Drug-induced movement disorders

Polygenic liability for antipsychotic dosage and polypharmacy - a real-world registry and biobank study

Genomic prediction of antipsychotic dose and polypharmacy has been difficult, mainly due to limited access to large cohorts with genetic and drug prescription data. In this proof of principle study, we investigated if genetic liability for schizophrenia is associated with high dose requirements of antipsychotics and antipsychotic polypharmacy, using real-world registry and biobank data from five independent Nordic cohorts of a total of N = 21,572 individuals with psychotic disorders (schizophrenia, bipolar disorder, and other psychosis). Within regression models, a polygenic risk score (PRS) for schizophrenia was studied in relation to standardized antipsychotic dose as well as antipsychotic polypharmacy, defined based on longitudinal prescription registry data as well as health records and self-reported data. Meta-analyses across the five cohorts showed that PRS for schizophrenia was significantly positively associated with prescribed (standardized) antipsychotic dose (beta(SE) = 0.0435(0.009), p = 0.0006) and antipsychotic polypharmacy defined as taking ≥2 antipsychotics (OR = 1.10, CI = 1.05-1.21, p = 0.0073). The direction of effect was similar in all five independent cohorts. These findings indicate that genotypes may aid clinically relevant decisions on individual patients´ antipsychotic treatment. Further, the findings illustrate how real-world data have the potential to generate results needed for future precision medicine approaches in psychiatry.

Consensus Paper: Cerebellum and Reward

Cerebellum is a key-structure for the modulation of motor, cognitive, social and affective functions, contributing to automatic behaviours through interactions with the cerebral cortex, basal ganglia and spinal cord. The predictive mechanisms used by the cerebellum cover not only sensorimotor functions but also reward-related tasks. Cerebellar circuits appear to encode temporal difference error and reward prediction error. From a chemical standpoint, cerebellar catecholamines modulate the rate of cerebellar-based cognitive learning, and mediate cerebellar contributions during complex behaviours. Reward processing and its associated emotions are tuned by the cerebellum which operates as a controller of adaptive homeostatic processes based on interoceptive and exteroceptive inputs. Lobules VI-VII/areas of the vermis are candidate regions for the cortico-subcortical signaling pathways associated with loss aversion and reward sensitivity, together with other nodes of the limbic circuitry. There is growing evidence that the cerebellum works as a hub of regional dysconnectivity across all mood states and that mental disorders involve the cerebellar circuitry, including mood and addiction disorders, and impaired eating behaviors where the cerebellum might be involved in longer time scales of prediction as compared to motor operations. Cerebellar patients exhibit aberrant social behaviour, showing aberrant impulsivity/compulsivity. The cerebellum is a master-piece of reward mechanisms, together with the striatum, ventral tegmental area (VTA) and prefrontal cortex (PFC). Critically, studies on reward processing reinforce our view that a fundamental role of the cerebellum is to construct internal models, perform predictions on the impact of future behaviour and compare what is predicted and what actually occurs.

Risk factors, clinical correlates, and social functions of Chinese schizophrenia patients with drug-induced parkinsonism: A cross-sectional analysis of a multicenter, observational, real-world, prospective cohort study

