Movement Disorders: Essential Tremor
Guest: Dr. Vanessa Hinson - Neurology
Host: Dr. Linda Austin – Psychiatry
Dr. Linda Austin: I’m Dr. Linda Austin. I’m interviewing Dr. Vanessa Hinson who is Assistant Professor of Neurology and Director of the Movement Disorders Program here at MUSC. Dr. Hinson, let’s talk about a pretty common condition, essential tremor. What is an essential tremor?
Dr. Vanessa Hinson: Essential tremor, first of all, is the most common movement disorder that we encounter. Essential tremor refers to shaking of the hands that happens when the patient holds out their hands in front of them or wants to use their hands. It can also affect the head and the voice. Usually, this tremor runs in families; it’s genetic. We often get a positive family history from the patient when they tell us that their mother had the same problem, father had it. It is autosomal dominant, so 50 percent of affected relatives can pass it to another family member. So, it’s very common, it’s genetic, and mostly affects the hands, but can affect the head and voice as well.
Dr. Linda Austin: At what age does it appear?
Dr. Vanessa Hinson: It occurs most commonly at around 50 or 60 years of age and, unfortunately, often worsens as one gets older. It can also occur in children. This is more unusual, but our pediatric neurology colleagues also treat children with essential tremor.
Dr. Linda Austin: When you think of older people, certainly, it seems that tremors are extremely common. In fact, charicatures of older people often show them with a tremor. Is there such a thing as just a tremor of old age that does not seem to be genetic?
Dr. Vanessa Hinson: No. I don’t think there’s any normal form of tremor. I think most people with a benign tremor that is not functionally interfering, and that they’re older, actually have essential tremor. Essential tremor is so common. And many of us now grow very old with all the available medical care that we just see so much of it and we think it’s normal, but it’s not.
It’s very important, though, to not take any form of tremor for essential tremor just because it’s common. There are many other causes of tremor, especially in the elderly. Let’s take the example of medication-induced tremor. There are many medicines that can cause tremor. The tremor would look exactly like essential tremor. For example, antidepressants, many of us take the so-called SSRIs, like Prozac or Zoloft, and these medicines can produce a tremor that looks just like essential tremor. So, it would take changing that medication to something else and see if the tremor would go away in order to define what we’re dealing with. So, taking a detailed medical history is very important.
The other very important task, for the neurologist, is to make sure this is not Parkinson’s disease. Obviously, Parkinson’s is also much more common in the elderly, so we have to perform a detailed neurological examination to test for that. There is not blood test or brain scan that would show essential tremor or Parkinson’s disease, so one relies on a clinic diagnosis.
Dr. Linda Austin: What is the difference in tremor in those two disorders?
Dr. Vanessa Hinson: The Parkinsonian tremor is a tremor that occurs at rest. , somebody would sit in a chair and their hand would shake fairly slowly at a set frequency, and the shaking would go away when they do something with their hands. So, when a Parkinson’s disease patient, in the earliest stages, eats, for example, holds a fork and brings the food to their mouth, they have no shaking, yet when they relax and watch television, their hands start shaking. We call this a rest tremor, whereas essential tremor happens with action. It’s almost the opposite. It happens when the patient wants to do something with their hand and it quiets down at rest.
The other difference is, and this is a very important difference, that Parkinsonian tremor always starts on one side of the body. So, the patient comes in and says, I have a right hand tremor, the left hand is normal. That makes me think of Parkinson’s disease, whereas if the patient says, I have a tremor in both of my hands, it’s equally bad on both sides, that makes me think of essential tremor.
Dr. Linda Austin: I’ve seen drug-induced tremors that can start on one side.
Dr. Vanessa Hinson: That would usually be a Parkinsonian drug-induced tremor, because certain drugs, especially used in psychiatry, can lead to Parkinsonism that starts on one side of the body. It would still be a Parkinsonian tremor though, but induced, probably, by a neuroleptic, which is one of the medicines that can induce a Parkinsonian tremor. Other drug-induced tremors can be worse on one side, but if you look closely, the other side is also affected, probably not as much as the original side, but there’s some involvement on both sides.
Dr. Linda Austin: How do you treat an essential tremor?
Dr. Vanessa Hinson: Treatment for essential tremor can be quite rewarding because there are two medicines that are quite effective. These medicines have been on the market for a long time and we know, very well, how to use them. One is a beta blocker called propranolol that we also use to treat high blood pressure. The other drug is a medicine called Primadone (Mysoline), which was originally developed to treat seizures but, very effectively, suppresses tremor.
Usually we start with one of these two medicines. And if we don’t get relief or if the patient doesn’t find that this is useful, we can resort to the tertiary or more rarely used medications. But there are also other options we have with medicines. If a patient does not respond to oral medication, we can also offer deep brain stimulation surgery here at MUSC, which is a surgical approach to treating tremor that is very effective.
Dr. Linda Austin: How about new research studies in this area, is there anything going on at MUSC.
Dr. Vanessa Hinson: Researchers have focused on developing new drug treatments for essential tremor. There is a new research study, at MUSC, that we’re just starting with that patients can be part of, through the Movement Disorders Program, that looks at a new compound called pregabalin that we also use for the treatment of pain disorders, for example, that has, in preliminary studies, proven to be very successful in patients with essential tremor. So, we will study this, actually, in many sites throughout the country, and we are one of the sites. Patients would be assigned to taking this new drug, for essential tremor, or a placebo pill, which will not have any active compound for tremor, and we’ll see which group of patients does better.
Dr. Linda Austin: If a person is interested in enrolling in that study, who should they contact?
Dr. Vanessa Hinson: They should contact the MUSC Movement Disorders Program at (843) 792-7262 or go to the Movement Disorders website through the main MUSC Health website.
Dr. Linda Austin: Good luck with the study.
Dr. Vanessa Hinson: Thank you.
Dr. Linda Austin: Thanks a lot for being on this podcast.
Dr. Vanessa Hinson: Thank you.
If you have any questions about the services or programs offered at the Medical University of South Carolina or if you would like to schedule an appointment with one of our physicians, please call MUSC Health Connection: (843) 792-1414.