Clinical Spectrum of Drug-Induced Movement Disorders: A Study of 97 Patients

Putative Mechanism of Action of Trazodone-Related Oromandibular Dyskinesia

This is a case report of three cases of trazodone-induced buccal-lingual dyskinesias. Each case demonstrated the distinct pattern of the development of this dyskinesia after trazodone exposure for several months. All cases showed abrupt cessation of the movement disorder when the drug was discontinued. One of the three cases demonstrated a highly unusual presentation of an on/off pattern of buccal dyskinesia directly related to repetitive exposure and termination of the drug trazodone. Two of the three cases had no prior exposure to any dopamine blocking agents. One of the three had a distant exposure to a dopamine antagonist. As opposed to other antidepressants, trazodone has a mechanism of action which can account for both the development and treatment of dyskinetic movements. Its metabolite, M/chlorophenylpiperazine (M-CPP) is a 5HT2C agonist capable of causing abnormal oral-facial movements in rodent models. The presence of oromandibular dyskinetic movements can occur spontaneously with age, with trazodone being a potential predisposing factor. This article will discuss proposed mechanisms for trazodone's action with an emphasis on case reports of dystonic movements.

Phenomenology, quality of life, and predictors of reversibility in patients with drug-induced movement disorders: a prospective study

BACKGROUND

Drug-induced movement disorders (DIMDs) form an important subgroup of secondary movement disorders, which despite conferring a significant iatrogenic burden, tend to be under-recognized and inappropriately managed.

OBJECTIVE

We aimed to look into phenomenology, predictors of reversibility, and its impact on the quality of life of DIMD patients.

METHODS

We conducted the study in the Department of Neurology at a tertiary-care centre in India. The institutional ethics-committee approved the study. We assessed 55-consecutive DIMD patients at presentation to our movement disorder clinic. Subsequently, they followed up to evaluate improvement in severity-scales (UPDRS, UDRS, BARS, AIMS) and quality of life (EuroQol-5D-5L). Wilcoxan-signed-rank test compared the scales at presentation and follow-up. Binary-logistic-regrerssion revealed the independent predictors of reversibility.

RESULTS

Fourteen patients (25.45%) had acute-subacute DIMD and 41 (74.55%) had tardive DIMD. Tardive-DIMD occurred more commonly in the elderly (age 50.73±16.92 years, p<0.001). Drug-induced-Parkinsonism (DIP) was the most common MD, followed by tardivedyskinesia. Risperidone and levosulpiride were the commonest culprit drugs. Patients in both the groups showed a statistically significant response to drug-dose reduction /withdrawal based on follow-up assessment on clinical-rating-scales and quality of life scores (EQ-5D-5L). DIMD was reversible in 71.42% of acute-subacute DIMD and 24.40% of patients with chronic DIMD (p=0.001). Binary-logistic-regression analysis showed acute-subacute DIMDs and DIP as independent predictors of reversibility.

CONCLUSION

DIP is the commonest and often reversible drug-induced movement disorder. Levosulpiride is notorious for causing DIMD in the elderly, requiring strict pharmacovigilance.

Overview of Movement Disorders Secondary to Drugs

Drug-induced movement disorders affect a significant percentage of individuals, and they are commonly overlooked and underdiagnosed in clinical practice. Many comorbidities can affect these individuals, making the diagnosis even more challenging. Several variables, including genetics, environmental factors, and aging, can play a role in the pathophysiology of these conditions. The Diagnostic and Statistical Manual of Mental Disorders (DSM) and the International Statistical Classification of Diseases and Related Health Problems (ICD) are the most commonly used classification systems in categorizing drug-induced movement disorders. This literature review aims to describe the abnormal movements associated with some medications and illicit drugs. Myoclonus is probably the most poorly described movement disorder, in which most of the reports do not describe electrodiagnostic studies. Therefore, the information available is insufficient for the diagnosis of the neuroanatomical source of myoclonus. Drug-induced parkinsonism is rarely adequately evaluated but should be assessed with radiotracers when these techniques are available. Tardive dyskinesias and dyskinesias encompass various abnormal movements, including chorea, athetosis, and ballism. Some authors include a temporal relationship to define tardive syndromes for other movement disorders, such as dystonia, tremor, and ataxia. Antiseizure medications and antipsychotics are among the most thoroughly described drug classes associated with movement disorders.

Fluoroquinolone-Associated Movement Disorder: A Literature Review

BACKGROUND

Fluoroquinolones (FQNs) are related to several central nervous system side effects. This review aims to evaluate the clinical-epidemiological profile, pathophysiological mechanisms, and management of FQNs-associated movement disorders (MDs).

METHODS

Two reviewers identified and assessed relevant reports in six databases without language restriction between 1988 and 2022.

