Drug-induced movement disorders

Movement disorders associated with pediatric encephalitis

New onset movement disorders are a common clinical problem in pediatric neurology and can be infectious, inflammatory, metabolic, or functional in origin. Encephalitis is one of the more important causes of new onset movement disorders, and movement disorders are a common feature (~25%) of all encephalitis. However, all encephalitides are not the same, and movement disorders are a key diagnostic feature that can help the clinician identify the etiology of the encephalitis, and therefore appropriate treatment is required. Movement disorders are a characteristic feature of autoimmune encephalitis such as anti-NMDAR encephalitis, herpes simplex virus encephalitis-induced autoimmune encephalitis, and basal ganglia encephalitis. Other rarer autoantibody-associated encephalitis syndromes with movement disorder associations include encephalitis associated with glycine receptor, DPPX, and neurexin-3 alpha autoantibodies. In addition, movement disorders can accompany acute disseminated encephalomyelitis with and without myelin oligodendrocyte glycoprotein antibodies. Extremely important infectious encephalitides that have characteristic movement disorder associations include Japanese encephalitis, dengue fever, West Nile virus, subacute sclerosing panencephalitis (SSPE), and SARS-CoV-2 (COVID-19). This chapter discusses how specific movement disorder phenomenology can aid clinician diagnostic suspicion, such as stereotypy, perseveration, and catatonia in anti-NMDAR encephalitis, dystonia-Parkinsonism in basal ganglia encephalitis, and myoclonus in SSPE. In addition, the chapter discusses how the age of the patients can influence the movement disorder phenomenology, such as in anti-NMDAR encephalitis where chorea is typical in young children, even though catatonia and akinesia is more common in adolescents and adults.

The enduring enigma of sporadic chorea: A single center case series

Chorea can have a wide variety of causes including neurodegenerative, pharmacological, structural, metabolic, infectious, immunologic and paraneoplastic processes. We reviewed the clinical records of patients with apparently sporadic choreic movements and no relevant family history, who presented to our neurology department (Hospital Fundación Jimenez Diaz) between 1991 and 2022. We detected 38 cases of apparent sporadic chorea (ASC); Our analysis revealed 5 cases of genetic chorea (including 3 cases with Huntington's disease) while 6 cases were autoimmune/hematological; 6 drug-related chorea, 5 metabolic-vascular, 5 due to miscellaneous conditions and 4 were of mixed etiology. No clear etiology was identified in 8 cases. The differential diagnosis of ASC is extensive and challenging.

Highlights

Chorea can have a wide variety of genetic and sporadic causesWe reviewed the clinical records of patients with apparently sporadic chorea (ASC), who presented to our neurology department over the last 30 yearsWe detected 38 cases of apparent ASC; Our analysis revealed a wide array of different sporadic conditions and 5 cases of genetic choreaThe differential diagnosis of ASC is extensive and challenging.

Lithium-induced parkinsonism associated with vocal cord paralysis: an atypical presentation

Drug-induced parkinsonism has been commonly studied and discussed regarding antipsychotic agents, but lithium-induced parkinsonism should also be considered when patients present with parkinsonian symptoms and chronic lithium use. There are several reports of parkinsonism arising during lithium administration and regressing following its reduction or discontinuation. Our case is, to date, the first case in the literature in which vocal cord paralysis occurred as the first symptom of lithium-induced parkinsonism, contributing to confuse doctors and patients and to delay diagnosis and treatment. In our clinical case prompt withdrawal of lithium and its reintroduction at lower doses led to complete resolution of this disabling clinical presentation. This report emphasizes the importance of careful monitoring of lithium levels, especially in elderly subjects, and the need to consider lithium-induced parkinsonism even when unusual motor symptoms appear in chronic lithium users.

Drug-Induced Movement Disorders

Drug-induced movement disorders (DIMDs) are most commonly associated with typical and atypical antipsychotics. However, other drugs such as antidepressants, antihistamines, antiepileptics, antiarrhythmics, and gastrointestinal drugs can also cause abnormal involuntary movements. Different types of movement disorders can also occur because of adverse drug reactions. Therefore, the important key to diagnosing DIMDs is a causal relationship between potential offending drugs and the occurrence of abnormal movements. The pathophysiology of DIMDs is not clearly understood; however, many cases of DIMDs are thought to exert adverse mechanisms of action in the basal ganglia. The treatment of some DIMDs is quite challenging, and removing the offending drugs may not be possible in some conditions such as withdrawing antipsychotics in the patient with partially or uncontrollable neuropsychiatric conditions. Future research is needed to understand the mechanism of DIMDs and the development of drugs with better side-effect profiles. This article reviews the phenomenology, diagnostic criteria, pathophysiology, and management of DIMDs.

