My son has a hand tremor. He's had an MRI of the brain and neck with no visible abnormalities. Well, actually, the neck MRI shows a bulging disc on the right side, the tremor is of the LEFT hand and slightly in left leg/stiffness. The tremor goes away when he sleeps... when it is just resting on his lap... and when he wakes up or when having pins and needles in his arm from sleeping on it, the tremor is completely gone. It is mostly apparent when he uses it. If he is distracted by something else that he is thinking intensely of, the tremor is gone. It is also supressed if and when he has a couple of drinks. He had an EMG of his arm which shows that all nerve and muscles in his arm are okay. We had that done because he also has fragments of a bullet lodged in his upper left arm and we thought that could be the cause. A neurologist said no, because the EMG on his arm turned out okay. The EMG shows a course tremor with frequency of 10 Hz. Blood work also turned out ok.