Background: Drug-induced parkinsonism (DIP) is the most prevalent neurological side effect of antipsychotics in the Chinese population. Early prevention, recognition, and treatment of DIP are important for the improvement of treatment outcomes and medication adherence of schizophrenia patients. However, the risk factors of DIP and the impact on the clinical syndromes of schizophrenia remain unknown. Aim: The goal of this study was to explore the risk factors, clinical correlates, and social functions of DIP in Chinese schizophrenia patients. Methods: A cross-sectional analysis of a multicenter, observational, real-world, prospective cohort study of the Chinese schizophrenia population with a baseline assessment was conducted from the year 2012 to 2018. Participants were recruited from four mental health centers in Shanghai and totaled 969 subjects. Sociodemographic data, drug treatment, and clinical variables were compared between the DIP group and the non-DIP group. Variables that correlated with the induction of DIP, and with p≤ 0.1, were included in the binary logistic model for analyzing the risk factors of DIP. First generation antipsychotics (FGA)/second generation antipsychotics (SGA) model and high and low/medium D2 receptor antipsychotics were analyzed respectively to control the bias of co-linearity. All risk factors derived from the a forementioned models and clinical variables with p≤ 0.1 were included in the multivariate analysis of clinical correlates and social function of DIP patients. The Positive and Negative Syndrome Scale (PANSS) model and the personal and social performance (PSP) model were analyzed separately to control for co-linearity bias. Results: Age (OR = 1.03, p< 0.001), high D2 receptor antagonist antipsychotic dose (OR = 1.08, p = 0.032), and valproate dose (OR = 1.01, p = 0.001) were the risk factors of DIP. FGA doses were not a significant contributor to the induction of DIP. Psychiatric symptoms, including more severe negative symptoms (OR = 1.09, p< 0.001), lower cognition status (OR = 1.08, p = 0.033), and lower excited symptoms (OR = 0.91, p = 0.002), were significantly correlated with DIP induction. Social dysfunction, including reduction in socially useful activities (OR = 1.27, p = 0.004), lower self-care capabilities (OR = 1.53, p< 0.001), and milder disturbing and aggressive behavior (OR = 0.65, p< 0.001), were significantly correlated with induction of DIP. Valproate dose was significantly correlated with social dysfunction (OR = 1.01, p = 0.001) and psychiatric symptoms (OR = 1.01, p = 0.004) of DIP patients. Age may be a profound factor that affects not only the induction of DIP but also the severity of psychiatric symptoms (OR = 1.02, p< 0.001) and social functions (OR = 1.02, p< 0.001) of schizophrenia patients with DIP. Conclusion: Age, high D2 receptor antagonist antipsychotic dose, and valproate dose are risk factors for DIP, and DIP is significantly correlated with psychiatric symptoms and social performance of Chinese schizophrenia patients. The rational application or discontinuation of valproate is necessary. Old age is related to psychotic symptoms and social adaption in Chinese schizophrenic patients, and early intervention and treatment of DIP can improve the prognosis and social performance of schizophrenia patients. Clinical Trial Registration: Identifier: NCT02640911.

An Updated Analysis of Psychotropic Medicine Utilisation in Older People in New Zealand from 2005 to 2019

BACKGROUND

Psychotropic medicine utilisation in older adults continues to be of interest because of overuse and concerns surrounding its safety and efficacy.

OBJECTIVE

This study aimed to characterise the utilisation of psychotropic medicines in older people in New Zealand.

METHODS

We conducted a repeated cross-sectional analysis of national dispensing data from 1 January, 2005 to 31 December, 2019. We defined utilisation using the Anatomical Therapeutic Chemical classification defined daily dose system. Utilisation was measured in terms of the defined daily dose (DDD) per 1000 older people per day (TOPD).

RESULTS

Overall, the utilisation of psychotropic medicines increased marginally by 0.42% between 2005 and 2019. The utilisation increased for antidepressants (72.42 to 75.21 DDD/TOPD) and antipsychotics (6.06-19.04 DDD/TOPD). In contrast, the utilisation of hypnotics and sedatives (53.74-38.90 DDD/TOPD) and anxiolytics decreased (10.20-9.87 DDD/TOPD). The utilisation of atypical antipsychotics increased (4.06-18.72 DDD/TOPD), with the highest percentage change in DDD/TOPD contributed by olanzapine (520.6 %). In comparison, utilisation of typical antipsychotics was relatively stable (2.00-2.06 DDD/TOPD). The utilisation of venlafaxine increased remarkably by 5.7 times between 2005 and 2019. The utilisation of zopiclone was far greater than that of other hypnotics in 2019.