Buspirone-associated Movement Disorder: A Literature Review

Buspirone (BUS) belongs to the azapirone chemical class. The aim of this literature review is to evaluate the clinical epidemiological profile, pathological mechanisms, and management of BUS-associated movement disorders (MD). Relevant reports in six databases were identified and assessed by two reviewers without language restriction. A total of 25 reports containing 65 cases were assessed. The MD associated with BUS were: dyskinesia in 14 cases, 10 of akathisia, 8 of myoclonus, 6 of Parkinsonism, and 6 of dystonia. The cases not clearly defined were 7 tension, 14 incoordination, and the undefined number of dyskinesia, tics, and Parkinsonism. The mean age was 45.23 years (range: 15-74). The male was the predominant sex in 60.86% and the most common BUS-indication was anxiety disorder. The mean BUS-dose was 42.16 mg (range: 5-100). The time from the beginning of BUS administration to the MD onset was one month or less in 76%. The time from BUS withdrawal to complete recovery was within one month in 87.5%. The most common management was BUS withdrawal. In 16 patients the follow-up was reported: 14 had a full recovery, but in two (1 dyskinesia + 1 dystonia) the symptoms continued after the BUS withdrawal. MD associated with BUS were scarcely reported in the literature. Moreover, in the majority of cases, no clear description of the clinical profile, neurological examination, or the time data of the movement disorder onset and recovery were given.

Where are oral and dental adverse drug effects in product information?

OBJECTIVES

Oral adverse drug reactions are common and are associated with some of our most frequently used medicines. It is important to identify and manage oral adverse drug effects promptly as they not only negatively impact dental health, but also adversely affect medication adherence, clinical outcomes and patient quality of life. This study assessed the location of oral drug-induced adverse effects in the registered drug company product information (PI) of the top 100 most commonly used drugs in Australia as dispensed on the Pharmaceutical Benefits Scheme in 2018.

METHOD

Publicly available data on dispensed medicines were accessed from the Australian Commonwealth Department of Health, to determine the top 100 medicines. The drug company PI for each of these drugs was manually searched to find their oral adverse effects. The number, type and location of the oral adverse drug reactions (ADRs) were recorded.

KEY FINDINGS

Oral ADRs were commonly found varying in nature and severity. However, they were difficult to find as there is no dedicated section for oral/dental adverse effects in the PI and the section they are in is inconsistently applied.

CONCLUSIONS

We recommend that regulatory authorities such as the Therapeutic Goods Administration in Australia create an additional section for oral/dental adverse effects so they are easier to find, which may assist health professionals detect recognise and report adverse drug effects manifesting in the oral cavity.

Impact of Safety Warning on Domperidone Prescribing for Geriatric Patients in South Korea: Analysis of National Insurance Claim Data

Domperidone is a dopamine antagonist used for the symptomatic management of nausea and vomiting. Many countries banned or add a black box warning due to an increased risk of serious adverse cardiac effects. In 2014, the Korea Ministry of Food and Drug Safety also released a safety warning to carefully consider adverse cardiac effects when prescribing domperidone. Therefore, we conducted this study to analyze the impact of the safety warning on domperidone prescribing. This study included patients 65 years or older who used national health insurance services in the years 2011 and 2016, using the national patient sample dataset in South Korea. We analyzed the characteristics of domperidone prescribing and compared on pre- and post-safety warning. Prescribing frequency of domperidone was significantly reduced from 603,962 cases in 2011 to 24,623 cases in 2016. In 2011, 53,272 (8.8%) prescriptions were for greater than 30 mg/day, whereas only 200 (0.8%) prescriptions were in 2016. The number of patients with one or more comorbidities and electrocardiogram monitoring showed positive changes after the safety warning. In conclusion, after the 2014 safety letter was issued, domperidone was more safely prescribed in various aspects in elderly patients, including frequency of prescribing, maximum daily dose, and duration of continuous prescription.

Tardive Dyskinesia Associated with Bupropion

Present report describes a 46 year old male patient with a diagnosis of major depression who developed tardive dyskinesia during bupropion therapy. Our patient had no history of neuroleptic use and his laboratory and neurologic examinations were normal. He had no family history of neurologic diseases. Although bupropion induced dyskinesia has been previously reported in the literature, it is rare and our case is the first case regarding tardive dyskinesia.

Psychomotor Tremor and Proprioceptive Control Problems in Current and Former Stimulant Drug Users: An Accelerometer Study of Heavy Users of Amphetamine, MDMA, and Other Recreational Stimulants

The recreational use of various stimulant drugs has been implicated in the development of movement disorders through dysregulation of the dopaminergic and serotoninergic neurotransmitter systems. The present study investigated psychomotor differences in current and former recreational stimulant drug users compared with nonusing controls. Sixty participants comprised 3 groups: 20 current stimulant drug users (CSUs; 11 men, aged 31.4 ± 9.1 years), 20 former stimulant drug users (FSUs; 5 men, aged 39.1 ± 8.5 years), and 20 nonuser controls (NUCs; 5 men, aged 35.7 ± 6.4 years). Psychomotor arm steadiness for each participant was assessed with a wrist-attached accelerometer during 5 arm positions with eyes open and then eyes closed. Arm-drop of arm position was indicated by the arm longitudinal rotation axis (ALoRA), and tremor was indicated by the overall vector of dynamic body acceleration (VeDBA). Overall, CSUs performed the most poorly on ALoRA (P < .05) and VeDBA indices (P < .05), and FSUs perform almost as poorly on VeDBA indices (P < .05) compared with NUCs. It was concluded that stimulant drug use, primarily MDMA and amphetamines, may result in acute stimulant-induced tremor as well as long-term proprioceptive deficits in terms of arm-droop.

