Anticonvulsant medications: an iatrogenic cause of tic disorders

Movement disorders associated with antiseizure medications: A systematic review

New-onset movement disorders have been frequently reported in association with the use of antiseizure medications (ASMs). The frequency of specific motor manifestations and the spectrum of their semiology for various ASMs have not been well characterized. We carried out a systematic review of literature and conducted a search on CINAHL, Cochrane Library, EMBASE, MEDLINE, PsycINFO, and Scopus from inception to April 2021. We compiled the data for all currently available ASMs using the conventional terminology of movement disorders. Among 5123 manuscripts identified by the search, 437 met the inclusion criteria. The largest number of reports of abnormal movements were in association with phenobarbital, valproic acid, lacosamide, and perampanel, and predominantly included tremor and ataxia. The majority of attempted interventions for all agents were discontinuation of the offending drug or dose reduction which led to the resolution of symptoms in most patients. Familiarity with the movement disorder phenomenology previously encountered in relation with specific ASMs facilitates early recognition of adverse effects and timely institution of targeted interventions.

Lacosamide-Induced Dyskinesia in Children With Intractable Epilepsy

Lacosamide, an antiepileptic drug prescribed for children with refractory focal epilepsy, is generally well tolerated, with dose-dependent adverse effects. We describe 4 children who developed a movement disorder in conjunction with the initiation and/or uptitration of lacosamide. Three patients developed dyskinesias involving the face or upper extremity whereas the fourth had substantial worsening of chronic facial tics. The patients all had histories suggestive of opercular dysfunction: 3 had seizure semiologies including hypersalivation, facial and upper extremity clonus while the fourth underwent resection of polymicrogyria involving the opercula. Onset, severity, and resolution of dyskinesias correlated with lacosamide dosing. These cases suggest that pediatric patients with dysfunction of the opercular cortex are at increased risk for developing drug-induced dyskinesias on high-dose lacosamide therapy. Practitioners should be aware of this potential side effect and consider weaning lacosamide or video electroencephalography (EEG) for differential diagnosis, particularly in pediatric patients with underlying opercular dysfunction.

Tics and other stereotyped movements as side effects of pharmacological treatment

Tics and other stereotyped abnormal movements can be seen as adverse effects of some pharmacologic drugs. Among these drugs, antipsychotics may provoke tardive syndromes after a chronic exposure, primarily in the case of typical antipsychotics. These syndromes include tardive tics, tardive dyskinesia, or tardive akathisia, which present with tics or stereotyped movements as a clinical phenomenon. Psychostimulants (mainly methylphenidate) have traditionally been associated with the appearance of tics due to the increased dopamine activity caused by stimulants. Nevertheless, in recent years, several studies have concluded not only that methylphenidate does not exacerbate or reactivate tics but also that tics can improve with its use in patients with associated attention deficit and hyperactivity disorder and tic disorder. Antiepileptic drugs, although infrequently, can also induce tics, with carbamazepine and lamotrigine described as tic inducers. Other antiepileptics, including levetiracetam and topiramate, have been proposed as a potential treatment for tic disorders due to a positive effect on tics, especially in those with associated epileptic disorder. Clinical and therapeutic approaches to tics and stereotyped movements after exposure to antipsychotics, stimulants, and antiepileptic drugs will be reviewed in this chapter.

Drug-induced hyperkinetic movement disorders by nonneuroleptic agents

Hyperkinetic movement disorders are characterized by excess movement, and include chorea, akathesia, asterixis, dystonia, tremor, myoclonus, and tics. A wide variety of pharmacologic agents may induce or exacerbate these disorders. Neuroleptic-induced tardive dyskinesia and levodopa-induced hyperkinesia are the most common causes of medication-induced chorea. However, several nonneuroleptic agents, including antidepressants and antiepileptic medications, may also worsen hyperkinetic movement disorders. Over-the-counter medications, such as analgesics and antiheartburn medications, have also occasionally been implicated as causing hyperkinetic movement disorders. Most information regarding drug-induced hyperkinetic disorders comes from case reports and anecdotes, rather than controlled clinical trials. Further research with larger controlled trials needs to verify many of these findings.

