Subclinical Epileptiform Discharges Research Articles

Subclinical epileptiform discharges in Alzheimer’s disease are associated with increased hippocampal blood flow

BackgroundIn epilepsy, the ictal phase leads to cerebral hyperperfusion while hypoperfusion is present in the interictal phases. Patients with Alzheimer’s disease (AD) have an increased prevalence of epileptiform discharges and a study using intracranial electrodes have shown that these are very frequent in the hippocampus. However, it is not known whether there is an association between hippocampal hyperexcitability and regional cerebral blood flow (rCBF). The objective of the study was to investigate the association between rCBF in hippocampus and epileptiform discharges as measured with ear-EEG in patients with Alzheimer’s disease. Our hypothesis was that increased spike frequency may be associated with increased rCBF in hippocampus.MethodsA total of 24 patients with AD, and 15 HC were included in the analysis. Using linear regression, we investigated the association between rCBF as measured with arterial spin-labelling MRI (ASL-MRI) in the hippocampus and the number of spikes/sharp waves per 24 h as assessed by ear-EEG.ResultsNo significant difference in hippocampal rCBF was found between AD and HC (p-value = 0.367). A significant linear association between spike frequency and normalized rCBF in the hippocampus was found for patients with AD (estimate: 0.109, t-value = 4.03, p-value < 0.001). Changes in areas that typically show group differences (temporal-parietal cortex) were found in patients with AD, compared to HC.ConclusionsIncreased spike frequency was accompanied by a hemodynamic response of increased blood flow in the hippocampus in patients with AD. This phenomenon has also been shown in patients with epilepsy and supports the hypothesis of hyperexcitability in patients with AD. The lack of a significant difference in hippocampal rCBF may be due to an increased frequency of epileptiform discharges in patients with AD.Trial registrationThe study is registered at clinicaltrials.gov (NCT04436341).

Assessing the impact of subclinical epileptiform discharges on driving ability in neuropsychology: A case study

Assessing the impact of subclinical epileptiform discharges on driving ability in neuropsychology: A case study

Pharmacological Management of Core Symptoms and Comorbidities of Autism Spectrum Disorder in Children and Adolescents: A Systematic Review.

PurposeThe pharmacological management of Autism Spectrum Disorder (ASD) in children remains a challenge due to limited effective management options and the absence of approved drugs to manage the core symptoms. This review aims to describe and highlight effective pharmacological management options employed in managing the core symptoms and comorbidities of ASD from eligible studies over the past decade.MethodsA search of databases; PubMed, Scopus, Science Direct, and PsychInfo for pharmacotherapeutic options for ASD was conducted in this systematic review. Duplicate studies were removed by utilizing the EndNote citation manager. The studies were subsequently screened independently by two authors. Eligible studies from 01 January 2012 to 01 January 2022 were included based on established eligibility criteria. A narrative synthesis was used for data analysis.ResultsThe systematic review provides a comprehensive list of effective management options for ASD comorbidities and core symptoms from 33 included studies. The management options for ASD comorbidities; insomnia, hyperactivity, irritability and aggression, gastrointestinal disturbances, and subclinical epileptiform discharges, were reviewed. Risperidone, aripiprazole, methylphenidate, guanfacine, levetiracetam, and atomoxetine are examples of effective pharmacological drugs against ASD comorbidities. Additionally, this review identified various drugs that improve the core symptoms of ASD and include but are not limited to, bumetanide, buspirone, intranasal oxytocin, intranasal vasopressin, and prednisolone.ConclusionThis review has successfully summarized the pharmacological advancements made in the past decade to manage ASD. Although there is still no pharmacological cure for ASD core symptoms or additional drugs that have obtained regulatory approval for use in ASD, the availability of promising pharmacological agents are under evaluation and study.

The Significance of Subclinical Epileptiform Activity in Alzheimer's Disease: A Review.