Adverse Drug Reactions in the Orofacial Region

A wide spectrum of drugs can sometimes give rise to numerous adverse orofacial manifestations, particularly dry mouth, taste disturbances, oral mucosal ulceration, and/or gingival swelling. There are few relevant randomized double-blind controlled studies in this field, and therefore this paper reviews the data from case reports, small series, and non-peer-reviewed reports of adverse drug reactions affecting the orofacial region (available from a MEDLINE search to April, 2003). The more common and significant adverse orofacial consequences of drug therapy are discussed.

Acute movement disorders in the medical setting

Objective Psychosomatic medicine psychiatrists are often tasked with the evaluation and treatment of complex neuropsychiatric states which may be motoric in phenotype. Little energy has been dedicated to understanding acute movement disorders in the hospital environment. Method Recognizing the importance of frontal-subcortical (corticostriatothalamocortical) circuitry and basal ganglia structures, we present a case series of acute movement disorder phenotypes resulting from underlying medical conditions, commonly-administered medications, or the interaction of both. We organize these scenarios into neurodegenerative disorders, primary psychiatric disorders, neuroinflammation, and polypharmacy, demonstrating a clinical example of each followed by background references on a variety of clinical states and medications contributing to acute movement disorders. In addition, we offer visual illustration of implicated neurocircuitry as well as proposed neurotransmitter imbalances involving glutamate, gamma aminobutyric acid, and dopamine. Furthermore, we review the various clinical syndromes and medications involved in the development of acute movement disorders. Results Acute movement disorder's involve complex interactions between frontal-subcortical circuits and acute events. Given the complexity of interactions, psychopharmacological considerations become critical, as some treatments may alleviate acute movement disorders while others will exacerbate them. Conclusion Integrating underlying medical conditions and acutely administered (or discontinued) pharmacological agents offers an interactional, neuromedical approach to acute movement disorders that is critical to the work of psychosomatic medicine.

Lithium Use in Older Adults is Associated with Increased Prescribing of Parkinson Medications

OBJECTIVE

To test the hypothesis of an increased incidence of antiparkinson drug prescribing or Parkinson disease (PD) diagnostic codes after chronic lithium treatment compared with chronic valproic acid or antidepressant treatment among older adults.

METHODS

A retrospective cohort study using healthcare administrative databases in Ontario, Canada included 1,749 lithium users, 1,787 valproic acid users, and 285,154 other antidepressant users ≥ 66 years old having used the drug continuously in monotherapy for at least 1 year. Outcome measures were start of (1) a dopaminergic medication (levodopa or a dopamine agonist), (2) any antiparkinson drug (levodopa, dopamine agonists, anticholinergic medication, amantadine, monoamine oxidase B inhibitors), (3) any antiparkinson drug or a diagnostic code for PD, and (4) any antiparkinson drug in the absence of a diagnostic code for PD.

RESULTS

For patients with no previous antipsychotic use, lithium monotherapy was associated with an increased incidence of dopaminergic drug use (adjusted HR: 1.87; 95% CI: 1.06-3.30) and an increased incidence of antiparkinson drug use or a PD diagnosis (adjusted HR: 1. 68; 95% CI: 1.13-2.48) compared with antidepressant monotherapy.

CONCLUSION

Chronic lithium use is associated with an increased incidence of dopaminergic drug use compared with antidepressants, identifying a prescribing cascade related to lithium use in the elderly. Whether this reflects inappropriate treatment of action tremor or treatment of drug-induced parkinsonism should be addressed by a close examination of prescribing practices.

Drug-induced movement disorders

INTRODUCTION

Drug-induced movement disorders (DIMDs) can be elicited by several kinds of pharmaceutical agents. The major groups of offending drugs include antidepressants, antipsychotics, antiepileptics, antimicrobials, antiarrhythmics, mood stabilisers and gastrointestinal drugs among others.

AREAS COVERED

This paper reviews literature covering each movement disorder induced by commercially available pharmaceuticals. Considering the magnitude of the topic, only the most prominent examples of offending agents were reported in each paragraph paying a special attention to the brief description of the pathomechanism and therapeutic options if available.

EXPERT OPINION

As the treatment of some DIMDs is quite challenging, a preventive approach is preferable. Accordingly, the use of the offending agents should be strictly limited to appropriate indications and they should be applied in as low doses and as short duration as the patient's condition allows. As most of DIMDs are related to an unspecific adverse action of medications in the basal ganglia and the cerebellum, future research should focus on better characterisation of the neurochemical profile of the affected functional systems, in addition to the development of drugs with higher selectivity and better side-effect profile.

Drug-induced akathisia as a cause of distress in spouse caregivers of cancer patients

OBJECTIVE

Family caregivers of cancer patients suffer from physical, psychological, and social distress and therefore are often referred to as second order patients. Akathisia is a common side effect of antipsychotics and antidepressants that causes great discomfort and even agitation and is often described by patients administered these drugs as the most distressing side effect of their treatment. Several studies of akathisia as a cause of distress in cancer patients have been reported. However, akathisia has not been reported as a cause of distress in family caregivers of cancer patients.

METHOD/CASE REPORT

A 74-year-old spouse caregiver who was under treatment for major depressive disorder was not able to visit the hospital where her husband, a terminally ill cancer patient, was being treated. Initially, the spouse caregiver thought that she could not visit the hospital because of the symptoms of her depression and her grief about losing her husband. However, careful clinical examination revealed that she was suffering from akathisia in addition to her grief.

