Selective mutism and obsessive compulsive disorders associated with zonisamide

Antiseizure medication-induced obsessive-compulsive disorder and tic disorder: a pragmatic review

INTRODUCTION

With a lifetime prevalence of 2.3%, obsessive compulsive disorder is a chronic, disabling condition that is associated with significant social and occupational impairment. Up to 30% of individuals with obsessive-compulsive disorder have a lifetime diagnosis of tic disorders. Antiseizure medication is increasingly used for a variety of physical and psychiatric illnesses. Clarification of the relationship between these symptoms/disorders and use of antiseizure medication is critically important for diagnostic and treatment purposes.

AREAS COVERED

Studies on antiseizure-induced obsessive-compulsive disorder and tic disorders are reviewed. The literature search strategy identified 89 articles. Twenty-nine articles were included in the final results. Of these, 24 are case reports or case studies, 2 cross-sectional studies, 1 chart review, 1 population-based case-control study and 1 observational prospective study assessing lamotrigine, levetiracetam, topiramate, zonisamide, and carbamazepine.

EXPERT OPINION

This study highlighted the temporal relationship of antiseizure medication use and onset of obsessive-compulsive symptoms and tics. Monitoring for medication-induced obsessive compulsions or tics should be undertaken when prescribing antiseizure medication for treatment of mood disorders or epilepsy. Further research identifying the causal relationship between antiseizure medication and de novo onset of obsessive-compulsive symptoms, obsessive-compulsive disorder and tic disorder is required.

Cognitive and Behavioral Comorbidities: An Unwanted Effect of Antiepileptic Drugs in Children

Epilepsy is one of the most common neurological disorders and, despite optimally chosen and dosed antiepileptic drugs (AEDs), approximately 20%-30% of patients will continue to have seizures. Behavior and cognition are negatively impacted by seizures, but AEDs are also a major contributor to behavioral and cognitive deficits. However, the cognitive and behavioral effect of AEDs in children is insufficiently emphasized in the literature. This review summarizes the cognitive and behavioral effects of AEDs in the pediatric population with the objective of helping pediatricians and pediatric neurologists to select the AEDs with the best profile for their individual patient's needs.

Epilepsy, Antiepileptic Drugs, and Aggression: An Evidence-Based Review

Antiepileptic drugs (AEDs) have many benefits but also many side effects, including aggression, agitation, and irritability, in some patients with epilepsy. This article offers a comprehensive summary of current understanding of aggressive behaviors in patients with epilepsy, including an evidence-based review of aggression during AED treatment. Aggression is seen in a minority of people with epilepsy. It is rarely seizure related but is interictal, sometimes occurring as part of complex psychiatric and behavioral comorbidities, and it is sometimes associated with AED treatment. We review the common neurotransmitter systems and brain regions implicated in both epilepsy and aggression, including the GABA, glutamate, serotonin, dopamine, and noradrenaline systems and the hippocampus, amygdala, prefrontal cortex, anterior cingulate cortex, and temporal lobes. Few controlled clinical studies have used behavioral measures to specifically examine aggression with AEDs, and most evidence comes from adverse event reporting from clinical and observational studies. A systematic approach was used to identify relevant publications, and we present a comprehensive, evidence-based summary of available data surrounding aggression-related behaviors with each of the currently available AEDs in both adults and in children/adolescents with epilepsy. A psychiatric history and history of a propensity toward aggression/anger should routinely be sought from patients, family members, and carers; its presence does not preclude the use of any specific AEDs, but those most likely to be implicated in these behaviors should be used with caution in such cases.

The safety and tolerability of newer antiepileptic drugs in children and adolescents

The newer antiepileptic drugs (AEDs) provide more therapeutic options and overall improved safety and tolerability for patients. To provide the best care, physicians must be familiar with the latest tolerability and safety data. This is particularly true in children, given there are relatively fewer studies examining the effects of AEDs in children compared with adults. Since we now have significant paediatric literature on each of these agents, we provide a comprehensive and current literature review of the newer AEDs, focusing on safety and tolerability data in children and adolescents. Because the safety profiles in children differ from those in adults, familiarity with this literature is important for child neurologists and other paediatric caregivers. We have organized the data by organ system for each AED for easier reference.

The adverse effects of antiepileptic drugs in children

Efficacy of antiepileptic drugs (AEDs) are often equivalent, hence selection of an AED is often determined by the adverse effects (AEs). The development of neurocognitive AEs is almost inevitable with use of AEDs, especially in high-risk groups. Teratogenesis with major or minor malformations is of great concern during the first trimester of pregnancy, but an increasing body of information suggests that potential neurocognitive developmental delay may also occur with use of AEDs in the latter part of pregnancy. Decreased bone mineral density has been found in adults and children receiving both enzyme-inducing AEDs and valproate, an enzyme-inhibiting drug. AEDs may influence the lipid profile, body weight, reproductive, hormonal and other endocrine functions, and sleep architecture. There are age-specific AEs related to pharmacokinetic differences that have been highlighted in this review with emphasis on the pediatric population. A classification of AEs using different parameters is also included.

Clinical experience with zonisamide monotherapy and adjunctive therapy in children with epilepsy at a tertiary care referral center

We evaluated our clinical experience with zonisamide, a broad-spectrum antiepileptic drug, in a group of children with predominantly medically refractory epilepsy. A retrospective chart review was conducted on patients at our tertiary referral center following Institutional Review Board approval. Observers documented reports of seizure frequency, and seizure types were identified either clinically or by prior video-electroencephalography monitoring. We identified 68 patients (age range 1.9-18.1 years [median 6.9 years]; male to female ratio 1.3:1) treated with zonisamide for 0.7 to 28.9 months; at the last visit, 22% and 78% were on monotherapy and adjunctive therapy, respectively. The median duration of treatment and maintenance dose at the end of the follow-up were 11.2 months and 8.0 mg/kg/day, respectively. Seizure types included generalized (primary generalized tonic-clonic, myoclonic, tonic, atonic, absence) and partial (simple, complex, and secondarily generalized tonic-clonic seizures); 10 (15%) patients had both partial and generalized seizures. Sixteen (25.8%) patients were seizure free, although five of them were already in remission prior to starting zonisamide. Thirteen (21.0%) patients had a > 50% seizure reduction, 10 (16.1%) patients had a < 50% seizure reduction, 14 (22.6%) had no improvement in baseline seizures, and 9 (14.5%) reported having increased seizures. The latter were mostly associated with dosage alterations in concomitant antiepileptic drugs. Common side effects were central nervous system related, including behavioral or psychiatric (23.5%), cognitive dysfunction (12.0%), and sedation (10.3%). Eleven (16.2%) patients ultimately discontinued zonisamide, but only five were strictly due to side effects. Zonisamide is clinically effective against multiple seizure types in a significant proportion of children with epilepsy across a broad age range. Drug discontinuation as a result of side effects is uncommon.