Hyperexcitability is a recently recognized contributor to the pathophysiology of Alzheimer's disease (AD). Subclinical epileptiform activity (SEA) is a neurophysiological sign of cortical hyperexcitability; however, the results of the studies in this field vary due to differences in the applied methodology. The aim of this review is to summarize the results of the related studies aiming to describe the characteristic features and significance of subclinical epileptiform discharges in the pathophysiologic process of AD from three different directions: (1) what SEA is; (2) why we should diagnose SEA, and (3) how we should diagnose SEA. We scrutinized both the completed and ongoing antiepileptic drug trials in AD where SEA served as a grouping variable or an outcome measure. SEA seems to appear predominantly in slow-wave sleep and in the left temporal region and to compromise cognitive functions. We clarify using supportive literature the high sensitivity of overnight electroencephalography (EEG) in the detection of epileptiform discharges. Finally, we present the most important research questions around SEA and provide an overview of the possible solutions.

Epilepsy and EEG Abnormalities in Children with Autism Spectrum Disorders.

To evaluate the prevalence of epilepsy and electroencephalographic abnormalities in children with autism spectrum disorders (ASD) and determine their risk factors. This cross-sectional study was conducted over one year in children with ASD aged between 3 and 14 y. Classification of epilepsy and routine electroencephalography (EEG) recordings were done for all the patients. Developmental and cognitive assessments were done using Developmental Profile 3. Children were divided into three groups: ASD with epilepsy, ASD with isolated electroencephalographic abnormalities, and ASD with neither epilepsy nor electroencephalographic abnormalities. One hundred children with ASD were enrolled. Epilepsy was reported in 23% and subclinical electroencephalographic abnormalities were documented in 8%. The most common seizure types were generalized-onset tonic-clonic (48%), focal-onset with impaired awareness (17%), and focal to bilateral tonic-clonic seizures (17%). In children with subclinical epileptiform discharges, focal abnormalities were most common (75%) and were maximally seen over the temporal region (50%). Subnormal intellect (88.6%) and abnormal global developmental score (82%) were noted in the majority of children. Female gender, abnormal neurological examination, and adverse perinatal events were significantly associated with epilepsy. Of these, female gender and adverse perinatal events were independent predictors of epilepsy. Isolated EEG abnormalities were significantly associated with abnormal neurological examination in comparison with autistic children without epilepsy/EEG abnormalities. Epilepsy is seen in up to one-fourth children with ASD. Female gender and adverse perinatal events are independent risk factors for epilepsy. Subclinical or isolated EEG abnormalities are associated with abnormal neurological examination.

Modulation of Brain Hyperexcitability: Potential New Therapeutic Approaches in Alzheimer's Disease.

People with Alzheimer’s disease (AD) have significantly higher rates of subclinical and overt epileptiform activity. In animal models, oligomeric Aβ amyloid is able to induce neuronal hyperexcitability even in the early phases of the disease. Such aberrant activity subsequently leads to downstream accumulation of toxic proteins, and ultimately to further neurodegeneration and neuronal silencing mediated by concomitant tau accumulation. Several neurotransmitters participate in the initial hyperexcitable state, with increased synaptic glutamatergic tone and decreased GABAergic inhibition. These changes appear to activate excitotoxic pathways and, ultimately, cause reduced long-term potentiation, increased long-term depression, and increased GABAergic inhibitory remodelling at the network level. Brain hyperexcitability has therefore been identified as a potential target for therapeutic interventions aimed at enhancing cognition, and, possibly, disease modification in the longer term. Clinical trials are ongoing to evaluate the potential efficacy in targeting hyperexcitability in AD, with levetiracetam showing some encouraging effects. Newer compounds and techniques, such as gene editing via viral vectors or brain stimulation, also show promise. Diagnostic challenges include identifying best biomarkers for measuring sub-clinical epileptiform discharges. Determining the timing of any intervention is critical and future trials will need to carefully stratify participants with respect to the phase of disease pathology.

