Cyndy,
Thanks for the post.
To tell you the truth, I'm never really heard of central nervous system syndrome and it is not something I would leap to based on your posted information.
That said, from the information you provide, all I can say is you have suboptimally treated hypertension.
Normal blood pressure fluctuates during the day with cyclic peaks and dips, and if Avapro is the only medication you are taking I wouldn't think too much of it, other to put you on another agent, preferably a diuretic and do a careful history and physical to establish there are no other causes of your blood pressure elevation.
good luck
Thanks!