Essential Tremor

What Is It?

Tremor is defined as rhythmic, shaky movements of your hands, limbs, head or voice that occur without your control. Sometimes tremor is a normal reaction to a situation (such as fear, fatigue, or anger), or it is a side effect of excess caffeine, a medication, or withdrawal from a drug or medicine. When tremor occurs during activities and there is no emotional or ingested cause, it can be a sign of a neurological disease called essential tremor.

Essential tremor causes its most noticeable symptoms when your body is in action, such as during the activities of writing, typing or pouring a beverage. This is one way that essential tremor is distinguished from Parkinson's disease, another neurological illness.

In Parkinson's disease, the tremor occurs when muscles are resting. For example, people with Parkinson's disease will watch their hands shake when they rest quietly in their lap, but when they reach out to grab or hold something, such as a cup of coffee, the shaking stops. Just the opposite happens in people with essential tremor. Their tremor begins when they use their hands, for example, when holding a pen or pencil. Essential tremor often begins in the dominant hand (the one used for writing).

Essential tremor is 20 times more common than is Parkinson's disease. It is much more common in the elderly, and as many as 23 percent of people develop essential tremor as they age. You are much more likely to develop essential tremor if you have a first-degree relative with the condition. People who have an elderly first-degree relative with essential tremor are five times more likely to develop tremor than are people without affected relatives. If your parent or sibling demonstrated essential tremor before age 50, then you are 10 times more likely to get it than average, and it may start at an early age.

Symptoms

The main symptom is uncontrollable shaking of one or both hands and/or the head. Sometimes, speech is tremulous. The tremor can spread to both hands. Stress, caffeine and certain medicines — stimulant drugs such as methylphenidate (Ritalin), lithium (Lithobid and other brand names) and valproate (Depacon) — may make the tremor worse. Recently, neurologists conducting a small study noticed that changes in speech, mood, and memory were more frequent than expected among a group of people who had longstanding essential tremor. These cognitive changes have not been proven to result from essential tremor.

Diagnosis

Your doctor will look for uncontrollable shaking that gets worse when you try to maintain one position (such as holding a pen or pencil), family history of tremor, or a medical history that includes the use of any medications that can cause tremor (stimulants, lithium, valproate).