Learning disabilities in epilepsy: neurophysiological aspects

Poor School Academic Performance and Benign Epilepsy with Centro-Temporal Spikes

BACKGROUND

Poor academic performance of students with epilepsy seems to be a multifactorial problem related to difficulties in reading, writing, math, and logic skills. Poor school and academic performances refer to learning problems in a specific academic area due to learning disorders and learning difficulties not excluding the ability to learn in a different manner during school and academic life. Sometimes, school, academic difficulties, and Rolandic epilepsy can coexist together, and there may be comorbidities. Consequently, the risk of impaired academic performance in people with epilepsy is high.

METHODS

This review analyzed the relationship between Benign Epilepsy with Centro-Temporal Spikes (BECTS) and poor school and academic performance (PSAP) in children and adolescents (aged 6 to 19), and in adults (aged 20 to no age limit). The PRISMA guideline was used to guide our review strategy.

RESULTS

This research shows that Benign Epilepsy with Centro-Temporal Spikes (BECTS) and poor school and academic performances are strongly correlated. An early onset age, as well as a long persistence of seizures, correlate more closely with PSAP. On the other hand, it appears that good pharmacological control of seizures and remission from the acute phase of the pathology support better school performance.

CONCLUSIONS

This review highlights how neuropsychological aspects are also involved in patients with BECTS and PSAP, both in the greater predisposition to the establishment of other neuropsychiatric conditions and in the possibility that stigma conditions and poor academic results may have repercussions on the adaptation and functioning of these subjects. Global management of the subject with BECTS and PSAP is essential, which also pays attention to the aspects of social and scholastic inclusion, both to achieve age-appropriate educational and behavioral objectives, to give the necessary tools for the growth of the individual, and to allow a serene transition to adulthood, favoring autonomous learning and better outcomes.

Comparison of screening tests in the evaluation of cognitive status of patients with epilepsy

Epilepsy, a chronic neurological condition which is associated with neurobiological and psychosocial changes, affects 0.5 to 1% of the world's population, presenting in most cases a deficit in reasoning, memory and attention.

Utility of the electroencephalogram in attention deficit hyperactivity disorder

An electroencephalogram (EEG) has not been routinely utilized in the evaluation of children with attention deficit hyperactivity disorder (ADHD). The utility of the EEG in ADHD is unclear. A recent study in our laboratory using sleep and sleep deprivation routinely found one in four non-epileptic children evaluated for attention deficit disorder has epileptiform discharges in the EEG, more than half focal. The majority of abnormalities (97.5%) occur in sleep and sleep-deprived records compared to 7% in prior wake only records. A review of eight publications showed that laboratories using awake only as routine EEG recordings report a relatively low prevalence of epileptiform discharges, whereas the higher prevalence of epileptiform discharges is seen in those with more prolonged sleep recordings. We have determined that sleep deprivation and sleep are essential to rule out an abnormal EEG in attention deficit disorder. In patients with attention deficit disorder complicated by epilepsy, stimulant therapy is generally safe, provided seizures are controlled by antiepileptic medication. Patients with epilepsy or subclinical electrographic abnormalities not treated with anticonvulsants are at increased risk of seizures when stimulant therapy is introduced, especially extended-release methylphenidate. Apart from an increase in risk of seizures and need for caution in use of stimulants, studies show that epileptiform discharges in the electroencephalogram are linked to a better response of attention deficit to methylphenidate and a higher cognitive performance. Transient cognitive impairment related to subclinical electrographic abnormalities responds to antiepileptic medication. An EEG is important in selected cases of attention deficit disorder and is useful in choice of medication, especially in children with lack of awareness and transient cognitive impairment.

Do recent seizures and recent changes in antiepileptic drugs impact performances on neuropsychological tests in subtle ways that might easily be missed?

PURPOSE

The possibility that a recent seizure or a recent change in antiepileptic medication might produce an occult change in neuropsychological performance is of interest, and especially so in the context of evaluation for epilepsy surgery. Such an evaluation is often done in a setting of video-EEG monitoring where a strong effort is made to produce seizures as quickly as possible with abrupt changes in medication, alterations in sleep, etc., which could impact the validity of neuropsychological findings.

