The effect of duration of epilepsy on IQ in children with CLRE; a comparison to SLRE and IGE.

Up to one third of the children with epilepsy are classified as having cryptogenic localization epilepsy (CLRE). Unfortunately, not much is known on the prognosis of CLRE; it is assumed to be somewhere between the benign course of many idiopathic epilepsies and the more malignant course of most symptomatic epilepsies. The risk of cognitive decline over time seems to be increased for children with epilepsy, but no data are available specifically for CLRE. This study was a systematic cross-sectional open clinical and non-randomized investigation, which included 68 children with CLRE, 24 children with symptomatic localization related epilepsy (SLRE) and 21 children with idiopathic generalized epilepsy (IGE). One-way between-groups ANOVAs with Tukey post hoc testing were used to test differences in demographical variables and IQ between CLRE, SLRE and IGE and to test the influence of duration of epilepsy and other epilepsy factors on IQ. To test whether there were IQ differences between the three types of epilepsy regarding duration of epilepsy and other epilepsy factors, the Kruskal-Wallis test was used. In CLRE, intelligence is stable over time; IQ scores do neither improve nor deteriorate. Age at onset, seizure type, seizure frequency and the use of AED appeared to have no influence on intelligence in CLRE. Furthermore, over time, there appeared to be no differentiation regarding IQ between CLRE, SLRE and IGE.

Cryptogenic localization related epilepsy in children from a tertiary outpatient clinic: is neurological and neuropsychological outcome predictable?

OBJECTIVES: Up to one-third of the children with epilepsy are diagnosed with cryptogenic localization related epilepsy (CLRE). As yet, there is a lack of studies that specify the short- and long-term prognosis for this group. In this study, we systematically established neurological outcome (represented by seizure frequency) as well as neuropsychological outcome in a cohort of 68 children with CLRE who had been referred to our tertiary outpatient clinic. Also, we analysed correlations with risk and prognostic factors. PATIENTS AND METHODS: A systematic cross-sectional open clinical and non-randomized design was used including 68 children admitted to our epilepsy centre in a child neurological programme between January 1999 and December 2004. A model was defined, distinguishing risk factors with a potential effect on epileptogenesis (history of febrile seizures, family history of epilepsy, history of early mild development delay and serious diagnostic delay) and prognostic factors, with a potential effect on the course of the epilepsy (neurological symptoms or soft signs, age at onset, duration of epilepsy, seizure type, percentage of time with epileptiform activity, localization of epileptiform activity, treatment history and treatment duration). Seizure frequency was used as the primary outcome variable, whereas three neuropsychological outcomes (IQ, psychomotor delay and educational delay) were used as secondary outcome variables. RESULTS: The children experienced a broad range of seizure types with the 'absence-like' complex partial seizure as the most commonly occurring seizure type. Almost half of the children of the study sample had a high seizure frequency. They experienced several seizures per month, week or even daily seizures. Also a substantial impact on neuropsychological outcome was observed. Mean full scale IQ was 87.7, mean academic delay was almost 1 school year and 27 children showed psychomotor delay on the Movement ABC. Only 'having more than one seizure type' showed a prognostic value for seizure frequency, and no factors were found to be correlated with the secondary outcome measures. None of the risk factors show a differential impact on seizure outcome. CONCLUSION: CLRE has a non-predictable course; clinical variability is high and prognosis in many children with CLRE is obscure. Having more than one seizure type was the only factor correlated to seizure frequency. Further longitudinal studies are needed.

The validity of a separate classification of cryptogenic localization related epilepsy amongst childhood epilepsies.

