Epilepsy in a large cohort of children diagnosed with attention deficit/hyperactivity disorders (ADHD)

Children with ADHD and EEG abnormalities at baseline assessment, risk of epileptic seizures and maintenance on methylphenidate three years later

PURPOSE

This study aimed to assess the incidence of EEG abnormalities (EEG-ab) in children diagnosed with ADHD, investigate the risk of epileptic seizures (SZ) and maintenance on methylphenidate (MPH) over a three-year period.

METHODS

A total of 517 ADHD children aged 6-14 years were included. Baseline assessments included the identification of EEG-ab, ADHD inattentive subtype (ADHD-I), comorbid epilepsy, the use of antiepileptic drugs (AEDs) and the use of MPH. At the 3-year follow-up, assessments included the presence of EEG-ab, maintenance on MPH, AED usage, SZ risk in cases with EEG-epileptiform abnormalities (EEG-epi-ab), compared with control ADHD cases without EEG-epi-ab matched for age and gender.

RESULTS

EEG-ab were identified in 273 (52.8%) cases. No statistically significant differences were observed between the EEG-ab and EEG-non-ab groups in terms of age, gender, ADHD-I type or initial use of MPH. EEG non-epileptiform abnormalities (EEG-non-epi-ab) were found in 234 out of 478 (49%) cases without EEG-epi-ab. Notably, EEG-non-epi-ab occurred more frequently in the group of 39 cases with EEG-epi-ab (30/39 (76.9%) vs. 9/39, (21.3%), a subset selected for 3-year follow-up. At 3-year-follow-up no statistically significant difference was found in maintenance on MPH in ADHD cases with and without EEG-epi-ab. Nobody of ADHD cases without comorbid epilepsy or with comorbid epilepsy with achieved SZ freedom developed new SZ. Only 3 children with drug resistant epilepsy experienced SZs, without increase in SZ frequency. The disappearance rate of EEG-epi-ab was higher than that EEG-non-epi-ab (71.8% vs. 33.3%).

CONCLUSIONS

Children with and without EEG-ab exhibited similar patterns of MPH use (initial use, positive response, and maintenance on MPH). The presence of comorbid epilepsy and EEG-ab, with or without EEG-epi-ab, was not associated with an increased risk of SZ despite the use of MPH.

Attention-deficit hyperactivity disorder in adults with epilepsy: An indirect relationship with suicide risk

PURPOSE

Studies on attention-deficit hyperactivity disorder (ADHD) are scarce in adults with epilepsy. This study aimed to investigate the risk factors for ADHD and determine whether ADHD is directly associated with the risk of suicide in adults with epilepsy.

METHODS

ADHD was assessed using the Structured Clinical Interview for the DSM-5 Disorders Clinical Version. The Mini International Neuropsychiatric Interview (MINI) Plus 5.0.0, Neurological Disorders Depression Inventory for Epilepsy (NDDIE), and Generalized Anxiety Disorder-7 (GAD-7) were also used. Suicide risk was defined as a MINI suicidality score of ≥ 1. Stepwise logistic regression and mediation analyses were conducted.

RESULTS

Of the 157 adults with epilepsy, 19 (12.1 %) were diagnosed with ADHD, including inattentive (5.7 %), hyperactive (3.8 %), and combined (2.5 %) types. Thirty-two subjects (20.4 %) had a risk of suicide. ADHD was insignificantly associated with any epilepsy-related factors. The diagnosis of ADHD was not associated with suicide risk independent of NDDIE ≥ 14 and GAD-7 ≥ 7. Mediation effects of ADHD on suicidality using NDDIE ≥ 14 (odds ratio [OR] 2.850, 95 % confidence interval [CI] 1.398-5.811, p = 0.004) or GAD-7 ≥ 7 (OR 3.240, 95 % CI 1.537-6.828, p = 0.002) were statistically significant, with the proportion mediated being 84.5 % or 92.0 % of the total ADHD effect, respectively. These models were adjusted for age, sex, and composite epilepsy severity scores.

CONCLUSIONS

ADHD was diagnosed in 12.1% of adults with epilepsy and was not associated with any epilepsy-related factors. ADHD was indirectly associated with the risk of suicide resulting from depression and anxiety in adults with epilepsy.

Epilepsy and psychiatric comorbidities: A bidirectional mendelian randomization study

STUDY OBJECTIVES

Psychiatric comorbidities are relatively common among patients with epilepsy; however, the underlying mechanisms of this association remain largely unknown. The objective of this Mendelian randomization (MR) study was to analyze the genetic correlations and causality underlying these reciprocal associations.

METHODS

Single-nucleotide polymorphisms associated with epilepsy (29,677 controls and 15,212 cases) and seven psychiatric comorbidities (485,436 controls and 269,495 cases) were identified from genome-wide association studies. Causal significance was estimated using inverse variance weighting. Sensitivity analyses included the weighted median, MR-Egger, and MR-PRESSO. The psychiatric comorbidities analyzed in this study included attention deficit hyperactivity disorder (ADHD), autism spectrum disorder, major depressive disorder, bipolar disorder, schizophrenia, obsessive-compulsive disorder (OCD), and anorexia nervosa.

RESULTS

Both forward and reverse genetic associations were observed for the selected psychiatric disorders. Notably, ADHD was significantly associated with an increased risk of generalized epilepsy (odds ratio [OR], 1.09; 95 % confidence interval [CI], 1.01-1.18; p = 0.013). However, MR-PRESSO detected the existence of pleiotropy (p = 0.001). Additionally, focal epilepsy was significantly associated with a higher risk of OCD (OR, 1.44; 95 % CI, 1.08-1.92; p = 0.013), and all sensitivity tests yielded favorably nonsignificant results. There was no significant genetic association between epilepsy and other examined psychiatric disorders. However, due to the detection of pleiotropy by MR-Egger and considerations related to the threshold for genetic instruments, a cautious approach is warranted in interpreting some of the results.

CONCLUSIONS

This study revealed significant genetic causality between focal epilepsy and OCD, as well as between ADHD and generalized epilepsy. However, no casual significance was observed with other psychiatric comorbidities examined. Considering the inherent limitations of MR studies, further research is warranted to definitively clarify these genetic causal associations.

Onset of Inattention and Hyperactivity in Children and Adolescents With Epilepsy 6 months After the Diagnosis

OBJECTIVE

Complete or major symptoms of ADHD are often present in epilepsy. This study evaluated inattention and hyperactivity symptoms over the first 6 months in newly diagnosed pediatric epilepsy without comorbid ADHD.

METHOD

Children and adolescents with newly diagnosed epilepsy were followed for 6 months after starting antiseizure medications. The Nisonger Child Behavior Rating Form (NCBRF), Adverse Event Profile (AEP), and the Revised Wechsler Intelligence Scale for Children were used.