METHODS

A total of 126 adults were studied who had seizures of strictly temporal origin (47 right, 79 left) and whose recent medication history and seizure occurrence prior to testing was as clear as possible. All were tested with an extensive neuropsychological battery with great attention to giving tests only when the patients appeared clinically not to be suffering from recent seizures (seizures occurring on the day of testing or on the day prior to testing) or medication change effects. The cognitive correlates of side of seizures were also evaluated in order to provide a strength-of-effect comparison with recency of AED changes and seizures.

RESULTS

Findings from three-way ANOVA showed a possible slight adverse effect of recent AED change, no effects of recent seizures, and a sizeable relationship with side of seizures. A simultaneous consideration of all three of these variables did not provide additional findings of interest.

CONCLUSIONS

Although it is not possible to completely rule out some subtle cognitive effects of recent changes in medication or recent seizures, this investigation does not provide evidence for such effects when the neuropsychological evaluation is conducted carefully with no testing during any questionable or definite postictal periods.

Balance performance in adult epilepsy patients

PURPOSE

To evaluate the magnitude of subclinical balance dysfunction in adult epilepsy patients and to assess the relative contribution of different variables to balance impairment.

METHODS

Balance performance was evaluated by computerized dynamic platform posturography (CDPP) in 25 adult patients following a generalized tonic-clonic seizure (GTCS) and in 11 healthy subjects.

RESULTS

The GTCS was a breakthrough seizure in 20 patients with epilepsy and a first seizure in 5. Seven of the patients had localization-related epilepsy and 13 had generalized epilepsy. Mean epilepsy duration was 6.6 years. Nineteen of the patients were treated with antiepileptic drugs (AEDs), 16 on monotherapy and three on polytherapy. Brain CT scan and EEG abnormalities were found in 7 and 14 patients, respectively. None of the patients had clinical signs of balance dysfunction. Postural function, measured by Sway Index (SI), was worse in the patients compared to controls. A lower SI was found in patients who did not receive AEDs, had one or two seizures, had a disease duration of less than a year and had a generalized epilepsy.

CONCLUSIONS

Although the study group was small and heterogeneous and only a small number of parameters have reached statistical significance, it seems that posturography can be helpful in the evaluation of postural stability in adult patients with epilepsy.

Severe Myoclonic Epilepsy of Infants (Dravet Syndrome): Natural History and Neuropsychological Findings

Severe Myoclonic Epilepsy in infancy (SMEI, or Dravet syndrome) is a drug-resistant epilepsy that occurs in the first year of life of previously healthy children. The main clinical features are prolonged and repeated febrile and afebrile generalized or unilateral convulsive seizures. In the course of the epilepsy, cognitive deterioration becomes evident, and interictal myoclonus, clumsiness and ataxia appear. One third of the children with SMEI show de novo mutations of the SCN1A gene, and additional familial genes probably contribute to the phenotype. While the clinical picture of SMEI has been well studied, neuropsychological data remain scarce. Global mental retardation, attention deficit and psychotic behavior have been reported but the long-term outcome has not been evaluated. We conducted a longitudinal neuropsychological study of children with SMEI. Twenty children, aged 11 months to 16 years, were prospectively examined using standardized neuropsychological tests. Correlation analysis with other clinical features was performed in 12 cases. Marked slowing or stagnation of psychomotor development, accompanied by psychotic or autistic traits and hyperactivity, was observed between the ages of one and four years. In the later stages (at ages 5 to 16 years), cognitive function stabilized but remained below normal. In children with a more favorable course, language capacities were better preserved than visuospatial functions, and behavior improved. The cognitive and behavioral impairment tended to correlate with the frequency of convulsive seizures (>5 per month). The data suggest that SMEI can be considered as a prototype of an epileptic encephalopathy.