An overview of the treatment of Tourette's disorder and tics

OBJECTIVE

The aim of this study was to review the efficacy of various treatments for Tourette's disorder (TD) and tics.

METHOD

This study is a historical review of the treatment modalities prior to the advent of neuroleptics. A review of double-blind and placebo-controlled clinical trials and open studies on the use of neuroleptics and selected reports was also carried out.

RESULTS

The literature review reveals that the treatment of TD and tics has evolved from an early history of marginally effective approaches to the advent of neuroleptics, which started a new era in TD and tic treatment, with a significantly broader range of effectiveness.

CONCLUSIONS

Although progress has been made, the literature review nevertheless reveals a great deal of confusion as related to the clinical heterogeneity of TD and tics, differences in populations, medication-dose combinations, and outcomes. However, a role for a limited number of pharmacologic agents, combined with psychosocial approaches, has been identified. There is a need for studies in larger, diagnostically homogenous samples and for the use of more sophisticated methodology, to identify intelligible models that would allow the development of more effective treatment approaches.

Tourette syndrome and comorbid early-onset schizophrenia

OBJECTIVE

A study of the shared phenomenology between Tourette syndrome (TS) and schizophrenia.

METHOD

An illustrative case report is presented. We used a chart review of 399 clinically ascertained patients with TS to identify 10 cases meeting criteria for schizophrenia. From our 10 patients, salient clinical characteristics were then tabulated. We then extracted similar clinical characteristics from a previously published series of patients with comorbid TS and schizophrenia in order to combine cases and allow for a comparison between childhood-onset schizophrenia (COS), adolescent-onset schizophrenia (AdolOS), and adult-onset schizophrenia (AduOS) cases in these groups.

RESULTS

We found 10 cases of schizophrenia (all were males) in the 399 TS patients for a prevalence rate of 2.5% (95% CI 0.96-4.04). Mean age of tic onset for TS diagnostic criteria ranged from 2-14 years with a mean of 8.2 years. The mean age of diagnosis for schizophrenia was 14.2 (range 9-23 years). We found six cases of schizophrenia with onset of positive psychotic symptoms by 13 years of age, two cases with onset after 13 years of age and before 18 years of age, and two cases with onset after 18 years of age. Attention deficit hyperactivity disorder was present at a higher rate (70%) than one would expect in a clinically ascertained group of patients with TS. Comparison between COS, AdolOS and AduOS in our pooled cases noted a sex bias skewed toward males. Catatonic symptoms may be more likely in child or adolescent onset cases and negative symptoms more likely in AduOS cases.

CONCLUSIONS

The 2.5% prevalence of schizophrenia in our TS sample exceeds the 1% expected rate of schizophrenia in the general population (chi-square=9.14; P=.0025). The six cases of COS (before 13 years of age) exceeds the expected rate of 1-2 per 100,000 (chi-square=4499; P=.0001). The 752-fold increase in observed rates of comorbid TS and COS over expected rates suggests a role for unknown common underlying etiologic factors. Based on clinical features, patients with TS and comorbid COS, AdolOS, or AduOS do not have different conditions. We conclude with suggestions for further research.

Pharmacological management of tics in patients with TS

This article reviews the evidence published in the English language literature concerning the pharmacological treatment of tics in patients with Tourette Syndrome. The focus is on the efficacy and safety of the current treatments. A clinical approach to pharmacological management of Tourette Syndrome patients is outlined.

Anticonvulsant-induced dyskinesia

Anticonvulsant-induced dyskinesia (AID) is an underdiagnosed side effect of many anticonvulsants that may take place during initial or chronic treatment at normal or toxic drug levels. The occurrence of AID subjects the patient to another medical condition and may prompt an extensive work-up. Similarities with other drug-induced dyskinesias and some animal studies suggest that dopaminergic dysfunction in the basal ganglia is pivotal in the occurrence of dyskinesia. Clinical presentation and outcomes are variable; however, in most cases, dyskinesias respond well to anticonvulsant withdrawal. Enhancing the awareness of AID is important in light of the recent development of many new anticonvulsants and their wider clinical use.