RESULTS

There was a marked increase in attention difficulties while a moderate increase in hyperactivity levels. AEP scores, changes in non-verbal aspects of intelligence, levels of hyperactivity at the follow-up, and attention at baseline were significant predictors for inattention. In contrast, only levels of hyperactivity at the baseline and inattention at the follow-up were significant predictors for hyperactivity.

CONCLUSION

Significant inattention and hyperactivity levels originated 6 months after the diagnosis of epilepsy and starting antiseizure medication.

Factor associated with the occurrence of epilepsy in autism: a systematic review

This systematic review aimed to identify factors significantly associated with the occurrence of epilepsy in autistic individuals and to consider the impact of study quality on findings. Electronic databases were systematically searched on October 2nd, 2020 and records retrieved were limited to those published from 2000 onwards. Study quality was categorised as 'good', 'moderate' or 'weak'. Fifty-three studies were included and in studies where the prevalence of epilepsy was reported (n = 257,892), 18,254 (7%) had co-occurring epilepsy. Intellectual disability/cognitive impairment was the most commonly reported risk factor associated with occurrence of epilepsy in autistic individuals. The evidence supporting other, potentially relevant factors was weak and inconsistent and requires further evaluation. Only 9/53 studies were considered 'good' quality.

Association between early-childhood exposure to perfluoroalkyl substances and ADHD symptoms: A prospective cohort study

There is evidence that exposure to perfluoroalkyl substances (PFAS) is associated with attention-deficit/hyperactivity disorder (ADHD) symptoms. Previous studies have focused on prenatal exposure to PFAS, and only few studies have examined the associations of early-childhood exposure, especially at low exposure levels. This study explored the association between early-childhood exposure to PFAS and ADHD symptoms later in childhood. In 521 children, we measured the serum levels of six PFAS in peripheral blood at the ages of 2 and 4 years, including perfluorooctanoate (PFOA), perfluornonanoicacid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA), perfluorohexane sulfonic acid (PFHxS), and perfluorooctane sulfonate (PFOS). The ADHD Rating Scale IV (ARS) was utilized to measure ADHD traits at 8 years of age. We explored the relationship between PFAS and ARS scores using Poisson regression models after adjusting for potential confounders. Levels of exposure to individual PFAS and the summed value were divided into quartiles to examine possible nonlinear relationships. All six PFAS exhibited inverted U-shaped curves. Children in the 2nd and 3rd quartile levels of each PFAS showed higher ARS scores than those in the1^st quartile level. Below the 3rd quartile of the summed levels of six PFAS (ΣPFAS), a doubling of the ΣPFAS was associated with an 20.0 % (95 % CI: 9.5 %, 31.5 %) increase in ADHD scores. However, at the age of 4 years, none of the evaluated PFAS exhibited linear or nonlinear associations with the ARS scores. Thus, school-aged children may be vulnerable to the neurotoxic effects of exposure to PFAS at age 2 that contribute to ADHD, particularly at low to mid-levels.

Epilepsy and attention-deficit/hyperactivity disorder in children and adolescents: An overview of etiology, prevalence, and treatment

Epilepsy and attention-deficit/hyperactivity disorder (ADHD) are closely connected and commonly seen in both children and adults. Each of the disorders has major psychosocial and quality of life (QOL) effects, and their co-occurrence makes coping even more challenging for both the patients and their families. Moreover, an adverse effect of some anti-seizure medications can potentially induce or exacerbate symptoms of ADHD on the one hand, while some ADHD medications may increase seizure risk on the other. The combination of proper diagnosis and appropriate treatment may improve or even prevent many of the complications associated with these conditions. The objectives of this review are to present the complex relationship between epilepsy and ADHD, looking into the pathophysiological, anatomical, and functional perspectives along with the psychosocial and QOL influences and the recommended treatment approaches in accordance with the latest literature.

Interventions for ADHD in children & adolescents with epilepsy: A review and decision tree to guide clinicians

Attention Deficit Hyperactivity Disorder (ADHD) is one of the most common pediatric epilepsy comorbidities. Treating ADHD in the context of epilepsy can be overwhelming for parents and clinicians. Current frontline treatment for ADHD is stimulant medication. However, some parents of pediatric patients with epilepsy have concerns about adding additional medication to their child's epilepsy regimen and/or about adverse effects of stimulant medication. Non-medication ADHD treatments including psychosocial interventions and ketogenic diet have also shown success in improving ADHD symptoms. Our focused review provides an easy-to-use guide for clinicians on ADHD interventions and combinations of interventions for pediatric patients with epilepsy and ADHD. Our guide includes information from 8 electronic databases for peer-reviewed, English language studies of psychosocial treatments for youth with epilepsy and ADHD. One hundred eight studies were selected based on inclusion criteria (21 systematic reviews, 12 meta-analyses, 8 literature reviews, 6 population surveys, 31 clinical trials, 20 cross-sectional studies, and 10 retrospective reviews). Results indicated that stimulant medication is a frontline treatment for ADHD symptoms in youth with epilepsy, with important caveats and alternatives.

Shared genetics and causality underlying epilepsy and attention-deficit hyperactivity disorder

The prevalence of attention deficit hyperactivity disorder (ADHD) in patients with epilepsy was much higher than prevalence in general population, and vice versa. The mechanisms underlying comorbid ADHD and epilepsy remained largely unknown. Here, we systematically analyzed the genetic correlation, causality, shared genetics and specific trait related tissues by using linkage disequilibrium score regression (LDSC), two sample Mendelian randomization (TwoSampleMR), bivariate causal mixture model (MiXeR), conjunctional false discovery rate (conjFDR) and LDSC applied to specifically expressed genes based on genome wide association studies (GWASs) data of ADHD and epilepsy. We found that ADHD had significant positive genetic association with epilepsy. Two-sample Mendelian randomization analysis with genome wide significant single nucleotide polymorphisms (SNPs) as instrument variables suggested a positively causal effect of ADHD on epilepsy. Using MiXeR, which estimates the total amount of shared variants, we observed 1 K causal variants overlapped between ADHD and epilepsy. At conjFDR <0.05, ADHD shared 2 distinct genomic loci with Epilepsy. Further disease-relevant tissues analysis showed that cortex, substantia nigra, amygdala and hippocampus were both associated with ADHD and epilepsy. Our results suggested that ADHD was genetically correlated with epilepsy, which might be due to the fact that they shared common pathogenic sites and tissues origin.

