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By X. Rufus. Oregon Health Sciences University. 2019.

The electrolyte disturbances in most cases are not severe enough to explain the encephalopathy; other pathologic mechanisms such as cerebral hypoperfusion or water intoxication have been suggested discount lamictal 100mg amex. Unlike many metabolic encephalopathies purchase lamictal 200 mg visa, adrenocortical insufficiency is associated with decreased muscle tone and deep tendon reflexes generic lamictal 25 mg fast delivery. Seizures and papilledema may appear when the patient has a profound adrenocorticotropic hormone deficiency and coma. The neurologic picture does not clear until cortisone replacement is given along with treatment of the electrolyte imbalances. These patients are also particularly sensitive to sedative medications and may lapse into coma with small doses of narcotics or barbiturates [45]. Excess steroids produce different forms of encephalopathy depending on whether the source is endogenous or exogenous. In Cushing’s disease, psychomotor depression and lethargy are the norm, whereas high doses of prednisone usually cause elation, delirium, or frank psychosis [46]. The behavioral changes are key to recognizing this problem because there are no specific metabolic markers [47]. Treatment consists of withdrawal of the steroids and sometimes temporary use of tranquilizers or lithium for the psychiatric features as well. It may be confused initially with other causes of hypotension, hypoventilation, and hyponatremia, such as septic shock, brainstem infarcts, or an overdose of sedatives. The diagnosis should be considered in any patient with hypothermia, pretibial edema, pseudomyotonic stretch reflexes (e. The constitutional symptoms may take several weeks to respond, but the neurologic picture clears promptly with proper treatment. Another form of hypothyroid-associated encephalopathy is seen in Hashimoto’s thyroiditis with a subacute subtle change in personality, memory deficits, and cerebellar ataxia accompanied by cerebellar atrophy on imaging studies. Elderly patients are more likely to appear depressed or stuporous and without evidence of hypermetabolism [49]. The key to the diagnosis in such cases is evidence of recent weight loss and atrial fibrillation, often with congestive heart failure and a proximal myopathy. In a thyroid storm, the patient with indolent hyperthyroidism may be stressed by an infection or surgery and responds with marked signs of hypermetabolism: tachycardia, fever, profuse sweating, and pulmonary or congestive heart failure. Neurologically, the individual becomes acutely agitated and delirious and then progresses into a stupor [50]. The subacute picture that precedes this is one of mild irritability, nervousness, tremors, and hyperactivity, and is often misconstrued as an affective disorder rather than endocrine in origin. Ophthalmologic signs such as proptosis, chemosis, and periorbital edema are useful in identifying this form of thyrotoxicosis. Therapy for thyrotoxic encephalopathy is aimed at ablation of the gland, but supportive care may require β-blockers, digoxin, diuretics, and sometimes dexamethasone and sedatives for the associated hypermetabolic state. Encephalopathy is also seen in disorders of the pituitary gland and parathyroid gland, although rarely as a primary process. Hypopituitarism may result from radiation or surgery to the area of the sella and can present as a chronic encephalopathy with features of thyroid or adrenal insufficiency, or both. An acute coma due to infarction or hemorrhage of the pituitary gland, known as pituitary apoplexy, can be seen in acromegalics with large adenomas or in patients with postpartum hemorrhage and hypotension (Sheehan’s syndrome) [51]. Subarachnoid blood and ocular abnormalities plus signs of increased intracranial pressure help to identify the pituitary lesion in such cases. Encephalopathy from hyperpituitarism reflects the specific neurohumoral substance that is being released in excess and does not represent a unique syndrome. A serum calcium more than 12 mg per dL and elevated parathormone levels are important diagnostic findings. Occasionally, psychiatric symptoms predominate, starting with delirium and psychosis, or obtundation and coma when the serum calcium exceeds 15 mg per dL. Hypercalcemia caused by metastatic bone lesions, paraneoplastic parathormone-like substances, sarcoidosis, primary bone diseases, and renal failure are associated with a subacute or chronic encephalopathy similar to hyperparathyroidism. Treatment in these cases must be directed toward the underlying disease rather than addressing the hypercalcemia alone. This is not always possible, because the glands often are ectopic