Language Lateralization in Children with Benign Partial Epilepsy

To investigate the relationship between epilepsy and hemispheric asymmetries for language, a dual-task procedure was used to assess language lateralization in children with benign rolandic childhood epilepsy. In the sample selection, care was taken to include factors believed to influence both the mental capabilities of epileptic patients and the individual functional cerebral organization. Results suggest that the interhemispheric prevalence pattern is related to the focus site. Controls as well as epileptic patients with a right hemispheric focus showed the expected left language lateralization; conversely, children with a left unilateral focus showed a different pattern of functional representation, suggesting an involvement of the right hemisphere in language mechanisms. It is emphasized that this atypical cerebral organization is found in subjects with no structural lesion and no therapy. It seems likely that the presence of a focal epileptic activity itself can alter the cerebral mechanisms underlying cognitive functions. A relationship between this modified hemispheric specialization and subtle neuropsychological dysfunctions observed in the children with focal epilepsy is suggested.     

Neuropsychological aspects of benign childhood epilepsy with centrotemporal spikes

PurposeTo establish whether the disability in benign epilepsy with centrotemporal spikes (BECTS) is the result of the number of seizures, the anti-epileptic therapy or is an inherent characteristic of the syndrome itself.MethodsThirty-six children with BECTS were tested for cognitive functions prior to commencing treatment with anti-epileptic drugs, and the findings were compared with those in 15 children with normal electroencephalograms, performed for unrelated reasons. The data in the study group were further correlated with the laterality of the epileptic focus and the number of seizures.ResultsScores for verbal functioning on neuropsychological tests were significantly lower in the study group than the control group. There was no relationship between the neuropsychological scores in the patients and either lateralization of the epileptic focus or number of seizures.DiscussionChildren with BECTS have an impaired ability to process verbal information. The deficiency is apparently a result of the pathological electrical discharges that are part of the syndrome and are not dependent on the epileptic focus laterality, the number of seizures, or the anti-epileptic treatment.     

Neurocognitive development of children with congenital unilateral brain lesion and epilepsy

The aim of this study was to specify the neuropsychological deficits characteristic of children with unilateral non-progressive brain lesion. In order to assess these specific functions, we used a comprehensive model of congenital hemiparesis with partial epilepsy and newly diagnosed partial epilepsy without hemiparesis. The neuropsychological examination was performed using the NEPSY test battery on 44 children aged from 4 to 9 years. The children were divided into three groups: 18 children suffering from congenital hemiparesis with chronic partial epilepsy, 12 children with newly diagnosed partial epilepsy prior to anti-epileptic treatment, and 14 healthy controls matched by sex, age, and socioeconomic status. Children with congenital hemiparesis and epilepsy had a more clearly expressed cognitive dysfunction, especially in language, visuo-perceptual and memory tasks, than children with newly diagnosed partial epilepsy. The profile of cognitive weakness appears to be diffuse and quite similar in both groups, and it did not demonstrate a clear effect of lateralization, according to the side of epileptic electroencephalogram discharges. Children within both groups are likely to have a high risk of developing attention, phonological, visuo-perceptual, and memory deficits in their life. Especially interesting and surprising was the fact that the newly diagnosed epilepsy group demonstrated impairment not only in attention, visuo-perceptual and short-term memory skills, but also in auditory perception, lexical function, and the comprehension of speech. Therefore, it is recommended that children with epilepsy would undergo neuropsychological examination in order to assess their cognitive abilities.     

Seizures During Cognitive Testing in Patients with Temporal Lobe Epilepsy: Possibility of Seizure Induction by Cognitive Activation

In 18 of 185 patients under consideration for epilepsy surgery, 20 seizures were observed during neuropsychological evaluation. We wished to determine whether the task at seizure onset corresponded neuropsychologically to lateralization of the epileptic focus. The patients' characteristics and the circumstances of the seizures were as follows: Fourteen patients had right temporal lobe epilepsy (RTE) and four had left temporal lobe epilepsy (LTE). Although a wide range of cognitive functions had been tested, all but one seizure occurred during assessment of memory performance. In the RTE patients, 12 of 16 seizures occurred during visual memory testing. Two seizures were observed during a verbal memory task, and one seizure was observed during mental rotation. In two LTE patients, seizures were elicited during verbal memory testing. Two LTE patients with seizures during visual memory testing had speech dominance of the right hemisphere. This high correspondence between the eliciting performance and the focus localization suggests that cognitive performances ipsilateral to the epileptic focus may affect seizure threshold in focal epilepsies.     

