If you want to pose a question to the doctor, go to the top of the page and click on the "Ask a Doctor" tab. Just be really detailed as to what therapies he has already tried, which tests have been done, how severe the pain is, where it is located on his head, etc. If you aren't detailed, you won't get any real response from the doctor.
Has your brother seen a neurologist, maybe one that specializes in headaches? If not, he really should. He needs blood tests and scans to make sure everything is normal. If they are just headaches (and not a symptom of something else) there are a lot of proven therapies for ones of various types. If regular pain medication doesn't help, other things like antidepressants, anti-seizure medications, and even Botox have been shown to improve the symptoms of headaches, especially migraines (although I don't know if that's what he is suffering from).
He also should start a diary of everything he does and eats, along with the timing, frequency, and severity of his symptoms. This will make it easier to pinpoint possible triggers for his pain.
As for the shaking, it may be unrelated, it may be from the pain, it may be a symptom that is related. Either way, he shouldn't ignore it. As soon as he returns to the U.S., he should see a doctor. If he experiences any other symptoms, he should see a doctor in England, if possible.
Let us know if you have any more information. Good luck. I hope your brother finds relief soon.