RESULTS

Discontinuation of her sulpiride treatment resulted in the disappearance of her akathisia symptoms, and therefore she became able to visit the hospital and care for her terminally ill husband.

SIGNIFICANCE OF RESULTS

Drug induced akathisia is a cause of distress in spouse caregivers taking certain drugs. It is important for clinicians to realize that family caregivers might suffer from not only socioeconomic, physical, and psychological problems but also side effects of medication.

Varenicline-induced acute dystonic reaction: a case report

Dystonia is a syndrome characterized by sustained muscle contractions frequently causing twisting and repetitive movements or abnormal postures. Dystonic reactions may be a complication of many drugs such as antipsychotics, anti-emetics and antidepressants. This report presents a 25-year-old patient who was admitted to an emergency department with acute dystonia following the use of varenicline, a pharmacological agent used for the treatment of nicotine addiction. Dystonic reactions may be related to the dopaminergic deficiency caused by the use of varenicline. In conclusion, this report suggests that varenicline can cause dystonic reaction in at least some patients.

Pharmacotherapy of essential tremor

Essential tremor (ET) is a common movement disorder but its pathogenesis remains poorly understood. This has limited the development of effective pharmacotherapy. The current therapeutic armamentaria for ET represent the product of careful clinical observation rather than targeted molecular modeling. Here we review their pharmacokinetics, metabolism, dosing, and adverse effect profiles and propose a treatment algorithm. We also discuss the concept of medically refractory tremor, as therapeutic trials should be limited unless invasive therapy is contraindicated or not desired by patients.

Acute, sustained chorea in children after supratherapeutic dosing of amphetamine-derived medications

Amphetamine-derived medications are being prescribed with increasing frequency to younger pediatric patients to treat attention deficit hyperactivity disorder. Although choreiform movements were reported in adults with amphetamine abuse and in those under therapeutic treatment for attention deficit hyperactivity disorder, previous literature concerning the pediatric population is spare. We describe two children who developed chorea after ingesting amphetamine-derived medications prescribed to treat attention deficit hyperactivity disorder. Patient 1, a 10-year-old boy, accidently received an extra dose of lisdexamfetamine dimesylate the night before the onset of acute chorea involving his arms, legs, and trunk. Patient 2, an 8-month-old boy, accidentally ingested his stepbrother's mixed amphetamine salts (Adderall XR) and developed acute chorea. Benzodiazepines, diphenhydramine, benztropine, and opioids did not suppress the chorea in either case. The 10-year-old received haloperidol, which significantly improved his abnormal findings, and he returned to baseline in approximately 48 hours. The 8-month-old was observed in the pediatric intensive care unit, and his signs resolved by 72 hours. Our cases demonstrate that choreiform movements of sustained duration can occur in children with acute supratherapeutic ingestions of amphetamine-derived medications.

Abnormal movements are associated with poor psychosocial functioning in adolescents at high risk for psychosis

The period immediately preceding the onset of overt psychosis is characterized by a range of symptoms and behaviors including emerging attenuated psychosis, spontaneous movement abnormalities, and a broad decline in role and social functioning. Recent evidence suggests that basal ganglia dysfunction, which is implicated in the development of psychotic symptomatology, may manifest in the form of both movement abnormalities and deficits in processes integral to psychosocial functioning. However, little is known about the relationship between abnormal movement function and the observed psychosocial deficits. In the present study, 40 clinical high-risk participants meeting criteria for a prodromal syndrome were assessed for movement abnormalities and global role and social functioning at baseline. Role and social functioning were then followed up after a one-year period. At baseline, the severity of spontaneous movement abnormalities was associated with poor role functioning. Further, when controlling for baseline functioning, movement abnormalities predicted changes in social functioning one-year later, with a trend in the same direction for role functioning. Exploratory analyses also indicated that elevated baseline movement abnormalities distinguished those at-risk participants who eventually converted to psychosis and that this was also the case for poorer baseline global role functioning (at the trend level). Taken together, the results suggest that movement abnormalities are closely associated with deficits in psychosocial functioning. Elucidating the link between these phenomena may serve to refine etiological models of frontal-subcortical circuit dysfunction and inform understanding of functioning and outcome of these affected youth.

Catatonia is hidden in plain sight among different pediatric disorders: a review article

Over the past two decades, catatonia has been better demarcated in adult psychiatry as a unique syndrome that consists of specific motor signs with a characteristic response to benzodiazepines and electroconvulsive therapy. Pediatric catatonia is considered rare, but may be underdiagnosed, and hence undertreated. Discussed here are the current diagnostic criteria of catatonia in individual cases of children and adolescents diagnosed with childhood disintegrative disorder, Kleine-Levin syndrome, Prader-Willi syndrome, tic disorder, and autoimmune encephalitis, and the effects of benzodiazepines and electroconvulsive therapy. In these cases, catatonia resolved safely once it was recognized and treated properly. Children and adolescents presenting with these disorders should be systematically assessed for catatonia; when the presence of catatonia is confirmed, the use of benzodiazepines and electroconvulsive therapy should be considered. The occurrence of catatonia in such a wide range of child and adolescent disorders supports the view that pediatric catatonia is not so rare, that there are shared elements in the etiology, psychopathology, and pathophysiology of these disorders, and that catatonia is best classified as a unique neurobiologic syndrome.