CONCLUSIONS

There was only a marginal increase in psychotropic medicines utilisation from 2005 to 2019 in older adults in New Zealand. There was a five-fold increase in the utilisation of antipsychotic medicines. Continued monitoring of psychotropic medicine utilisation will be of interest to understand the utilisation of antidepressants and antipsychotic medicines during the coronavirus disease 2019 pandemic year.

Differentiating tardive dyskinesia: a video-based review of antipsychotic-induced movement disorders in clinical practice

Accurate diagnosis and appropriate treatment of tardive dyskinesia (TD) are imperative, as its symptoms can be highly disruptive to both patients and their caregivers. Misdiagnosis can lead to incorrect interventions with suboptimal or even deleterious results. To aid in the identification and differentiation of TD in the psychiatric practice setting, we review its clinical features and movement phenomenology, as well as those of other antipsychotic-induced movement disorders, with accompanying links to illustrative videos. Exposure to dopamine receptor blocking agents (DRBAs) such as antipsychotics or antiemetics is associated with a spectrum of movement disorders including TD. The differential diagnosis of TD is based on history of DRBA exposure, recent discontinuation or dose reduction of a DRBA, and movement phenomenology. Common diagnostic challenges are the abnormal behaviors and dyskinesias associated with advanced age or chronic mental illness, and other movement disorders associated with DRBA therapy, such as akathisia, parkinsonian tremor, and tremor related to use of mood stabilizing agents (eg, lithium, divalproex). Duration of exposure may help rule out acute drug-induced syndromes such as acute dystonia or acute/subacute akathisia. Another important consideration is the potential for TD to present together with other drug-induced movement disorders (eg, parkinsonism, parkinsonian tremor, and postural tremor from mood stabilizers) in the same patient, which can complicate both diagnosis and management. After documentation of the phenomenology, severity, and distribution of TD movements, treatment options should be reviewed with the patient and caregivers.

VMAT2 Inhibitors for the Treatment of Tardive Dyskinesia

Psychiatric nurses are at the forefront of optimizing psychiatric care, including educating patients and caregivers on the risks of antipsychotic-induced movement disorders such as tardive dyskinesia (TD). Nurses should be aware that all patients taking antipsychotics should be regularly monitored for the development of TD. Given the current pandemic and increase in telehealth, assessing for TD is challenging; however, evaluation can be successfully completed by implementing the best practices described in this paper. Once TD is diagnosed, nurses can reassure patients that safe and effective FDA-approved treatments for TD (e.g., valbenazine) are now available.

Paroxysmal Genetic Movement Disorders and Epilepsy

Paroxysmal movement disorders include paroxysmal kinesigenic dyskinesia, paroxysmal non-kinesigenic dyskinesia, paroxysmal exercise-induced dyskinesia, and episodic ataxias. In recent years, there has been renewed interest and recognition of these disorders and their intersection with epilepsy, at the molecular and pathophysiological levels. In this review, we discuss how these distinct phenotypes were constructed from a historical perspective and discuss how they are currently coalescing into established genetic etiologies with extensive pleiotropy, emphasizing clinical phenotyping important for diagnosis and for interpreting results from genetic testing. We discuss insights on the pathophysiology of select disorders and describe shared mechanisms that overlap treatment principles in some of these disorders. In the near future, it is likely that a growing number of genes will be described associating movement disorders and epilepsy, in parallel with improved understanding of disease mechanisms leading to more effective treatments.

Gabapentin-Induced Myokymia: A Case Report

BACKGROUND

Gabapentin is a commonly used medication for neuropathic pain and epilepsy that is prescribed by a wide range of medical specialties. Adverse effects including asterixis and myoclonus have been described in patients with chronic kidney disease, but myokymia has not been previously reported.

