Tremors exist in many conditions. This article describes, the diagnosis, treatment and care of those with tremors. It is presented here for education and research. Tremor Marjorie M. Gillespie ABSTRACT: Tremor is a rhythmic, involuntary muscular contraction with consistency of rate, amplitude and pattern. It is the most common of all involuntary movements. Several systems for classifying tremor exist with the most frequent system classed according to behavioral context, ie, resting, postural and action. Clinical recognition of tremor type is extremely important as type determines prognosis, treatment, and need for genetic counseling. The most common forms are parkinsonian, physiological, cerebellar intention and essential tremor. Essential or hereditary tremor is the most common of all neurologic conditions with 3-4 million Americans affected. Nursing implications of caring for essential tremor patients are presented. J Neuroscience Nursing 1991;23(3):170-174. Questions or comments about this article may be directed to Marjorie M. Gillespie, RNC,BS,FNP at the National Institute of Health, 9000 Rockville Pike, Bldg. 10, Room 5c103, Bethesda, Maryland 20892. She is a research nurse. Copyright American Association of Neuroscience Nurses 0047-2603/91/2303-0170$1.25 Introduction Almost everyone experiences tremor at some point in life. It is a symptom which occurs as an exaggeration of normal physiologic mechanisms, in isolated monosymptomatic syndromes (essential tremor) or as a manifestation of a variety of neurologic diseases (the most common being Parkinson's disease).[1] This article describes and differentiates the major forms of tremor while focusing on the movement disorder known as essential or hereditary tremor. Tremor Characteristics Tremor is described as a rhythmic, involuntary muscle contraction with consistency of rate, amplitude and pattern. Most tremors result from regular, oscillatory contractions of agonistic and antagonistic muscles.[2] The involuntary oscillation is often continuous, but as with other movement disorders disappears with sleep. Two important characteristics of tremor are amplitude or size of tremor and frequency or rate of oscillation. Frequency is described in units called Hertz (Hz) with one Hertz equal to one cycle per second. With the use of computerized accelerometers, the physiologic characteristics of tremor can be precisely measured. This becomes important in a research setting, but in the average clinical setting they are generally estimated by observing the patient. Tremor characteristics can also be categorized by electromyographic (EMG) activity. Tremor can affect various body parts such as the hands, head, facial structures (chin, tongue, lips and ears), vocal cords, trunk and legs. Ninety-four percent of all tremors occur in the hands and may be unilateral or bilateral. Tremor has been classified in various ways, most commonly by behavioral context or position. Resting or static tremor occurs when the muscle is at rest such as when the hands are on the lap. Postural tremor occurs with attempting to maintain a posture, for example, with hands extended. Action or intention tremor occurs during purposeful movement. Tremor is a clinical sign which may be caused by numerous conditions (Table 1). Since postural end action tremors often occur together, they are combined here. There can be overlap with some conditions having tremor in more than one behavioral context. The tremor of Parkinson's disease is the most common resting tremor, while physiologic, exaggerated physiologic and essential are the most common postural action tremors. Cerebellar dysfunction is the primary cause of intention tremor. Occasionally essential tremor can occur at rest and parkinsonian tremor can be present during posture and intention, but this is usually seen in the more severe cases. Listed under exaggerated physiological tremor are various causal factors, all of which may increase other tremors as well. Variants of essential tremor include primary writing tremor (occurs only when writing) and orthostatic tremor (occurs in legs and trunk when standing, but not walking). In addition to distinguishing one tremor type from another, there are other abnormal involuntary movements which can sometimes resemble tremor. These include psychogenic or hysterical tremor, myoclonus, asterixis, spasms of dystonia, tics or chorea. Hysterical tremor is suspected when tremor is not rhythmic and changes or stops when the patient is distracted or asked to perform mental calculations. Myoclonus and asterixis are brief irregular jerky movements often caused by metabolic encephalopathies or a structural central nervous system lesion. Dystonic spasms, tics and chorea are other involuntary movements which can appear as tremors when they have a regular