Mercury intoxication presenting with tics

A 5 year old Chinese boy presented with recurrent oral ulceration followed by motor and vocal tics. The Chinese herbal spray he used for his mouth ulcers was found to have a high mercury content. His blood mercury concentration was raised. Isolated tics as the sole presentation of mercury intoxication has not previously been reported.

Lamotrigine-induced tic disorder: report of five pediatric cases

PURPOSE

To describe the clinical spectrum of lamotrigine (LTG)-induced tics (an uncommon side effect) in children.

METHODS

Retrospective analysis of patients from our hospital-based practice who developed tics while on LTG. Data obtained from medical records, interviews with parents, video-EEGs, and homemade videotapes.

RESULTS

Three males and two females (range, 2.5-12 years; mean, 6.9 years) developed a movement disorder within the first 10 months of therapy (maintenance doses, 4-17 mg/kg/day). Four patients exhibited simple motor tics; one patient experienced mostly vocal (i.e., gasping sounds) tics. Laryngoscopic evaluation of one 2.5-year-old with repetitive gasping sounds was normal. In three cases, tics resolved completely within 1 month of drug cessation; tics recurred in two of these patients after reintroduction of LTG. A fourth patient experienced gradual improvement after stopping LTG over 4 months; the fifth patient's simple motor tics improved spontaneously with a reduction in medication. None of the patients had clinical features of a neurodegenerative disorder, and none met diagnostic criteria for Tourette syndrome. Two patients, however, had a diagnosis of acquired epileptic aphasia syndrome, and one patient had nonprogressive expressive and receptive language dysfunction. A fourth patient had global static encephalopathy, and the fifth patient had only attentional problems. In all patients, tics were not associated with ictal EEG changes.

CONCLUSIONS

LTG may infrequently induce simple motor tics, vocal tics, or both. Patients with severe language dysfunction may be particularly susceptible to this uncommon side effect. Further studies are necessary to clarify the population at risk.

Tourette syndrome. Secondary tic disorders

The putative relationship between a variety of neurologic and neuropsychiatric disorders, which have been reported in association with tics, is reviewed. Tics also may be increased or exacerbated by drugs affecting a variety of neurotransmitter systems. Recognition and study of these secondary tic disorders may further our understanding of basal ganglia physiology and the pathogenesis of Tourette syndrome.

Tic disorders in childhood (and beyond)

Tic disorders are classified into three main categories: transient (duration more than 1 month but less than 1 year), chronic (duration more than 1 year), and Tourette's syndrome (multiple motor and vocal tics lasting more than 1 year to life). Typically, symptoms increase with emotional stress, diminish with distraction or concentration, and disappear during sleep. Because of the risks involved and the lack of any truly curative value, drug therapy should be used only when tics are seriously disabling. Haloperidol (Haldol), the most widely prescribed medication, is efficacious in about 80% of patients with Tourette's syndrome. Psychotherapy is not effective as a primary therapeutic strategy; it may, however, be indicated in selected cases to relieve the grief and frustration of parents and to help affected children deal with the disorder.

A clinical pharmacological approach to treating Tourette syndrome in children and adolescents

Tourette Syndrome (TS) is a neuropsychiatric movement disorder characterized by the presence of multiple motor and phonic tics. Monoamine neurotransmitter dysfunction has been implicated in the expression of the condition. Standard as well as novel pharmacologic treatments for TS as a sole entity or as a condition co-morbid with attention deficit-hyperactivity disorder (ADHD) and/or obsessive-compulsive disorder (OCD) target these presumed neurotransmitter abnormalities. Choice of a specific medication is also predicated upon an individual patient's symptom profile, a cost-benefit analysis of desired effects versus side effects, and the impact on co-morbid conditions. Maximum involvement of the patient and parent or significant other is encouraged. It is emphasized that pharmacologic treatment is primarily symptomatic, usually not affecting the longer term outcome of specific syndromes per se. The integration of pharmacologic with psychoeducational interventions is encouraged.