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Objective: Caring for a child with a chronic illness adds stress to the typical parenting stress in healthy developing children. This stress can place a heavy burden on parents and may increase when a child displays problem behavior. In general, parenting and child's behavior problems are associated. Furthermore, externalizing (more outgoing) behavior is reported frequently in children with frontal lobe epilepsy (FLE). Therefore, in this study, we first investigated the burden of parents of children with FLE, and second, we investigated the relation between the experienced burden and reported behavioral problems. The validity of parents' reports on proxy measures as well as duration of epilepsy is taken into account.Methods: Thirty-one parents of children with FLE completed validated questionnaires about behavioral problems and burden of parenting. To examine if parents tend to be inconsistent or unusually negative, we used the two validity scales of the Behavioral Rating Inventory of Executive Function (BRIEF) (Negativity and Inconsistency).Results: Only parents of children with FLE who have had epilepsy for 5 years or longer report more problems on the Nijmeegse Vragenlijst voor de Opvoedingssituatie (NVOS) subscales 'Able to manage', 'Child is a burden', and 'Good Interaction' compared with the healthy controls. The subscale 'Child is a burden' significantly predicts scores in about 20% to 49% on the main scales of the Child Behavior Checklist (CBCL), the Global Executive Composite (GEC), and Behavioral Regulation Index (BRI) of the BRIEF. Only 6% of parents scored in the dinical range of the negativity scale of the BRIEF. For the inconsistency scale, this was 45%.Conclusion: Parents of children with FLE do not report excessive parental burden. Longer duration of epilepsy might be a risk factor in experiencing burden. The findings suggest a link between parental burden and behavioral problems in children with FLE. Externalizing behavioral problems are the most marked behavioral problems, which relate to the parental burden. Parents tend to be inconsistent in their ratings. (C) 2019 Elsevier Inc. All rights reserved.

Purpose Studies in adults with epilepsy, mainly in specialized epilepsy clinics, have shown that sleep disturbances were twice as prevalent in people with epilepsy as in healthy controls. Our aim was to determine the prevalence of sleep disturbances in people with epilepsy treated in district hospitals, as well as the impact of it on Quality of Life. Method Adults with epilepsy, attending outpatient clinics in three district hospitals were invited to participate. Those who accepted (N = 122) provided their own controls matched for age and sex. Both groups completed four questionnaires (Groningen Sleep Quality Scale (GSQ), Medical Outcomes Study-Sleep scale (MOSS), Sleep Diagnosis List (SDL) and Epworth Sleepiness Scale) to measure their sleep over different periods and the 36-Item Short Form Health Survey (SF-36) to measure Quality of Life (QoL). The prevalence of sleep disturbances and scores on QoL were compared between both groups. Results Sleep quality, measured by the SDL, was in the pathological range 50% more often in the epilepsy group than in controls. This was confirmed by the MOSSINDEX and GSQ. People with epilepsy experienced excessive daytime sleepiness more often than controls. The lowest scores on nearly all domains of the SF-36 were seen in people with epilepsy and associated sleep disturbances. Conclusion We confirmed the higher prevalence of sleep disturbances in people with epilepsy compared to controls as previously reported from specialized settings. The (co-morbid) sleep disturbances result in lower QoL scores, in both people with epilepsy and in controls, but more in people with epilepsy.

As children with epilepsy may have a number of learning and behavioral problems, it is important that insight into the underlying neurocognitive differences in these children, which may underlie these areas of challenge is gained. Executive function (EF) problems particularly are associated with specific learning abilities as well as behavioral problems. We aim to review systematically the current status of empirical studies on the association between EF problems and behavior and socioemotional problems in children with epilepsy. After search, 26 empirical studies were identified, most of them of moderate quality. Overall, attention problems were the most reported cognitive deficit in test assessment and the most reported problem by parents. In 54% of the studies, children with epilepsy scored below average compared to controls/normative samples on different aspects of EF. Most studies reported behavior problems, which ranged from mild to severe. Forty-two percent of the studies specifically reported relationships between EF deficits and behavioral problems. In the remaining studies, below average neuropsychological functioning seemed to be accompanied by above average reported behavioral problems. The association was most pronounced for cognitive control and attention in relation to externalizing behavior problems. This cognitive control is also associated with social functioning. Relevant epilepsy variables in this relationship were early age at onset and high seizure frequency. Future research should distinguish specific aspects of EF and take age into account, as this provides more insight on the association between EF and behavior in pediatric epilepsy, which makes it possible to develop appropriate and early intervention.

