Tremors are rhythmic, involuntary muscular contractions characterized by oscillations (to-and-fro movements) of a part of the body. The most common of all involuntary movements, a tremor can affect various body parts such as the hands, head, facial structures, vocal cords, trunk and legs; most tremors, however, occur in the hands. Tremors often accompany neurological disorders associated with aging. Although the disorder is not life-threatening, it can be responsible for functional disability and social embarrassment.
There are many types of tremor and several ways in which tremors are classified. The most common classifications are by behavioral context and position. There are five such categories of tremor:
- Resting. Resting or static tremor occurs when the muscle is at rest, for example when the hands are lying on the lap. This tremor usually stops during deliberate movement and is often seen in patients with Parkinson’s disease. While commonly referred to as ‘pill rolling’ tremor of the hands, it can also affect the head, trunk, jaw and lips. It is often associated with other symptoms such as generalized slowness of motor activity, rigidity and postural instability.
- Postural. Postural tremor occurs when a patient attempts to maintain posture, such as holding the hands outstretched. Postural tremors include physiological tremor, essential tremor, tremor with basal ganglia disease (also seen in patients with Parkinson’s disease), cerebellar postural tremor, tremor with peripheral neuropathy, post-traumatic tremor, and alcoholic tremor.
- Kinetic. Kinetic or intention (action) tremor occurs during purposeful movement, for example during finger-to-nose testing.
- Task-specific. Task-specific tremor appears when performing goal-oriented tasks such as handwriting, speaking, or standing. This group consists primarily of writing tremor, vocal tremor, and orthostatic tremor.
- Hysterical. Hysterical tremor, or psychogenic tremor, occurs in both older and younger patients. The key feature of this tremor is that it dramatically lessens or disappears when the patient is distracted.
Drugs can also cause tremor. The list includes caffeine, fluoxetine (Prozac), haloperidol (Haldol), lithium, methylphenidate (Ritalin), metoclopramide (Reglan), phenylpropanolamine, pseudoephedrine, theophylline and valproic acid.
Essential tremor (ET) is the most common movement disorder. It is a syndrome characterized by a slowly progressive postural and/or kinetic tremor, usually affecting both upper extremities. Tremor amplitude slowly increases over time. Tremor frequency decreases with increasing age. An 8 to 12 cycle per second tremor is seen in young adults and a 6 to 8 cycle per second tremor is seen in the elderly. Essential tremor can develop with aging and has no known cause.
Alcohol intake temporarily reduces tremor amplitude in approximately 50-70% of cases and 50 to 60% have a family history of ET. If shaking or trembling has been present for two or more years and you do not have an endocrine or hormonal imbalance, you may have essential tremor or Parkinson disease.
Conventional medications used for ET include primidone and propranolol. These medications provide good benefit in reducing tremor amplitude in 75% of patients.
If shaking or trembling has been present for less than 2 years, it may be caused by temporary conditions such as:
- Increased anxiety or stress
- Certain medications
- Caffeine excess or caffeine withdrawal
- Nicotine or smoking excess nicotine withdrawal
- Alcohol excess or alcohol/drug withdrawal
Effective treatment of tremor requires distinguishing this type of movement disorder from other movement disorders. Without being seen and examined by a physician, the cause of your tremor may be difficult to determine.
Risk factors for Tremors
Hyperthyroidism
Hyperthyroidism can cause tremors. If this is the case, then the hyperthyroidism must be treated, not the symptom of tremors.
Hypoglycemia
Early symptoms of hypoglycemia, such as hand tremors, are similar to those which occur as the result of experiencing a sudden and violent fear.
Magnesium Requirement
Early symptoms of magnesium deficiency can include fatigue, anorexia, irritability, insomnia, and muscle tremors or twitching.
Recommendations for Tremors
Caffeine/Coffee Avoidance
Although commonly believed that caffeine can cause or make tremors worse in those who are sensitive, one small study showed that it not only fails to increase tremor size but also fails to increase perception of the tremor that already exists. [Tremor (1990), pp. 140-141]
Conventional Drugs / Information
The following drugs, medications, substances or toxins are some of the possible causes of Tremors as a symptom.
This list is incomplete and various other drugs or substances may cause your symptoms.
* Alcohol
* Amphetamine intoxication – in high doses.
* Ancobon
* Blanex
* Caffeine
* Certain asthma medications
* Certain epileptic medications
* Chlorofon-F
* Chlorphenesin Carbamate
* Cocaine
* Compazine
* Dilantin
* Enoxacin
* Enoxin
* Flexaphen
* Flucytosine
* Illicit drugs
* Lobac
* Maolate
* Miflex
* Mus-Lac
* Paraflex
* Parafon Forte DSC
* Pargen Fortified
* Polyflex
* Skelex
* Theophylline
* Valproic acid (Depakote)
Key
| Weak or unproven link |
| Strong or generally accepted link |
| May do some good |
| May have adverse consequences |
Glossary
Parkinson's Disease
A chronic, slowly-progressing disease of the nervous system characterized clinically by the combination of tremor, rigidity, extreme slowness of movement, and stooped posture. It is characterized pathologically by loss of dopamine in the substantia nigra.
Ganglion
A group of nerve cell bodies clustered together in a uniform mass outside of but often close to the brain or spinal chord. Nerves run to or from the ganglia in passage to or from the brain to specific sites on the body.
Neuropathy
A group of symptoms caused by abnormalities in motor or sensory nerves. Symptoms include tingling or numbness in hands or feet followed by gradual, progressive muscular weakness.
Psychogenic
Of a psychological origin.
Anxiety
Apprehension of danger, or dread, accompanied by nervous restlessness, tension, increased heart rate, and shortness of breath unrelated to a clearly identifiable stimulus.
Hyperthyroidism
An abnormal condition of the thyroid gland resulting in excessive secretion of thyroid hormones characterized by an increased metabolism and weight loss.
Hypoglycemia
A condition characterized by an abnormally low blood glucose level. Severe hypoglycemia is rare and dangerous. It can be caused by medications such as insulin (diabetics are prone to hypoglycemia), severe physical exhaustion, and some illnesses.
Magnesium
An essential mineral. The chief function of magnesium is to activate certain enzymes, especially those related to carbohydrate metabolism. Another role is to maintain the electrical potential across nerve and muscle membranes. It is essential for proper heartbeat and nerve transmission. Magnesium controls many cellular functions. It is involved in protein formation, DNA production and function and in the storage and release of energy in ATP. Magnesium is closely related to calcium and phosphorus in body function. The average adult body contains approximately one ounce of magnesium. It is the fifth mineral in abundance within the body--behind calcium, phosphorus, potassium and sodium. Although about 70 percent of the body's magnesium is contained in the teeth and bones, its most important functions are carried out by the remainder which is present in the cells of the soft tissues and in the fluid surrounding those cells.
Anorexia Nervosa
An eating disorder characterized by excess control - a morbid fear of obesity leads the sufferer to try and limit or reduce their weight by excessive dieting, exercising, vomiting, purging and use of diuretics. Sufferers are typically more than 15% below the average weight for their height/sex/age and typically have amenorrhea (if female) or low libido (if male). 1-2% of female teenagers are anorexic.