pattern. ----------------------------------------------------------- Table 1 Classification of Tremor Rest tremors Parkinson's disease Other parkinsonian syndromes (less commonly) Wilson's disease Essential tremor-only if severe Postural action tremors Physiological tremor Exaggerated physiological tremor (the following factors can also aggravate other forms of tremor) Stress, fatigue, anxiety, emotion Endocrine: hypoglycemia. thyrotoxicosis, pheochromocytoma, adrenocorticosteroids Drugs and toxins: beta agonists, dopamine agonists. amphetamines, lithium, tricyclic antidepressants, neuroleptics, theophylline, caffeine, valproic acid, alcohol withdrawal, mercury, lead arsenic and others Essential tremor (hereditary or sporadic) Other neurologic disorders Parkinson's disease (occasionally) Dystonia Peripheral neuropathy Cerebellar tremor Intention tremors Disease of cerebellum Multiple sclerosis, trauma, tumor, vascular, acquired hepatocerebral degeneration, drugs, toxins (eg, mercury) and others Adapted from Weiner WJ, Lang AE: Tremor. Page 245 in: Movement Disorders: A Comprehensive Survey. Futura Publishing. 1989. ----------------------------------------------------------- Tremor Types Tremor in Parkinson's disease is predominantly of a resting type although postural and intentional tremors can be present as well. Stressful situations may enhance the tremor. Resting tremor is somewhat of a misnomer because when patients are lying entirely relaxed, there is often no tremor. On the other hand, when they are relaxing with some tone (ie, holding hands on lap), an involuntary tremor of the hands and sometimes a similar tremor of the face, jaw, neck and legs appears. When the patient voluntarily uses the limb or changes its position, the tremor either entirely disappears or is markedly reduced.[3] After a while, sometimes only seconds, tremor returns when the limb is held in a new position. This tremor is often described as "pill rolling" because the thumb and finger movements give the appearance of rolling a small object. Parkinsonian tremor is present when walking, disappears with sleep, increases with stress and does not improve with alcohol. The frequency is characteristically 4-5 Hz but can be between 3 and 7Hz on occasions. In addition to tremor, parkinsonian patients usually have other basal ganglia symptoms of bradykinesia, rigidity and abnormalities of postural reflexes. The etiology of Parkinson's disease is unknown but many theories exist, including environmental and genetic causes. The pathophysiology of the parkinsonian tremor is thought to be substantia nigral degeneration with striatal dopamine deficiency.[3] Tremor at rest is more of an embarrassment than a handicap because it tends to disappear during purposeful action. However, some patients find tremor the most annoying symptom. Occasionally, resting tremor can produce functional disability such as difficulty dressing or eating. The tremor usually responds to dopaminergic or anticholinergic therapy, but can be the most difficult of the parkinsonian symptoms to treat. Physiological Tremor Everyone has a very low amplitude tremor that can occasionally be observed when the arms are extended and made even more obvious by placing a paper over the hands. This is a normal physiological phenomenon. During times of stress or for various other reasons, the tremor amplitude becomes enlarged and it is called exaggerated physiological tremor. The frequency is usually 8-12 Hz. The pathophysiology is thought to involve the sympathetic nervous system and in particular the noradrenergic system. Experiments have shown physiologic tremor can be increased by intravenous or intraarterial infusions of adrenalin and can he blocked by beta blockers. The best treatment for enhanced physiological tremor is to withdraw the precipitating cause if possible. If this is not possible, such as with a musician or actor with stage fright, treatment with low dose beta-adrenoreceptor antagonists may be useful. If this is a very rare event, an occasional dose of diazepam may be effective. Reassuring patients this is a normal response may help to set their minds, at ease. Cerebellar Intention Tremor Cerebellar intention tremor is an action tremor which occurs during goal-directed movement such as touching finger to nose. Tremor intensity increases as the target is approached. Intention tremor without postural tremor most frequently results from cerebellar dysfunction. It can be flapping or wing beating in character, resembling a bird flapping its wings. Cerebellar intention tremor can be extremely disabling with some patients unable to perform any purposeful actions. It is believed to be caused by a loss of modulatory control and feedback mechanisms in the cerebellar connections. Most cerebellar intention tremors are difficult to treat, such as those seen in patients with multiple sclerosis. There is no drug which significantly improves cerebellar intention tremor and although stereotactic thalamotomy may improve the tremor it does not improve function.