Time of onset and/or diagnosis of ADHD in European children: a systematic review

BACKGROUND

Attention-Deficit/ Hyperactivity Disorder (ADHD) is one of the most common childhood neurobehavioral conditions. Symptoms related to this disorder cause a significant impairment in school tasks and in the activities of children's daily lives; an early diagnosis and appropriate treatment could almost certainly help improve their outcomes. The current study, part of the Models Of Child Health Appraised (MOCHA) project, aims to explore the age at which children experience the onset or diagnosis of ADHD in European countries.

METHODS

A systematic review was done examining the studies reporting the age of onset/diagnosis (AO/AD) of ADHD in European countries (28 European Member States plus 2 European Economic Area countries), published between January 1, 2010 and December 31, 2019. Of the 2276 identified studies, 44 met all the predefined criteria and were included in the review.

RESULTS

The lowest mean AO in the children diagnosed with ADHD alone was 2.25 years and the highest was 7.5 years. It was 15.3 years in the children with ADHD and disruptive behaviour disorder. The mean AD ranges between 6.2 and 18.1 years.

CONCLUSIONS

Our findings indicate that there is a wide variability in both the AO and AD of ADHD, and a too large distance between AO and AD. Since studies in the literature suggest that an early identification of ADHD symptoms may facilitate early referral and treatment, it would be important to understand the underlying reasons behind the wide variability found.

TRIAL REGISTRATION

PROSPERO registration: CRD42017070631 .

Effect of anti-attention-deficit hyperactivity disorder (ADHD) medication on clinical seizures and sleep EEG: A retrospective study of Japanese children with ADHD

Aims

Patients with attention‐deficit hyperactivity disorder (ADHD) often exhibit basic or paroxysmal wave abnormalities on electroencephalography (EEG). Methylphenidate (MPH), an anti‐ADHD stimulant, has been reported to lower the seizure threshold. However, there have been no reports comparing EEG changes before and after administration of the central nervous system (CNS) stimulant MPH, or atomoxetine (ATX) hydrochloride, a non‐CNS stimulant. In this study, we investigated changes in sleep EEG before and after the administration of ADHD treatment drugs.

Method

With the approval of the ethics committee, the medical records of 28 children with ADHD (23 men and 5 women) who gave consent were retrospectively investigated. The appearance of sudden abnormal waves during a 10‐minute sleep EEG recording was measured in 0.1‐second units, and the duration of these waves was calculated as the paroxysmal index (PI).

Results

Paroxysmal index did not differ significantly between patients who received MPH and those who received ATX. In addition, there were no exacerbations of clinical seizures.

Conclusion

It was concluded that ADHD medications do not have an adverse effect on epileptic seizures or abnormal sleep EEGs.

Patients with attention‐deficit hyperactivity disorder (ADHD) often exhibit basic or paroxysmal wave abnormalities on electroencephalography (EEG). We investigated changes in sleep EEG before and after the administration of ADHD treatment drugs. ADHD medications do not have an adverse effect on epileptic seizures or abnormal sleep EEGs.

ADHD and epilepsy-related QoL in youth with epilepsy

OBJECTIVE

Pediatric epilepsy and attention-deficit/hyperactivity disorder (ADHD) present a cumulative vulnerability to youth, particularly in the domains of executive function (EF) and quality of life (QoL). The aim of this study was to explore the relationships between EF and epilepsy-specific QoL in youth with epilepsy (YWE) who also have ADHD.

METHODS

Youth with epilepsy aged 5-18 years and caregivers participated in a large multi-site national validation of the PedsQL™ Epilepsy Modules. YWE and their caregivers were asked to complete measures of epilepsy-specific QoL, ADHD symptoms, and EF. Previous ADHD diagnosis was reported by caregivers as well as abstracted from the medical record.

RESULTS

Caregiver and YWE reports of current ADHD symptoms significantly predicted all epilepsy-specific QoL domains. Suboptimal QoL was reported for those YWE whose ADHD symptoms were above the clinical threshold compared to YWE whose ADHD symptoms were within the average range. Results were similar for YWE with a documented ADHD vs no ADHD diagnosis. In addition, poorer metacognition and behavioral regulation EF was associated with lower epilepsy-specific QoL for both YWE with ADHD and without ADHD diagnosis. However, in YWE with ADHD, effect sizes were consistently larger for behavioral regulation compared to metacognition across epilepsy-specific QoL domains, with behavioral regulation accounting for 50% of the variance in each of the EF and mood QoL domains.

SIGNIFICANCE

Addressing ADHD symptoms, epilepsy-specific, QoL, and EF as part of routine epilepsy care may promote optimal outcomes for YWE with ADHD as well as relieve burden on the healthcare system.

Disconnecting surgery at alveus and cornu ammonis of hippocampus, amygdala superficialis, and amygdala medial nuclei for epilepsy associated with attention deficit hyperactivity disorder

The neural basis for epilepsy and attention deficit hyperactivity disorder (ADHD) is currently incompletely known. We reported a young girl with both epilepsy and ADHD, who had a calcified lesion in the right basolateral amygdalo-hippocampal region extending to the ventral striatum. The child underwent disconnecting surgery and biopsy of the lesion. Fascinatingly, the child's behavior changed immediately after the surgery from inattentive and impulsive to nearly normal behavior experiencing no more breakthrough seizures since after 3 years of surgery. The Schaltenbrand Wahren Brain Atlas revealed alveus, cornu ammonis, amygdala superficialis, and medium as the disconnected region in this surgery.

Interictal Epileptiform Discharges are Task Dependent and are Associated with Lasting Electrocorticographic Changes

The factors that control the occurrence of interictal epileptiform discharges (IEDs) are not well understood. We suspected that this phenomenon reflects an attention-dependent suppression of interictal epileptiform activity. We hypothesized that IEDs would occur less frequently when a subject viewed a task-relevant stimulus compared with viewing a blank screen. Furthermore, IEDs have been shown to impair memory when they occur in certain regions during the encoding or recall phases of a memory task. Although these discharges have a short duration, their impact on memory suggests that they have longer lasting electrophysiological effects. We found that IEDs were associated with an increase in low-frequency power and a change in the balance between low- and high-frequency oscillations for several seconds. We found that the occurrence of IEDs is modified by whether a subject is attending to a word displayed on screen or is observing a blank screen. In addition, we found that discharges in brain regions in every lobe impair memory. These findings elucidate the relationship between IEDs and memory impairment and reveal the task dependence of the occurrence of IEDs.