Hemispheric lateralization of cognitive functions in children with centrotemporal spikes

We assessed the impact of unilateral epileptic foci in benign idiopathic partial epilepsy of childhood with rolandic discharges (BECT) on performance and hemispheric specialization in lateralized cognitive functions. Six children with BECT with a left-sided focus (BECT-L), 6 children with BECT with a right-sided focus (BECT-R), and 12 control children were tested in verbal, visual-spatial, and visual-attention tasks, with visual hemifield presentation. Children with BECT-R were impaired in the visual-spatial task relative to those with BECT-L, and the typical left-hemisphere (LH) advantage was not reported in the verbal task in children with BECT-L. Additionally, the classic global superiority effect was lacking in children with BECT-R, which may be due to impaired performance of the right hemisphere specialized in global (vs local)-level processing. These data argue for the deleterious effect of epileptic discharges per se on cognitive functions in the developing brain, and the decisive role of epileptic focus lateralization in specific cognitive impairments and hemispheric specialization.     

Psychosocial impairments in children with epilepsy depend on the side of the focus

This article explores the idea that epileptic activity may interfere with psychosocial functions and development in children. In an adult population with epilepsy, left hemispheric seizure focus predicts worse psychosocial functioning. The developmental aspects of these disturbances require further studies. We studied self-report measures of cognitive (locus of control) and emotional (Beck Youth Inventories of Emotional and Social Impairment) functions in 30 children with partial epilepsy (6–15 years) and 60 healthy matched controls. Multivariate statistics revealed significant lateralization effects, with left-sided foci (n = 15) leading to more external locus of control. Opposite to adults, the children with right hemispheric foci (n = 15) exhibited more emotional impairments (anger, disruptive behavior) than the left hemispheric group. The cognitive and emotional dysfunctions in epilepsy may result from the interaction of focus lateralization and brain development. The cognitive disturbances beginning in childhood may lead to the stronger emotional impairments observed in adults with left hemispheric seizures.     

Neuropsychological Evaluation before and after Surgical Treatment of Temporal Lobe Epilepsy

Abstract: We present the results of pre- and postoperative neuropsychological evaluations of 58 :patients with temporal lobe epilepsy who underwent a chronic intracranial EEG monitoring and a subsequent standard anterior temporal lobectomy. Wada's test provided valuable information on the speech dominant side and on the focus lateralization. Some warning signs as well as verbal automatisms indicated the effect for focus localization and lateralization. The results of interictal neuropsychological tests suggested that each subgroup of TLE performed differently. A postoperative neuropsychological performance has improved in many tests that may be explained by the diminished epileptic bombardment resulting from the resection.     

Neuropsychological deficits in monozygotic twins with childhood epilepsy with occipital paroxysms

We report a unique pair of monozygotic twins with childhood epilepsy with occipital paroxysms who showed subtle cognitive deficits. The twin with a more severe epileptic disorder showed a more severe impairment of cognitive functioning. We suggest that epileptic focus may act as an element of disturbance in the development of primary functions and may give rise to a neuropsychological impairment proportionate to the severity of the epileptic activity.     

Attention Problems in Epilepsy: Possible Significance of the Epileptogenic Focus

Summary: Investigation of the relation between epilepsy and cognition presents serious methodologic problems because several factors may contribute to impair neuropsychological performances in epileptic persons. Benign epilepsy of childhood with rolandic paroxysmal discharges (EPR) may be a very useful model of investigation in relation to opportunity to examine subjects without brain damage, therapy, and negative environmental influences. Thus, neuropsychological dysfunction in patients with EPR may support the hypothesis that epilepsy itself plays a specific role in the genesis of cognitive disturbances. We assessed the impact of the laterality of the epileptogenic focus on cognition of children with EPR. All subjects performed a figure cancellation task, a test used to evaluate mainly attention mechanisms and abilities in processing visuospatial information. Results showed that children with right-sided (or bilateral) focus scored worse, whereas children with left-sided focus performed as well as the control subjects. Our data agree with those of studies suggesting that focal discharges may be related to poor cognitive performance. Evidence of a concordance between neurophysiologic and neuropsy-chologic findings may have great practical and theoretical implications in management of epileptic patients.     

