Post written by Dr. Serena Hung
A month or so ago, I gave a talk at the Community Education center about essential tremor. I didn’t anticipate such an enthusiastic response. I know we have been focusing on Parkinson’s disease (PD) on this blog, but I figure, why not talk about essential tremor? After all, it is the most common movement disorder.
Essential tremor (ET) is the name given to this disorder which consists of only tremor and not much else. It doesn’t mean that it’s not disabling because it can be. I’ll get to that later. Other names for this disorder include: benign essential tremor and familial tremor. It can start at any age and the youngest I have read about was a baby of 2 months. About 60 percent or so of the patients have a family history, but that also means almost half won’t have any family members with this disorder. It is definitely more common in people who are older. Frequently, patients would report that alcohol makes the tremors much better (but that doesn’t mean that we encourage alcohol abuse). The most common body parts involved are the hands, but the tremors can involve any part of the body. Most of the time, the tremors involve both sides symmetrically (unlike PD where symptoms on one side may be much more prominent than the other). Another difference between ET and PD is that the tremor in ET happens more frequently with action and with posture (e.g., when people hold their arms up in front of them) whereas in PD, the tremor frequently happens when people are at rest.
Again, the only symptom in this disorder is the tremor. That’s also different from PD where there are other features such as slowness in movement, stiffness and balance problems. Over time, the tremors tend to get worse. Sometimes it can be quite disruptive. Patients report trouble holding a glass of water, writing, cutting food, eating soup, putting on make up and shaving, etc. In more severe cases, patients may require a lot of help with daily activities.
Treatment options most commonly include oral medications. The two groups of medications we call first-line agents (because we know the most about them and they seem to be the most effective) are beta-blockers, such as propranolol or Inderal, metoprolol, and anti-seizure medication, such as primidone or mysoline. Both work about 50 to 60 percent of the time. The trick is to gradually increase the dose so that patients may have a better chance of tolerating these medications. The limiting factor is side effects. How we titrate the medications are based on symptoms. If a patient is not having side effects, we can continue to increase the dose until control of tremor is satisfactory. This is a trial-and-error approach and sometimes, it takes a little while and a few trials to find the best combination of drugs in the appropriate doses. If the first line agents do not work well enough, we can use other anti-seizure medications such as clonazepam, topirimate and gabapentin. There are various levels of evidence proving that they are or are not effective, but if the first two agents do not work, personally I think the rest are worth a shot.
If medications do not work well enough, sometimes we would proceed to think about brain surgery called deep brain stimulation. Simply put, this is a surgery where holes are drilled into the brain and very thin electrodes are placed in very specific parts of the brain. The other end of the electrode is hooked up to a wire which subsequently is connected to a battery that is placed underneath the skin below the collar bone. A small current is sent through the wire into the brain at all hours of the day to try and fix the abnormal rhythm generated by brain cells. In appropriately selected patients, this surgery can work well up to 90 percent of the time. Of course, brain surgery carries real risks which include: bleeding, infection, trouble with talking, memory and balance. It is a fine act of balancing the risks and the benefits.
Unfortunately for this disorder, we do not yet have a cure. However, there are a lot of treatment options. The first step to get help is to see a specialist who is familiar with this condition and all the treatment options. We are beginning an Essential Tremor Support Group in August. See our support group flyer
. Excellent information is available through the International Essential Tremor Foundation: http://www.essentialtremor.org