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Dr. Miller: You have a tremor in your hand. What's that all about? This is Dr. Tom Miller here today to tell you about that on Scope Radio.

Hi, I'm here with Dr. Lauren Schrock. She's an assistant professor of neurology and specializes in movement disorders. Today, she's going to help us try to figure out what tremors are about. Lauren, my patients talk to me about tremors pretty frequently, and there are different kinds, right? Could you clue us in and tell us a little bit about the different kinds of tremors that people might experience.

Essential Tremor Vs. Tremor From Parkinson's Disease

Dr. Schrock: There are several types of tremors, but there are two most common ones that people will see in friends or family. Those include Parkinson's disease tremor and . . .

Dr. Miller: That's the one you don't want to have, right? That's what people, I think, might be worried about.

Dr. Schrock: That's what people worry about most commonly when they come in, actually, but they happen to have something called essential tremor.

Dr. Miller: That's more common.

Dr. Schrock: That's more common than Parkinson's disease. There are clear differences between the two. With essential tremor it's mostly tremor, and that's your main symptom. What's unique about it is it doesn't occur when you're resting. If you're resting and not doing anything, your hands are very still, whereas when you try to do something with your hands, such as writing or even holding a coffee cup, your hands will be tremoring. That's something unique.

Dr. Miller: This is interesting, because I remember my grandfather when he reached out to pick up his peas with a fork he would have a lot of trouble with that. Then, of course, when he was resting he didn't have that tremor. He would always tell me that he thought this was Parkinson's, and I guess that's not true.

Dr. Schrock: That's a common misconception, and people really worry about it. That's what they come in frequently to my office worrying about. The reason why they worry is they think of Parkinson's disease, correctly, as more of a progressive disorder.

Dr. Miller: They worry that that might be the start of a long, progressive problem. Essential tremor, it can start mild and stay mild, or does it progress also? Does the essential tremor get worse?

Can Essential Tremor Get Worse?

Dr. Schrock: Essential tremor definitely can get worse. Really, when it comes down to it, probably two decades from now we're going to find out there are many different types of essential tremors. There are a lot of varieties of the different severity of tremor, what part of the body it includes. Most commonly . . .

Dr. Miller: So it's not just the hands?

Dr. Schrock: It's not just the hands. Head tremor can be involved, head and voice tremor.

Dr. Miller: I've heard some people that sound like their voice is almost trembling when they talk, and you wonder if they're anxious. Actually, it's the essential tremor, that type of tremor at least, right?

Dr. Schrock: It definitely can be. There's one other thing that can be mixed up or misdiagnosed as essential tremor, and that's something that's much more rare, so most people haven't heard of it. It's something called dystonic tremor, something when someone has dystonia, meaning abnormal spasm of a muscle that causes either pulling or abnormal postures.

Dr. Miller: Is essential tremor mostly in both hands, or is it usually in one?

Dr. Schrock: In most people, essential tremor will come on in both hands. Most patients who come in will complain of it more in their dominant hand, of course, but when you actually examine them they'll have the tremor in both hands. Whereas with Parkinson's disease, by definition it starts with one hand and at rest, so the Parkinson's tremor will be where someone is just sitting down. You see their hand moving on its own, tremoring rhythmically. Often, people describe it as a pill rolling tremor. You'll see the movement of the thumb and the finger kind of together.

Dr. Miller: But the essential tremor is a little finer tremor, it's worse as you move towards something or try to do something. It's a finer base tremor. I guess sometimes it can actually be a pretty marked tremor, depending on who has it.

Dr. Schrock: Yeah, it can become severe. Most people don't come into a doctor for essential tremor. There's a lot more essential tremor out there than we see in our clinics.

When people have done studies just knocking on doors and seeing if someone has tremor, the rates are much higher than would be estimated just by how many people come to clinic. Because the majority of people, really it's probably relatively mild, so they don't see a physician about it. In general, when you look at essential tremor you can have some people who have a very fine tremor, almost even a jerky sort of tremor, and then you can have other people who will have a tremor that is much more severe. For example, when they hold up their hand in front of them their finger may move up to three inches.

Can Essential Tremor Be Inherited?

Dr. Miller: Wow, that would be very difficult to live with, I would think. Do essential tremors travel in families? Are they associated with a family history? Because many of my patients will say, "Yeah, I really haven't worried about it because I knew my dad had it and his mother had it."

Dr. Schrock: Yes. It's very common to see essential tremor strongly travel in families. In medical school, we're taught that it's what they call autosomal dominant disorder, so that each child has a 50 percent chance of getting the gene.

Dr. Miller: Is that still true? Does that hold?

Dr. Schrock: I would say there's definitely a sub-group where you definitely see that, but as I mentioned before, essential tremor probably includes many different tremors, some of them where you see clear family inheritance and others where you actually don't.

What Age Do You Get Hand Tremors?

Dr. Miller: What about the age difference when these tremors might develop? Does the Parkinson's tremor occur a little bit later, that pill rolling tremor you described? Is that a little bit later on in life, or essential tremor earlier in life?

Dr. Schrock: On average, when you look at the large groups, you will see that essential tremor comes on a little bit earlier than Parkinson's disease. However, even within a single family who has multiple family members with this essential tremor, you may have one family member who has the onset at age 20 and another family member at age 75. There really is not a clear indicator of what your diagnosis is based on the age of onset.

In Parkinson's disease, the large majority of patients have their onset in their 60s, 70s. However, there is a small subset of patients who can have early onset Parkinson's disease. A great example of that would be Michael J. Fox who had his onset around age 30.

Dr. Miller: Also, tremors are related to certain drugs, I think. A lot of us think about people who maybe are withdrawing from alcohol having a tremor. Is that actually a tremor? Is that something that is separate from what we've been talking about?

Do Drugs Cause Tremors?

Dr. Schrock: The answer is yes and no. You can get that with certain drugs. Most commonly, I'm thinking of drugs that block dopamine. That would be in a class of medicines called anti-psychotic medications or medications that can be used for mood stabilization. An old one is called Haldol. Those can cause a Parkinsonian tremor. That's a very true tremor. The tremor will go away when the medication is taken away, but it may take up to six to 12 months for the tremor to actually go away.

Dr. Miller: A long time. I didn't know that.

Dr. Schrock: Then, there is another. You're talking about withdrawal of alcohol, for example, or someone who is under stress. This is something I often describe to my patients who have tremors, because tremors always worsen with stress, whether it be stress of having the flu or stress of having your mother in law coming to dinner.

Every single human being has the potential to have tremor. What we call that is physiologic tremor. Whenever someone is extremely hungry, didn't get enough sleep, they will get some very fine tremor in their hand. There are sayings called to shake with rage. Well, there's a reason for that. Because humans . . .

Dr. Miller: I've had that. It seems like that's about three times a week.

Dr. Schrock: . . . have a natural inherent tendency to have some tremor during times of stress.

Dr. Miller: What would you say to the person that develops a tremor? Should they see a physician about the type of tremor they have if they're concerned? Could they by looking on the web to figure out if it was an essential tremor and maybe diagnose themselves?

Dr. Schrock: In self-diagnosis, I've definitely had patients who've correctly done that, but I would beware. I think that anyone who has a tremor and has a concern about it should bring it up to his or her primary physician. If you're worrying and it's bothering you, then you definitely should see a physician about it.

Dr. Miller: Finally, there's treatment for both types, correct?

Dr. Schrock: Yes. There are treatments for both types. They are very different, the approaches to treatment.

Dr. Miller: That would require a physician to make the diagnosis and provide the treatment. Thanks very much, Dr. Schrock.