The intra-carotid amobarbital test--indications--procedure--results]

In presurgical assessment of epilepsy, the intracarotid amobarbital procedure (IAP) is used for the detection of functional asymmetries of the cerebral hemispheres with respect to cognitive functions. The IAP permits a precise and reliable determination of patterns of language dominance, although analysis of the lateralization of specific memory functions is constrained by methodological problems. In addition, the IAP yields information on the lateralization of other cognitive functions such as attention, consciousness, and emotion. It may also serve as a means of delineating the primary epileptic focus. Furthermore, the IAP may also be helpful in the assessment of non-epileptic patients prior to elective operations in brain regions relevant to cognition.     

Neuropsychological Findings in Rolandic Epilepsy and Landau-Kleffner Syndrome

Summary:  In an attempt to correlate neuropsychological deficits and various neurophysiological aspects of focal epileptic activity in benign childhood epilepsy, we have reviewed the findings of a longitudinal group study of benign childhood epilepsy with centrotemporal spikes (BCECTS) and several case studies of continuous spike-waves during slow sleep syndrome (CSWS). We first distinguish the temporary neuropsychological impairments often observed in the natural history of BCECTS from the more long-lasting and more specific neuropsychological deficits associated with CSWS, of which the Landau-Kleffner syndrome (LKS) is the most studied clinical form. A series of metabolic findings from ¹⁸FDG-PET studies in BCECTS and CSWS children have shown that specific cognitive impairment is related to increased glucose uptake in cortical areas restricted to the associative cortex coincident with the focus of spike-wave discharges. From recent functional neuroimaging data of three patients recovered from LKS, we address the issue of the pathophysiology of cognitive impairment persisting after complete recovery of epilepsy. Finally, we discuss the reliability of the study of mismatch negativity to address the issue of the early effect of interictal discharges in typical and atypical BCECTS on the auditory cortex and the development of speech processing essential to verbal learning.     

Persistent uncrossed corticospinal connections in patients with intractable focal epilepsy

Corticospinal connections may be bilateral at birth, but a predominantly unilateral and crossed pattern develops by the toddler years. Acquired injury can alter the normal development of laterality such that uncrossed corticospinal connections persist, particularly if the injury is early in life and involves the motor system. Whether other developmental insults, such as childhood epilepsy, affect the development of crossed laterality in the motor system is unknown, although this topic has relevance for understanding the broader impact of epilepsy on brain development. Accordingly, in a cohort of children with intractable focal epilepsy, we tested by neuronavigated transcranial magnetic stimulation (nTMS) whether childhood epilepsy is associated with persistent uncrossed corticospinal connections. Specifically, we hypothesized that in contrast to early-life neuroclastic corticospinal tract injury that induces preservation of uncrossed corticospinal connections in the contralesional hemisphere, uncrossed corticospinal connections will be preserved in the epileptic hemisphere where the corticospinal tract is intact, but overstimulated by ongoing seizures and epileptic interictal discharges. Motor cortex mapping was performed by nTMS as part of a clinical presurgical evaluation, and the analysis was limited to patients with radiographically intact motor cortices and corticospinal tracts. Given that foot motor cortex representation is often bilateral, we focused on the lateralization for the tibialis anterior muscle cortical motor representation and its relation to the seizure focus. We demonstrate preserved uncrossed corticospinal connections for the tibialis anterior region of the hemisphere affected by the epilepsy. These findings indicate a pathologically preserved immature motor lateralization in patients with epilepsy and suggest that developmental processes associated with hemispheric lateralization are affected by epilepsy.     

The relative influence of epileptic EEG discharges, short nonconvulsive seizures, and type of epilepsy on cognitive function

PURPOSE: This study addressed whether cognitive impairment in children with epilepsy is caused by disease-related stable factors, such as the type of epilepsy, or by acute effects of paroxysmal epileptic activity such as epileptic EEG discharges. We studied a nonselected group with short nonconvulsive seizures, as these seizures may elude detection and may therefore persist over a longer period. In this group, the diagnostic issue is to differentiate between the combined effects of several epilepsy-related factors on cognition. METHODS: All children were assessed with 32-channel EEG, synchronized with a computerized cognitive test system and a video-monitoring system. Recording time was 2 h. The primary inclusion criteria were unclear seizures and fluctuations in cognitive performance and/or frequent epileptic EEG discharges in a recent EEG. RESULTS: One hundred fifty-two patients met the inclusion criteria; 31 patients appeared not to have a diagnosis of epilepsy and were used as a nonepilepsy control group. Our results show that type of epilepsy has an impact on stable cognitive functions, such as educational achievement. Paroxysmal epileptic activity (acute effects of seizures and epileptic EEG discharges) affects primarily transient mechanistic cognitive processes (alertness, mental speed). CONCLUSIONS: These results suggest that the effects of paroxysmal epileptic activity on transient cognitive mechanisms may accumulate over time and consequently affect the more stable aspects of cognitive function such as educational achievement. The clinical relevance is that early detection of the cognitive impact of seizure-related activity and subsequent treatment may prevent its detrimental impact on cognitive and educational development.     