INTRODUCTION: One-third of children with epilepsy are classified as having a cryptogenic localization related epilepsy (CLRE). In cohort studies CLRE is often grouped together with either symptomatic localization related epilepsy (SLRE) or idiopathic generalized epilepsy (IGE). Therefore, this categorization is not specific enough and will not lead to prognostic or treatment information. We objectified the classification differences between these categories. METHODS: A total of 114 children admitted to our epilepsy centre underwent a standardized clinical analysis, which yielded age at onset, duration of the epilepsy, seizure frequency, seizure type, percentage of interictal epileptiform activity on EEG (IEA), type of treatment, and full scale IQ. These variables are regarded the characteristics of the epilepsy, and used in a discriminant function analysis. RESULTS: IEA was found to be the only variable to distinguish between groups of epilepsy. SLRE could easily be distinguished significantly from IGE and CLRE, while the latter two did not differ significantly. Discriminant function analysis combined the variables into two functions, applicable to classify the children. By applying this statistical analysis method, the groups clinically classified as SLRE and IGE were mostly classified as SLRE (71.4%) and IGE (57.9%). However, CLRE appeared difficult to classify (49.2%), and most children were classified as either SLRE (19%) or IGE (31.7%). CONCLUSION: The current opinion that CLRE is 'probably symptomatic' cannot be confirmed in all cases in this study. It is most likely that the current CLRE population consists of both children with eventually SLRE, as well as yet to be described syndromes to be classified as idiopathic epilepsies. We emphasize the need for separate studies regarding children with 'probably symptomatic' (cryptogenic) localization related epilepsy, as this will maximally help children, caretakers and treating physicians to achieve the best possible outcome.

The development of visual- and auditory processing in Rett syndrome: an ERP study.

Rett syndrome is a neurodevelopmental disorder that occurs almost exclusively in females. It is characterized by a progressive loss of intellectual functioning and motor skills, and the development of stereotypic hand movements, that occur after a period of normal development. Event-related potentials were recorded to a passive auditory- and visual oddball task in 17 females with Rett syndrome aged between 2 and 60 years, and age-matched controls. Overall the participants with Rett syndrome had longer ERP latencies and smaller ERP amplitudes than the Control group suggesting slowed information processing and reduced brain activation. The Rett groups also failed to show typical developmental changes in event-related brain activity and revealed a marked decline in ERP task modulation with increasing age.

Behavior in children with cryptogenic localization related epilepsy: a follow-up study.

Using the Child Behavior Checklist, the behavior of 16 children with cryptogenic localization-related epilepsy was assessed at first admission to our epilepsy center, and approximately 2 years later. Behavior improved substantially from t(1) (first assessment, when patients were admitted to our center) to t(2) (reassessment after approximately 2 years) on almost all subscales of the Child Behavior Checklist. At t(2), all subscales scored within normal range. Furthermore, seizure frequency improved considerably in the 2 years between assessments. After a period of approximately 2 years, normalization of behavior in children with cryptogenic localization-related epilepsy occurred.

Psychomotor and motor functioning in children with cryptogenic localization related epilepsy.

The aim of this study is to investigate psychomotor- and motor functioning in children with cryptogenic localization related epilepsy (CLRE) and to explore possible relationships between these two functions. Eighty-nine children were included. Results of reaction times measurements and motor functioning tasks were compared to age-related normative values. Correlations between the psychomotor and motor tasks were computed. Manual dexterity and balance problems are present in about 35% of CLRE-children. Ball skills are problematic in approximately 55% of the children. Simple reaction time measurements showed significantly slowing for CLRE children relative to the reference values. Also, performance on the m-ABC was significantly lower than the reference values. The better the child's performance on the simple reaction time measurements, the better the performance on the m-ABC.

Motor function in children with cryptogenic localization related epilepsy.

INTRODUCTION: In CLRE specific learning difficulties and motor problems may occur. The aim of this study is to examine whether CLRE or the accompanying specific learning difficulties are associated with the occurring problems in motor function. METHODS: Motor functioning in 140 children with CLRE and without epilepsy, as well as with and without specific learning difficulties is compared using Chi-square. RESULTS: In the CLRE group 35% score below the 5th percentile (poor motor function). No correlations with epilepsy variables or the occurrence of specific learning difficulties is found. DISCUSSION: A subgroup of about one-third of children with CLRE are at risk for poor motor function. Their development is best monitored using a multi-dimensional approach, including cognitive development and motor functioning.

Behavioral status of children with cryptogenic localization-related epilepsy.

Using the Child Behavior Checklist, behavior of 51 children with cryptogenic localization-related epilepsy was studied. According to parent report, children with cryptogenic localization-related epilepsy scored in the clinical range on the subscales "internalizing behavior," ''total behavior,'' and "attentional problems.'' No relation between the epilepsy factors seizure frequency, age at onset, duration of epilepsy or the number of antiepileptic drugs, and the subscales of the Child Behavior Checklist was found. Only for seizure type a relationship was found. Although in the normal range, the more severe the seizure type, the more delinquent, aggressive, and externalizing behavioral problems. Other studies have demonstrated that in children with epilepsy, internalizing problems are more common than externalizing problems, and that attentional, social, and thought problems are relatively specific. Therefore, we can conclude that the behavioral problems we found in our cohort are not very different from behavioral problems described in other epilepsy types.