Markers of basal ganglia dysfunction and conversion to psychosis: neurocognitive deficits and dyskinesias in the prodromal period

BACKGROUND

Movement abnormalities and cognitive deficits may represent external markers of an underlying neural process linked with the early etiology of psychosis. As basal ganglia function plays a governing role in both movement and cognitive processes, an understanding of the relationship between these phenomena stands to inform etiologic conceptualizations of vulnerability and psychotic disorders.

METHODS

In this investigation, trained raters coded movement abnormalities in videotapes from structured interviews of adolescents and young adults with a prodromal risk syndrome (n = 90). The participants were administered a neuropsychological battery including measures of verbal comprehension, perceptual organization, immediate/delayed auditory memory, and an estimate of full-scale intelligence quotient. Diagnostic status was followed for a 2-year period utilizing structured clinical interviews, during which time 24 high-risk participants (26.66%) converted to an Axis I psychotic disorder.

RESULTS

Elevated dyskinetic movements in the upper-body region were correlated with deficits in domains of verbal comprehension, perceptual organization, and both immediate and delayed auditory memory. Further, discriminant function analyses indicated that baseline movement abnormalities and neurocognitive deficits significantly classified those high-risk participants who would eventually convert to a psychotic disorder (72.3%).

CONCLUSIONS

Results support a common cortico-striato-pallido-thalamic circuit irregularity, underlying both movement abnormalities and cognitive deficits in individuals at high risk for psychosis. Models incorporating external markers of progressive basal ganglia dysfunction may enhance detection and preventive intervention for those high-risk individuals most in need of treatment.

Treatment strategies for dystonia

IMPORTANCE OF THE FIELD

Dystonia is a neurological syndrome characterized by involuntary twisting movements and unnatural postures. It has many different manifestations and causes, and many different treatment options are available. These options include physical and occupational therapy, oral medications, intramuscular injection of botulinum toxins, and neurosurgical interventions.

AREAS COVERED IN THIS REVIEW

In this review, we first summarize the treatment options available, then we provide suggestions from our own experience for how these can be applied in different types of dystonia. In preparing this review article, an extensive literature search was undertaken using PubMed. Only selected references from 1970 to 2008 are cited.

WHAT THE READER WILL GAIN

This review is intended to provide the clinician with a practical guide to the treatment of dystonia.

TAKE HOME MESSAGE

Treatment of dystonia begins with proper diagnosis and classification, followed by an appropriate search for underlying etiology, and an assessment of the functional impairment associated with the dystonia. The therapeutic approach, which is usually limited to symptomatic therapy, must then be tailored to the individual needs of the patient.

Acute hemifacial dystonia possibly induced by clebopride

Dystonic reactions produce twisting and repetitive movements or abnormal posturing. Severe dystonic reactions have been shown to occur in concert with numerous medications. This report details the case of a patient who developed hemifacial dystonia as acute side reaction from administration of clebopride for dyspeptic prophylaxis. When the drug was immediately stopped, the dystonic posture disappeared completely within 2 weeks. The use of clebopride may be associated with not only a reversible or persistent parkinsonism syndrome but also hemifacial dystonia; therefore, attention must be drawn to this possible side effect.

Postural induced-tremor in psychiatry

Postural tremor is the most common movement disorder in psychiatry, and often a difficult problem for clinicians. It can be classified as physiological, essential, drug-induced, and postural tremor in Parkinson's disease. Drugs used in psychiatry that can produce postural tremor, include lithium, valproic acid, lamotrigine, antidepressants, and neuroleptics. Clinical characteristics of postural tremor induced by each of these drugs are described. Pharmacological strategies for therapy in disabling drug-induced tremor include beta-blockers, primidone, gabapentin, topiramate, and benzodiazepines; their utility, doses and side-effects are also discussed.

Catatonia in autism: implications across the life span

BACKGROUND

There is increasing evidence that catatonia is an important source of impairment in adolescents and adults with autism.

AIM

Review of the evaluation, diagnosis, differential diagnosis, and treatment of catatonia in autism.

METHOD

Presentation and discussion of a case-vignette spanning early childhood to adulthood.

RESULTS

Autistic and catatonic symptoms overlap, yet catatonia is diagnosable in about one of seven adolescents and young adults with autism. Case-reports suggest that benzodiazepines and electroconvulsive therapy are effective treatments in the acute and maintenance phase for people with autism who develop catatonia.

CONCLUSIONS

Catatonia should be assessed in people with autism when there is an obvious and marked deterioration in movement, vocalizations, pattern of activities, self-care, and practical skills. Benzodiazepines and electroconvulsive therapy are favored options for acute and maintenance treatment in these cases. Further studies on the possible biological-genetic overlap between autism and catatonia would be helpful.