Concurrent EEG monitoring helps interpret neuropsychological testing results in patients with epilepsy

ObjectiveWe sought to determine if global cognitive function in patients with epilepsy (PWE) differs when electroencephalographic (EEG) abnormalities are present during concurrent neuropsychological (NP) evaluation. MethodsWe explored the association between subclinical epileptiform discharges (sEDs) and interictal epileptiform discharges (IEDs) and global aspects of cognition in 79 consecutive PWE who underwent continuous EEG monitoring during NP evaluation for diagnostic (15%) or presurgical (85%) purposes while on their standard antiseizure medication (ASM) regimens. As some researchers have suggested that the apparent link between IEDs and cognition represent epiphenomena of an underlying damaged neural substrate, we used functional status as a stratifying covariate to allow us to address this position. ResultsDespite being on their standard ASM regimen, EEG was abnormal in 68% of patients. Epileptiform abnormalities (IEDs, sEDs, or both) were seen in isolation or coupled with diffuse or focal slowing in 38% of patients. Individuals with IEDs occurring during their NP evaluation demonstrated poorer scores in attention/working memory (forward and backward digit span), processing speed (symbol searching and coding), and speeded components of language (semantic fluency) tests compared with those with normal EEG tracings matched by their real-world, functional status. In two high functioning patients, performance was significantly better when these individuals were tested in the absence of IEDs, with performances appearing invalid when tested during periods of IED activity. No significant association was found between NP performance and nonepileptiform EEG abnormalities. SignificanceA substantial proportion of PWE undergoing NP evaluation manifest concurrent EEG abnormalities, with epileptiform abnormalities associated with poorer global cognitive performance. As this pattern was observed regardless of functional status, this association appears to represent more than unrelated features coincidentally shared by the lowest functioning cohort. Coupled with our individual case data, our findings suggest that NP testing may be adversely affected by IEDs and sEDs going unrecognized in the absence of simultaneous EEG recordings, and set the stage for future studies to definitively establish this possible relationship.

Levetiracetam Protects Against Cognitive Impairment of Subthreshold Convulsant Discharge Model Rats by Activating Protein Kinase C (PKC)-Growth-Associated Protein 43 (GAP-43)-Calmodulin-Dependent Protein Kinase (CaMK) Signal Transduction Pathway.

BackgroundSubclinical epileptiform discharges (SEDs) are defined as epileptiform electroencephalographic (EEG) discharges without clinical signs of seizure in patients. The subthreshold convulsant discharge (SCD) is a frequently used model for SEDs. This study aimed to investigate the effect of levetiracetam (LEV), an anti-convulsant drug, on cognitive impairment of SCD model rats and to assess the associated mechanisms.Material/MethodsA SCD rat model was established. Rats were divided into an SCD group, an SCD+ sodium valproate (VPA) group, and an SCD+ levetiracetam (LEV) group. The Morris water maze was used to evaluate the capacity of positioning navigation and space exploration. The field excitatory post-synaptic potentials (fEPSPs) were evaluated using a bipolar stimulation electrode. NCAM, GAP43, PS95, and CaMK II levels were detected using Western blot and RT-PCR, respectively. PKC activity was examined by a non-radioactive method.ResultsLEV shortens the latency of platform seeking in SCD rats in positioning navigation. fEPSP slopes were significantly lower in the SCD group, and LEV treatment significantly enhanced the fEPSP slopes compared to the SCD group (P<0.05). The NCAM and GAP-43 levels were increased and PSD-95 levels were increased in SCD rats (P<0.05), which were improved by LEV treatment. The PKC activity and CaMK II levels were decreased in SCD rats and LEV treatment significantly enhanced PKC activity and increased CaMK II levels.ConclusionsCognitive impairment in of SCD model rats may be caused by decreased PKC activity, low expression of CaMK II, and inhibition of LTP formation. LEV can improve cognitive function by activating the PKC-GAP-43-CaMK signal transduction pathway.