and may escape discovery on selective angiography or exploratory surgery. Hypocalcemia due to hypoparathyroidism produces an encephalopathy that parallels the depression of serum calcium levels. The motor signs of hypocalcemia, that is, tetany or neuromuscular irritability, should make one suspicious of a metabolic disturbance [39]. Another diagnostic dilemma is the occasional presentation of hypocalcemia with papilledema and headache. Furthermore, the presence of cataracts and mental dullness in a previously normal individual should lead one to check the serum calcium and parathormone levels. The mechanism by which hypocalcemia and hypoparathyroidism produce these varied neurologic symptoms is not known. Supplementation with vitamin D and calcitriol enhances the absorption and utilization of oral calcium. Other Causes of Encephalopathy the list of causes of diffuse or metabolic encephalopathies is so lengthy that the problem of diagnosis must be resolved by a process of elimination. Drugs and toxins lead all other possible causes, with a frequency of approximately 50% (see Chapters 97 through 126). Hepatic, renal, or pulmonary failure is causative in another 12% and endocrine or electrolyte disturbances in approximately 8%. Other less common etiologies include thiamine deficiency (Wernicke’s encephalopathy), cardiac bypass surgery, subacute bacterial endocarditis, and hyperthermia. All of these disorders produce microembolic or microhemorrhagic/petechial lesions in specific areas of the brain. The hallmark of this entity is a striking impairment of ocular movements, causing an external ophthalmoplegia, nystagmus, and diminished oculocephalic responses. If untreated, the patient may lapse into a coma due to autonomic failure with accompanying shock and hypothermia and often death. Repeated or untreated episodes of Wernicke’s disease may result in a chronic Korsakoff’s psychosis with profound memory impairment [49]. Hyperthermia due to heat stroke also has a characteristic clinical setting—young individuals experiencing excessive sweating caused by overactivity and elderly people receiving anticholinergics who are exposed to a hot environment [51]. The patient may become agitated and confused with intermittent generalized seizures or may immediately lapse into a coma as if due to a stroke.

Tus purchase lamictal 200 mg free shipping, even in patients with good compliance purchase lamictal 100 mg overnight delivery, a greater reduction in follicular activity can reduce the possibility of breakthrough ovulations and contraceptive failure 25 mg lamictal with visa. This would be difcult and expensive to document because it would require a clinical trial with a very large num- ber of patients. A regimen is available that supplies a package containing the number of pills required for 84 days of daily administration, a reduction of men- strual frequency to 4 per year. Eforts to improve steroid contracep- tion are now focusing on maximizing adherence to treatment and minimizing pregnancies from contraceptive failures. The 24-day regimen ofers clinicians and patients the important advantage of reduced bleeding and the possible advantage of greater efcacy because of better compliance as well as a reduc- tion in ovarian activity. Continuous Dosing More and more women are embracing the idea that fewer menstrual periods provide a welcome relief from bleeding and menstrual symptoms. Clini- cians for years have prescribed unlimited daily oral contraceptives to treat conditions such as endometriosis, bleeding disorders, menstrual seizures, and menstrual migraine headaches, even to avoid bleeding in athletes and busy individuals. Many women do not require the periodic experience of vaginal bleeding to assure themselves they are not pregnant. And of course, modern society is long past the notion that menstrual bleeding is a cleans- ing event, a detoxifcation. Any com- bination oral contraceptive can be used on a daily basis; even the lowest estrogen dose formulations provide excellent bleeding and side efect pro- fles in a continuous regimen. Continuous dosing can also be achieved with the contraceptive vaginal ring and the contraceptive patch. The return of ovula- tion and achievement of pregnancy are not delayed afer discontinuation of continuous dosing. Tese products are less expensive, marketed by pharmaceutical companies afer patent expiration of the original drug. Generic oral contraceptives need only meet the test of bioequivalence; studies to demonstrate efcacy, side efects, and safety are not required. Meeting the test of bioequivalence requires demonstration in a small number of subjects that absorption, con- centrations, and time curves are comparable to the reference drug. The generic product will be approved if the