CASE PRESENTATION

A 69-year-old man with a history of traumatic brain injury, peripheral neuropathy, amnesia, and posttraumatic stress disorder presented to the hospital after multiple falls attributed to acute onset muscle spasms. He reported taking a total daily dose of 9600 mg of gabapentin, as prescribed. Physical examination demonstrated stimulus-sensitive myoclonus, painful muscle spasms in all extremities, and myokymia in his bilateral calves. Diffuse action tremors, as well as tongue tremors, were also observed.Initial workup, including basic laboratory investigations, brain imaging, and electroencephalogram, was unrevealing. Gabapentin toxicity was suspected, and a gabapentin holiday was initiated with the improvement of myokymia by hospital day 3. The patient was found to have a high gabapentin level (25.8 μg/mL; reference range, 2.0-20.0 μg/mL) measured the morning after hospital presentation. After restarting on a lower dose of gabapentin with multimodal pain control, the patient continued to improve with diminution of his myoclonus, tremor, and gait instability.

CONCLUSIONS

Myokymia is a newly described motor symptom associated with gabapentin toxicity. The mechanism of gabapentin-associated myokymia is currently unknown. A brief medication holiday resulted in the resolution of motor symptoms without significant withdrawal symptoms. Knowledge of this newly reported adverse manifestation can aid physicians in the diagnosis of gabapentin toxicity and prompt treatment, as gabapentin levels are not widely or immediately available.

Psychotropic Medications-Induced Tardive Dyskinesia and Associated Factors Among Patients with Mental Illness in Ethiopia

BACKGROUND

Tardive dyskinesia (TD) remains a significant burden especially among patients taking psychotropic medications, and it is associated with adverse effects that can lead to subjective suffering, stigma, poor compliance to medication, and poor quality of life. However, it is unrecognized and overlooked in clinical settings. So, this study aimed to assess the magnitude of tardive dyskinesia and associated factors among mentally ill patients attending follow-up treatment at Jimma University Medical Center Psychiatry clinic, Jimma, Southwest Ethiopia, 2019.

METHODS

Institutional-based cross-sectional study design was conducted in 417 samples. Participants were selected by systematic random sampling techniques. Data were collected by a semi-structured interviewer-administered questionnaire, and the document was reviewed to obtain the patient's profile. Tardive dyskinesia was assessed by using the Extrapyramidal Symptom Rating Scale after informed consent was obtained from respondents. Data entry was done by EpiData version 3.1, and analysis was done by using SPSS 22.0 statistical software. Binary logistic regression and multivariate logistic regression were used to see the association and to identify independent factors at a p-value of <0.05.

RESULTS

Prevalence of drug-induced tardive dyskinesia was 15.4% (CI 95%: 12.0, 19.3). Female, age range between 30 and 44 years, having a diagnosis of major depressive disorder with the psychotic feature, taking chlorpromazine equivalent dose ˃600mg, and taking anticholinergic medications were variables positively associated with tardive dyskinesia, whereas cigarette smoking was negatively associated with tardive dyskinesia.

CONCLUSION

The prevalence of drug-induced tardive dyskinesia in this study was high. Prescribing medications less than 600mg equivalent dose of chlorpromazine, giving attention for female patients, patients having a diagnosis of major depressive disorder, and reducing giving anticholinergic medications will be important measures for clinicians to reduce the occurrence of tardive dyskinesia.

Pediatric Anti-N-methyl-D-aspartate Receptor Encephalitis Mimicking Glutaric Aciduria Type 1: A Case Report

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an immune-mediated disease that induces a wide spectrum of symptoms, especially in toddlers. These include acute-onset movement disorders, with neurological regression, and other associated neurological symptoms. Anti-NMDAR encephalitis remains a diagnostic challenge, especially in toddlers, with better prognosis associated with early treatment. We report the case of a 15-months-old boy who initially presented with vomiting and later with acute-onset dystonia after the administration of antiemetics. Within 14 days, the patient developed neuropsychomotor developmental regression and worsening dystonia. After ruling out an acute dystonic reaction and glutaric acidemia type 1 (GA-1), a final diagnosis of anti-NMDAR encephalitis was made. The patient responded well to immunomodulatory therapy. The present case underscores the importance of early treatment for patient prognosis and of including anti-NMDAR encephalitis in the differential diagnosis of acute-onset movement disorders.