Epilepsy and interictal epileptiform activity in patients with autism spectrum disorders

PurposeThe purpose of this study was to determine the prevalence of epilepsy and subclinical epileptiform abnormalities in children with autism spectrum disorder (ASD), and to investigate its effects on core autistic symptoms and adaptive behavior skills. MethodsPatients with diagnosis of ASD who met full criteria on Autism Diagnostic Interview-Revised (ADI-R) were included in the study. Adaptive behavior skills were assessed by Vineland Adaptive Behavior Scale-II (VABS-II). Clinical assessment for epilepsy and video electroencephalography (EEG) (v-EEG) examinations during wakefulness and/or sleep were prospectively performed in all patients. ResultsA total of 112 patients with diagnosis of ASD of mean age 6.58 ± 3.72 were included in the study. Based on clinical and v-EEG assessments, three groups of patients were defined: 1) patients with epilepsy (n = 17; 15.2%); 2) patients with epileptiform discharges in absence of clinical seizures (n = 14; 12.5%); 3) patients without epilepsy and without epileptiform discharges (n = 81; 72.3%). There were no significant differences between three groups of patients on ADI-R subscores. Speech development was also not significantly related to epilepsy. There was a slight tendency of the VABS-II motor skills score to be higher in the group of patients with autism without clinical diagnosis of epilepsy and without subclinical epileptiform discharges (p < 0.05) in comparison with the two other groups. According to this tendency, we might claim that patients with higher scores on motor skills could have 0.88 times lower odds for having epileptiform EEG activity. ConclusionsAccording to our results, we were not able to detect differences in the ADI-R between the three populations with ASD, all with unknown etiology. Epilepsy, as well as subclinical epileptic discharges, showed small effects on Motor Skills in patients with autism, and had no effect on adaptive behavior Communication/Socialization/Daily Living Skills.

Disabling portosystemic encephalopathy in a non-cirrhotic patient: Successful endovascular treatment of a giant inferior mesenteric-caval shuntviathe left internal iliac vein

Hepatic encephalopathy is suspected in non-cirrhotic cases of encephalopathy because the symptoms are accompanied by hyperammonaemia. Some cases have been misdiagnosed as psychiatric diseases and consequently patients hospitalized in psychiatric institutions or geriatric facilities. Therefore, the importance of accurate diagnosis of this disease should be strongly emphasized. A 68-year-old female patient presented to the Emergency Room with confusion, lethargy, nausea and vomiting. Examination disclosed normal vital signs. Neurological examination revealed a minimally responsive woman without apparent focal deficits and normal reflexes. She had no history of hematologic disorders or alcohol abuse. Her brain TC did not demonstrate any intracranial abnormalities and electroencephalography did not reveal any subclinical epileptiform discharges. Her ammonia level was > 400 mg/dL (reference range < 75 mg/dL) while hepatitis viral markers were negative. The patient was started on lactulose, rifaximin and low-protein diet. On the basis of the doppler ultrasound and abdomen computed tomography angiography findings, the decision was made to attempt portal venography which confirmed the presence of a giant portal-systemic venous shunt. Therefore, mechanic obliteration of shunt by interventional radiology was performed. As a consequence, mesenteric venous blood returned to hepatopetally flow into the liver, metabolic detoxification of ammonia increased and hepatic encephalopathy subsided. It is crucial that physicians immediately recognize the presence of non-cirrhotic encephalopathy, in view of the potential therapeutic resolution after accurate diagnosis and appropriate treatments.

Levetiracetam is associated with decrease in subclinical epileptiform discharges and improved cognitive functions in pediatric patients with autism spectrum disorder.

ObjectiveSubclinical epileptiform discharges (SEDs) are common in pediatric patients with autism spectrum disorder (ASD), but the effect of antiepileptic drugs on SEDs in ASD remains inconclusive. This physician-blinded, prospective, randomized controlled trial investigated an association between the anticonvulsant drug levetiracetam and SEDs in children with ASD.MethodsA total of 70 children with ASD (4–6 years) and SEDs identified by electroencephalogram were randomly divided into two equal groups to receive either levetiracetam and educational training (treatment group) or educational training only (control). At baseline and after 6 months treatment, the following scales were used to assess each individual’s behavioral and cognitive functions: the Chinese version of the Psychoeducational Profile – third edition (PEP-3), Childhood Autism Rating Scale (CARS), and Autism Behavior Checklist (ABC). A 24-hour electroencephalogram was recorded on admission (baseline) and at follow-up. The degree of satisfaction of each patient was also evaluated.ResultsRelative to baseline, at the 6-month follow-up, the PEP-3, CARS, and ABC scores were significantly improved in both the treatment and control groups. At the 6-month follow-up, the PEP-3 scores of the treatment group were significantly higher than those of the control, whereas the CARS and ABC scores were significantly lower, and the rate of electroencephalographic normalization was significantly higher in the treatment group.ConclusionLevetiracetam appears to be effective for controlling SEDs in pediatric patients with ASD and was also associated with improved behavioral and cognitive functions.