bioequivalence testing ranges from 80% to 125% of the values for the reference drug (diferences no >20% lower or 25% higher). Approved, patented products must not vary more than ±10%; therefore, a generic oral contraceptive could contain only 70% of the standard dose. However, we should hasten to point out that there has been no evi- dence or even anecdotal suggestions that generic oral contraceptives have reduced efcacy or cause more side efects such as breakthrough bleeding. Off-Label Uses of Steroid Contraception Steroid contraception is ofen used for noncontraceptive purposes. The list is long, including treatment of acne, dysmenorrhea, heavy or irregular vaginal bleeding, menses-associated mood changes, the polycystic ovary syndrome, and endometriosis. For most of the oral contraceptive’s 50-year history, all of these have been “of-label” applications, but recently pharma- ceutical companies have conducted trials to obtain label “indications” to use in advertising directed to both clinicians and consumers. Because these trials usually compare a product to a placebo or just to another contraceptive formulation, the studies do not reveal whether the product receiving approval for an “indication” is really better than others. Prices and formularies restrict patient access to the full range of oral contraceptives96; therefore, clinicians must make judgments by comparing fndings from unrelated studies and experience to decide which A Clinical Guide for Contraception pill to use for a specifc purpose in an individual patient. In most cases, as we will emphasize, it is unlikely that there are major diferences among similar products. Potency For many years, clinicians, scientists, medical writers, and even the phar- maceutical industry attempted to assign potency values to the various progestational components of oral contraceptives. In the past, animal assays, such as the Clauberg test (endometrial change in the rabbit) and the rat ventral prostate assay, were used to determine progestin potency. Although these were considered acceptable methods at the time, a better understanding of steroid hor- mone action and metabolism and a recognition that animal and human responses difer have led to greater reliance on data collected from human studies. Historically, this has been a confusing issue because publications and experts used potency ranking to provide clinical advice. Oral contraceptive progestin potency is no longer a consideration when it comes to prescribing oral contraception, because the potency of the various progestins has been accounted for by appropri- ate adjustments of dose. In other words, the biologic efect (in this case the clinical efect) of the various progestational components in current low-dose oral contraceptives is approximately the same. The potency of a drug does not determine its efcacy or safety, only the amount of a drug required to achieve an efect. Clinical advice based on potency ranking is an artifcial exercise that has not stood the test of time. Tere is no clinical evidence that a particu- lar progestin is better or worse in terms of particular side efects or clinical responses. Tus, oral contraceptives should be judged by their clinical char- acteristics: efcacy, side efects, risks, and benefts. Our progress in lowering the doses of the steroids contained in oral contraceptives has yielded prod- ucts with little serious diferences. Mechanism of Action The combination pill, consisting of estrogen and progestin components, prevents ovulation by inhibiting gonadotropin secretion via an efect on both pituitary and hypothalamic centers. It provides stability to the endometrium so that irregular shedding and unwanted breakthrough bleeding can be minimized; and the presence of estrogen is required to potentiate the action of the progestational agents. The mechanism for this action is probably estrogen’s efect in increasing the con- centration of intracellular progestational receptors. Terefore, a minimal pharmacologic level of estrogen is necessary to maintain the efcacy of the combination pill. Because the efect of a progestational agent will always take precedence over estrogen (unless the dose of estrogen is increased many, many fold), the endometrium, cervical mucus, and perhaps tubal function refect pro- gestational stimulation. The progestin in the combination pill produces an endometrium that is not receptive to ovum implantation, a decidualized bed with exhausted and atrophied glands. It is possible that progestational infuences on secretion and peristalsis within the fallopian tubes provide additional contraceptive efects. Even if there is some ovarian follicular activity (espe- cially with the lowest dose products), these actions serve to ensure good contraceptive efcacy.