Sex Differences in the Epilepsies and Associated Comorbidities: Implications for Use and Development of Pharmacotherapies

The epilepsies are common neurologic disorders characterized by spontaneous recurrent seizures. Boys, girls, men, and women of all ages are affected by epilepsy and, in many cases, by associated comorbidities as well. The primary courses of treatment are pharmacological, dietary, and/or surgical, depending on several factors, including the areas of the brain affected and the severity of the epilepsy. There is a growing appreciation that sex differences in underlying brain function and in the neurobiology of epilepsy are important factors that should be accounted for in the design and development of new therapies. In this review, we discuss the current knowledge on sex differences in epilepsy and associated comorbidities, with emphasis on those aspects most informative for the development of new pharmacotherapies. Particular focus is placed on sex differences in the prevalence and presentation of various focal and generalized epilepsies; psychiatric, cognitive, and physiologic comorbidities; catamenial epilepsy in women; sex differences in brain development; the neural actions of sex and stress hormones and their metabolites; and cellular mechanisms, including brain-derived neurotrophic factor signaling and neuronal-glial interactions. Further attention placed on potential sex differences in epilepsies, comorbidities, and drug effects will enhance therapeutic options and efficacy for all patients with epilepsy. SIGNIFICANCE STATEMENT: Epilepsy is a common neurological disorder that often presents together with various comorbidities. The features of epilepsy and seizure activity as well as comorbid afflictions can vary between men and women. In this review, we discuss sex differences in types of epilepsies, associated comorbidities, pathophysiological mechanisms, and antiepileptic drug efficacy in both clinical patient populations and preclinical animal models.

Methylphenidate for attention problems in epilepsy patients: Safety and efficacy

Children with attention deficit hyperactivity disorder (ADHD) have an increased risk of seizures, and children with epilepsy have an increased prevalence of ADHD. Adults with epilepsy often have varying degrees of attentional dysfunction due to multiple factors, including anti-seizure medications, frequent seizures, interictal discharges, underlying lesions, and psychiatric comorbidities. Currently, there are no approved medications for the treatment of epilepsy-related attentional dysfunction. Methylphenidate (MPH) is a stimulant, FDA-approved for the treatment of ADHD, and often used for ADHD in the setting of pediatric epilepsy. Large database and registry studies indicate safety of MPH in children with ADHD and epilepsy, with no significant effect on seizure frequency. Small single-dose and open-label studies suggest efficacy of MPH in adults with epilepsy-related attention deficits. Methylphenidate represents a possible treatment for attentional dysfunction due to epilepsy, but large, randomized, placebo-controlled, double-blinded studies are needed.

Evaluation of psychiatric comorbidity in attention-deficit hyperactivity disorder with epilepsy: A case-control study

OBJECTIVE

Attention deficit/hyperactivity disorder (ADHD) is a developmental disorder caused by structural and functional brain abnormalities as well as genetic and environmental factors. ADHD symptoms are commonly observed in individuals with epilepsy. A few studies have reported a pattern of behavioral problems in children with combined epilepsy and ADHD. We aimed to evaluate comorbid behavioral problems and mental health concerns among children with epilepsy with ADHD and without ADHD including autism spectrum disorder, anxiety, depression, somatic problems, oppositional defiant disorder, and conduct disorder.

METHODS

A total of 100 children aged between 6 and 11 years were recruited and categorized into 1 of 5 groups (20 child/group): (1) epilepsy, (2) epilepsy with ADHD, (3) ADHD with electroencephalogram (EEG) changes, (4) ADHD without EEG changes, and (5) healthy control. The scales used in our study included the Childhood Autism Spectrum Test (CAST) to screen autism spectrum conditions and related social and communication conditions, Conners' Parent Rating Scale (CPRS) to assess ADHD and other comorbid behavioral and social-emotional difficulties, and Children Behavior Checklist (CBCL) to evaluate behavior problems.

RESULTS

The CAST scale score showed no significant difference among the studied groups. Regarding the Conners-3 scale, the combined type of ADHD was predominant in the ADHD with EEG changes group and the ADHD with epilepsy group, while hyperactive ADHD was predominant in the ADHD without EEG changes group. The ADHD with EEG changes group and the ADHD with epilepsy group had equally high clinical rating scores for CBCL in internalizing and externalizing problems. There was a significant difference in the profile of all Diagnostic and Statistical Manual of Mental Disorders (DSM-5) scales of CBCL among the studied groups.

CONCLUSION

This is the first study to use EEG in patients with ADHD in comparison with epilepsy. ADHD with epilepsy is closely related to ADHD with EEG changes regarding psychiatric comorbidity in terms of anxiety, depression, somatic problems, oppositional defiance problems, and conduct problems.

Comparison of cognitive function, socioeconomic level, and the health-related quality of life between epileptic patients with attention deficit hyperactivity disorder and without

Background

Epilepsy is one of the most common neurological conditions. Attention deficit hyperactivity disorder (ADHD) in children with epilepsy proves to be very common. Both epilepsy and ADHD impair quality of life. We aimed to evaluate cognitive function, socioeconomic level, and quality of life (QOL) among children with ADHD and epilepsy. A total of 100 children were divided into 5 groups (20 children/group) as (I) epilepsy, (II) ADHD with epilepsy, (III) ADHD with EEG changes, (IV) ADHD without EEG changes, and (V) control. Children aged between 6 and 11 years were recruited for this study. Early Childhood Epilepsy Severity Scale (E-Chess), Conners’ Parent Rating Scale (CPRS), Wechsler Intelligence Scale for Children-3rd edition (WISC-III), socioeconomic scale for assessment of social burden and socioeconomic classes, and PedsQL (quality of life measure) assessed.

Results

Children with ADHD and epilepsy had the lowest PedsQL total scores and lower scores than other groups especially in performance IQ score. The highest percentage of low socioeconomic class (25%) was observed in the group of ADHD with epilepsy and the group of epilepsy.

Conclusion

ADHD with epilepsy is associated with low performance IQ, poor socioeconomic level, and quality of life. Pediatric Quality of Life Inventory scores show significant correlation with total IQ score in the group of ADHD with epilepsy.

ADHD: Current Concepts and Treatments in Children and Adolescents

Attention deficit hyperactivity disorder (ADHD) is among the most frequent disorders within child and adolescent psychiatry, with a prevalence of over 5%. Nosological systems, such as the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) and the International Classification of Diseases, editions 10 and 11 (ICD-10/11) continue to define ADHD according to behavioral criteria, based on observation and on informant reports. Despite an overwhelming body of research on ADHD over the last 10 to 20 years, valid neurobiological markers or other objective criteria that may lead to unequivocal diagnostic classification are still lacking. On the contrary, the concept of ADHD seems to have become broader and more heterogeneous. Thus, the diagnosis and treatment of ADHD are still challenging for clinicians, necessitating increased reliance on their expertise and experience. The first part of this review presents an overview of the current definitions of the disorder (DSM-5, ICD-10/11). Furthermore, it discusses more controversial aspects of the construct of ADHD, including the dimensional versus categorical approach, alternative ADHD constructs, and aspects pertaining to epidemiology and prevalence. The second part focuses on comorbidities, on the difficulty of distinguishing between "primary" and "secondary" ADHD for purposes of differential diagnosis, and on clinical diagnostic procedures. In the third and most prominent part, an overview of current neurobiological concepts of ADHD is given, including neuropsychological and neurophysiological researches and summaries of current neuroimaging and genetic studies. Finally, treatment options are reviewed, including a discussion of multimodal, pharmacological, and nonpharmacological interventions and their evidence base.