Self and informant report ratings of psychopathology in genetic generalized epilepsy.

The psychological sequelae of genetic generalized epilepsies (GGE) is of growing research interest, with up to a third of all adults with GGE experiencing significant psychiatric comorbidity according to a recent systematic review. A number of unexplored questions remain. Firstly, there is insufficient evidence to determine relative prevalence of psychopathology between GGE syndromes. Secondly, the degree to which self-report and informant-report questionnaires accord in adults with epilepsy is unknown. Finally, while epilepsy severity is one likely predictor of worse psychopathology in GGE, evidence regarding other possible contributing factors such as epilepsy duration and antiepileptic drugs (AEDs) has been equivocal. The potential impact of subclinical epileptiform discharges remains unexplored. Self-report psychopathology symptoms across six DSM-Oriented Subscales were prospectively measured in 60 adults with GGE, with informant-report provided for a subset of 47. We assessed the burden of symptoms from both self- and informant-report, and the relationship between clinical epilepsy variables and self-reported symptoms. Results showed elevated symptoms in almost half of the sample overall. Depression and anxiety were the most commonly reported types of symptoms. There was a trend towards greater symptoms endorsement by self-report, and relatively modest interrater agreement. Symptoms of ADHD were significantly positively associated with number of AEDs currently prescribed. Other psychopathology symptoms were not significantly predicted by epilepsy duration, seizure-free duration or total duration of epileptiform discharges over a 24-hour period. The high prevalence of psychological needs suggests that routine screening of psychopathology and provision of psychoeducation may be essential to improving patient care and outcomes. Further investigation is required to better understand predictive and causal factors for psychopathology in GGE.

The subclinical epileptiform discharges among nonepileptic cerebral palsy patients

Background Subclinical epileptiform discharges (SEDs) are assumed to play a role in the development of cognitive dysfunction in cerebral palsy (CP) patients. Purpose The aim of this study was to estimate the prevalence of SEDs among nonepileptic CP patients and their cognitive correlates. Patients and methods Fifty-one nonepileptic CP patients were recruited. All patients were subjected to history taking, neurological examination, assessment using Gross Motor Function Classification System for CP, the Stanford–Binet scale (5th edition), encephalography, and MRI of the brain. They were divided into two groups: group 1, which included 19 CP patients without SEDs, and group 2, which included 32 CP patients with SEDs. A comparison between patients’ features studied in groups 1 and 2 was made using independent-samples t-test and the χ2-test. A correlation between SEDs and the studied features was made using Spearman’s rank correlation coefficient (ρ). Results The prevalence of SEDs among nonepileptic CP patients was 62.7%. The presence of MRI abnormality and moderate mental retardation showed a highly significant positive correlation with SEDs. Meanwhile, central nervous system malformation and severe mental retardation showed a significant positive correlation with SEDs. However, normal intelligence showed a highly significant negative correlation with SEDs. Kernicterus and dyskinetic CP showed a significant negative correlation with SEDs. Conclusion SEDs are a common finding among nonepileptic CP children. They are positively correlated to cognitive dysfunction. This finding supports the assumption that SEDs are therapeutic target in mentally subnormal children. Larger studies are needed to confirm our results and to evaluate the clinical benefit of treating SEDs.

Autistic disorder with complex IV overactivity: A new mitochondrial syndrome

Although mitochondrial disease is usually associated with reductions in electron transport chain complex activity, a few reports have associated mitochondrial disease with complex overactivity. This is the first report to associate complex IV overactivity with autistic disorder. Five patients with a significant elevation in complex IV activity, abnormal muscle electron microscopy and autistic disorder with developmental regression are reported. The majority, 80%, manifested either epilepsy or subclinical epileptiform discharges on electroencephalogram. Cerebral folate deficiency was found in the three patients evaluated for this disorder. The majority of patients had potentially detrimental nuclear and mitochondrial abnormalities. This series represents a new mitochondrial syndrome characterized by autistic disorder with complex IV overactivity. The association with cerebral folate deficiency is important as cerebral folate deficiency is treatable with folinic acid. The significance of an increase in complex IV function is discussed in the context of the associated physiological disturbances reported in autism spectrum disorder.

