what you described sounds very similar to what i am experiencing at this time, my surgery was Feb 11, of this year so im like 5 weeks out. I found out what was causing the pulsating heartbeat sound and the pressure in my head along with other issues, was that i have a blood clot in one of my veins, they say it can happen as a result of surgery and for those with bigger tumors it may have even developed before the tumor was taken out becuase of compromised blood flow. I am on a diuretic and baby asprin, but they arent doing me that much good, I went and got another CT scan today and they are going to start working on some plans on what else they can put me on and do for me, the pulsatile tinnitus can be very debilitating and somedays when its worse, it literally makes me crazy and i cant stop crying...I feel for you and hope they will find what specifically is causing your symptoms. Good luck:)!