Do you also notice a "whooshing" sound at those times?
Are your neck muscles tight or in spasm?
If so, you can get PT for the tight muscles , that may resolve the worst of it..

During my acute RSI/TOS injury stages I had spasms in my scalenes and SCM,
those made the neck muscles tighten down on my arteries , so much so that I could hear in my head , a whooshing pulse sound.
Found out later it is called bruit, my chiro told me about it, none of the MDs I described it to gave any indication of what it might be..