Distúrbio cognitivo transitório associado a atividade epileptiforme generalizada ou difusa durante o eletrencefalograma

Atividade epileptiforme (AE) no eletrencefalograma (EEG) é achado comum entre as crises epilépticas e, menos freqüentemente, em outras condições clínicas. AE "subclínica" pode estar acompanhada de distúrbio cognitivo transitório (DCT). Foram estudados 30 pacientes (27 com epilepsia) com AE generalizada ou difusa, freqüente, em EEG inicial. Em EEG subseqüente, foi avaliado o desempenho em testes de classificação visual de animais e objetos, discriminação de cores, memória verbal e auditiva, reconhecimento de padrões e estimação de tempo. Foi comparado, estatisticamente, o número de respostas corretas ou incorretas durante a AE e fora dela. DCT foi caracterizado em 43,3% dos casos. Em 23,3% a AE foi rara, não permitindo avaliação de DCT. Assim, pôde ser caracterizado comprometimento transitório de atividades cognitivas durante AE até então considerada "subclínica". Há necessidade de pesquisar a importância desse fator em pacientes com comprometimento cognitivo e de caracterizar as situações de eventuais benefícios na medicação dirigida à AE.

Idiopathic epileptic syndromes and cognition

Epilepsy is frequently associated with cognitive impairments which result from various interacting factors. The present paper deals with the contribution of neuropsychology to the characterization of the type of epilepsy and the possible mechanisms underlying idiopathic epileptic syndromes. The non-lesional, so-called idiopathic epilepsies, constitute an interesting model for assessing the relationship between epileptiform EEG discharges and cognition. Among the idiopathic generalized epilepsies, disorders of social integration and personality have been frequently reported in juvenile myoclonic epilepsy (JME). Since similar disturbances are observed in frontal-lobe-lesioned patients, impairments in other frontal lobe functions (e.g. executive functions) might be expected in JME. This gives rise to speculation about the possible underlying pathophysiological mechanisms in JME. With regard to partial idiopathic epilepsies, benign childhood epilepsy with centrotemporal spikes (BCECTS) may provide a useful model for the study of the relationship between epileptiform EEG discharges in the peri-sylvian region and language functions. Furthermore, the description of mild cognitive dysfunctions in BCECTS, and their persistence into adulthood, can provide information about compensatory mechanisms and may allow for the generation of remedial strategies. Thus, 'lesional' neuropsychology has given way to 'dynamic' neuropsychology based on specific postulates. By using the cognitive profile to specify the mechanism underlying the behavioral disturbances observed in different types of epilepsy, neuropsychology may eventually contribute to a revision of the present classification of epileptic syndromes. In addition, the neuropsychological data may help predict the extent and limits of functional recovery and cerebral plasticity.

Intelligence functions disorders in patients with complex partial epilepsy

OBJECTIVES: To compare the performance of patients with complex partial epilepsy with the normal controls in the subtests of an instrument used to assess intelligence function. METHOD: Fifty epileptic patients, whose ages ranged from 19 to 49 years and 20 normal controls without any neuropsychiatric disorders. The Wechsler-Bellevue adult intelligence test was applied in groups, epileptic patients and control subjects. This test is composed of several subtests that assess specific cognitive functions. A statistical analysis was performed using non-parametric tests. RESULTS: All the Wechsler-Bellevue subtests revealed that the intelligence functions of the patients were significantly inferior to that of the controls (p<0.05). This performance was supported by the patient's complaints in relation to their cognitive performance. CONCLUSION: Patients with complex partial epilepsy presented poorer results in the intelligence test when compared with individuals without neuropsychiatric disorders.

Lateralization of Temporal Lobe Epilepsy and Learning Disabilities, as Defined by Disability‐related Civil Rights Law

PURPOSE

Epilepsy research has identified higher rates of learning disorders in patients with temporal lobe epilepsy (TLE). However, most studies have not adequately assessed complex functional adult learning skills, such as reading comprehension and written language. We designed this study to evaluate our predictions that higher rates of reading comprehension, written language, and calculation disabilities would be associated with left TLE versus right TLE.

