Bloods rush feeling head. What do we do?

Wife ,50, has been found to have high blood pr since 5 months . tablet tazloc 40 started . since 45 days pr is stabilised to 80-82/ 130-134. however she complains of blood rushing to head from shoulders onwards or rather a feeling that my wife has developed high blood pr since 6 months. tazloc 40 pescribed alongwith diet changes etc. pr now in control since 45 days to around 80-82 to 130-134.complint is whenever she bends down to do housework she feels that blood is rushing to her head right up to shoulder area . .lot of sweating happens when she has to bend her head down for longer period . no dizziness while getting up from floor after sleeping why is this happening .this goes away when the head is straightened . What test needs to be done . Our GP has advised Brain+Mri Angio . Shall we go ahead with it or do we consult NEUROLOGIST first . Could it be Carotid OR Vertigo . what do we do