Ask the Doctors by Eve Glazier, M.D. and Elizabeth Ko, M.D

Not All Tremors Point to Parkinson’s Disease

Dear Doctor: My wife does calligraphy, but she’s having trouble because her hands have started shaking. She’s worried it’s Parkinson’s disease. What else could be the cause?

Dear Reader: Uncontrolled shaking, trembling or quivering, which is known as a tremor, occurs as the result of sustained and involuntary muscle contractions in the affected area. A tremor can range from something so slight that the person barely notices, to more pronounced movement that interferes with daily activities. Although tremors mostly involve the hands, they can affect virtually any muscle in the body, including those in the head and neck, vocal cords, legs, feet, arms and torso. The movement may occur at irregular intervals with periods of stillness in between episodes, or it can be constant. And while the condition becomes more common as people enter their later years, it can occur at any age.

There are two major types of tremor -- resting and action. In resting tremor, which most often involves the hands and fingers, the affected body part shakes or trembles when the muscles are relaxed and at rest. An action tremor occurs when the muscles are engaged. This can happen during general movement, like when you pat a dog or pass a plate; while bracing a body part, such as holding out an arm; when engaging in a fine motor task, such as writing; or while zeroing in on a specific target, such as touching the tip of one’s nose.

Tremors can occur without a discernible cause; may be a symptom of a physical, medical or neurological condition; or can result from medical treatment. Many of us have experienced the shaky hands that can accompany fear, anxiety, anger, anticipation and exhaustion. Substances like caffeine, alcohol and nicotine can contribute to tremors. So can a range of drugs, both legal and illicit. Medications that may cause tremor include those used to manage asthma, certain antidepressants, some types of blood pressure drugs, thyroid medications, weight-loss medications, anti-inflammatory drugs and antivirals.

It’s true that tremor can be a symptom of a neurological disorder, including Parkinson’s disease. In your wife’s case, it is likely an action tremor because it occurs while she is writing. Parkinsonian tremor falls into the category of the resting tremor: A person with Parkinson’s disease will notice that their fingers or hands tremble while at rest, and that as soon as the muscles are engaged in activity, the tremor disappears. However, since any type of tremor can be a symptom of an underlying condition, it’s a good idea for your wife to speak about it with her family doctor.

Diagnosis entails a comprehensive physical and neurological exam, a detailed medical history, performance tests and certain laboratory tests. Imaging tests such as CT scans or MRI don’t diagnose tremor, but may be used to rule out other conditions. There is no cure for tremor at this time, but with medication and, in some cases, surgery, the condition often can be successfully managed.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)