METHODS

Reading comprehension, written language, and calculation skills were assessed by using selected subtests from the Woodcock-Johnson Psycho-Educational Tests of Achievement-Revised in a consecutive series of 31 presurgical patients with TLE. Learning disabilities were defined by one essential criterion consistent with the Americans with Disabilities Act of 1990. Patients had left hemisphere language dominance based on Wada results, left or right TLE based on inpatient EEG monitoring, and negative magnetic resonance imaging (MRI), other than MRI correlates of mesial temporal sclerosis.

RESULTS

Higher rates of reading comprehension, written language, and calculation disabilities were associated with left TLE, as compared with right TLE. Nearly 75% of patients with left TLE, whereas fewer than 10% of those with right TLE, had at least one learning disability.

CONCLUSIONS

Seizure onset in the language-dominant hemisphere, as compared with the nondominant hemisphere, was associated with higher rates of specific learning disabilities and a history of poor literacy or career development or both. These results support the potential clinical benefits of using lateralization of seizure onset as a predictor of the risk of learning disabilities that, once evaluated, could be accommodated to increase the participation of patients with epilepsy in work and educational settings.

Attentional Ability in Children with Epilepsy

Attention problems are frequently seen in children with epilepsy. This review gives an overview of the most used constructs of attention and analyzes the available evidence for attention deficits in children with epilepsy, the effects of epilepsy variables on attention, and the possible pathophysiological mechanisms involved. Children with benign childhood epilepsy with centrotemporal spikes (BCECTS) have sustained attention difficulties. Right (R)-sided interictal epileptiform activity in these children interferes with R hemisphere function including sustained attention. Children with BCECTS also show selective and divided attention deficits if they have epileptiform discharges during sleep. Children with complex partial seizures (CPSs) have sustained attention deficits but no difficulties in selective or divided attention. Cognitive difficulties in children with epilepsy arise more frequently the earlier the onset of the epilepsy, and this could influence attentional ability development. Antiepileptic drug treatment is unlikely to impair attention, but phenobarbital has behavioral side effects similar to those in attention deficit-hyperactivity disorder. Concerning pathophysiology, evidence indicates that interictal epileptiform activity in children with BCECTS impairs sustained attention and that ongoing epileptiform discharges during sleep may impair attention. Further systematic studies of different aspects of attention in children with epilepsy are needed. Attention in children with drug-resistant epilepsy has not been addressed, and prospective studies before and after epilepsy surgery could be a useful model to study the influence of seizures on attentional ability.

Learning and behavior in children with epilepsy

Learning and behavioral concerns in children with epilepsy are reviewed and general guidelines for assessment are presented. The case of Peter is used to illustrate these issues followed by interventions that may be helpful in working with learning and behavioral difficulties in children with epilepsy.

Clinical guidelines for the management of epilepsy in adults with an intellectual disability

Clinical guidelines exist for the treatment of chronic epilepsy and epilepsy in women (2). This publication provides guidance for the clinician investigating and managing epilepsy in adults who have an intellectual disability as defined by an Intelligence Quotient (IQ) of less than 70, onset in the developmental period and difficulties with adaptive functioning.

Transitory cognitive impairment in epileptic children during a CPT task

EEGs and behavioral responses were studied in two sex matched groups of 58 epileptic and 20 healthy children between 8 and 12 years of age, during the execution of a go-no go CPT (X; A-X) task to determine transitory cognitive impairment (TCI) incidence. Paroxysmal discharges were found on 87.9% and 5% of the EEGs in the epileptic and control groups respectively, with no differences related to sex. The predominant EEG findings with respect to paroxysmal discharges were the association of two or more types of paroxysms with frequency higher than 5/minute, an average duration less than 0.5 second and topographical distribution over temporal-parietal-occipital areas without significant interhemispheric differences. TCI was detected in 36.2% of epileptic children. The epileptic group showed significantly higher numbers of behavioral errors and longer reaction times (RTs) in relation to the control group. Analyzing RTs on the two blocks of the task, linear discriminant analysis showed an acceptable classification of TCI incidence between groups.

