How Can Tremors In The Hand Be Treated?

My 21 yr old son recently develop a tremor in his right hand. He has also had a couple of episodes where he nearly passed out after physical training exercises (he is in the army). This last time that he nearly passed out, the hand tremor became worse afterwards. The MRI he had approximately a month ago did not show anything abnormal. He is otherwise healthy and athletic. The army has sent him to an Airforce Neurologist but it has been a month and we still do not have a diagnosis. Please help!