Are dyslexia and dyscalculia associated with Rolandic epilepsy? A short report on ten Italian patients.

Rolandic epilepsy (RE) is the most common childhood epilepsy syndrome with a good, long-term outcome. Nevertheless, some studies indicate that children with RE have more scholastic and neuropsychological problems than controls. The purpose of this study was to describe neuropsychological findings in a small group of Italian children with RE, focusing on dyslexia and dyscalculia. Possible correlations between these findings and the age-at-onset of seizures, duration of active epilepsy, frequency, type and localization of epileptic discharges were examined. Children affected by RE, aged nine to eleven years were selected from patients admitted to the outpatient service of our Clinic. They underwent cognitive evaluation, specific evaluation for dyslexia and dyscalculia, and awake and sleep EEG recordings. We found two patients out of the ten with dyscalculia, one of whom also had characteristics of dyslexia. This small study suggests that dyscalculia and dyslexia might be more frequent than expected in children with RE. No significant correlations between this finding and EEG, seizure-frequency or age-at-onset of epilepsy were found in our patients.     

Cognitive deterioration and electrical status epilepticus during slow sleep

The results of long-term follow-up of 10 children with global or specific cognitive deterioration and, on the electroencephalogram, electrical status epilepticus during sleep (ESES) are described. They were referred because of cognitive deterioration and underwent repeated neurological and neuropsychological examinations and all-night electroencephalography. A previous cognitive level was known or could be estimated in all. Seven children had a continuous spikes and waves during sleep (CSWS) syndrome, with global cognitive deterioration in four and more specific cognitive decline in three, and another three children had Landau-Kleffner syndrome (LKS). Of the last three, two children never had seizures, while the other had localization-related epilepsy. No children experienced aggravation of clinical seizures. However, therapy was disappointing. Cognitive dysfunction did not respond to valproate and/or benzodiazepines in 9 of the 10 children. A frontal epileptic focus was found in 5 of 7 children with CSWS, and a left temporal focus in 2 of 3 children with LKS. The ESES persisted in CSWS for 5-9 years and in LKS for 1-5 years, and disappeared at puberty. Good cognitive recovery after disappearance of ESES occurred in only one child, and partial recovery in four. An unfavorable prognosis of cognitive deterioration seems to be related to long-duration ESES and/or early onset epileptic activity. The authors are of the opinion that cognitive deterioration in children, with or without manifest epileptic seizures, should mandate electroencephalographic investigation during sleep.     

Outcome at adulthood of the continuous spike-waves during slow sleep and Landau-Kleffner syndromes

PURPOSE: The aim of this study was to determine the clinical, social, and/or professional and cognitive outcomes in adulthood of the continuous spike-waves during slow sleep (CSWS) and Landau-Kleffner syndromes, which are two rare epileptic syndromes occurring in children. METHODS: We enrolled seven young adults, five who had a CSWS syndrome, and two, a Landau-Kleffner syndrome in childhood. We evaluated their intellectual level as well as their oral and written language and executive functions. RESULTS: This study confirmed that the epilepsy associated with these syndromes has a good prognosis. Only one patient still had active epilepsy. However, the neuropsychological disorders particular to each syndrome persisted. Only two patients had followed a normal pathway in school. Three of the five patients with a CSWS syndrome during childhood remained globally and nonselectively mentally deficient. We found no evidence of the persistence of a dysexecutive syndrome in this study group. The intellectual functions of the two patients with Landau-Kleffner syndrome were normal; however, their everyday lives were disrupted by severe, disabling language disturbances. We discuss the role of some prognostic factors such as the location of the interictal electric focus and the age at onset of CSWS. CONCLUSIONS: These two epileptic syndromes of childhood are very similar in many respects, but their clinical outcomes in adulthood are different.     

Atypical Evolutions of Benign Localization‐Related Epilepsies in Children: Are They Predictable?

