does he eat sugary food shortly before the energy rush? Sugary foods contain quick release energy which could explain the crazy energy, but then sugar levels drop rapidly which could explain the headaches.
I eliminate sugary foods from my ds's diet as much as possible because he gets crazy from it too - he gets fruity treats instead of sweets and chocolate - raisins are a great treat for out and about!
If you go to the GP, they will prob ask about his diet - limit sugar intake for a week and see if its any better.