Potential risk for neuropsychological deficits from subclinical epileptiform discharges in children with benign rolandic epilepsy

Benign rolandic epilepsy (BRE) is a benign condition, but may display different degrees of neuropsychological deficits, such as cognitive disturbances, attention deficit hyperactivity disorder, and other behavioral deficits. The aim of this study was to assess the neuropsychological functions and their relationship to the characteristics of interictal epileptiform discharges in children with BRE. A total of 33 children with newly diagnosed BRE (19 males/14 females, 8.2 ± 2.4 yr) were involved in the study. All children underwent a sleep electroencephalography and a comprehensive neuropsychological evaluation, which included Korean versions of the Wechsler intelligence scale for children III, frontal executive neuropsychological test, Rey complex figure test, Wisconsin card sorting test, attention deficit diagnostic scale, and child behavior checklist. The average monthly seizure frequency of the subjects was 0.8 ± 0.8, and the spike index was 14.1 ± 18.4/min (right) and 18.8 ± 22.1/min (left). On the whole, subjects exhibited normal cognitive function, frontal executive function, memory and other neuropsychological sub-domain scores. The group with a higher spike index on the left hemisphere scored lower on attention deficit diagnostic scale, auditory verbal learning test, and stroop test (P min) scored lower on full scale and performance intelligence quotient (110.7 ± 18.0 vs. 96.8 ± 11.2; 107.4 ± 16.4 vs. 94.3 ± 12.8) (P

Cognitive and electrophysiological characteristics of children with specific language impairment and subclinical epileptiform electroencephalogram

The current study is a preliminary examination of cognitive profiles and cortical distribution of the spectral power of different electroencephalogram (EEG) rhythms in children with specific language impairment and subclinical epileptiform discharges. Although a number of empirical studies point to higher incidence of abnormal EEGs in children with specific language impairment, only a few studies were found examining electrophysiological characteristics, such as locus of discharges and connections with cognitive functioning in this population of children. The sample included 12 children with specific language impairment (SLI) and abnormal EEG who underwent testing of cognitive functioning using the Wechsler Intelligence Scale for Children (WISC). The control sample included 13 children with specific language impairment and regular EEG. Results point to lower scores on several subtests of the performance scale for children with abnormal EEG than for the group with regular EEG. Detailed EEG analysis of cortical distribution of the spectral power of different EEG rhythms partially confirms the results of neuropsychological assessment, pointing to abnormal function of frontal and temporal regions. Higher values of spectral power of the delta brain rhythm in frontal regions are associated with lower results on the WISC performance scale. Results are discussed in the context of subgroups of the population of children with SLI.