Epilepsy and intellectual disability

A Medline and Psychline literature review of epilepsy in people with intellectual disability was performed. The review has highlighted the importance of the impact of epilepsy on the lives of individuals and their families, affecting physical morbidity, leading to an increased mortality and increasing the care-giving burden. Interventions with a strong evidence base are mainly pharmacological with an increasing body of work on the novel antiepileptic drugs. Surprisingly little research exists into the quality of service provision for this population. The authors suggest three areas for future work: (1) an increasing application of research methodologies such as direct observation and qualitative studies into this field; (2) an exploration of the broad impact of treatment and (3) the possibility that epilepsy is a barrier to care provision.

The impact of epilepsy from the patient's perspective I. Descriptions and subjective perceptions

This study surveyed the perceptions about and subjective experience of 1023 people with epilepsy in two community-based samples: one from a national postal survey; the other callers to the Epilepsy Foundation. Response to a mail survey was 49%. In comparison with US Census Bureau norms, respondents had received less education, were less likely to be employed or married, and came from lower income households. Complex partial seizures were the most prevalent seizure type, but a convulsion had occurred in 61%. Fifty percent of respondents reported incomplete control of their seizure disorder, although 25% of these had a seizure in the prior year. Thirteen percent had a longest inter-seizure interval of a year or greater, 37% of 3 months, 22% of 1 month, 10% of 1 week and 4% of 1 day. Respondents listed uncertainty and fear of having a seizure as the worst thing about having epilepsy. Lifestyle, school, driving, and employment limits were also listed as major problems. When asked to rank a list of potential problems, cognitive impairment was ranked highest. These data indicate that ongoing medical and psychosocial problems continue for those with epilepsy in the view of those questioned and their families, even in a sample where the majority report good control of their epilepsy.

Social aspects of epilepsy in the adult in seven European countries. The RESt-1 Group

PURPOSE

The social implications of epilepsy are ill-defined, and there are no comparative findings from different countries. A multicenter cohort study has recently been completed on the risk of morbidity and accidents. The main social issues in the study population (patients with epilepsy and control subjects) are investigated and correlated to the clinical features of the disease.

METHODS

Seven hundred six adult patients with idiopathic or remote symptomatic epilepsy and 662 matched controls without epilepsy were enrolled by secondary and tertiary centers in seven European countries (Italy, Germany, Spain, the Netherlands, England, Portugal, and Russia). At entry, patients and controls were interviewed, and data were collected on social variables (education, current occupation, marital status, driving, involvement in sports, and insurance). The main clinical features of epilepsy (seizure types, frequency and timing, disease duration, and syndrome) were also recorded.

RESULTS

The sample included 690 men and 678 women aged 18 to 86 years. The level of education (mostly basic or high school) was slightly higher among patients with epilepsy. More patients than controls were single (56% versus 50%) or unemployed (18% versus 13%). Fewer patients than controls held a driver's license (44% versus 67%) or practiced sports (30% versus 41%). The distribution of each social variable varied significantly across countries, but with few exceptions, the differences between patients and controls were fairly similar. Based on multivariate analysis, for patients with epilepsy the odds ratio for driving was 0.27, and the corresponding odds ratios for sports involvement, better education, better occupation, and insurance were 0.59, 1.30, 0.60, and 1.49. Among patients with epilepsy, social variables were correlated to seizure remission and selected clinical features.

CONCLUSIONS

Comparative findings from different European countries support the concept that epilepsy has a considerable impact on driving and-to a lesser extent-on education, occupation, leisure activities, and insurance. The social implications of epilepsy in this sample are partly related to its severity and clinical features.

