Essential tremor is a movement disorder commonly affecting older adults. While it can occur in almost any part of the body, it usually affects the hands when trying to perform simple tasks. There can also be trembling of the head, voice or arms.
The specific cause of essential tremor is unknown. Some research suggests that the cerebellum, the part of the brain that controls muscles movements, does not work correctly in patients with essential tremor. Although it is sometimes confused with Parkinson's disease, essential tremor is defined as not being caused by other diseases or conditions.
For more information about essential tremor, or to schedule an appointment, call (206) 341-0420.
Risk Factors of Essential Tremor
It is possible to inherit essential tremor, an autosomal dominant disorder, from one parent who has a defective gene. That means the child of a parent with essential tremor has a 50 percent chance of inheriting the condition. The only other known risk factor for essential tremor is older age.
Symptoms of Essential Tremor
Tremors are frequently associated with Parkinson's disease, but there are key differences in the movements caused by each condition.
- Essential tremor begins in the hands and typically occurs when the hands are in use. Parkinson's tremors are most prominent when the hands are at rest.
- Essential tremor isn't associated with other health problems, while Parkinson's is linked to stooped posture, slowed movement and problems with walking.
- Typically the hands, head and voice are affected by essential tremor. Parkinson's does not usually affect the head or voice.
In addition, essential tremor can be aggravated by stress, fatigue, caffeine or extreme temperatures.
Diagnosing Essential Tremor
There is no specific test that confirms essential tremor. Making the diagnosis is often done by ruling out other conditions that could be causing symptoms. Some of the ways to do this include:
- A medical history — Taking a thorough medical history will help rule out other things that can cause tremors, such as smoking, alcohol withdrawal, excessive caffeine and the use of certain medications.
- A neurological exam — This physical exam will check things like reflexes, muscle strength, coordination and ability to feel certain sensations.
- Lab tests — Blood or urine may be tested for signs of thyroid disease, disruptions of certain hormone levels and other disorders.
- Performance tests — To evaluate the severity of the tremor, patients may perform some easy tasks, such as drinking from a glass, holding arms outstretched or writing.
Treatment of Essential Tremor
If symptoms of essential tremor are mild, no treatment may be necessary. However if tremors are interfering with performing daily activities it may be time to consider treatment options.
Medications may relieve essential tremor symptoms, but their effectiveness varies in individual patients, as does the severity of side effects. The medications used to treat essential tremor include:
- Beta blockers —These medications, known by the names propranolol (Inderal), atenolol, metoprolol and nadolol, are normally used to treat high blood pressure. They relieve tremors for some patients, but may not be appropriate for those who suffer from asthma, diabetes or certain heart problems.
- Anti-seizure drugs — For patients who don't respond to beta blockers, drugs which are used to treat epilepsy can reduce tremors by controlling the function of certain neurotransmitters. Side effects of these drugs can include fatigue and flu-like symptoms.
- Tranquilizers — Drugs with a sedative effect can help reduce tremors made worse by anxiety. Tranquilizing medication must be used with caution as it can be habit-forming. Side effects can include confusion and memory problems.
- Botox —Botox injections given at the site of tremor can reduce movement by weakening the muscles. Injections to the hand, however, can sometimes cause weakness in the fingers.
Specialized physical therapy services to help improve muscle control and coordination may help reduce the severity of tremor. Experienced physical and occupational therapists at Virginia Mason are available to work one-on-one with patients to address individual needs. Sometimes adaptive devices can be used to reduce tremor, such as wider writing implements.
When patients have disabling tremors that don't respond to medications, surgery may be an option.
The most common procedure is called deep brain stimulation (DBS), in which a neurosurgeon places electrodes in a particular part of the brain. The electrodes are connected by slender wires to a type of pacemaker device called an impulse generator which is implanted under the skin on the chest, below the collarbone. When the device is activated, a low-level electrical current is sent to the brain, blocking the impulses that cause tremors.
Like any other surgery, DBS has risks - such as stroke-like hemorrhaging in the brain. If infection occurs additional procedures may be needed. The unit beneath the skin of the chest contains a battery which must be surgically replaced every few years.