[4] It is believed thalamotomy works by eliminating tremor from the contralateral side by interruption of circuits mediating input to the motor system from both basal ganglia and cerebellum.[3] Essential Tremor Essential tremor is the most common of all neurologic conditions. An estimated 2-4 million people in the United States have such tremor In approximately one-half of the cases the disease is familial. The disease is an autosomal dominant trait which means children of an affected individual will have a 50% chance of developing tremor. Essential tremor is characterized by the presence of a postural action tremor seen especially in the upper extremities without parkinsonian, cerebellar or other neurologic signs. When there is a family history, it is called familial tremor. When it is sporadic, it is called essential or benign, although it is often not benign for the patient. When it is sporadic without family history and onset over age 65 it is sometimes called senile tremor. For the purposes of this discussion it will be called essential tremor. Age of onset varies widely from childhood through adulthood with a mean age of 45 years. Onset is usually insidious beginning unilaterally with progressive involvement of upper extremities over 2-3 years, and sometimes lower extremities. Head and voice involvement are very common. The head tremor may be either affirmative (up and down in direction) or negative (side to side) and is often the least responsive to treatment. Speech has a characteristic quivering intonation which results in a fluctuating and rhythmical sound. The tremor time progression is variable. The tremor frequency is characteristically 4-9 Hz. The amplitude varies greatly and is influenced by the same factors as physiological tremor. Usually essential tremor is most evident with hands held in posture and during voluntary movement. When it is severe, it may persist even at rest making distinction from parkinsonian tremor difficult. It is estimated 10% of patients diagnosed with Parkinson's disease really have essential tremor[3] Other factors distinguishing essential tremor from parkinsonian tremor are the lack of accompanying symptoms of bradykinesia, rigidity and impaired reflexes, absence during walking, lack of response to conventional parkinsonian medication, response to alcohol and beta adrenoreceptor antagonists and positive family history. The etiology and pathophysiology of essential tremor are not known, but research has led to many theories implicating both the central and peripheral nervous systems. These include central oscillator defects, altered mechanical properties of the limb and alteration in motor neuron firing patterns. It is generally felt combination of both central and peripheral mechanisms are responsible for producing the tremor.[1] Neuropathologic studies of autopsy cases have found no significant pathology. No abnormalities in muscle spindle feedback or sensitivity of peripheral beta receptors has been detected. Yet unpublished preliminary results using positron emission tomography (PET) scanning show alteration of glucose metabolism) in the thalamus and inferior olives of essential tremor patients. The inferior olives are in the medulla and serve as input pathways to the cerebellum. The thalamus has long been suspected because stereotactic thalamotomy has been shown to stop tremor in severe refractive cases. The thalamus relays muscle control signals from the cerebellum and brainstem to the motor cortex and basal ganglia. The treatment of essential tremor depends upon degree of functional disability. This tremor is more disabling than parkinsonian tremor because it occurs with action. An estimated 15% of patients are forced to retire from their jobs and 3% are totally disabled.[1] When essential tremor is mild and causes no disability, medication may not be necessary and simply reassuring patients the tremor is not indicative of a serious neurologic disease may be sufficient. Drug treatments currently in use are unpredictable, often do not completely relieve the tremor and have unpleasant side effects. Some patients may require only periodic treatment and others continuous drug therapy. As a last resort, a few patients with very severe and disabling tremor (who do not respond to medical treatment) may be helped by thalamotomy. Sedatives and minor tranquilizers (such as diazepam) were the first drugs used to treat essential tremor. Many patients still rely on this treatment to quiet the tremor in specific situations. Alcohol in small quantities (a single cocktail or beer) will often suppress the tremor for 30-60 minutes. This response is sometimes used as a diagnostic measure.