Role of inflammation in childhood epilepsy and ADHD comorbidity

Epilepsy is a heterogeneous disorder that is not limited to experiencing seizures but also includes multiple neuropsychiatric squeal (i.e. attention-deficit/hyperactivity disorder (ADHD), depression and anxiety) that adversely impact a child quality of life. However, the underlying mechanism linking both disorders is not yet thoroughly explored. Our objective was to assess pro-inflammatory cytokines levels in children with seizure controlled epilepsy and explore the association between pro-inflammatory cytokines and the co-occurrence of ADHD in such children. A cross-sectional study included 50 children with controlled epilepsy for at least one year, in addition to 30 neurotypical children as controls. All children were assessed by the Conner parent scale for ADHD. Serum interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) levels were measured and correlated to clinical data. In the present study, 23 out of 50 children with epilepsy also had ADHD (46%). Children with ADHD have been found to have a significantly lower age of onset, longer duration of epilepsy, and a higher serum level of IL-6 and TNF-α than those without ADHD. The Conner's parent rating scale overall total score yielded significant negative correlations with the age of onset of epilepsy and a significant positive correlation with the duration of epilepsy and pro-inflammatory cytokine levels. In addition to active seizures, the presence of elevated circulating inflammation markers may be associated with increased frequency of ADHD in children with epilepsy aged 6-14 years.

Prevalence of Epilepsy and Inter-Ictal Epileptiform Discharges in Children with Autism and Attention-Deficit Hyperactivity Disorder

OBJECTIVE

To study the prevalence of epilepsy and Inter-ictal epileptiform discharges (IED) in children with Autism spectrum disorder (ASD) and Attention-deficit hyperactivity disorder (ADHD), and the factors associated with occurrence of epilepsy in these children.

METHODS

Children between 6 and 12 y attending the Child Development Centre of a tertiary-care institute in India were evaluated for ASD and ADHD as per Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5). Childhood Autism Rating Scale was used to assess ASD severity, and Conner's Rating Scales were used to sub-classify children with ADHD. Intelligence quotient was assessed if not assessed in the previous 1 y. History of seizures was taken, and electroencephalography was done in all children. Epilepsy was diagnosed and classified according to International League Against Epilepsy.

RESULTS

Of the 130 children enrolled (90 ASD, 40 ADHD), 56 (43%) had epilepsy and 55 (42.3%) had IED. The proportion of both epilepsy and IED was higher among ASD (both 45.5%) as compared to ADHD (37.5% and 35%), although not statistically significant. Among children with ASD, epilepsy was common in those with severe ASD (P < 0.001), and IED were more common in those with IQ <80 (P = 0.047). There were no significant differences between occurrence of epilepsy/IED and subtypes of ADHD.

CONCLUSIONS

The high prevalence of epilepsy and IED among children with ASD and ADHD emphasizes the need for guidelines for identifying and diagnosing epilepsy in this group. This will ensure appropriate management and improve patient outcomes.

Behavioural changes in dogs with idiopathic epilepsy

BACKGROUND

Breed-specific and broader cohort studies have shown behavioural changes in dogs following the onset of idiopathic epilepsy (IE).

METHODS

A cross-sectional, case-control questionnaire study was carried out to strengthen this body of evidence. Owners of eight breeds of dog completed an online questionnaire about their dogs' behaviour; once for control dogs and twice for dogs with IE, for both pre-IE and post-IE onset behaviour.

RESULTS

Ninety-six (24.74 per cent) dogs with IE and 292 (75.26 per cent) age and breed-matched control dogs met the inclusion criteria. Control dogs had significantly higher 'Trainability' scores than dogs with IE (P=0.04). After IE, dogs had significantly higher 'Dog-Directed Fear or Aggression' (P=0.02), 'Non-Social Fear' (P=0.01), 'Attachment/Attention-Seeking Behaviour' (P=0.04), 'Attention-Deficit' (P=0.02) and significantly lower 'Trainability' (P=0.02) than prior to the onset of IE. Medication status did not significantly affect any behavioural factor, but drug-resistant dogs had significantly less 'Trainability' than drug-responsive (P=0.04) and partially drug-responsive dogs (P=0.03).

CONCLUSION

Behavioural differences related to cognitive function are seen between dogs with IE and controls. Behavioural changes related to anxiety, attention and cognition are seen in dogs following the onset of IE. The ability to clinically define and diagnose behavioural comorbidities in dogs is much needed from both a clinical and research perspective.

Relationship Between Aggravation of Seizures and Methylphenidate Treatment in Subjects with Attention-Deficit/Hyperactivity Disorder and Epilepsy

OBJECTIVES

We aimed to investigate the effectiveness and safety of methylphenidate (MPH), and especially its influence on seizures, in subjects with attention-deficit/hyperactivity disorder (ADHD) and epilepsy through a retrospective chart review of subjects treated with MPH in a clinical setting. We also evaluated factors that could affect seizure aggravation during MPH treatment.

METHODS

From April 2004 to July 2011, MPH was prescribed to 105 subjects with ADHD and epilepsy. The demographic characteristics, psychiatric and medical history, and electroencephalography (EEG) results were reviewed. Two pediatric neurologists reviewed seizure type, epilepsy diagnosis, changes in seizure frequency, and EEG parameters during MPH treatment. Pediatric neurologists and psychiatrists determined the temporal relationship between seizure aggravation and MPH treatment.

RESULTS

The mean age of the subjects was 14.8 ± 3.4 years (range: 7-24 years). Sixty-five (61.9%) of the subjects were male. The mean duration of MPH treatment was 22 months (range: 2 weeks to 89 months) and the mean dose of MPH was 0.84 mg/kg/day. MPH was effective in controlling ADHD symptoms in both the seizure aggravation and nonaggravation groups. However, 21 (20%) subjects had aggravated seizures and 32 (32.3%) subjects had worsened EEG findings. Subjects with uncontrolled seizure or anxiety disorders at baseline were more likely to show aggravated seizures. Subjects who had epileptiform discharges, anxiety disorders, or were free of antiepileptic drug use at baseline experienced EEG worsening more frequently. The median duration of MPH treatment was significantly longer in subjects who did not show seizure aggravation than in those who did (p < 0.001).

