I Had A Stroke 2015, And Taking Aggrenox Due To

I had a stroke 2015, and taking aggrenox due to adverse reaction to plavix. I can only tolerate 200mg vs the 400mg dose, due to GI upset. I have internal cerebral artery stenosis, and have concerns due to feeling dizzy most of the time, with light pressure in area of my head where stroke damage to the thalmus occured. Have right hand numbness since the stroke that has not subsided.

How does aggrenox un stick platelets and what causes them to stick in the first place? Thank you