[1] Beta adrenoreceptor antagonists (beta blockers) provide the most effective treatment of essential tremor. This was discovered serendipitously when a physician noticed the effect of propranolol (Inderal) on a patient's tremor while treating him for atrial tachycardia. Propranolol is the most commonly used drug with an optimal dose of 120 mg producing improvement in 75% of patients with essential tremor.[3] Other beta blockers have also been shown to be effective in reducing tremor. Table 2 shows frequently used medications, contraindications, and adverse effects. In addition, primidone (Mysoline) has also been found effective in reducing amplitude of tremor in doses of 50-250 mg/day. Primidone is an antiepileptic drug with two active metabolites, phenyl-ethyl malonamide (PEMA) and phenobarbital. Its method of action is not known. ------------------------------------------------------------------------ Table 2 Essential Tremor Medications Medication Initial/Max Dose Contraindications Adverse effects 1. Beta adrenorecptor Heart block Bradycardia antagonists Sinus Bradycardia Hypotension propranolol (Inderal) 10/480 mg tid Bronchial asthma(except Depression nadolol (Corgard) 40/240 mg qd metoprolol) General slowing timolol (Blocadren) 10/60 mg bid Congestive Heart Fail Hallucinations metoprolol (Lopressor)50/200 mg bid Diabetes mellitus Insomnia atenolol (Tenormin) 50/200 mg qd Weight gain Impotency Nausea and vomiting 2. Primidone (Mysoline)25/250 mg qd Porphyria Ataxia Phenobarbital Vertigo hypersensitivity Nausea and vomiting Hyperirritability Impotency Anemia Depression Sedation -------------------------------------------------------------------------- Nursing Implications The nursing care of patients with essential tremor varies with severity of the tremor and disability. Some patients (especially mild or familial cases) accept the tremor, learn to live with it and may never seek medical attention. Other more severely affected individuals may require extensive treatment and nursing care. In assessing and caring for tremor patients, there are several important factors specific to this illness the neuroscience nurse should keep in mind. When eliciting a tremor history it is important to know the age at onset, pattern of onset and progression, factors improving or exacerbating tremor, any medications tried and the response, any history of other medications which may cause tremor, caffeine and alcohol intake, effect of alcohol on the tremor and family history. It is also important to question the patient about any history of bronchial asthma which be exacerbated by beta adrenoreceptor antagonists or any history of heart block, sinus bradycardia, congestive heart failure or diabetes which would be contraindications to beta adrenoreceptor antagonist therapy. In addition, the pulse rate should be greater than 50 with no lying or standing hypotension if beta adrenoreceptor antagonists are to be used. The physical assessment begins by carefully observing for resting tremor in the head, face, arms, hands, trunk, legs and feet while the patient is sitting quietly. Listen to voice quality for any vocal tremor. If present, the voice will have a quivering intonation. Then ask the patient to sit with hands on lap, arms outstretched and touch finger to nose. These positions will allow you to assess resting, postural and action tremors in arms. If resting tremor is present, you should also check for rigidity and have the patient touch each finger to thumb to assess rapid alternating movements. Writing is also important in assessing upper extremity tremor It is useful to have the patient draw a spiral and write his name. Unlike the micrographia of Parkinson's disease, the essential tremor patients writing is very large and shaky. Observe the lower extremities at rest, hold legs out, tap toes and run the heel down the shin. As the patient walks, observe the gait as well as tremor in hands and arm swing. Check balance by asking the patient to stand with feet together and gently pulling toward you. Unlike parkinsonian patients, essential tremor should not cause loss of balance, decreased arm swing or gait abnormalities. It is important in reporting the tremor to note the body part or parts involved, the positional context in which the tremor occurs, any additional neurologic findings and the approximate frequency and amplitude of the tremor (can be described as coarse, fine, rapid, slow, etc). If there is a family history, a family genogram would provide useful information. When planning nursing interventions or teaching the patient or caregiver, the nurse needs to assess ability to perform functions of daily living and provide assistance where needed. Many of these patients have