[Intermittent apomorphine injections as rescue therapy for advanced Parkinson's disease. Consensus statement]

Intermittent subcutaneous apomorphine therapy should be considered in patients with advanced Parkinson's disease who experience recurrent off periods despite optimised oral treatment (according to guidelines), for reliable and quick reversal of these otherwise refractory periods. Such treatment is also called rescue therapy. At present, apomorphine injections with the apomorphine pen are underutilised, considering its current indications and contraindications. In the present consensus statement, concepts for the use of apomorphine are presented and discussed based on existing study results, indications, and contraindications. Recommendations for a practical approach are also provided.

Late life psychosis: assessment and general treatment strategies

With the increased number of elderly patients suffering from mental illness, an increased incidence of psychiatric conditions including psychotic disorders is also expected. When psychosis occurs in the elderly, its assessment and treatment may pose a challenge for primary care clinicians and caregivers. This article will review the assessment and treatment of late life psychosis.

Duration of therapy with metoclopramide: a prescription claims data study

PURPOSE

Metoclopramide-induced tardive dyskinesia is associated with cumulative drug exposure, which can result from prolonged use of the drug. We estimated therapy duration with metoclopramide, and measured the extent of therapy beyond the maximum time period of 12 weeks evaluated in the clinical trials and recommended in the label.

METHODS

Prescription claims for metoclopramide from 2002 to 2004 were extracted for participants residing throughout the US and contained within the Caremark pharmacy benefit manager (PBM) database. An episode of therapy was defined as one or a series of consecutive claims with no more than a 30-day lag between the dispensing date of a new claim and the ending date of the preceding claim. Episode duration was calculated by subtracting the start date from the end date for each episode.

RESULTS

During the study period, almost 80% of participants (total = 200 907) had only one episode of therapy. The length of the longest episode for most patients (85%) varied from 1 to 90 days, yet 15% of the patients appeared to have received prescriptions for metoclopramide for a period longer than 90 days. Cumulative therapy for longer than 90 days was recorded for almost 20% of the patients.

CONCLUSIONS

These results suggest that despite the known risk of tardive dyskinesia and the labeled recommendations on duration of metoclopramide use, many patients appear to use the drug for relatively long time periods beyond the labeled recommendations. Physicians should carefully consider the risk-benefit profile of the drug and, if possible, avoid increased risk of tardive dyskinesia due to prolonged exposure.

Parkinson's disease: genetics and beyond

Parkinson's disease (PD) is characterized clinically by resting tremor, rigidity, bradykinesia and postural instability due to progressive and selective loss of dopamine neurons in the ventral substantia nigra, with the presence of ubiquitinated protein deposits called Lewy bodies in the neurons. The pathoetiology of cell death in PD is incompletely understood and evidence implicates impaired mitochondrial complex I function, altered intracellular redox state, activation of proapoptotic factors and dysfunction of ubiquitinproteasome pathway. Now it is believed that genetic aberration, an environmental toxin or combination of both leads to a cascade of events culminating in the destruction of myelinated brainstem catecholaminergic neurons. Also the role of production of significant levels of abnormal proteins, which may misfold, aggregate and interfere with intracellular processes causing cytotoxicity has recently been hypothesized. In this article, the diverse pieces of evidence that have linked the various factors responsible for the pathophysiology of PD are reviewed with special emphasis to various candidate genes and proteins. Furthermore, the present therapeutic strategies and futuristic approaches for the pharmacotherapy of PD are critically discussed.

Practical considerations for the treatment of elderly patients with migraine

Treatment of migraine presents special problems in the elderly. Co-morbid diseases may prohibit the use of some medications. Moreover, even when these contraindications do not exist, older patients are more likely than younger ones to develop adverse events. Managing older migraine patients, therefore, necessitates particular caution, including taking into account possible pharmacological interactions associated with the greater use of drugs for concomitant diseases in the elderly. Paracetamol (acetaminophen) is the safest drug for symptomatic treatment of migraine in the elderly. Use of selective serotonin 5-HT(1B/1D) receptor agonists ('triptans') is not recommended, even in the absence of cardiovascular or cerebrovascular risk, and NSAID use should be limited because of potential gastrointestinal adverse effects. Prophylactic treatments include antidepressants, beta-adrenoceptor antagonists, calcium channel antagonists and antiepileptics. Selection of a drug from one of these classes should be dictated by the patient's co-morbidities. Beta-adrenoceptor antagonists are appropriate in patients with hypertension but are contraindicated in those with chronic obstructive pulmonary disease, diabetes mellitus, heart failure and peripheral vascular disease. Use of antidepressants in low doses is, in general, well tolerated by elderly people and as effective, overall, as in young adults. This approach is preferred in patients with concomitant mood disorders. However, prostatism, glaucoma and heart disease make the use of tricyclic antidepressants more difficult. Fewer efficacy data in the elderly are available for selective serotonin reuptake inhibitors, which can be tried in particular cases because of their good tolerability profile. Calcium channel antagonists are contraindicated in patients with hypotension, heart failure, atrioventricular block, Parkinson's disease or depression (flunarizine), and in those taking beta-adrenoceptor antagonists and monoamine oxidase inhibitors (verapamil). Antiepileptic drug use should be limited to migraine with high frequency of attacks and refractoriness to other treatments. Promising additional strategies include ACE inhibitors and angiotensin II type 1 receptor antagonists because of their effectiveness and good tolerability in patients with migraine, particularly in those with hypertension. Because of its favourable compliance and safety profile, botulinum toxin type A can be considered an alternative treatment in elderly migraine patients who have not responded to other currently available migraine prophylactic agents. Pharmacological treatment of migraine poses special problems in regard to both symptomatic and prophylactic treatment. Contraindications to triptan use, adverse effects of NSAIDs, and unwanted reactions to some antiemetics reduce the list of drugs available for the treatment of migraine attacks in elderly patients. The choice of prophylactic treatment (beta-adrenoceptor antagonists, calcium channel antagonists, antiepileptics, and more recently, some antihypertensive drugs) is influenced by co-morbidities and should be directed at those drugs that are believed to have fewer adverse effects and a better safety profile. Unfortunately, for most of these drugs, efficacy studies are lacking in the elderly.