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A number of studies have demonstrated correlations between elevations of troponin and early graft failure [19 generic lamictal 50mg amex,20] order 100 mg lamictal overnight delivery. These data should be analyzed closely with the patient’s hemodynamic function and echocardiographic findings buy lamictal 50mg fast delivery. A transplant center may request that a second echocardiogram be performed if the first echocardiogram was performed shortly after herniation. Catecholamine-induced left ventricular dysfunction can improve significantly in a short period of time and not preclude excellent short-and long-term outcomes. One must also take into consideration the ischemic time that will be incurred with procurement and travel time. The majority of transplant centers are willing to accept an ischemic time up to 4 hours for adult donors but no more than 6 hours. The advent of ex vivo perfusion offers the possibility of warm perfused preservation of thoracic organ grafts. Ex vivo perfusion uses warm oxygenated blood and an extracorporeal pump to perfuse organs during transport and preservation. This technology offers the potential for longer extracorporeal periods and possibly altering the paradigm of cold preservation. During this inspection, one should palpate the coronary arteries to discern any calcifications and also palpate the aortic root for calcifications. External evaluation of the heart is not a reliable evaluation of function unless there is something grossly abnormal, such as severe bruising from a myocardial contusion or a dilated right ventricle. Once it is determined that the heart is appropriate for transplantation and all of the other organ teams are ready, the donor is heparinized and cannulated. If the lungs are being harvested, a pulmonary artery cannula will be placed in the main pulmonary artery. The heart is vented via the left atrial appendage, excised, and is then submerged in ice slush saline, packaged sterilely, and placed in a cooler for rapid transport to the center caring for the recipient. Recipient Operation Once the recipient is prepared and draped, the median sternotomy incision is made and the heart is dissected free of any adhesions, and then cardiopulmonary bypass is established. The recipient is placed on total cardiopulmonary bypass, before the cross-clamp is applied to the aorta, and the heart is excised along the atrioventricular groove. The anastomoses are performed in the following order: left atrial, inferior vena caval, pulmonary arterial, aortic, and superior vena caval [22]. Isoproterenol is used to maintain an appropriate heart rate if bradycardia is a problem or the heart is paced. The pulmonary artery catheter should be floated through the new heart so that pulmonary artery pressures can be monitored closely and any signs of right heart failure can be detected early. Postoperative Care the immediate postoperative management of a heart transplant recipient is by and large not unlike that of other cardiac surgery patients. A pulmonary artery catheter is used with continuous mixed venous oximetry and preload is optimized with either volume or diuretic. Usually patients come out of the operating room on Isuprel (isoproterenol) to stimulate the heart rate and/or the temporary pacemaker set to a back-up rate of 90 to 100 bpm or higher. After the first several days, the heart rate is allowed to drift to its baseline as the cardiac index allows. Occasionally, patients exhibit a distributive shock immediately postoperatively characterized by low systemic vascular resistance and vasopressin or neosynephrine is used to treat it. The ideal patient who is hemodynamically stable and has no signs of surgical bleeding can be extubated within a few hours. Sometimes, patients with right ventricular failure owing to pulmonary hypertension need to be treated with inhaled nitric oxide or epoprostenol (Flolan) and thus mechanical ventilation is continued. These patients have a tendency to bleed more postoperatively and one should keep a low threshold to return to the operating room for exploration if bleeding persists. Serious ventricular failure after cardiac transplantation is unusual and can be related to poor donor-organ selection, poor graft preservation, a long ischemia time, or rejection owing to the presence of preformed antibodies. Early rejection is often heralded by atrial fibrillation and the manifestation of arrhythmias should prompt an immediate workup and treatment. Plasmapheresis can be very effective in removing preformed antibodies responsible for humoral rejection. Inotropes and pulmonary vasodilators are also often used to manage the right heart failure that frequently accompanies rejection, with the addition of an intra-aortic balloon pump if necessary. Immunosuppression Balanced triple-drug immunosuppression is still the most commonly used protocol, consisting of calcineurin inhibitors, an antimetabolite, and corticosteroids (Table 60. Cyclosporine is largely recognized as the agent that moved cardiac transplant from a feasible medical option to an acceptable medical treatment. The physicians at Stanford University performed a randomized controlled trial in cardiac transplant patients that demonstrated that cyclosporine immunosuppression improved 1- year survival to 80% from the mid-50% range [23]. Patients receiving either cyclosporine or tacrolimus have similar survival rates in heart transplantation, both long and short term [24–26]. In addition, median serum creatinine and triglyceride levels were lowest in the tacrolimus and mycophenolate group. Cyclosporine is well known to also cause postoperative hypertension, nephrotoxicity, hepatotoxicity, gingival hyperplasia, hypertrichosis, and tremor. Tacrolimus also causes nephrotoxicity and many of the other side effects of cyclosporine but to a lesser extent, in particular, posttransplant hypertension and gingival hyperplasia. A review article from Stanford confirmed improved survival with the use of tacrolimus and improved postoperative infection prophylaxis [28]. There are multiple regimens for early corticosteroid reduction to avoid the serious associated side effects including systemic hypertension, obesity, osteoporosis, and glucose intolerance. In spite of the negative side effects, in 2004, approximately 75% of patients were still taking corticosteroids 1 year following their transplants [30]. Results from the group at Stanford confirm that therapy with tacrolimus and limited corticosteroid are linked to improved recipient and graft survival [28]. They have shown promise in significantly reducing the severity of cardiac allograft vasculopathy, the main threat of long-term graft survival. But they remain only an adjunct to the calcineurin inhibitors that are still more effective in preventing acute rejection.

