I have been on verapamil for 4 years. I was initially put on topomax, which did nothing for the episodes and caused me several side effects. I eventually saw a neurologist who specializes in migraines and she took me off the topomax, replacing it with verapamil. It was been nothing short of amazing for me. I am lucky in that I do not get the headache portion of the migraine, only the aura. Daily I would go through complete paralysis of my right side, lasting ten-sixty minutes with lingering effects for approximately another hour. A couple of time the episodes were aphasic, where I would try to say a word/phrase and something completely different would come out of my mouth. During these episodes I felt "off", knowing that what was happening was not normal but not completely comprehending what was going on. I have never experienced agitation, only frustration. It's possible he is frustrated and it's coming out as agitation because he's not in control of what is going on. Since the day I started verapamil, over 4 years ago, I have not had one episode of full blown paralysis. If I miss a dose or if I drink caffiene (or ingest another trigger) I can feel the episode coming on, but with the medicine it only presents as mild numbness in my cheek, arm and occasionally leg. Probably 99% of the time I can function through it without anyone even knowing.
Good luck, I'm sorry your son is having to go through this. I hope he starts feeling better soon.