Treatment of dystonia

Dystonia may be a sign or symptom, that is comprised of complex abnormal and dynamic movements of different etiologies. A specific cause is identified in approximately 28% of patients, which only occasionally results in specific treatment. In most cases, treatment is symptomatic and designed to relieve involuntary movements, improve posture and function and reduce associated pain. Therapeutic options are dictated by clinical assessment of the topography of dystonia, severity of abnormal movements, functional impairment and progression of disease and consists of pharmacological, surgical and supportive approaches. Several advances have been made in treatment with newer medications, availability of different forms of botulinum toxin and globus pallidus deep brain stimulation (DBS). For patients with childhood-onset dystonia, the majority of whom later develop generalized dystonia, oral medication is the mainstay of therapy. Recently, DBS has emerged as an effective alternative therapy. Botulinum toxin is usually the treatment of choice for those with adult-onset primary dystonia in which dystonia usually remains focal. In patients with secondary dystonia, treatment is challenging and efficacy is typically incomplete and partially limited by side effects. Despite these treatment options, many patients with dystonia experience only partial benefit and continue to suffer significant disability. Therefore, more research is needed to better understand the underlying cause and pathophysiology of dystonia and to explore newer medications and surgical techniques for its treatment.

IN SILICO PREDICTION OF DRUG BINDING TO CYP2D6: IDENTIFICATION OF A NEW METABOLITE OF METOCLOPRAMIDE

Patients with cancer often take many different classes of drugs to treat the effects of their malignancy and the side effects of treatment, as well as their comorbidities. The potential for drug-drug interactions that may affect the efficacy of anticancer treatment is high, and a major source of such interactions is competition for the drug-metabolizing enzymes, cytochromes P450 (P450s). We have examined a series of 20 drugs commonly prescribed to cancer patients to look for potential interactions via CYP2D6. We used a homology model of CYP2D6, together with molecular docking techniques, to perform an in silico screen for binding to CYP2D6. Experimental IC50 values were determined for these compounds and compared with the model predictions to reveal a correlation with a regression coefficient of r2= 0.61. Importantly, the docked conformation of the commonly prescribed antiemetic metoclopramide predicted a new site of metabolism that was further investigated through in vitro analysis with recombinant CYP2D6. An aromatic N-hydroxy metabolite of metoclopramide, consistent with predictions from our modeling studies, was identified by high-performance liquid chromatography/mass spectrometry. This metabolite was found to represent a major product of metabolism in human liver microsomes, and CYP2D6 was identified as the main P450 isoform responsible for catalyzing its formation. In view of the prevalence of interindividual variation in the CYP2D6 genotype and phenotype, we suggest that those experiencing adverse reactions with metoclopramide, e.g., extrapyramidal syndrome, are likely to have a particular CYP2D6 genotype/phenotype. This warrants further investigation.

Cardiac 123I-MIBG scintigraphy in patients with drug induced parkinsonism

Cardiac sympathetic dysfunction was investigated using 123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy in 20 patients with drug induced parkinsonism (DIP). The mean heart to mediastinum ratio was significantly greater in patients with DIP than in those with Parkinson's disease (mean (SD): 2.07 (0.39) v 1.28 (0.15), p<0.001). MIBG uptake was not different between the DIP patients and controls. Two DIP patients whose MIBG uptake was significantly reduced showed persistent parkinsonism and responded dramatically to levodopa.

Antipsychotic-induced Extrapyramidal Syndromes in Psychiatric Practice: A Case-control Study

BACKGROUND

While several clinical trials showed that atypical antipsychotics have a low risk of extrapyramidal side effects (EPS), this observation is not undisputed. This study compared the risk of EPS between specific subgroups of antipsychotics.

METHODS

Using the automated dispensing records of a large psychiatric hospital in The Netherlands, we defined cases as first-time users of anticholinergic antiparkinson drugs. Controls were all patients with no recorded use of such medication. Cases and controls were compared with regard to previous use of antipsychotics and relevant co-factors.

RESULTS

Out of 1403 patients, we identified 105 cases and 330 controls. Compared to non-users, antipsychotic-users were 10 times more likely to start with anticholinergic antiparkinson medication (adjusted odds ratio: 10.1; 95 CI 4.6-22.3). Depot and non-depot antipsychotics had similar adjusted odds ratios of 10.9 (95 CI 3.7-32.6) and 8.8 (95% CI 3.8-20.4) respectively. Low and high potency antipsychotics gave odds ratios of 3.0 (95% CI 0.9-10.3) versus 10.8 (95% CI 4.7-25.1). Classical and atypical antipsychotics showed comparable odds ratios: 10.0 (95% CI: 4.4-22.5) versus 8.0 (95% CI: 2.6-24.5). Applied doses of classical and atypical antipsychotic drugs were much lower and more equivalent than those used in previous clinical trials.

