Drug-induced Movements Research Articles

Beyond tics: movement disorders in patients with Tourette syndrome.

Tics are the hallmark of Tourette syndrome (TS). However, TS patients may have a particular vulnerability to develop other movement disorders (MDs), such as dystonia, chorea, stereotypy, and other hyperkinetic disorders that may be wrongly attributed to tics. We studied a cohort of 201 patients with motor and phonic tics associated with TS to determine if they have additional, co-existent, MDs. There were 67 (33.3%) patients with comorbid non-tic MDs. Phenomenology-wise, piano-playing movements resembling chorea or myoclonus, were the most common non-tic movement, observed in 11% of cases, followed by stereotypies (8.0%), tremor, dystonia and parkinsonism, 5.0% each. Drug-induced was the most common etiology (6.0%), followed by functional movement disorders (5.0%) and tardive phenomena (5.0%). No clear etiology was identified in most patients. Piano-playing movements, were associated with a younger age at onset (P = 0.004) and younger age at presentation (P < 0.001). Patients with drug-induced movements and tardive phenomena had a lower frequency of craniofacial tics. FMDs, and idiopathic MDS showed no specific associations with TS. Tic severity was not a predictor of any co-existent MD. About a third of patients with TS present with comorbid MDs which should be differentiated and distinguished from tics as their etiopathogenesis and treatment may be different.

RE-KINECT, A REAL-WORLD, PROSPECTIVE TARDIVE DYSKINESIA SCREENING STUDY: AN EVALUATION OF BASELINE CHARACTERISTICS IN OLDER PATIENTS

Introduction Older age is a risk factor for developing tardive dyskinesia (TD), a persistent movement disorder associated with prolonged exposure to antipsychotics. In older patients, TD symptoms may appear after shorter antipsychotic treatment. RE-KINECT (NCT03062033), a real-world study of outpatients prescribed antipsychotics, was designed to identify the presence of drug-induced involuntary movements consistent with TD (i.e., “possible TD”) and to characterize the impact of these movements on health-related quality of life. Baseline data from RE-KINECT were analyzed to explore the patient experience of possible TD and how it affects functioning in older adults (≥55 years). Methods Adults with ≥3 months of lifetime exposure to antipsychotics and ≥1 psychiatric disorder were recruited. The presence of possible TD was based on clinicians’ observation and assessment of involuntary movements in 4 body regions (head/face, trunk/neck, upper extremities, and lower extremities). Patients were categorized into Cohort 1 (without visible movements or possible TD) or Cohort 2 (with visible movements and confirmed by clinician as consistent with possible TD). Baseline outcomes for all patients included demographics, clinical history, patient-reported health status (score range, 0 [“no health problems”] to 10 [“health as bad as you can imagine”]), and the patient-reported EuroQoL 5-Dimensional 5-Level questionnaire (EQ-5D-5L; domain score range, 1 [no problems or symptoms] to 5 [extreme problems or symptoms]). Clinicians also assessed the location and severity (ratings, “none”, “some”, or “a lot”) of abnormal movements in Cohort 2 patients. Exploratory statistical testing was conducted between older adults (≥55 years) in Cohorts 1 and 2. Results Of the 738 patients enrolled in the study, the results of those ≥55 years (N=300, 41%) are presented here. Within this subgroup, 114 (38%) had clinician-confirmed possible TD (Cohort 2) and 186 (62%) had no visible movements or had movements that were inconsistent with TD (Cohort 1). In Cohort 2 patients, the highest frequencies of severe abnormal movements (severity rating: “a lot”) were observed in the head/face (25%) and upper extremities (14%). Cohort 2 patients were less likely to be married, more likely to live in care homes, and were more likely to have longer lifetime exposure to antipsychotics than Cohort 1 patients (Table). More patients in Cohort 2 had schizophrenia or schizoaffective disorder, while those in Cohort 1 were more likely to have a mood disorder. Patients in Cohort 2 also had slightly higher mean EQ-5D-5L scores at baseline in four EQ-5D-5L domains, suggesting a somewhat greater impact on health-related quality of life, particularly in the domain of self-care. Conclusions Results from this real-world sample of older psychiatric outpatients suggest that the greater risk and severity of TD in this population may be associated with more limited support systems and reduced quality of life, which are separate from the effects of age itself. This research was funded by This research was fully funded by Neurocrine Biosciences, Inc.

