Essential tremor, the most common form of abnormal tremor, is a nerve disorder in which tremors or shakes occur without an identifiable cause. The tremor resembles an exaggerated shaking and occurs when a person is moving or trying to move, but not while they are at rest. The shaking may first become noticeable while engaging in normal activities such as pouring a cup of coffee or using a tool, such as a screwdriver.
Some degree of tremor during movements is normal for everyone and this shaking primarily involves the hands. Stress, fatigue, anger, fear, caffeine, and cigarettes may temporarily worsen this type of normal tremor to the point that it becomes visible to the naked eye.
For an appointment, phone 314-362-6908.
Patient records are required prior to the appointment, and can be faxed to (314) 747-3258.
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| Essential Tremor |
Treatment Specialists
Joel Perlmutter, M.D., Movement Disorder Section Chief
Susan Criswell, M.D.
Paul Kotzbauer, M.D., Ph.D.
Brad Racette, M.D.
Samer Tabbal, M.D.
Commonly Asked Questions
Essential tremor can occur at any age but is most common in people older than 65. It is a relatively benign condition, affecting movement or voice quality, but with no other effects. It involves a rhythmic, moderately rapid tremor of voluntary muscles.
Purposeful movements may make the tremor worse, while avoiding hand movements may suppress the tremor completely. There may be difficulty holding or using small objects (such as silverware or writing utensils).
Over time, the tremor may affect the hands, arms, head, voice box, eyelids, or other muscles. An essential tremor rarely involves the legs or feet. It may start in one body part but can progress to include other parts.
Symptoms
May be occasional (sporadic), temporary or occurring intermittently.
Occur at a rate of about 6 to 10 oscillations per second.
May affect the head, hands, arms, eyelids, voice.
Less commonly affect the legs and feet.
May not affect both sides of the body equally.
Worsen with voluntary movement or emotional stress.
Disappear during sleep.
Typically improve with alcohol.
Essential tremor is worsened by the same factors that enhance normal tremors. Although the cause is unknown, new research shows that one part of the brain, called the cerebellum, does not appear to function properly in patients with essential tremor.
The cerebellum is the part of the brain that coordinates muscle movements and provides accuracy and harmony to voluntary movement. Nevertheless, no brain lesions have been identified in patients with this form of tremor.
There is evidence of several different types of essential tremor (such as young-onset essential tremor or essential tremor with head tremor). The types of tremor differ in their response to treatment.
Testing and Diagnosis
There is not a specific, diagnostic laboratory test for essential tremor. Therefore the experience and specialized training of the evaluating physician plays an important part in establishing an accurate diagnosis. The patient's history and an extensive physical examination revealing tremor on voluntary movement, and no other abnormalities, are the basis for diagnosis.
However, some testing may rule out other causes of tremors, such as excessive caffeine or tobacco use, alcohol withdrawal, use of certain medications (some asthma drugs, some antidepressants, lithium, some anti-seizure drugs), hyperthyroidism, pheochromocytoma, Wilson's disease (a rare condition in which copper accumulates in the brain and liver), and other disorders.
Family History of Tremors
If an essential tremor occurs in more than one member of a family, it is called a familial tremor. It appears that essential tremor has some genetic basis, not only because of the hereditary pattern observed in some families, but also because an identical twin (who shares the same genes) of a person with essential tremor is twice as likely as a fraternal twin (who has different genes) to have essential tremor.
Since some identical twins do not share this condition, environmental factors must play a role as well.
Treatment and Medications
Treatment may not be necessary unless tremors interfere with the patient's ability to perform daily activities or if they are considered embarrassing to the patient.
Medications result in symptom improvement in most patients. Two medications are considered the first line of therapy: propranolol and primidone.
Propranolol blocks the action of stimulant substances called neurotransmitters, particularly compounds related to adrenaline.
Primidone is an anti-seizure medication, which also modulates the function of some neurotransmitters. Both medications are considered equally efficacious.
However, both have significant side effects. The side effects of propanolol include:
Fatigue
Shortness of breath (people with asthma should not use this drug)
Slowing of the heart rhythm
Nose stuffiness
The problems associated with primidone include:
Drowsiness
Difficulty concentrating
Nausea
Poor gait (walking style), balance, and coordination
Other medications that may reduce tremors include anti-seizure drugs such as gabapentin, mild tranquilizers such as alprazolam or clonazepam, and calcium-channel blockers (flunarizine and nimodipine).
Recently, intramuscular injections of botulinum toxin in the hand have been used to reduce tremor by weakening local muscles. Intramuscular botulinum toxin is mostly useful for cervical tremor (neck) and possibly voice. The benefit for limb tremor is much less clear.
If the tremor is severe enough to interfer with an individual's ability to function, surgery may also be an option to alleviate the tremor. Such surgery usually involves implanting a device called deep brain stimulator in a specific area of the brain called the basal ganglia.
Caffeine, found in substances such as coffee and soda, and other stimulants should be avoided. Alcoholic beverages in small quantities may markedly decrease tremors but can lead to alcohol dependence if used in excess. The mechanism by which alcohol decreases an essential tremor is unknown.
For more information on referring a patient or to find out how to make an appointment please call 314-362-6908. Patients records should be mailed or faxed to the office.