CONCLUSIONS

MPH treatment may be related to aggravation of seizures or significant worsening of EEG findings in subjects with ADHD and epilepsy. Thus, clinicians should closely monitor seizure aggravation after MPH administration, especially for high-risk subjects with uncontrolled seizures or anxiety disorders at baseline.

Oxidative stress contribution to attention deficit hyperactivity disorder in children with epilepsy

Children with epilepsy have a high incidence of attention deficit hyperactivity disorder (ADHD). Oxidation stress and disturbed neurotransmitters are suggested mechanisms; however, their role is not fully explored. This study evaluates the association between circulating malondialdehyde as an oxidation stress marker, apelin neuropeptide, and ADHD in children with epilepsy. Fifty children with epilepsy of unknown etiology, of which 25 have ADHD, as well as 35 healthy children were included. Serum levels of malondialdehyde and apelin were estimated. We investigated the association between seizure severity, response to medications, malondialdehyde, apelin levels, and ADHD in children with epilepsy. Serum malondialdehyde and apelin levels were higher in children with epilepsy, especially those with ADHD. Malondialdehyde and apelin levels have significant positive correlation with the Chalfont Seizure Severity Score. Regression analysis showed that elevated malondialdehyde is an independent risk factor for ADHD in children with epilepsy (OR: 1.401, 95%CI: 1.056-1.859, p= 0.02). No significant association was found between malondialdehyde and apelin levels and the type of epilepsy or ADHD. Longer duration of epilepsy, increased seizure severity, and uncontrolled seizures are associated with increased oxidation stress, which further increased susceptibility for ADHD. In spite of elevated apelin in children with ADHD, the elevation did not increase the risk of ADHD in children with epilepsy.

The Challenge of Pharmacotherapy in Children and Adolescents with Epilepsy-ADHD Comorbidity

Epilepsy is common in children and adolescents where its prevalence is 3.2-5.5/1000. About one-third of patients also have attention deficit hyperactivity/impulsivity disorder (ADHD). The possible relationship between epilepsy and ADHD is still unclear, and ADHD symptoms (such as inattention, hyperactivity, behavioral disturbances) are frequently considered as adverse effects of antiepileptic drugs (AEDs). The literature was searched for data on the behavioral effects of AEDs. Phenobarbital is the most frequently reported medication to induce symptoms of ADHD, followed by topiramate and valproic acid. Phenytoin seems to exert modest effects, while for levetiracetam there are contrasting data. Lacosamide induces some beneficial effects on behavior; carbamazepine and lamotrigine exert favorable effects on attention and behavior. Gabapentin and vigabatrin have limited adverse effects on cognition. Oxcarbazepine, rufinamide, and eslicarbazepine do not seem to aggravate or induce ADHD symptoms, whereas perampanel can lead to a high incidence of hostile/aggressive behavior, which increases with higher dosages. Information about the behavioral effects of ethosuximide, zonisamide, tiagabine, pregabalin, stiripentol, and retigabine is still limited. Because ADHD significantly affects the quality of life of epilepsy patients, the clinical management of this neuropsychiatric disorder should be a priority. Methylphenidate is effective most children and adolescents with ADHD symptoms and comorbid epilepsy, without a significant increase of seizure risk, although data are still limited with few controlled trials.

Adult ADHD and Comorbid Somatic Disease: A Systematic Literature Review

OBJECTIVE

To systematically review, synthesize, and appraise available evidence, connecting adult ADHD with somatic disease.

METHOD

Embase, Psychinfo, and Medline databases were searched for studies published from 1994 to 2015 addressing adult ADHD and somatic comorbidity. Somatic conditions were classified according to International Classification of Diseases (ICD-10) codes. Levels of evidence were graded as inconclusive, tentative, or well documented.

RESULTS

Most of the 126 studies included in the qualitative synthesis were small and of modest quality. Obesity, sleep disorders, and asthma were well-documented comorbidities in adult ADHD. Tentative evidence was found for an association between adult ADHD and migraine and celiac disease. In a large health registry study, cardiovascular disease was not associated with adult ADHD.

CONCLUSION

There are few large systematic studies using standardized diagnostic criteria evaluating adult ADHD and somatic comorbidities. Significant associations are found between adult ADHD and several somatic diseases, and these are important to consider when assessing and treating either adult ADHD or the somatic diseases.

Medical and Psychiatric Comorbidities in Korean Children and Adolescents with Attention-Deficit/Hyperactivity Disorder

OBJECTIVE

Attention-deficit/hyperactivity disorder (ADHD) is associated with a high rate of comorbid disorders. We aimed to investigate the medical and psychiatric comorbidities of Korean children and adolescents with ADHD.

METHODS

Data were obtained from Korean National Health Insurance Review and Assessment Service-National Patient Sample (HI-RA-NPS) for 2011. We included 2,140 (mean age, 10.9±3.1 years; boys, 1,710) and 219,410 (non-ADHD; mean age, 12.4±3.7 years; boys, 113,704) children and adolescents with and without ADHD, respectively. We compared medical and psychiatric comorbidities between the groups, and performed weighted logistic regression analyses to obtain odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Most medical comorbidities were more likely in patients with ADHD and included nervous system disease (OR, 2.59; 95% CI, 2.52-2.66); endocrine, nutritional, and metabolic disease (OR, 2.09; 95% CI, 2.04-2.15); and congenital malformations, deformations, and chromosomal abnormalities (OR, 2.00; 95% CI, 1.90-2.11). Oppositional defiant disorder and conduct disorder were more prevalent in patients with ADHD (OR, 81.88; 95% CI, 79.00-84.86), followed by learning (OR, 75.61; 95% CI, 69.69-82.04), and depressive disorders (OR, 55.76; 95% CI, 54.44-57.11).

CONCLUSION

Our results suggest that Korean children and adolescents with ADHD are more likely to suffer medical and psychiatric comorbidities than those without ADHD.