38.2 Commonly Occurring Movement Disorders in Children: Prevalence, Identification, Measures Used to Understand the Movements, and How to Evaluate

At the conclusion of this presentation, participants will be able to do the following: 1) identify tools for measuring abnormal movements in youth with mental illnesses; 2) identify associated movements with ASD, Tourette's disorder, and drug-induced movements in this population; and 3) identify appropriate treatment or referral decision based on the clinical presentation and type of abnormal movement. Abnormal movements in youth can be part of several neuropsychiatric conditions, such as Tourette's disorder and ASD, or an adverse effect of medication. This presentation will focus on teaching the various forms of abnormal movements in clinical practice.

Drug-induced purposeless chewing: animal model of dyskinesia or nausea?

Drug-induced purposeless chewing movements in rodents are often considered to represent movement disorders or dyskinesias. We have compared the ability of drugs to induce chewing and retching or emesis in squirrel monkeys; such studies are not possible in rodents, which do not vomit. Acute administration of oxotremorine (3.3-33 micrograms/kg IM), SKF38393 (1-30 mg/kg SC) or ipecacuanha (0.5-0.75 mg/kg PO) caused dose-related increases in purposeless chewing which was frequently associated with retching and emesis. Treatment with haloperidol (0.015-0.06 mg/kg IM) did not induce chewing. Rather, haloperidol decreased spontaneous chewing at doses of 0.03 and 0.06 mg/kg. Our findings indicate that at least some drug-induced oral behaviours in rodents may reflect nausea rather than dyskinesia.

Skin conductance responding in Schizophrenic patients with abnormal involuntary movements

The present study tested the hypothesis that neuroleptic treatment modifies the skin conductance response (SCR) to loud tones. Schizophrenic patients with and without drug-induced abnormal involuntary movements were tested before and after drug withdrawal. During the on-drugs session, habituation of SCR correlated with the daily neuroleptic dose, and patients with tardive dyskinesia (TD) showed the fastest habituation of SCR. These findings were interpreted as indicating that SCR is attenuated by neuroleptics present during the examination and that TD patients demonstrate a preferential susceptibility to this effect. Withdrawal of medication resulted in slowing of SCR habituation only in TD patients, following which the entire sample showed a similar rate of habituation. These findings suggest that accelerated SCR habituation is not a stable trait of TD patients.

Seizures during Opioid Anesthetic Induction—Are They Opioid-Induced Rigidity?

The tape recorded EEGs of 127 patients anesthetized with large doses of opioids were retrospectively analyzed for evidence of opioid-induced seizures, and in particular, correlated with movements that occurred during induction and could be clinically interpreted as seizures. Bilateral EEG leads in patients receiving fentanyl (20), sufentanil (20), or alfentanil (87) were recorded. Forty-six of these patients from all opioid groups manifested intense rigidity, as assessed both clinically and by EMGs recorded from eight muscles in 69 of the patients receiving alfentanil. This intense rigidity often resembled seizures, in that the phenomenon entailed severe stiffness of both limbs and trunk, with an explosive onset of myoclonic limb movements, and associated vertical nystagmus. Electroencephalographic observations were extensive, entailing 69 h of paper recordings played back from the tapes, at paper speeds of 30 or 60 mm/s, with detailed annotations from the voice track. These paper recordings were examined in detail independently by three of the investigators, who were unaware of the clinical phenomena that had occurred. The only observed EEG activity that could have been interpreted as epileptiform consisted of small sharp waves related to muscle activity or other artifact. The EEG never indicated seizure activity during these drug-induced movements and rigidity. Reports of opioid-induced seizures are reviewed and a set of criteria is offered to help achieve future consistency and credibility in evaluating this phenomenon. The available evidence does not support the existence of opioid-induced seizures in the clinical setting.