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Concern regarding the adequacy of fetal oxygen supply is further reduced if a normal maternal PaO of 902 mm Hg or greater is achieved without too great a risk of maternal barotrauma or oxygen toxicity [5] 100 mg lamictal sale. The increased frequency of thromboembolic disease in pregnancy may be attributable to a hypercoagulable state along with venous stasis purchase 50 mg lamictal visa. The activity of plasminogen activator inhibitor types 1 and 2 generic lamictal 50 mg overnight delivery, which are inhibitors of fibrinolysis, also increases [8]. Venous stasis may occur because of a hormonally induced dilation of capacitance veins and uterine pressure on the inferior vena cava [9]. The usefulness of the serum D-dimer levels in diagnosing thromboembolic disease in pregnancy is limited because D- dimer levels are increased during normal pregnancy, with levels increasing as gestation progresses and peaking at delivery and in the early postpartum period [10]. Fetal exposure to radiation during imaging studies can be minimized by abdominal shielding and using brachial access. Suggested risk factors include older maternal age (mean, 32 years), multiparity (88% of cases), amniotomy, cesarean section, abruptio placentae, insertion of intrauterine fetal or pressure monitoring devices, and term pregnancy in the presence of an intrauterine device [16]. Amniotic fluid enters the maternal circulation through one of three ports: endocervical veins, uterine tears (small tears may occur in the lower uterine segment as a part of normal labor), and uterine injury secondary to iatrogenic manipulation, such as cesarean section, insertion of monitoring devices, or membrane rupture. Elevation of the pulmonary capillary wedge pressure and reduction in cardiac output and left ventricular stroke work index have been documented [17]. Acute left heart failure contributes to the development of pulmonary edema, which leads to dyspnea, tachypnea, and cyanosis. Other factors potentially contributing to pulmonary edema include cardiodepressive humoral factors from the amniotic fluid, vigorous fluid resuscitation, increased permeability pulmonary edema, and hypoxia causing myocardial ischemia [18]. Other complications, such as acute renal failure and signs of central nervous system injury, are probably secondary to hypotension and hypoxemia. Prodromal symptoms, such as vomiting and shivering, are nonspecific and frequently associated with otherwise uneventful deliveries. Cardiac echo may show decreased left ventricular function or echodense material in the right atrium or right ventricular outflow tract [17]. The perinatal mortality from national registries ranges from 7% to 38%, with up to 50% of the surviving children experiencing permanent neurologic injury [18]. Venous Air Embolism Venous air embolism is the entrainment of air into the venous system where it then travels to the right ventricle and the pulmonary circulation. Venous air embolism has been described during normal labor, delivery of patients with placenta previa, criminal abortions using air, and insufflation of the vagina during gynecologic procedures. Presumably, the subplacental venous sinuses are the sites of air entry when antepartum or peripartum air embolism occurs. The clinical presentation of venous air embolism varies according to the volume and speed of air entrainment into the vascular circulation. The classic sign associated with air embolism is the mill wheel murmur, which is audible over the precordium [19]; a drum-like or bubbling sound may also be heard. Electrocardiographic evidence of ischemia, right heart strain, and arrhythmias have been described, and metabolic acidosis, presumably caused by lactic acid production, may be present [19] (see Chapter 198). Neurologic symptoms develop as a consequence of cerebral hypoperfusion from cardiovascular collapse and from paradoxic embolization if a patent foramen ovale is present [19]. Based on data from surgical procedures, precordial Doppler ultrasound can be used for surveillance of air embolism by detection of alterations in the ultrasonic pattern caused by the embolism and is able to detect as little as 0. The volume of air that is likely to be lethal seems to vary with the rate of infusion and patient position. A bolus of 200 to 300 mL of air or 3 to 5 mL per kg has been reported to be the lethal dose in humans [19,20]. It is thought that entrapment of air bubbles in the pulmonary circulation leads to activation of complement, neutrophils, and platelets, resulting in mediator release, protease activation, oxidant stress, and endothelial injury [19]. Aspiration of Gastric Contents Aspiration of acidic gastric contents into the tracheobronchial tree was first described in 1946 by Mendelson [21] in women during labor and delivery. Maternal deaths from pulmonary aspiration have been steadily declining as a result of changing anesthesia practices, including a shift to regional anesthesia from general anesthesia