Neuropsychological profile of children with cryptogenic localization related epilepsy.

Up to one third of the epilepsy population consists of children with cryptogenic localization related epilepsy (CLRE). Unfortunately, the effect of CLRE on the development is still unclear. Behavioral and academic problems have been reported, but no conclusive study concerning the impact of CLRE on neuropsychological functioning is yet published. This study was a systematic cross-sectional open clinical and nonrandomized investigation, which included 68 children with CLRE. Several neuropsychological tests were analyzed and age-related normative values were used as reference. Differences between CLRE and reference values were tested with Paired-Samples t-tests. Z scores were computed to compare the different neuropsychological tests and to inspect whether a characteristic neuropsychological profile exists for CLRE. The Independent-Samples t-test was used to explore which epilepsy factors (seizure type, seizure frequency, age at onset, duration of epilepsy, and drug load) were influencing the cognitive profile of CLRE. There seems to be a characteristic cognitive profile for children with CLRE; children with CLRE experience cognitive difficulties on a wide range of areas-in particular, alertness, mental speed, and memory. Seizure type, seizure frequency, duration of epilepsy, and drug load do not influence this neuropsychological profile. Age at onset was an important risk factor; the earlier the age at onset, the worse the cognitive performance. In spite of the influence of age at onset, the revealed profile can be seen as a stable, independent of temporary factors, neuropsychological profile for children with CLRE.

EEG characteristics related to educational impairments in children with benign childhood epilepsy with centrotemporal spikes.

PURPOSE: Learning and behavioral difficulties often occur in benign childhood epilepsy with centrotemporal spikes (BCECTS). In recent years, several electroencephalogram (EEG) characteristics have been related to the occurrence of learning and behavioral problems. METHODS: From 28 children medical, school and psychological reports were present and children were rated according to a 4-point scale for educational and behavioral impairment (Part 1). Thirty 24-h EEG recordings were reanalyzed for spike frequency, the presence of atypical EEG criteria, and the presence of a nondipole spike. EEGs were scored during wakefulness, first hour of sleep and whole night sleep (minus the first hour of sleep) separately (Part 2). RESULTS: The presence of I: an intermittent slow-wave focus during wakefulness, II: a high number of spikes in the first hour of sleep (and during whole night sleep), and III: multiple asynchronous bilateral spike-wave foci in the first hour of sleep correlates significantly with a sum score > or = 3 which indicates a complicated course with educational or behavioral impairment. It is sufficient to analyze an EEG during wakefulness and a sleep EEG for only the first hour of sleep instead of a whole night recording to demonstrate those EEG criteria. CONCLUSIONS: On basis of our reanalysis we can possibly conclude that the aforementioned EEG characteristics correlate with educational impairments, and that analysing an EEG recording during wake and the first hour of sleep is sufficient to look adequately for those EEG criteria in children with BCECTS.

Cryptogenic localization-related epilepsy with childhood onset: The problem of definition and prognosis.

BACKGROUND: Up to one-third of children with epilepsy are diagnosed with cryptogenic localization-related epilepsy (CLRE). CLRE is a large nonspecific category within the ILAE classification. For this population no unequivocal prognosis exists. METHODS: Twenty-five articles describing aspects of CLRE were included in this review. RESULTS: As a result of the progress in epilepsy research, as well as more advanced investigation in individual cases, the population with CLRE constantly changes. Also, disagreement on interpretation of the classification has resulted in striking differences between the populations described. High remission rates are reported, but relapse occurs frequently, leaving the long-term prognosis unforeseeable. This is reflected in academic and psychosocial prognosis, which is described to be problematic in CLRE specifically. Possible prognostic factors of CLRE in children have been identified: age at onset, seizure semiology, seizure frequency, intractability, interictal epileptiform activity on EEG, and premorbid IQ. These factors are explored to define subgroups within the CLRE population. DISCUSSION: Prospective studies on well-defined CLRE cohorts are needed to identify factors that distinguish various prognostic subgroups. Specific attention should be focused on course of the epilepsy, scholastic achievement, and psychosocial outcome.