Effects of nicardipine, an antagonist of L-type voltage-dependent calcium channels, on kindling development, kindling-induced learning deficits and hippocampal potentiation phenomena

Kindling is considered to be a useful experimental model for investigating drug effects on the convulsive component of epilepsy and related alterations at the behavioural level. It was demonstrated that pentylenetetrazol (PTZ)-kindled rats show diminished learning performance in shuttle-box training. We used this model to study the influence of nicardipine, an antagonist of L-type voltage-dependent calcium channels, on kindling seizure development as well as related learning impairments. Additionally, we tested the influence of nicardipine on kindling-induced potentiation, a special form of long-term enhancement of evoked potentials in the dentate gyrus after kindling. Therefore, monosynaptic evoked field potentials in the dentate area upon test stimuli to the perforant pathway were recorded in freely moving kindled and control rats at different times after injection of PTZ. The results indicate that the blockade of L-type voltage-dependent Ca2+-channels during the kindling procedure attenuates PTZ-kindling, antagonizes a kindling-induced learning deficit in an active avoidance test and decreases a novel form of kindling-related potentiation, the long-lasting amplitude enhancement of the monosynaptic evoked field potential in the dentate gyrus after injection of a small test dose of PTZ. This potentiation can also be prevented in kindled animals by nicardipine injection in an acute experiment.

[Memory disorders in epileptic patients]

The author studied the mnemonic activity from epileptic patients with complex partial seizures (CPS), with the aims: 1) to identify memory disorders; and 2) to compare the patients' with the controls' results. Fifty adult patients and 20 subjects without neuropsychiatric disorders were studied. The methods consisted in: 1) investigation of the mnemonic activity through the Wechsler Memory Test (subtests: Storage and Recall, Recent Memory, and Immediate Memory); 2) comparison among the results of both groups; association from mnemonic activity with brain SPECT. In the three subtests, the patients showed cognitive performance significantly lower than the controls (p < 0.05). It was found association from reduced blood flow, mainly in left temporal region, with memory impairment of the three subtetsts. The conclusion was that the CPS are associated to memory impairment.

Academic achievement in children with epilepsy or asthma

The purposes of the study were to compare academic achievement between children with epilepsy and those with asthma and to identify child perception, school adaptive functioning, and condition severity factors related to academic achievement. Subjects were 225 children (117 with epilepsy and 108 with asthma) aged between 8 and 12 years. Academic achievement was measured using school-administered group tests. Self-report questionnaires were used to measure child attitudes and school self-concept. Teachers rated school adaptive functioning. Data were analyzed using ANCOVA and multiple regression. Children with epilepsy had significantly lower achievement scores than children with asthma. Boys with severe epilepsy were most at risk for underachievement. Factors related to poor academic achievement in both samples were: high condition severity, negative attitudes, and lower school adaptive functioning scores. Less variance was accounted for in the model for epilepsy (R2=0.25) than for asthma (R2=0.36). Boys with high seizure severity were most at risk for achievement-related problems. Future research in epilepsy should consider additional factors in the model predicting academic achievement.

Identification of side of seizure onset in temporal lobe epilepsy using memory tests in the context of reading deficits

Sixty patients with temporal lobe epilepsy were classified into reading deficient (RD; n = 21) and non-reading deficient (non-RD; n = 39) groups. Selective deficits in verbal or nonverbal memory, consistent with side of seizure onset, were evident in the non-RD patients. Both verbal and nonverbal memory performance were reduced equivalently in individuals with RD, regardless of side of seizure onset. As a result, memory tests that were accurate in identifying side of seizure onset in the non-RD group were not as accurate in the RD group. When individual cases were classified using a clinically applicable decision rule, significantly more RD patients were either unclassifiable or incorrectly classified than were non-RD patients. Findings suggest that preoperative memory data obtained from individuals with epilepsy and evidence of RD may not be as valid an indicator of side of seizure onset as are those obtained from patients without RD.