Mirtazapine-associated movement disorders: A literature review

Mirtazapine (MTZ) is an atypical antidepressant approved by the FDA, which mechanism of action involves the antagonism of alpha-2, H1, 5-HT2A, 5-HT2C, and 5-HT3 receptors. In this context, the aim of this literature review is to evaluate the clinical epidemiological profile, pathological mechanisms, and management of MTZ-associated movement disorders (MDs). Relevant reports of six databases were identified and assessed by two reviewers without language restriction. Fifty-two reports containing 179 cases from 20 countries were assessed. The mean age was 57 year (range, 17-85). The majority of the individuals were female (60%) and of European origin. The mean time from MTZ start to symptom onset was 7.54 days; the time from management to MD improvement was within one week in 82.60% of the individuals. The MDs associated with MTZ were 69 restless legs syndrome (RLS), 35 tremors, 10 akathisia (AKT), 9 periodic limb MD, 6 dystonia, 4 rapid eye movement sleep behavior disorders, 3 dyskinesia, 2 parkinsonism, and 1 tic, and in the group not clearly identified, 18 restlessness, 15 hyperkinesis, and 1 extrapyramidal symptom. In the literature, the majority of the reports lack important information about the neurological examination. The management should be the MTZ withdrawal, except in RLS that other options are possible. In AKT, the MTZ should not be rechallenge, and if available, the prescription of a benzodiazepine may reduce recovery time.

Psychotropic medications induced parkinsonism and akathisia in people attending follow-up treatment at Jimma Medical Center, Psychiatry Clinic

OBJECTIVE

To determine the magnitude and factors associated with psychotropic drug-induced parkinsonism and akathisia among mentally ill patients.

METHODS

A hospital-based cross-sectional study was conducted with a total of 410 participants attending a follow-up treatment service at Jimma Medical Center, a psychiatry clinic from April to June 2019. Participants were recruited using a systematic random sampling method. Drug-induced parkinsonism and akathisia were assessed using the Extra-pyramidal Symptom Rating Scale. Substance use was assessed using the World Health Organization Alcohol, Smoking, and Substance Involvement Screening Test. Data entry was done using EpiData version 3.1, and analysis done by the Statistical Package for Social Sciences version 22. Statistically, the significant association was declared by adjusted odds ratio, 95% confidence interval, and p-value less than or equal to 0.05.

RESULTS

The mean age of the respondents was 33.3 years (SD ± 8.55). Most of the participants 223 (54.4%) had a diagnosis of schizophrenia. The prevalence of drug-induced parkinsonism was 14.4% (95% CI: 11.0 to 18.0) and it was 12.4% (95% CI: 9.3 to 15.4) for drug-induced akathisia. The result of the final model found out drug-induced parkinsonism was significantly associated with female sex, age, type of antipsychotics, physical illness, and anti-cholinergic medication use. Similarly, female sex, chlorpromazine equivalent doses of 200 to 600 mg, combined treatment of sodium valproate with antipsychotic, and severe khat/Catha edulis use risk level was significantly associated with akathisia.

CONCLUSION

One of seven patients developed drug-induced parkinsonism and akathisia. Careful patient assessment for drug-induced movement disorders, selection of drugs with minimal side effects, screening patients for physical illness, and psycho-education on substance use should be given top priority.

Geriatric oral and maxillofacial dysfunctions in the context of geriatric syndrome

OBJECTIVES

To propose the application of the concept of geriatric syndrome for common geriatric oral and maxillofacial dysfunctions and to suggest the necessity of developing effective evaluation methods for oral and maxillofacial frailty.