Benign Childhood Epilepsy with Centrotemporal Spikes: To Treat or Not to Treat

Background and Purpose:The aim of this study was to evaluate the benefits and risks of oxcarbazepine (OXC) monotherapy in children with newly diagnosed, benign partial epilepsy based on clinico-electrical and neuropsychological evaluation over time.Methods:The study was open label, prospective, multicenter based. A total of 39 children with BRE were involved in the study. They were randomized into two groups (T; treatment with OXC, NT; No treatment) to compare the effectiveness of OXC treatment. All children underwent EEGs with quantification and a comprehensive battery of neuropsychological tests at the first visit and follow up visit at 6 months.Results:The subjects made a slight progress in general intelligence measures over time in both groups (95.4±10.5 to 97.6±7.5 for T, 107.6±17.3 to 111.4±18.6 for NT). Memory and frontal executive functions did not change over time in both groups in terms of the memory quotient (MQ) (106.7±27.5 to 103.4± 19.3 for T, 105.8±13.2 to 104.9±17.2 for NT) and executive intelligence quotient (EIQ) (114.7±18.3 to 108.9±12.5 for T, 100.6±25.1 to 101.2±13.9 for NT). However, when sub-domain scores were compared between the two groups, the treatment group got significantly worse over time in the verbal fluency test (11.5±3.8 to 8.0±1.4 for T, 10.3±3.9 to 11.5±2.1 for NT; p<0.05) and level 1 of Stroop test (9.3±3.0 to 7.5±1.3 for T, 11.0±3.7 to 11.2±2.6 for NT; p<0.05). The subjects might have cognitive and behavioral difficulties in association with frontal lobe dysfunctions, but these difficulties did not seem to be dependent on the number of seizures, the abundance of subclinical epileptiform discharges, or the anti-epileptic treatment.Conclusions:We think that OXC monotherapy is effective for children with BRE, but is to be given to the selected patients such as patients with prolonged or frequent seizures. However, further studies are needed to have a better understanding in this matter.

Chronic epileptic encephalopathy in adult patients with bilaterally synchronous frequent and/or prolonged subclinical epileptiform discharges

We followed four patients with infrequent convulsive seizures for four to 10years, with periodic EEGs and neuropsychological tests. All four had bursts of frontally predominant, bilaterally synchronous 1.5–3‐Hz spike or polyspike and slow-wave discharges (SWDs) that initially comprised 15% to 88% but were reduced to 5% or less of total EEG time with appropriate antiepileptic drugs. Case 1 showed a 30-point improvement in his verbal WAIS‐R score and Case 4 a 21-point improvement in his performance WAIS‐R score, over nine- and five-year periods, respectively, with normalization of frontal executive function. Cases 2 and 3 showed no improvement in frontal executive dysfunction despite being free of SWDs for nine and five years, respectively. These patients had variable degrees of epileptic encephalopathy and subclinical SWDs. They illustrate the importance of minimizing the occurrence of SWDs with appropriate antiepileptic drugs and long-term monitoring with neuropsychological tests because chronic cognitive deficits are potentially reversible.

Attention-Deficit Disorders and Epilepsy in Childhood: Incidence, Causative Relations and Treatment Possibilities

At least 20% of children with epilepsy have clinical attention-deficit hyperactivity disorder (ADHD) compared to 3% to 7% of the general pediatric population. Several mechanisms may account for the high prevalence, such as a common genetic propensity, noradrenergic system dysregulation, subclinical epileptiform discharges, or even seizures, antiepileptic drug effects, and psychosocial factors. At the same time, children with attention-deficit hyperactivity disorder have a higher than normal rate of electroencephalography abnormalities (5.6-30.1% vs. 3.5%). Methylphenidate treatment is equally efficient in children with isolated attention-deficit hyperactivity disorder and in children with attention-deficit hyperactivity disorder and epilepsy (70%-77%). Electroencephalography screening in patients with attention-deficit hyperactivity disorder in the absence of other clinical indications or before starting methylphenidate treatment is not currently indicated. Methylphenidate is considered safe for use in children who are seizure-free. However, the few reports of seizure aggravation in methylphenidate-treated children with uncontrolled epilepsy have raised concern.

Bilateral Operculum Syndrome in Childhood

We describe 3 patients with bilateral operculum syndrome. They presented with various degrees of suprabulbar (pseudobulbar) signs in addition to delay in cognitive, motor, and speech development in 2 children and developmental language disorder in the third one. A patient with schizencephaly in the left perisylvian area and contralateral polymicrogyria had spastic hemiparesis on the right side, whereas another patient showed bilateral underdevelopment of the opercula in association with axial hypotonia and spastic diplegia. Both of them had epileptiform discharges on the electroencephalogram without clinical manifestations of seizures. The magnetic resonance imaging of the third child with developmental language disorder was normal; however, his electroencephalogram showed frequent bilateral subclinical centrotemporal epileptiform discharges, probably responsible for the speech delay. Structural or functional involvement of the opercula bilaterally was a common finding in all the 3 patients and they had symptoms similar to those described in the developmental type of Foix-Chavany-Marie and Worster-Drought syndromes.