Health & Wellness

Understanding Essential Tremor

While the condition isn’t life-threatening, it can be life-changing

By Wendy Haaf

When she was in her late 60s, Heather Wright began to notice involuntary movements in her hands. “If I held my hand on the steering wheel a certain way, it trembled,” says Wright, a freelance writer and workshop leader in Kitchener, Ont. “If I was carrying a bag of groceries or my handbag with my arm down, my hand would shake. I immediately thought, ‘Oh, my God, Parkinson’s.’”
Wright’s family physician sent her to a neurologist, who, after some in-office tests, told Wright that she in fact had a condition called “essential tremor” (ET).

One of the most common movement disorders—at least eight times more common than Parkinson’s disease—ET affects an estimated four per cent of adults over the age of 40 worldwide, typically appearing after the age of 55. While the exact cause is unknown, more than half of cases appear to be inherited (familial tremor). According to one line of thinking, the problem underlying the rhythmic shaking is abnormal brain activity that is processed through the thalamus, a sort of junction box in the brain that relays sensory impulses to the cerebral cortex, which decodes those signals. “Essential tremor usually starts from the hands, and then other body parts can be affected, such as the trunk and the legs,” says Dr. Alfonso Fasano, a clinical investigator with the Krembil Research Institute and the Centre for Advancing Neurotechnological Innovation to Application (CRANIA, hosted by the University Health Network’s KITE Research Institute and the University of Toronto).

In a sense, Wright’s diagnosis was good news. For starters, the condition isn’t life-threatening. In addition, Fasano says, “in other neurological conditions where you have tremor, the tremor is combined with other problems.” In Parkinson’s disease, for example, “there’s tremor, but there’s also slowness, muscle stiffness, and balance problems.” The absence of such symptoms is one of the criteria for diagnosing ET. Another is that the tremor affects both arms and has been present for at least three years.

“The lack of any other signs and symptoms is more important than the presence of an action [or kinetic] tremor,” says Dr. Mandar Jog, director of the National Parkinson Foundation Centre of Excellence in Parkinson Disease and the Movement Disorders Program at London Health Sciences Centre in London, Ont., and a professor of neurology at Western University’s Schulich School of Medicine & Dentistry. A kinetic tremor usually comes on when someone tries to do something with their hands—unlike the tremor that begins in the earlier stages of Parkinson’s disease, which characteristically occurs when a person is at rest.

Not Entirely Benign

In one sense, then, ET is harmless, in that it causes difficulty only with certain movements—in fact, at one time, it was known as “benign essential tremor.” However, that description belies the extent to which the condition can affect someone’s quality of life.

“It can take your confidence and throw it right out the window,” says Silvia MacLean, a retired teacher in London, Ont., who at 69 has been living with familial tremor since at least age 10. “People who didn’t know me would come up to me and touch my arm and ask if I was okay.”
MacLean hid her shaking from those other than her family and close colleagues by avoiding certain activities and situations. In public, she would decline coffee if it was offered because her shaking hands would have sloshed the liquid everywhere. Eating soup around others was similarly out of the question. “If I went to a restaurant, I had to have a hamburger or a sandwich, because I couldn’t use a fork or a spoon,” she says. “You want to volunteer to serve soup with some community group, but you can’t ladle the soup and you can’t hand out the bowls. You’re not going to be social if you feel you look like a freak. You’re not—but you feel like one.” And self-consciousness, as well as anxiety and nervousness, can exacerbate the symptoms. “If you’re stressed, you shake more,” MacLean says.

While MacLean didn’t let the tremor interfere with most of the things she wanted to do when she was younger—including teaching and being involved in the PTA—she did raise the issue with doctors periodically. “When you tell your doctor ‘I shake a lot and I don’t know why,’ the doctor will often say ‘I’ll give you anti-anxiety medication—you must have anxiety because you have four kids,’” she says. “Or ‘I’ll give you an antidepressant, because you’re a teacher.’ So you start to think there must be something wrong with you—until you find the right doctor.”

Eventually, MacLean’s family doctor referred her to Jog. “He checked me for Parkinson’s and the whole bit, but, no, it was familial tremor,” she says.

What happens after diagnosis depends on how bothersome a patient finds the symptoms and how much the tremor affects the ability to carry out the activities of daily living. Wright’s neurologist explained her options. “[He said] there’s no cure—the best you can do is manage it,” she says. “If it gets really intrusive, then he would look at some interventions.” There is some evidence that upper-body resistance training, including exercises such as bicep curls, can reduce tremor severity in addition to improving strength and coordination.

To some extent, how disturbing you find living with ET hinges “on what you normally do,” Wright says. If tennis is your passion, for example, you’re in luck: ET won’t interfere. “I knit and crochet,” she says, “but if someone loved doing very intricate needlework, not being able to pursue that would be very frustrating.”

At least for now, Wright, now 72, has opted not to pursue treatment. Though her tremor has worsened somewhat since she was first diagnosed five years ago, she’s found ways to accommodate it. An active freelance writer (she’s now working on screenplays), she’s been able to keep using her preferred method by making one small modification: “I still use a pen and paper, but holding a pen that I not only have to move but press down on is really tiring. So [now] I write with fountain pens, because the ink flows out and I only have to move it in space.”

A long-time voice student, Wright has continued with lessons and recitals but no longer holds the microphone, preferring to use a stand instead. And when she bakes, she puts sugar in a little bowl and uses her fingers, rather than a spoon, to sprinkle it on cookies or scones.


