Ask the doctors: Essential tremor not linked to neurological disease

Dear Doctors: I think I’m coming down with essential tremors, which run in my family. At age 81, my left hand and left leg are making movements that I’m not initiating. My dad died at 95, and because I’m otherwise healthy, I expect to live with this for many years. I need to know what to expect.

Dear Reader: When someone experiences shaking, trembling or other types of uncontrolled or jerky small movements, it is known as a tremor. Although it often becomes evident in the hands, it can also affect the limbs, neck, torso or voice.

Tremor arises from problems in the regions of the nervous system that oversee movement. These can be due to a neurological condition, such as Parkinson’s disease or multiple sclerosis; metabolic diseases, such as hyperthyroidism; or a medical incident, such as a stroke. Tremor may also be caused by muscle fatigue, extreme emotion, such as fear or anxiety; or as a side effect of medications.

Essential tremor is the most common form of the condition linked to a glitch in the nervous system. The causes are not yet clear, but heredity does appear to play a role. It is not connected to a neurological disease or disorder, and thus is not considered a danger to health. However, because it can interfere with actions that involve small and precise movements, and can adversely affect grip, essential tremor can affect quality of life. The onset of the condition is typically mild. Over time, though, and with advancing age, it can become more pronounced, and also affect additional areas of the body.

The first line of treatment is a class of medications known as beta blockers, which can modulate nerve impulses. Finding the specific beta blocker that works best for a patient, as well as determining the optimal dosage, can take a bit of time. Additionally, these medications can cause side effects, such as slow heart rate and low blood pressure, so they may not be for everyone. Depending on the specific case, medications to treat seizure – such as those used in Parkinson’s disease, certain antidepressants and botulinum toxin (aka Botox) – may also be considered.

When medications are ineffective, or if the side effects pose a danger, some people explore surgical treatment. One option is deep brain stimulation, which uses surgically implanted electrodes to manage electrical disruptions. More recently, a noninvasive form of neurosurgery known as targeted ultrasound has been approved by the Food and Drug Administration. With the aid of MRI images, this approach uses focused ultrasound energy to interrupt errant signals in a tiny part of the brain associated with movement. Success rates vary, but the data suggest an improvement of 50% or more, with gains that last more than five years.

Tremor has many potential causes, so it is important to see a neurologist. The evaluation will include a physical exam, a review of your medical and family history, and a neurological exam to test muscle tone and strength, reflexes, balance and speech. A treatment plan will be devised based on these findings, and should your condition change or advance, will be adjusted accordingly.

Send your questions to askthedoctors@mednet.ucla.edu.