DESIGN

The concepts of frailty and geriatric syndrome based on multi-morbidity and polypharmacy were applied to five common geriatric oral medicinal dysfunctional problems: salivary gland hypofunction (dry mouth), chronic oral mucosal pain disorders (burning mouth symptoms), taste disorders (taste disturbances), swallowing disorders (dysphagia), and oral and maxillofacial movement disorders (oromandibular dyskinesia and dystonia).

RESULTS

Each of the dysfunctions is caused by various kinds of diseases and/or conditions and medications, thus the concept of geriatric syndrome could be applied. These dysfunctions, suggested as components of oral and maxillofacial geriatric syndrome, are associated and interacted with each other in a complexity of vicious cycle. The resulting functional impairments caused by this syndrome can cause oral and maxillofacial frailty.

CONCLUSIONS

Geriatric oral and maxillofacial dysfunctions could be better appreciated in the context of geriatric syndrome. The development of effective methods for evaluating the severity of these dysfunctions and the resulting frailty is essential.

Blepharospasm 40 years later

Forty years ago, C.D. Marsden proposed that blepharospasm should be considered a form of adult-onset focal dystonia. In the present paper, we provide a comprehensive overview of the findings regarding blepharospasm reported in the past 40 years. Although prolonged spasms of the orbicularis oculi muscles remain the clinical hallmark of blepharospasm, patients with blepharospasm may be characterized by various types of involuntary activation of periocular muscles. In addition to motor features, blepharospasm patients may also have nonmotor manifestations, including psychiatric, mild cognitive, and sensory disturbances. The various motor and nonmotor symptoms are not present in all patients, suggesting that blepharospasm is phenomenologically a heterogeneous condition. This emphasizes the need for tools for severity assessment that take into account both motor and nonmotor manifestations. The cause of blepharospasm remains elusive, but several lines of evidence indicate that blepharospasm is a multifactorial condition in which one, or several, as yet unknown genes together with epigenetic and environmental factors combine to reach the threshold of the disease. Although blepharospasm was originally believed to be solely a basal ganglia disorder, neurophysiological and neuroimaging evidence point to anatomical and functional involvement of several brain regions. The contribution of multiple areas has led to the hypothesis that blepharospasm should be considered as a network disorder, and this might reflect the varying occurrence of motor and nonmotor manifestations in blepharospasm patients. Despite advances in the aetiology and pathophysiology, treatment remains symptomatic. © 2017 International Parkinson and Movement Disorder Society.

Genetics of Common Antipsychotic-Induced Adverse Effects

The effectiveness of antipsychotic drugs is limited due to accompanying adverse effects which can pose considerable health risks and lead to patient noncompliance. Pharmacogenetics (PGx) offers a means to identify genetic biomarkers that can predict individual susceptibility to antipsychotic-induced adverse effects (AAEs), thereby improving clinical outcomes. We reviewed the literature on the PGx of common AAEs from 2010 to 2015, placing emphasis on findings that have been independently replicated and which have additionally been listed to be of interest by PGx expert panels. Gene-drug associations meeting these criteria primarily pertain to metabolic dysregulation, extrapyramidal symptoms (EPS), and tardive dyskinesia (TD). Regarding metabolic dysregulation, results have reaffirmed HTR2C as a strong candidate with potential clinical utility, while MC4R and OGFR1 gene loci have emerged as new and promising biomarkers for the prediction of weight gain. As for EPS and TD, additional evidence has accumulated in support of an association with CYP2D6 metabolizer status. Furthermore, HSPG2 and DPP6 have been identified as candidate genes with the potential to predict differential susceptibility to TD. Overall, considerable progress has been made within the field of psychiatric PGx, with inroads toward the development of clinical tools that can mitigate AAEs. Going forward, studies placing a greater emphasis on multilocus effects will need to be conducted.