Could Pressure In Head Be Due To Change From Fentanyl Patch To Hydro Morph Contin?

My husband recently changed medication. He has gone from fentynal patch to Hydromorph Contin 24mg. We are wondering if this change can cause pressure and numbness in the head, staring from the base of the neck and engulfing the entire head. He suffered a stroke in Nov. 2014. The medication is treating a chronic pain issue he has had for 18 years. YYYY@YYYY