difficulty with personal hygiene, dressing, writing and feeding. Ambulation, especially on stairs may also be a problem if the patient has head or lower extremity tremor or even upper extremity involvement making holding onto hand railings impossible. Nutritional status may be compromised due to difficulties eating. drinking and preparing food. These patients may have inadequate caloric intake and should have their weight monitored regularly. They may require food supplements. In addition to functional disabilities, the social and psychological impact of the disease must also be assessed. Many of these patients tend to withdraw from social situations, especially those requiring eating and drinking. Depression is common due to the altered physical appearance and loss of function. Family relationships may be affected because of the functional disabilities which may cause role reversals or the need to relinquish duties previously performed. Teaching is a very important part of the nursing care. It should include education about the illness, practical solutions to annoying disabilities and medication information. Some practical suggestions include velcro closure on clothes instead of buttons and zippers, use of special eating utensils, increased use of finger foods and straws. Many banks will now approve the use of signature stamps for patients who cannot write their names, a very common problem. Caregivers should also be taught to let patients care for themselves as much as possible without becoming frustrated. This is often very difficult. Medication teaching should be frequently reinforced. Patients receiving any of the beta adrenoreceptor antagonists should be aware of adverse effects and taught to take their pulse daily (at least in the beginning stages of treatment). They should also have frequent lying and standing blood pressure checks. These drugs should not be stopped abruptly, because of possible rebound cardiac effects. When primidone is used, patients should be instructed about possible adverse effects and the fact this drug should also be tapered to avoid rebound tremor phenomenon. It should be started at very low doses and gradually increased since there is a high initial incidence of adverse effects. Patients should be warned of the potential for alcohol or sedative addiction if they frequently use these methods to control the tremor. The patient and family should be educated about the disease itself. One good source of information is the International Tremor Foundation in Chicago.* The foundation supplies printed information, patient and family services, newsletters and educational symposia for patients and families. Depending upon the individual's life situation, some patients may benefit from referrals to occupational therapy as well as genetic and vocational counseling. Occupational therapy can often provide useful advice and tools to help with activities of daily living. Genetic counseling is especially important for young patients who may worry about passing the tremor to future generations. patients with a positive family history should know their children will have a 50% chance of inheriting the tremor. * International Tremor Foundation, 360 West Superior Street, Chicago, Illinois 60610, 312-664-2344. Vocational and educational counseling may include direction of young patients or children with strong family histories to careers which do not require fine motor skills or public appearances. Career changes may be necessary for those who cannot function in their current occupation. Summary Essential tremor, although not life threatening as many neurologic disorders are, can none the less be very disabling for affected individuals. It is by no means a benign tremor as it is often termed. However, effective treatment is available for most tremor patients. Neuroscience nurses can make significant contributions to the assessment, treatment and day to day living of tremor patients. Acknowledgment The author wishes to thank Mark Hallett, MD and Thomas Chase, MD for their assistance and ongoing support and to express deep gratitude to Donna Thomas for her assistance. References 1. Weiner WJ. Lang AE: Tremor. Pages 221-249 in: Movement Disorders: A comprehensive Survey, Futura Publishing,1989 2. Malasanos LJ: Tremors; Associations and assessment. J Neurosurg Nurs 1982; 14(6):290-294. 3. Young RR: Tremor. Pages 435-451 in: Diseases of the Nervous System: Clinical Neurobiology, Asbury AK. McKhann GM, McDonald WI (editors). WB Sanders, 1986. 4. Hallett M; Differential diagnosis of tremor. Pages 553-595 in: Handbook of Clinical Neurology, Vikin PJ, Bruyn GW. KIawans HL (editors). Elsevier Science Publishers, 1989. 5. Findlay LJ, Koller WC; Essential tremor: A review, Neurology 1987; 37:1194-1197. 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