The Safety of Atomoxetine for the Treatment of Children and Adolescents with Attention-Deficit/Hyperactivity Disorder: A Comprehensive Review of Over a Decade of Research

Atomoxetine is a noradrenergic reuptake inhibitor prescribed for attention-deficit/hyperactivity disorder (ADHD) that first gained approval in the USA in 2002 and has been authorized in 97 countries worldwide. The aim of this paper is to comprehensively review publications that addressed one or more of seven major safety topics relevant to atomoxetine treatment of children and adolescents (aged ≥6 years) diagnosed with ADHD. While the review focuses on children and adolescents, publications in which data from patients aged >18 years and from 6 to 18 years were analyzed in the same dataset were included. Using a predefined search strategy, including agreement of two reviewers when selecting papers, reduced the potential for bias. Using this process, we identified 70 eligible papers (clinical trials, epidemiological studies, and case reports) across the seven topics. We also referred to the European Summary of Product Characteristics (SPC) and US label. We found 15 papers about suicidality, three about aggression/hostility, seven about psychosis/mania, six about seizures, seven about hepatic effects, 29 about cardiovascular effects, and 28 about growth and development. The main findings (i.e., those from the largest and most well-conducted studies/analyses) are as follows. A large register-based study of pediatric and adult patients (6818 received atomoxetine) calculated a hazard ratio of 0.96 for suicide-related events during treatment with atomoxetine, and a meta-analysis of 23 placebo-controlled studies (N = 3883), published in 2014, found no completed suicides and no statistically significant association between atomoxetine and suicidality. The frequency of aggression/hostility was not statistically significantly higher with atomoxetine, e.g., experienced by 1.6 % (N = 21/1308) of atomoxetine-treated patients versus 1.1 % (N = 9/806) of placebo-treated patients in one meta-analysis. Symptoms of psychosis and mania were mainly observed in patients with comorbid bipolar disorder/depression. Based on spontaneous reports, during a 2-year period when 2.233 million adult and pediatric patients were exposed to atomoxetine, the reporting rate for seizures was 8 per 100,000 patients. In the manufacturer's database, atomoxetine was a "probable cause" of three hepatic adverse events (AEs) (all reversible hepatitis), and 133 hepatic AEs had possible confounding factors and were "possibly related" to atomoxetine, during 4 years when atomoxetine exposure had reached about 4.3 million patients. Rare cases of severe liver injury are described in the US label and European SPC; a case requiring liver transplantation is described in the US label. In a comprehensive review of a clinical trials database (N = 8417 received atomoxetine), most pediatric patients experienced modest increases in heart rate and blood pressure, and 8-12 % experienced more pronounced changes (≥20 bpm, ≥15 to 20 mmHg). However, in three long-term analyses (≥2 years), blood pressure was within age norms, and few patients discontinued due to cardiovascular AEs. As described in the European SPC, QT interval prolongation is uncommon, e.g., in an open-label study, 1.4 % of 711 children and adolescents had prolonged QTc intervals (≥450 ms in males, ≥470 ms in females) that were not clinically significant at ≥3 years of treatment with atomoxetine. The European SPC warns about potential QT interval prolongation in patients with a personal or family history, or if atomoxetine is administered with other drugs that potentially affect the QT interval. Decreases in growth (weight and height gain) occurred and were greatest in patients of above average weight and height, but appeared to recover over 2-5 years of atomoxetine treatment. In conclusion, suicidality, aggression/hostility, psychosis, seizures, liver injuries, and prolonged QT interval are uncommon or rare in children and adolescents treated with atomoxetine, based on data from the predefined search and from the European SPC. Overall, the data that we assessed from our search do not suggest that associations exist between atomoxetine and suicidality or seizures. The data also suggest that an association may not exist between atomoxetine and aggression/hostility. While atomoxetine may affect the cardiovascular system, the data suggest these effects are not clinically significant in most patients. Reductions in growth appear to be reversible in the long term.

Attention Deficit Hyperactivity Disorder in Adolescents With Epilepsy

BACKGROUND

We examined attention-deficit hyperactivity disorder in adolescents with epilepsy and the association with seizure-related and sociodemographic variables.

METHODS

Strengths and Weakness of Attention-Deficit Hyperactivity Disorder Symptoms and Normal Behaviors rating scale was administered to 122 children with epilepsy and 50 children with asthma, aged 10 to 18 years attending mainstream schools.

RESULTS

Twenty-nine (23.7%) adolescents with epilepsy compared with five (10%) with asthma had attention deficit hyperactivity disorder (P = 0.037). Adolescents with epilepsy had a significantly higher score in the inattention subscale when compared with those with asthma (-0.25 ± 1.2 vs -0.64 ± 1.07, P = 0.049). Combined subtype was most frequent in the epilepsy group. Oppositional defiant disorders were more prevalent in those having attention deficit hyperactivity disorder. Psychiatric assistance had only been provided to one third of our patients with epilepsy and attention deficit hyperactivity disorder at the time of study. There was a negative correlation between attention deficit hyperactivity disorder scores and age of seizure onset. A positive correlation was observed between the number of antiepileptic drugs and the inattentive subscale score. The impact of various correlates on individual subtypes was not identical. Independent risk factors associated with attention deficit hyperactivity disorder were medical comorbidities (odds ratio = 12.82, 95% confidence interval 4.44, 37.03, P < 0.0001) and age at seizure onset (odds ratio = 0.73, 95% confidence interval 0.56, 0.94, P = 0.016).

CONCLUSIONS

Attention deficit hyperactivity disorder is overrepresented in adolescents with epilepsy; screening for its symptoms should be an integral part of management in adolescents with epilepsy.

Speed and complexity characterize attention problems in children with localization-related epilepsy

OBJECTIVE

Children with epilepsy (EPI) have a higher rate of attention-deficit/hyperactivity disorder (ADHD; 28-70%) than typically developing (TD) children (5-10%); however, attention is multidimensional. Thus, we aimed to characterize the profile of attention difficulties in children with epilepsy.

METHODS

Seventy-five children with localization-related epilepsy ages 6-16 years and 75 age-matched controls were evaluated using multimodal, multidimensional measures of attention including direct performance and parent ratings of attention as well as intelligence testing. We assessed group differences across attention measures, determined if parent rating predicted performance on attention measures, and examined if epilepsy characteristics were associated with attention skills.

RESULTS

The EPI group performed worse than the TD group on timed and complex attention aspects of attention (p < 0.05), whereas performance on simple visual and simple auditory attention tasks was comparable. Children with EPI were 12 times as likely as TD children to have clinically elevated symptoms of inattention as rated by parents, but ratings were a weak predictor of attention performance. Earlier age of onset was associated with slower motor speed (p < 0.01), but no other epilepsy-related clinical characteristics were associated with attention skills.

SIGNIFICANCE

This study clarifies the nature of the attention problems in pediatric epilepsy, which may be under-recognized. Children with EPI had difficulty with complex attention and rapid response, not simple attention. As such, they may not exhibit difficulty until later in primary school when demands increase. Parent report with standard ADHD screening tools may under-detect these higher-order attention difficulties. Thus, monitoring through direct neuropsychological performance is recommended.

Attention problems in children with epilepsy. How is the long-term outcome?

