What Causes Tremors In The Hands?

My wife today for the first time had problems at first with shaking in her hands when she tried to do things such as put in ear rings. If she rested and didn t attempt to do anything, nothing did shake. After several hours of this increasing, she also found that all her muscles would do this. She was suddenly unable to walk, fell and could not get up. All efforts to move or use any muscle caused the shaking to increase in proportion to the amount of effort being attempted. I took her to the emergency room. They found the CAT scan of her head negative, no issues in her heart from an Ultra Sound Scan and no blood work abnormalities. She is 5 1 tall, 140 lbs and drinks several glasses of wine daily in the evening. She has been admitted to the hospital for observation today. The doctors have no diagnosis. They have not done an arterial scan leading into her brain or and eeg yet. I don t understand these symptoms and haven t heard of shaking only when attempting to use a muscle but none when resting. Any ideas to share with the neurologist tomorrow?