MacLean, on the other hand, did decide to start down the treatment path several years ago.
The first line of therapy is some form of medication. While no drug currently on the market was developed specifically to treat ET, some used for other conditions “have been tested and shown in controlled trials to be of value,” Jog says. One is propranolol, a beta blocker prescribed primarily for high blood pressure. Some anti-seizure medications—namely primidone and topiramate—also number among the drugs that have been validated for use with ET. In some situations, anti-anxiety medications such as clonazepam may also be tried. (Alcohol may temporarily reduce tremor, but this can also lead to a more severe rebound tremor a few hours later. And obviously ongoing heavy alcohol use isn’t recommended due to an increased risk for serious health problems.)

Overall, these drugs reduce tremor in about 50 per cent of patients, but finding out whether you’re one of them is a process of trial and error. In addition, as with any medication, they’re contraindicated in some circumstances and can sometimes cause side effects significant enough that people aren’t willing to put up with them. For example, because beta blockers lower blood pressure and heart rate, “they can cause dizziness,” Jog explains. “And you can’t use primidone with people who are on warfarin or other blood thinners or in people with liver disease.” And since primidone is a barbiturate, it can also cause confusion and excessive drowsiness. Similarly, “topiramate can have an impact on memory,” Jog says.

For MacLean, “finding the right cocktail of medications was hard.” Gabapentin, used to treat seizures, helped for a while, but as is often the case, gradually provided less and less benefit.
People with ET that doesn’t respond adequately to medications and is so severe it’s disabling (Fasano cites the example of a woman who fell and fractured her leg but couldn’t dial the phone to call for help) may want to consider more invasive options.

“Brain surgery, targeting the thalamus, is the only approved treatment at the moment,” Fasano says. “There are two basic ways to change the activity of the neurons involved in provoking the tremor. One is to numb them with electrical stimulation, which is deep brain stimulation [or DBS, which involves implanting a device something like a pacemaker]. “The other is to kill these neurons.” Called thalamotomy, this “can be done in three different ways,” he says. “The classic way that’s been used for 70 or 80 years is with radio-frequency—inserting an electrode and using it to burn the neurons.” The procedure requires opening the skull. But thalamotomy can be done without an exterior incision, too. One method, now used less than it once was, uses highly focused radiation to target the neurons—an approach called “gamma knife surgery.” A newer approach, not yet widely available, Fasano says, “is MRI-guided focused ultrasound,” which essentially accomplishes the same thing without radiation. Instead, it uses sound waves to heat and destroy the small targeted area of brain tissue.

According to Fasano, these procedures work better than drugs. “We are seeing a reduction in tremor of 80 per cent in 80 per cent of patients.”

Both the invasive and non-invasive surgeries do carry some degree of risk. Because DBS and standard thalamotomy necessitate an incision, “they can cause bleeding and infection,” Fasano says. And with all four options, there’s a possibility of causing damage to more than just the nerve fibres that must be disabled to reduce tremor. “Then the patient might be left with some permanent deficit, such as weakness on one side, tingling, or speech or balance problems.”

A New Approach

Going from drugs to surgery is a big leap. For something in between, Jog took a new approach to a treatment that was tried and abandoned 20 years ago: injecting botulinum toxin to paralyze the nerves and muscles involved in the involuntary shaking. Botulinum toxin is the active ingredient in Botox, but it’s also approved for conditions such as migraine and stroke-related spasticity.

Rather than giving all patients the same pattern of injections (the previous method), “we designed a system of measuring the amplitude and the angles of tremor very accurately,” Jog explains. (This technology has since been patented.) Treatment is then individualized based on those results. “We inject a variety of muscles from wrist to elbow to shoulder,” Jog explains. “It starts working in about three to five days, peaks at about four to six weeks, and then wears off at about three months.”
One phase 2 clinical trial testing this treatment strategy is still under way, and the results of a second are now being analyzed. (Phase 2 trials are the second of three stages of research that must be completed before Health Canada will consider approving a drug or device for a specific indication. And only once Health Canada has approved a drug will provincial authorities consider whether to cover it.) Based on existing data, Jog says, “about 75 to 80 per cent of people will get good benefit. About 20 per cent will get some benefit, but it will also cause some weakness.”
Over roughly the past decade, Jog and his colleagues have developed a large program in which botulinum toxin is used off label to treat ET. Since it’s not covered by the province, and only a few private plans will pick up the tab, most patients pay the cost out of pocket—up to $600 every three months, depending on the dose.

In the wake of her husband’s death a few years ago, MacLean’s social life had shrunk. One day she was in a store that was offering lessons in watercolour painting, and when the woman working there asked MacLean if she’d like to sign up, “[she] left in a hurry,” MacLean says. Later on, however, she decided to see whether botulinum toxin injections might allow her to control a paintbrush. Her first attempt—a rose stem—was a success. “I could have cried,” she recalls. She now sees Jog for injections—about 15 per session—every three months and continues to take classes to this day. “It’s changed my life 100 per cent,” she says.

For her part, Wright has the following advice for others in her situation: “Don’t assume there isn’t a way around the tremor, because I think for most people, there are ways. It may just mean you can’t do something for as long. But it does take patience and being kind to yourself.”

Wright says she views ET the way Elizabeth Gilbert wrote about her critical inner voice in her memoir Big Magic: Creative Living Beyond Fear. “She says that you can’t leave it at home—it has to sit in the car, but it has to sit in the back seat and it doesn’t get to drive. When you first get diagnosed, it’s such a major focus, it does drive. So you say ‘Okay, how do I get this to sit in the back seat?’ You have think about all the things you’ve learned to do in your life, and then you’ll know you can learn to deal with this.”