low, then there is a chance that the vessels will collapse. However, I think my bp is too high right now. High bp also has an affect on one's

, so I know high bp for a significant period of time isn't good as well.
After reading others' posts to your question,
I'm wondering what "borderline high" means? 120/80-140/90? 
What does it mean in terms of numbers. So..to Google I went and found some info... One thing to remember, many things I find on Google doesn't take MM into consideration*, so I always have to remind myself of this. Thus, as said millions of times on this site..it is very important to seek medical advice from a MM specialist.

;

"Uncontrolled mild-to-moderate hypertension will reduce the life expectancy of a typical 35-year-old person by 16 years. Even the mildest form of high blood pressure, "borderline hypertension," can cut your life span by two to four years.*"
http://www.healthsquare.com/fgpd/fg4ch02.htm
This article focuses on children, but I'm sure "adults" could also be substituted here...

"The risks of the surgery seem to be more due to the risk of being under general anaesthesia for an extended period of time then to the actual surgical manipulations.
The moyamoya vessels and the involved brain are very sensitive to changes in blood pressure, blood volume and the relative amount of carbon dioxide in the blood. When awake, the Childs brain is able to regulate these factors fairly well. However, under general anaesthesia these parameters are much harder to artificially control and this can lead to bleeding or strokes. It is crucial for surgery that the anaesthesiologist have experience in managing these children as the type of anaesthesia they require is very different from the standard anaesthetic children get for almost any other type of neurosurgical procedure."
http://www.health.adelaide.edu.au/paed-neuro/vascular.html
http://www.sutterhealth.org/health/hi_hbp-guidelines.html
Is Matt on any bp medications at the moment?
I am also in a delima about anesthesia and bleeding as well. And, I know that many, if not most of us are on some type of blood thinning medication which may attribute to us bleeding a little more than the average person. I'm actually in the process of checking with my neurosurgeon to see how long he recommends I wait to go under general anesthesia after my surgery. I've read other posts where people went under general anesthesia couple of months after...and in some cases even sooner when they had both sides done.
Well...I look forward to reading other responses to your post. Hope this helped a little..
Take care,
Shan