Head pain is not common during, or after, a stroke. When it occurs, it may be a sign of 1) bleeding, 2) a tear in one of the arteries, 3)
a clot in one of the veins, 4) opening up of smaller arteries when one of the larger ones is occluded, or 4) a side effect of his medicine. I typically evaluate this by obtaining an image of the brain and its vessels, and checking the medication list. One medicine that is not infrequently associated with headaches is Aggrenox. If he is taking that, it may be worth trying a different medicine.
If imaging is negative, and it does not appear to be one of his medicines, than the headache sounds more benign, and can be treated conservatively with headache medicines. There are several medicines that help prevent nerve pain after stroke, and you should inquire with your Neurologist about an appropriate choice of medicine.
I hope that helps.