Altered cognitive functioning in children with idiopathic epilepsy receiving valproate monotherapy

Once a child is diagnosed with epilepsy, a primary concern is whether or not the child's behavior and cognitive abilities will be affected by the disease, by the drug prescribed for seizure control, or both. Direct cognitive effects by the epileptic condition have been described. On the other hand, cognitive effects in epilepsy have been attributed to antiepileptic drug therapy. Valproate is an antiepileptic drug of choice in managing the commonest childhood epilepsy syndromes. Although frequently prescribed in pediatric neurology practice, there have been relatively few studies investigating the cognitive effects of valproate therapy in children. Cognitive effects of valproate reported in normal adult volunteers and in adults with epilepsy cannot be generalized to the pediatric population. The results of investigations on children are less conclusive. Guidelines for antiepileptic drug trials in children have recently been formulated. Carefully designed studies are required in determining the cognitive effects of valproate in the pediatric population. Neuropsychological measures that are likely to assess subtle changes in higher brain functions crucial to learning in children should be employed. We propose a test battery to assess for cognitive changes associated with anticonvulsant therapy in children.

Valproic acid treatment of learning disorder and severely epileptiform EEG without clinical seizures

Using a single-patient (n = 1) clinical trial, we studied a 7-year-old boy who presented with unsatisfactory progress in school and whose electroencephalogram had very active independent frontal spike discharges. He had not had clinical seizures. The patient was randomized to receive valproic acid, 125 mg twice daily, (four periods) or matching placebo (four periods) over 8 weeks. Primary endpoints were the Wechsler Intelligence Scale for Children-Revised Coding sub-test and a handwriting sample. Behavior was monitored using teacher's and parent's Conners questionnaires. His score on the Wechsler Intelligence Scale for Children-Revised Coding subtest was significantly improved while he was taking valproic acid (P = .03). His electroencephalogram improved from a pretreatment recording of 28 spike discharges per minute to a normal recording while on valproic acid. We conclude that in this patient, valproic acid had a cognitive enhancing effect, probably by reducing epileptiform discharges.

The place of the EEG and imaging in the management of seizures

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Learning disorders and delinquency

Learning disorders of various types are relatively common, and the reaction of the affected child can lead to social problems. The higher the children's intelligence the more frustrated they can become. Lack of self-esteem can cause unacceptable behaviour in trying to counteract this, and boost the child's confidence. There is evidence that learning disabilities are prevalent among those who are delinquent. Theories suggest this may be due directly to the learning difficulties, or to failure at school, starting a series of events leading to delinquency, or to the idea that those with learning difficulties are treated differently, especially when it comes to legal proceedings. Epilepsy can easily lead to learning disorders; particularly if the temporal lobes are involved, there are associated emotional disorders, or side effects of treatment. Also this association is often found amongst children with attention deficit disorders. If the link between learning disorders and delinquency is recognised there is considerable scope for prevention.

[Psychosocial approach of the epileptic patient: analysis of 30 adults]

Psychosocial aspects of patient's life were analysed in 30 patients with epilepsy aged over 18 years old. At this age people usually are apt by themselves to exert several psychosocial activities. Professional, familial, social, scholar, affective, sexual and religious activities were evaluated in our group of patients. Results evidence that epileptic patients studied show several kinds of difficulties in their psychosocial adjustment.

Amygdala kindling-induced seizures selectively impair spatial memory. 1. Behavioral characteristics and effects on hippocampal neuronal protein kinase C isoforms

Protein kinase C (PKC) comprises a family of kinases consisting of nine subspecies that are differentially distributed in the central nervous system. This implies distinct functions. Its involvement is suggested in cellular and molecular mechanisms by which the hippocampus exerts influence on information processing. In this study, it was questioned whether abnormal activity in the neuronal substrate, particularly the hippocampal formation, induced by amygdala kindling indeed impairs spatial memory performance and correlated alpha, beta I/II, and gamma PKC subspecies expression. Rats were trained in a spatial discrimination task (SDT) and simultaneously kindled in the amygdala to induce abnormal, epileptiform activity. Control rats were only trained in the holeboard, a "free choice" maze, in which working (WM) and reference memory (RM) were simultaneously examined. Halfway through and at the end of the experiments the influence of kindling and SDT training on the immunoreactivity for PKC subspecies alpha, beta I/II, and gamma was evaluated in the hippocampal formation. Kindling resulted in a gradual increase in afterdischarge duration and motor seizure (MS) severity. Repeated SDT training ultimately resulted in an asymptotic level of WM and RM performance. As soon as generalized MSs developed, kindled rats failed to improve RM, whereas WM was not influenced. Compared to untrained rats, in trained controls PKC gamma but not PKC alpha beta I/II immunoreactivity was elevated in CA1 pyramidal and dentate gyrus granular cells. Generalized but not partial MSs abolished these alterations in PKC gamma immunoreactivity. The present data indicate that repeated training in a SDT affects the expression of PKC subspecies gamma but not of alpha or beta in the rat hippocampus. Generalized epileptiform activity impair both acquisition of new spatial RM information and PKC gamma expression. It is argued that PKC gamma plays a role in cellular mechanisms through which pathological brain activity impairs certain aspects of spatial memory.