for delivery [22]. At term, several factors contribute to an increased risk of aspiration of stomach contents: (a) increased intragastric pressure caused by external compression by the gravid uterus, (b) progesterone-induced relaxation of the lower esophageal sphincter, (c) delayed gastric emptying during labor, (d) supine position, and (e) analgesia-induced decreased mental status and decreased vocal cord closure [23]. The pulmonary pathophysiologic consequences of gastric aspiration are a consequence of the acidity and the particulate content of the gastric contents and the risk of bacterial superinfection. An inflammatory response is also triggered by the acid aspiration, leading to an increase in alveolar permeability with a loss in lung compliance and a decrease in ventilation–perfusion matching [23]. Aspiration of smaller volumes may go unnoticed clinically until 6 to 8 hours later, when tachypnea, tachycardia, hypoxemia, hypotension, bronchospasm, and production of frothy, pink sputum are noted in association with diffuse opacities on chest radiography. The clinical course may follow one of three patterns: (a) rapid improvement during 4 to 5 days, (b) initial improvement followed by deterioration caused by supervening bacterial pneumonia, and (c) early death as a result of intractable hypoxia [23]. Predictors of poor outcome include low pH, large volume, and a greater amount of particulate content of the aspirate. The bacterial pathogens in this setting are usually oropharyngeal anaerobes, although the longer the patient is in the hospital before clinical development of pneumonia, the greater the likelihood of facultative, Gram-negative bacillary, and Staphylococcus aureus infections [23]. The maternal mortality rate from pneumonia has decreased from 20% to 3% since the advent of antibiotics [24]. The major factors in improving fetal and maternal outcome seem to have been earlier presentation and prompt institution of antibiotic therapy. Although pneumonia rarely progresses to respiratory failure, it is advisable to assess maternal oxygenation in all cases of maternal pneumonia. The spectrum of organisms to consider is similar to that in the nonpregnant population; the most common organisms are Streptococcus pneumoniae, Haemophilus influenzae, and Mycoplasma pneumoniae. These particular infections can be virulent in the pregnant patient because of alterations in the immune status. Specifically, during pregnancy, there is a decreased lymphocyte proliferative response, a decrease in the natural killer cell activity, and a decrease in the number of helper T4 cells [24]. Fortunately, the impairment in maternal immune response is mild, and the increase in maternal morbidity is small. In the influenza pandemics of 1918, 1957, and 2009, an excess incidence of influenza pneumonia was noted among pregnant women. A 50% incidence of influenza pneumonia and an overall mortality of 27% for influenza in pregnancy were found in 1918 [26]. In the 1957 pandemic, several studies noted that 50% of deaths from influenza in women of childbearing age were in pregnant patients [26]. Autopsy reports noted that the cause of death in pregnant women was respiratory insufficiency caused by fulminant influenza pneumonia, rather than secondary bacterial infection, the more common cause of death in nonpregnant influenza patients.

Dystonia Both agonist and antagonist muscles of a body region contract simultaneously to produce a twisted posture of the limb quality lamictal 200 mg, neck purchase lamictal 50 mg online, or trunk proven lamictal 25 mg. Myoclonus Sudden, brief, shocklike jerks are caused by muscular contraction (positive myoclonus) or inhibition (negative myoclonus, such as asterixis). Restless legs An unpleasant, crawling sensation in the legs (or arms), particularly syndrome during sitting and relaxation, is most prominent in the evening (but can also occur during the day). Tics Abnormal, stereotypic, repetitive movements (motor tics) or abnormal sounds (phonic tics) can be suppressed temporarily but may need to be “released” at some point. Tremor An oscillatory, usually rhythmic (to-and-fro) movement of one or more body parts, such as the neck, tongue, chin, or vocal cords or a limb. Athetosis has been used in two senses: to describe a class of slow, writhing, continuous, involuntary movements and to describe the syn- drome of athetoid cerebral palsy. Dystonia is characterized by involuntary, sustained, patterned, and often repetitive contractions of opposing muscles, causing twisting movements or abnormal postures. This often occurs with progression of the disease 14 I GettInG Started and is called overfow dystonia. Therefore, organicity of the dystonia is often questioned when the abnormal posturing occurs suddenly and is initially present at rest, rather than during action. Although oculogyria is commonly associated with dopamine receptor blockers, it was initially associated with encephalitis lethargica and has been documented to occur along with other parkinsonian