PURPOSE: To emphasize that, in some patients, different atypical evolutions occur in the course of so-called benign focal epilepsies of childhood (BFEC) and to promote interest in finding clinical and/or electroencephalographic (EEG) clues to which patients might be prone to these risky evolutions. METHODS: Twenty-six patients who started with the typical clinical and EEG features of benign childhood epilepsy with centrotemporal spikes (BCECTS) but who had reversible or persistent, serious epileptic events including status epilepticus and language, cognitive, or behavioral impairments were followed for 相似文献   

Cognitive functions evaluated by P300 and visual and auditory number assays in children with childhood epilepsy with occipital paroxysms (CEOP).

PURPOSE: This study was planned to evaluate cognitive functions, especially attention and immediate recall, in children with childhood epilepsy with occipital paroxysms (CEOP), by using P300 and neuropsychological tests, which included visual and auditory number assays. Thirty patients with CEOP, ages ranging from 5 to 17 years were enrolled in the study. Twenty-five healthy children were taken as the control group. METHODS: Oddball paradigm was used in P300 recordings. The latency and the amplitude of the P300 wave recorded from Cz were taken into consideration. The neuropsychological test battery included visual and auditory number assays. RESULTS: P300 latency was significantly longer in the CEOP group (p=0.014). The results of the visual and auditory number assay test showed significant decline in the patient group when compared with the normal controls. CONCLUSIONS: Attention and immediate recall deficits as well as prolonged P300 latencies in children with CEOP can be due to an ongoing epileptic activity either influencing the whole brain or only the occipital lobe which can also be involved in the neuropsychological organization of the human cortex. Therefore, children with CEOP should be evaluated with more detailed neuropsychological tests for possible cognitive deficits.     

Language lateralization correlates with verbal memory performance in children with focal epilepsy

Purpose: Assessment of language dominance with functional magnetic resonance imaging (fMRI) and neuropsychological evaluation is often used prior to epilepsy surgery. This study explores whether language lateralization and cognitive performance are systematically related in young patients with focal epilepsy. Methods: Language fMRI and neuropsychological data (language, visuospatial functions, and memory) of 40 patients (7–18 years of age) with unilateral, refractory focal epilepsy in temporal and/or frontal areas of the left (n = 23) or right hemisphere (n = 17) were analyzed. fMRI data of 18 healthy controls (7–18 years) served as a normative sample. A laterality index was computed to determine the lateralization of activation in three regions of interest (frontal, parietal, and temporal). Results: Atypical language lateralization was demonstrated in 12 (30%) of 40 patients. A correlation between language lateralization and verbal memory performance occurred in patients with left‐sided epilepsy over all three regions of interest, with bilateral or right‐sided language lateralization being correlated with better verbal memory performance (Word Pairs Recall: frontal r = ?0.4, p = 0.016; parietal r = ?0.4, p = 0.043; temporal r = ?0.4, p = 0.041). Verbal memory performance made the largest contribution to language lateralization, whereas handedness and side of seizures did not contribute to the variance in language lateralization. Discussion: This finding reflects the association between neocortical language and hippocampal memory regions in patients with left‐sided epilepsy. Atypical language lateralization is advantageous for verbal memory performance, presumably a result of transfer of verbal memory function. In children with focal epilepsy, verbal memory performance provides a better idea of language lateralization than handedness and side of epilepsy and lesion.     

Computerized neuropsychological testing in epilepsy: Overview of available tools

PurposeNeuropsychology has become an essential diagnostic tool for epilepsy-related cognitive comorbidities and treatment evaluation. However, a lack of resources may prevent routine neuropsychological assessments outside specialized epilepsy centers. Computerized testing appears to offer a time- and cost-effective approach to assess cognitive functions in patients with epilepsy. Moreover, the technical advances of computerized tests provide interesting tools to address specific diagnostic questions around epilepsy. This review is intended: (1) to outline the advantages and disadvantages of computerized testing, (2) to delineate its indications and fields of application, and (3) to give an overview of available tools that have been applied in epilepsy or antiepileptic drug research.MethodIterative review of computer-based neuropsychological assessment batteries previously applied in clinical epileptological settings or antiepileptic drug trials.ResultsAmong nine reviewed computer tests merely three were explicitly devised for epilepsy and showed sensitivity to clinical parameters like focus lateralization or localization or the presence/absence of epileptiform activity. Concurrent validity with established measures was demonstrated for two of these three tests. Some sensitivity to antiepileptic pharmacotherapy was reported for seven of all nine reviewed test batteries.ConclusionAdditional studies are needed to demonstrate the sensitivity and specificity of computerized neuropsychological tests to epilepsy and treatment related variables. In most clinical scenarios exclusive computerized testing cannot substitute a thorough neuropsychological examination in patients with epilepsy at present.