Tremor: a question and an answer

Another of my readers emailed me this question. My response to it follows:

Jeff Street
on October 16, 2008 said:

I’ve been having tremors over the past 4 months in my hands, feet and legs, and lips. They are more prominent (especially in my hands) after exercise. My physician did blood work and it indicated I was “mildly” hyperthyroid (slightly low TSH, normal T3/T4). He blames the tremors on this condition. He has prescribed propranolol 20mg BID for the tremors, but wants to wait and see if the thyroid might correct itself before putting me on Methimazole (due to its side effects). My symptoms seem rather profound for a “mild” case of hyperthyroidism. Do you have any further suggestions or input?

Dear Jeff,
thank you writing in. As I stated in my earlier post on tremors (you can read my post at my website ) tremors can be of various kinds. The kind of tremors you are describing when your hands are outstretched (but you also have them in your feet and lips) are likely not due to a neurological condition per-se. We all have a subtle tremor in our hands, this is called physiological tremor. If you make people hold their hands out in front of you, you shall be able to notice it is you pay close attention. Now suppose this person goes and drinks 6 cups of large Starbucks coffee and you again make him or her stretch their arms in front of you, the tremor shall be more prominent. This is called enchanced physiological tremor. As the name says, these tremors are physiological and not pathological (we all have them, some more prominently than others).
There are certain medical conditions which may cause tremors or make the physiological tremor more prominent. One such condition is hyperthyroidism. Patients who have hyperthyroidism do have tremors of their hands and also of their tongue (if you make them stick their tongue out, you shall be able to notice the tremor). Some medicines and drugs of abuse also cause tremors. Patients who drink alcohol heavily are tremulous, especially if they stop drinking suddenly.

Not all tremors need to be treated. We only treat a tremor if it becomes disabling for a patient or causes social embrassement. Propanolol (a beta blocker drug used as an anti-hypertensive medication) does have a role in treating postural tremors. Your doctor may like to slowly taper the dose up and see if it gives you any relief. I cannot comment if hyperthyroidism indeed is the cause of your tremor. As you can see from what I wrote above there can be protean causes of tremor some neurological (neurodegenerative in etiology like Parkinsos’s disease), other more benign (Benign Essential Tremor) and toxic/ metabolic causes of tremors (hyperthyroidism, drug induced tremors etc).
My advise to you would be to follow your doctors instructions and see if the propanolol gives you benefit. As I stated earlier, he has started you on a low dose and may taper it up over a period of time. If this tremor does not subside, then you may need a neurological work-up to try to determine the etiology of the tremor.
Please feel free to write in again.

Personal Regards,
Nitin Sethi, MD

Tremor: its essentials and management

In this post I shall talk a little bit about tremors. What exactly is a tremor you may ask. The way we define tremor in neurology is a rhythmic oscillatory movement across a joint. One may have a hand tremor (your hands shake), leg tremors, head tremor and even speech and tongue tremors. One way to classify tremors is to divide them into physiological and non-physiological tremor.

Physiological tremor is present in each and every one of us. If you hold your hands straight out and balance a sheet of paper on it, you can see the paper shaking a little. This is due to the physiological tremor in our hands. We all have it and the thinking behind it is that it is due to cardioballistic motion. Now suppose you go and have a large (I think they call it venti size) Starbucks coffee and repeat the above test again. You shall find that your tremor is now more prominent, this enhancement of the physiological tremor by coffee and some drugs like aminophylline is what is called enhanced physiological tremor. Physiological and enhanced physiological tremors do not need to be treated as they do not disturb the patient in any way. You may ask the patient to cut down on his coffee though.

Non-physiological tremor: as the name suggests these tremors are pathological. One way to classify pathological tremors is on the basis of how they present. So one may have a tremor which is most prominent when the hands are completely at rest and is not present once the hands come into motion (or start doing some activity). This is called a resting tremor (tremor at rest) and is classically seen in patients with Parkinson’s disease. Other tremors are prominent only when the hand is engaged in some action and hence those tremors are called action tremor.

When a patient comes to us for the evaluation of a tremor what we look for is whether the tremor is isolated (meaning there are no other manifestations apart from the tremor) or whether the tremor is a part of a larger neurological syndrome. We want to rule out neurodegenerative conditions like Parkinson’s disease which may present with tremor. Secondly we want to know whether the tremor shall remain static or whether it is going to worsen as time goes by. Then we try to classify the type of tremor and try to identify its etiology. Is it drug induced? What are its exacerrbating factors and what factors make the tremor become less prominent? Does the tremor become less prominent after consuming alcohol? Does the tremor run in the family (meaning is there a family history of tremors)? What does the tremor involve: just the limbs or also the head and speech?

In my next post I shall talk about the management of tremors.

Dr. Sethi