RESULTS

A total of 45 reports containing 51 cases who developed MDs secondary to FQNs were reported. The MDs included 25 myoclonus, 13 dyskinesias, 7 dystonias, 2 cerebellar syndromes, 1 ataxia, 1 tic, and 2 undefined cases. The FQNs reported were ciprofloxacin, ofloxacin, gatifloxacin, moxifloxacin, levofloxacin, gemifloxacin, and pefloxacin. The mean and median age were 64.54 (SD: 15.45) and 67 years (range: 25-87 years). The predominant sex was male (54.16%). The mean and median time of MD onset were 6.02 (SD: 10.87) and 3 days (range: 1-68 days). The mean and median recovery time after MD treatment was 5.71 (SD: 9.01) and 3 days (range: 1-56 days). A complete recovery was achieved within one week of drug withdrawal in 80.95% of the patients. Overall, 95.83% of the individuals fully recovered after management.

CONCLUSIONS

Future cases need to describe the long-term follow-up of the individuals. Additionally, FQN-induced myoclonus should include electrodiagnostic studies.

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.

A new era in the diagnosis and treatment of tardive dyskinesia

Tardive dyskinesia (TD) is a heterogeneous, hyperkinetic movement disorder induced by dopamine-receptor blocking agents that presents a unique challenge in the treatment of psychosis. Although acceptance of TD as a serious consequence of antipsychotic treatment was resisted initially, subsequent research by many investigators in psychopharmacology contributed to a rich store of knowledge on many aspects of the disorder. While basic neuroscience investigations continue to deepen our understanding of underlying motor circuitry, past trials of potential treatments of TD focusing on a range of theoretical targets were often inconclusive. Development of newer antipsychotics promised to reduce the risk of TD compared to older drugs, but their improved tolerability unexpectedly enabled an expanding market that paradoxically both increased the absolute number of patients at risk and diminished attention to TD which was relegated to legacy status. Fortunately, development and approval of novel vesicular monoamine transporter inhibitors offered evidence-based symptomatic treatment of TD for the first time and rekindled interest in the disorder. Despite recent progress, many questions remain for future research including the mechanisms underlying TD, genetic predisposition, phenomenological diversity, whether new cases are reversible, how to implement best practices to prevent and treat TD, and whether the development of novel antipsychotics free of the risk of TD is attainable. We owe our patients the aspirational goal of striving for zero prevalence of persistent symptoms of TD in anyone treated for psychosis.

Phenytoin-associated movement disorder: A literature review

Phenytoin (PHT) was first synthesized as a barbiturate derivative and was approved in 1953 by the Food and Drug Administration. This work aimed to review the pathophysiology, epidemiology, clinical presentation, and treatment of PHT-associated movement disorders (MDs). Studies were searched in relevant databases (ScienceDirect, Google Scholar, Excerpta Medica, Latin American and Caribbean Health Sciences Literature, Medline, and Scientific Electronic Library Online) and were selected by two reviewers irrespective of language between 1963 and 2021. Papers of PHT-induced ataxia alone or tremor were excluded. In total, 127 reports with 219 individuals who developed MDs associated with PHT were encountered. MDs found: 126 dyskinesias, 49 myoclonus, 19 dystonia, 14 parkinsonism, 6 tics, 3 stuttering, and 2 restless legs syndrome. The mean age was 35 years (standard deviation [SD]: 23.5) and the predominant sex was male (53.4%). The mean PHT dose when the MD took place was 370.4 mg (SD: 117.5). A serum PHT concentration was reported in 103 cases, ranging from 4 to 110 μg/mL (median: 27.7 μg/mL). No significant relationship was found between PHT dose and age or PHT level. The mean onset time of PHT-associated MD was 23.4 months (SD: 4.4). The mean recovery time after MD management was 3.7 weeks (SD: 1.1). Regarding management, the most common form was PHT withdrawal in 90.4%. 86.3% of the individuals recovered fully. PHT-induced MD was extensively reported in the literature. Only general terms were used in the majority of the reports. The mechanisms underlying the adverse events caused by PHT probably depend on the presence of predisposing factors.

A Rare Case of Domperidone-Induced Acute Dystonia in a Young Adult Due to Consumption of Combination Drug (Proton Pump Inhibitors With Domperidone) and Its Possible Pathomechanism

Globally, a substantial number of people are tormented by dystonia. Domperidone, a D-2 receptor antagonist acts outside the blood-brain barrier in the brain stem as well as on the gastrointestinal tract. In India, domperidone is conveniently obtainable over the counter as a combination drug with proton pump inhibitors (PPIs) for dyspepsia and gastro-esophageal reflux disease. We present a rare case of domperidone-induced acute dystonia in a young adult presented within 72 hours after consuming two oral doses of this combination drug (PPIs with domperidone) for dyspepsia. Drug-induced extra pyramidal symptoms (EPS) are often misdiagnosed as some psychiatric condition and undoubtedly its expeditious diagnosis staves off unnecessary investigations and ameliorates prognosis. Our case ignites alertness amongst practitioners in India over the judicious use of PPIs with domperidone as the latter may trigger EPS. Such combination drugs can be prescribed if absolutely mandatory by the treating physician. The possible pathomechanism of this hyperkinetic motor phenomenon, perturbing the equilibrium of the cortical-subcortical circuit and resulting in an overflow of muscular activity, is attempted to be explained here, although the explicit mechanism is still blurry.