INTRODUCTION

Attention deficit/hyperactivity disorder (ADHD) is one of the most common childhood disorders and frequently seen in other conditions like epilepsy as well. The prevalence of ADHD in the general paediatric population is estimated at 3-6% persisting into adulthood in up to one third of persons affected. The prevalence of ADHD in epilepsy is understood to be significantly higher. Approximately one third of children with epilepsy do also have a diagnosis of ADHD. How these attention problems develop over the years is however not clear. We therefore evaluated the severity of attention problems in children with epilepsy at late childhood and assessed it again in adolescence. Data was being compared with attention problems of children with developmental ADHD.

METHOD

16 boys with diagnosed combined idiopathic epilepsy/ADHD and 14 boys with developmental ADHD were investigated twice; at a mean age of 10.94 (SD = 1.63) and then again at a mean age of 15.82 (SD = 2.0). At the baseline examination all patients completed Raven's Progressive Matrices to assess intelligence. To measure symptom severity of ADHD, parents were asked to complete the short version of the Conner's Rating Scale for Parents at both times. Parents of children with combined epilepsy/ADHD furthermore gave information about seizure frequency and intake of anticonvulsants.

RESULTS

Patient groups did not significantly differ in age and IQ. Results of the baseline examination revealed elevated scores in both patient groups for the Conner's Rating Scales; ADHD group: M = 16.86 (SD = 5.35); Epilepsy/ADHD group: M = 14.77 (SD = 4.76) but no differences between the groups (p = .29; z = .39). Qualitatively, patients with developmental ADHD showed more abnormalities in the area of hyperactivity/impulsivity while patients with epilepsy/ADHD had more problems with inattention. Results of the follow-up examination showed a significant reduction of symptoms in the ADHD group of minus 4.23 points; M = 12.63 (SD = 3.89) (p = .02); The reduction in the epilepsy/ADHD group was even bigger with minus 6.77 points; M = 8.00 (SD = 6.46) (p = .03). However, difference between the two groups reached no significance (p = .079; z = 1.19). None of the patients with epilepsy has had seizures in the meantime.

CONCLUSION

We found a significant reduction of ADHD symptoms in our patients from the time of late childhood to adolescence. That symptoms of ADHD, especially hyperactivity, lessen with age is known from the literature (Biedermann et al., 2010). We found the same data for patients with idiopathic epilepsy and ADHD. Over the same period of time problems of attention improved substantially. We conclude that development and brain maturation may have a similar positive effect on attention problems in children with epilepsy than in developmental ADHD.

Cognitive function in childhood epilepsy: importance of attention deficit hyperactivity disorder

Background and Purpose

To determine how cognitive function is related to epilepsy classification and comorbid attention deficit hyperactivity disorder (ADHD) in children with newly diagnosed epilepsy of genetic or unknown etiology.

Methods

The medical records of children aged 6-16 years with newly diagnosed epilepsy of genetic or unknown etiology were reviewed retrospectively. The Korean Education Development Institute-Wechsler Intelligence Scale for Children and the Comprehensive Attention Test were used to evaluate intelligence and attention/executive function, respectively.

Results

The data of a total of 149 children, 103 with focal seizures and 46 with generalized seizures, were reviewed. The prevalence of ADHD was 49.2% (59 out of 120 examined patients), and ADHD patients exhibited significantly worse auditory selective attention, flanker test results, and spatial working memory. Patients with generalized seizures exhibited significantly worse auditory selective and sustained attention than patients with focal seizures. In patients with generalized seizures, sustained attention, flanker test findings, and spatial working memory were found to be affected by ADHD, and auditory selective and sustained attention were significantly worse in patients with benign childhood epilepsy with centrotemporal spikes and ADHD than in their counterparts without ADHD.

Conclusions

Cognitive processes are affected by seizure type and comorbid ADHD. Proper characterization of these neuropsychiatric impairments may allow earlier intervention during the disease course.

Reappraisal of abnormal EEG findings in children with ADHD: on the relationship between ADHD and epileptiform discharges

INTRODUCTION

Attention-deficit hyperactivity disorder is suggested to be closely related to epilepsy. A recent large-scale study revealed that ADHD in children is often accompanied by epilepsy. In Japan, methylphenidate (MPH) as a sustained-action tablet and atomoxetine (ATX) became commercially available as medications for children recently. Since then, the number of prescriptions of both medicines has increased rapidly. Methylphenidate, as a psychostimulant, has been a source of concern because of the perceived lowered threshold for convulsions in children. Based on this background, reappraisal of EEG findings in children with ADHD is important in order to detect indications of potential comorbid epilepsy and to investigate the developmental mechanisms of the neurophysiological manifestations in patients with ADHD.

MATERIAL AND METHOD

EEG findings in children newly diagnosed with ADHD and their relationship with clinical findings were investigated. The author evaluated 208 patients with ADHD newly diagnosed between 2008 and 2013. Of these, there were 145 patients for whom EEG findings were obtained along with a clinical follow-up for at least three months. Patients with IQ<70 were excluded in order to obtain a homogenous group of patients with ADHD. The male-to-female ratio was 130:15, and the age range was between 5 years, 9 months and 19 years, 9 months, with mean age of 11 years, 4 months.

RESULTS

The results revealed that about half (48.3%) of the children with ADHD had abnormal EEG findings and that 22.1% of them had epileptiform discharges. Patients without comorbidity of autism spectrum disorder (ore homogenous group with ADHD) were especially likely to show abnormal EEG findings (51.0%) including epileptiform discharges (24.5%). Afebrile seizures, that is, epileptic seizures, occurred in a boy three days after commencement of administration with MPH as a sustained-action tablet. In four patients with a past history of epilepsy, neither relapse of EEG abnormality nor epileptic seizures were observed during the follow-up period.

CONCLUSION

There was to be a significantly close relationship between ADHD and epileptiform discharges. Therefore, in patients with ADHD, it is important to obtain more precise information about seizures and presence of epilepsy from the personal and family histories, as well as to undertake a thorough EEG examination.

Key issues in addressing the comorbidity of attention deficit hyperactivity disorder and pediatric epilepsy

Attention deficit hyperactivity disorder (ADHD) is a common comorbidity of epilepsy encountered by clinicians. However, relatively little information is available to guide optimal diagnostic and treatment strategies. Differentiating ADHD from effects of epilepsy requires careful history taking and emphasis upon characteristic symptoms and course of illness. Rating scales for ADHD are well validated and may aid clinical management. Use of antiepileptic drugs may cause cognitive or behavioral side effects yet may improve behavior in some cases. Historically, clinicians have been hesitant to treat ADHD comorbidity for fear of lowering the seizure threshold. However, an aggregate of recent evidence now suggests that stimulants may be well tolerated and effective for ADHD comorbid with epilepsy. Studies that further clarify pathophysiology and treatment outcomes are needed in order to enhance clinical efficacy and quality of life for this population.