CONCLUSIONS

Low potency antipsychotics had a much lower risk of EPS than other antipsychotics. However, we did not corroborate the reduced risk with atypical antipsychotics observed in several clinical trials. This discrepancy may result from the high and non-equivalent doses of classical antipsychotics used in many of these trials.

Tardive Dyskinesia Risks and Metoclopramide Use Before and After U.S. Market Withdrawal of Cisapride

OBJECTIVE

To assess risk factors for tardive dyskinesia (TD) in spontaneous reports of metoclopramide and TD and evaluate metoclopramide prescribing patterns before and after withdrawal of cisapride from the market in the United States.

DESIGN

Retrospective and observational analyses.

SETTING

International metoclopramide adverse event reports and domestic drug-use data for the continental United States.

PATIENTS

Users of metoclopramide for 30 days or more who experienced adverse events reported as TD.

INTERVENTIONS

Analyses of the Food and Drug Administration Adverse Event Reporting System (AERS) and IMS HEALTH data.

MAIN OUTCOME MEASURES

Pharmacoepidemiological patterns in AERS reports and utilization data from IMS HEALTH.

RESULTS

The case series comprised 87 reports of primarily older (mean+/-SD, 60+/-22 years ) women (67% of all cases). While average metoclopramide daily dose (33+/-14 mg) was within recommended product labeling limits, duration of use was considerably longer (753+/-951 days). Overall, 37% of the reports included concomitant drugs believed to be TD risk factors. Similarly, 18% of the reports noted comorbid diseases that are considered risk factors for development of TD. Metoclopramide utilization decreased following cisapride marketing in 1993 and increased following cisapride withdrawal in 2000. The majority (62%) of metoclopramide prescriptions were intended for women. Intended use overall increased with age and was highest in the seventh and eighth decades, with nearly one quarter of all utilization being in persons older than 70 years.

CONCLUSION

Well-described TD risk factors were common in metoclopramide-associated TD reports. Given the cisapride market withdrawal and associated increased metoclopramide utilization, the incidence of TD may increase accordingly. TD risk factors relative to the intended benefit and duration of use should be considered in metoclopramide prescribing.

Efficacy of pharmacological treatment of dystonia: evidence-based review including meta-analysis of the effect of botulinum toxin and other cure options

The treatment of both generalized and focal dystonia is symptomatic. There is no evidence-based information about the efficacy of the different methods of the pharmacological therapeutic options currently being applied in dystonia. The specific questions addressed by this study were which treatments for dystonia have proven efficacy and which of them have unproven results. Following evidence-based principles, a literature review based on MEDLINE and the Cochrane Library, augmented by manual search of the most important journals was performed to identify the relevant publications issued between 1973 and 2003. All articles appearing in the professional English literature, including case reports, were considered. In the presence of comparable studies the meta-analysis was performed to obtain pooled information and make a reasonable inference. Based on this review, we conclude: (i) botulinum toxin has obvious benefit (level A, class I-II evidence) for the treatment of cervical dystonia and blepharospasm; (ii) trihexyphenidyl in high dosages is effective for the treatment of segmental and generalized dystonia in young patients (level A, class I-II evidence); (iii) all other methods of pharmacological intervention for generalized or focal dystonia, including botulinum toxin injections, have not been confirmed as being effective according to accepted evidence-based criteria (level U, class IV studies).

[Drug-induced parkinson syndromes]

Parkinsonism is defined by the association of akinesia with one of the following symptoms: extrapyramidal rigidity, tremor at rest, or postural instability. A drug-induced aetiology must always be suspected when parkinsonian symptoms appear, or increase in a patient receiving drug treatment. Indeed drug-induced is the more frequent aetiology of secondary parkinsonism. The main treatments involved are antipsychotic and other neuroleptic drugs (accounting for up to two-thirds of drug-induced parkinsonism), and calcium-channel entry blockers. The risk associated with antipsychotics is often dose dependent and related to dopamine D2 striatal receptor occupancy induced by the antipsychotic drug. This risk is inferior for the second generation antipsychotics. The other treatments more rarely involved are antidepressants (tricyclic and selective serotonin reuptake inhibitors), lithium, valproic acid, and others. The main criterium for imputability is chronological, regression of symptoms being observed in 40-74% of cases, after a mean delay of 3 months from cessation of treatment. However, 15% of cases persist after drug withdrawal, leading to a diagnosis of underlying idiopathic Parkinson's disease.

Parkinson's disease

Parkinson's disease is the most common serious movement disorder in the world, affecting about 1% of adults older than 60 years. The disease is attributed to selective loss of neurons in the substantia nigra, and its cause is enigmatic in most individuals. Symptoms of Parkinson's disease respond in varying degrees to drugs, and surgery offers hope for patients no longer adequately controlled in this manner. The high prevalence of the disease, and important advances in its management, mean that generalists need to have a working knowledge of this disorder. This Seminar covers the basics, from terminology to aspects of diagnosis, treatment, and pathogenesis.