syndromes due to biochemical defciencies of the monoamine pathways, such as pterin defciency and aromatic amino acid defciency. Patients often describe an unpleasant, crawling sensation in the legs, particularly when they are sitting and relaxing in the evening, that disappear when they are walking. Tremors are oscillatory, usually rhythmic, to-and-fro regular movements affecting one or more body parts, such as the limbs, neck, tongue, chin, or vocal cords. Different types of action tremor: Postural Evident during maintenance of an antigravity posture, such as keeping the arms in an outstretched horizontal position Kinetic Evident when the voluntary movement starts (initial tremor), during the course of the movement (dynamic tremor), or as the affected body part approaches the target (terminal tremor) Task- Evident or exacerbated only while a certain task is performed specifc (eg, handwriting tremor, voice tremor) Position- Evident while a certain posture is maintained specifc Isometric Evident during voluntary muscular contraction without a change in the position of the body part Table 1. Movements are continual if they appear as recurring episodes, whereas continuous episodes are nonstop and nonrepetitive. Some types of hyperkinesia appear only when a limb is at rest, and others appear only during active limb movement. Dyskinetic movements can also be associated with characteristic symptoms that can help focus the differential diagnosis (Table 1. Being aware of these symptoms and includ- ing them in the description of the phenomenology may help in narrowing the etiology. In clini- cal practice, characterization of tremor is important for etiologic consideration and treatment. Common types include resting tremor, postural tremor, kinetic tremor, intention tremor, and task-specifc tremor. Parkinsonian tremors may originate in the basal ganglia, and essential tremors may originate within the inferior olives and thalamus. Resting tremor occurs when the affected extremity is at complete rest and diminishes with movement of the affected body part. Intention (or terminal) tremor manifests as a marked increase in tremor amplitude during the terminal portion of a targeted movement. Essential Postural and Usually symmetric, responds to alcohol, bimodal tremor kinetic age at onset (teens, > 50 y), 4–10 Hz. Cerebellar Intention Postural component may be present, other tremor cerebellar features on examination. Holmes Rest, postural, Seen in multiple sclerosis and traumatic brain tremor and intention injury, 2–5 Hz. Dystonic Postural and Abnormal posture of affected limb may be tremor intention observed, variable frequency, 4–8 Hz. Enhanced Postural Check for metabolic disorders (thyroid, diabetes, physiologic renal failure, liver disease) or tremor-inducing tremor drugs, 8–12 Hz. Enhanced Physiologic Tremor Enhanced physiologic tremor is a high-frequency, low-amplitude, visible tremor that occurs primarily when a specifc posture is maintained. Trem- ors can emerge during posture (reemergent tremor when it occurs a few seconds after the hands have been held in sustention) and action. Holmes Tremor Holmes tremor or rubral tremor designates a combination of rest, postural, and action tremors due to midbrain lesions in the vicinity of the red nucleus. Dystonic Tremor As the name implies, dystonic tremor is a tremor that occurs in a body region affected by dystonia. Neuropathic Tremor Neuropathic tremors are mostly postural or action tremors that occur in the setting of a peripheral neuropathy. Palatal Tremor Palatal tremors (see also Chapter 7) are brief, rhythmic, involuntary, low- frequency movements of the soft palate. Palatal tremors are classifed in two forms: ▪ Symptomatic palatal tremor is believed to arise from a lesion of the brain- stem or cerebellum (within the guillain-Mollaret triangle), resulting in a rhythmic contraction of the levator veli palatini. Drug-Induced Tremors Types of tremors induced by drugs include enhanced physiologic tremor, rest tremor, and action tremor. The signs and symptoms of drug-induced tremors depend on the drug used and on a patient’s predisposition to its side effects. Hysterical Tremors Also known as psychogenic tremors, hysterical tremors usually present a chal- lenge in any neurological practice. This diagnosis should be con- sidered for any patient with a movement disorder presenting before the age of 50 years. It may be combined with dopamine agonists or anticholinergic agents in patients with resistant tremors. Propranolol and primidone are the preferred frst-line treatments for essential tremor, alone or in combination (Table 2. Toxicology Assess for drug-induced Drug abuse or withdrawal (eg, screen tremors, illicit drug use, ethanol withdrawal) may be toxic etiology (mercury, associated with tremors. Medications that can be tried include clonazepam, pro- pranolol, trihexyphenidyl, levodopa, physostigmine, and topiramate. Head, arm, and voice tremors resulting from dystonia have been shown to improve with botulinum toxin injections.