Partial childhood epilepsy and reaction time: the effect of interictal EEG discharges

A study was conducted on seven children (five females and two males, aged 5.7-13.1 years) affected with partial epilepsy which was well controlled by therapy. A computer was connected on-line to a polygraph and during two EEG recordings, the subject had to react to the appearance of a colored rectangle on the display screen by pushing a key on the keyboard: these events were automatically marked on the trace of a polygraphic channel. By means of Anova analysis it was demonstrated that during the same recording, reactions simultaneous to paroxysmal discharges were not significantly slower than those measured during free intervals. However, in the same patient, reaction times were significantly prolonged during recordings characterized by a higher rate of EEG paroxysmal activity.

Daytime sleep tendency before and after discontinuation of antiepileptic drugs in preadolescent children with epilepsy

In 9 preadolescent children treated for epilepsy who had been free from seizures long enough for treatment to be discontinued, daytime vigilance was studied before and after discontinuation of antiepileptic drugs (AEDs). Comparisons were made with healthy controls. Multiple sleep latency test (MSLT), EEG, and a questionnaire were used. As part of the analysis of the MSLT, a new measure, the daily average sleep tendency (DAST), was constructed to overcome the problems with data censoring of the classic MSLT analysis. The patients had significantly (p less than 0.001) higher daytime sleep tendency, even after drug discontinuation, than controls, a result that could neither be attributed to AED treatment nor to recent epileptic seizures or complicated epilepsy.

Neuropsychological assessment of cognitive functioning in children with epilepsy

The variety of cognitive dysfunctions related to learning disabilities in children with epilepsy have been studied by linking electroencephalogram (EEG) and computerized neuropsychological testing. This showed that "subclinical" discharges impaired performance in 61% of the patients on a simple and a choice reaction time test, although some discharges lasted 1 s only. Neuropsychological investigation of subclinical EEG discharges may help to determine their adverse effect on learning.

Antiepileptic drugs, cognitive function, and behavior in children: evidence from recent studies

The effects of antiepileptic drugs (AEDs) on cognitive function and behavior in children are reviewed on the basis of published studies. Individual AEDs have been shown to differ--the deleterious effects of phenytoin generally contrasting with the relatively minimal effects of valproate and carbamazepine. Some of the differences between results may be attributed to the psychological tests used and to age differences. However, there appears to be a dissociation between AEDs that affect higher cognitive function, e.g., phenytoin, and those mainly affecting motor function, e.g., carbamazepine, which appears to increase speed of performance, AEDs should be prescribed with care in children with epilepsy, taking account of their differing effects on cognitive function and behavior.

Electroencephalographic parameters in assessing the cognitive function of children with epilepsy

Many biological and psychological possibilities have to be considered when attempting to explain cognitive dysfunction in the individual child with epilepsy. Electroencephalographic (EEG) information, which may be particularly relevant in some children, has mainly been studied in relation to the possible direct effects of seizure discharges on learning and behavior. Such discharges can be divided into transient, brief or prolonged. Prolonged seizure discharges includes nonconvulsive status epilepticus during wakefulness and status epilepticus during slow-wave sleep. In addition to the influence of seizure discharges, preliminary findings suggest that some children with epilepsy might have a subtle disorder of arousal mechanisms in sleep, possibly associated with impaired daytime performance.