SummaryObjective Automated seizure detection and alarming could improve quality of life of and potentially prevent sudden, unexpected death in patients with severe epilepsy. As currently available systems focus on tonic-clonic seizures, we want to detect a broader range of seizure types including tonic, hypermotor and clusters of seizures. Methods In this multi-centre, prospective cohort study, non-EEG signals heart rate and accelerometry were measured during the night in patients undergoing a diagnostic video-EEG examination. Based on clinical video-EEG data seizures were classified and categorized as clinically urgent or not. Seizures included for analysis were tonic, tonic-clonic, hypermotor and clusters of short myoclonic/tonic seizures. Features reflecting physiological changes in heart rate and movement were extracted. Detection algorithms were developed based on stepwise fulfillment of conditions during increases in either feature. A training set was used for development of algorithms and an independent test set for assessing performance. Results 95 patients were included, but due to sensor failures, data from only 43 (out of whom 23 patients had 86 seizures, representing 402 hours of data) could be used for analysis. The algorithms yield acceptable sensitivities, especially for clinically urgent seizures (sensitivity 71%-87%), but come with high false alarm rates (2.3-5.7 per night, positive predictive value 25-43%). There was a large variation in number of false alarms per patient. Significance It seems feasible to develop a detector with a high sensitivity but false-alarm rates are too high for use in clinical practice. For further optimization, personalization of algorithms may be necessary. This article is protected by copyright. All rights reserved.

Objective: To detect determinants for photoparoxysmal EEG response (PPR) in SCN1A -related Dravet syndrome (DS). Methods: Data were studied from nationwide medical histories and EEGs of DS-patients ( n =53; 31 males, age 2–19years). Detailed questionnaires on visual stimuli were completed by parents ( n =49). Results: PPR was found in 22 patients (42%; median age 1.25yr), and repeatedly in 17%. PPR (17% of 249 intermittent photic stimulation (IPS)-EEGs) occurred more often with optimal IPS protocols (OR 2.11 [95%CI 1.09–4.13]) and in EEGs showing spontaneous epileptiform abnormalities (OR 5.08 [95%CI 2.05–12.55]). PPR-positive patients tended to be younger at first ( p =0.072) and second seizure ( p =0.049), showed severe intellectual disability ( p =0.042), and had more often spontaneous occipital epileptiform abnormalities ( p Clinical sensitivity was reported in medical files in 22% of patients and by parents in 43% (self-induction 24%). Clinical or EEG proven visual sensitivity was detected in 65% of cases. Conclusions: Sensitivity to visual stimuli is very common in DS and more often noticed by parents than confirmed by EEG. Detection of PPR improves with repetitive tests using accurate IPS protocols. Significance: Photosensitivity is an important feature in DS and seems to be a marker of the severity of the disorder. Therefore repeated standardized IPS should be encouraged.

Thirty-two children with frontal lobe epilepsy (FLE) were assessed using different working memory measures. In addition, parents and teachers completed the working memory scale of the Behavioral Rating Inventory of Executive Functioning (BRIEF) to assess the children's "daily life behavior." Results suggested minimal working memory deficits as assessed with performance-based measures. However, the BRIEF showed more working memory deficits suggesting that, on a daily life level, working memory problems seem to be associated with FLE. We discuss why the results of the performance-based measures are not consistent with results of the BRIEF.HighlightsParents as well as teachers report working memory dysfunction in daily life to the same extent.Performance based measures show minimal deficits of working memory.Correlation between working memory tasks and proxy measures are low.

Context Sleep-related breathing disorders (SRBD) are common in people with Prader-Willi syndrome (PWS). Young adults with PWS benefit from GH continuation after attaining adult height by maintaining the improved body composition obtained during childhood. There are, no studies about the effects of GH on SRBD in young adults with PWS who were treated with GH during childhood. Objective Investigate the effects of GH vs placebo on SRBD in young adults with PWS who were treated with GH during childhood and had attained adult height. Design Two-year, randomized, double-blind, placebo-controlled, crossover study in 27 young adults with PWS, stratified for sex and body mass index. Setting Dutch PWS Reference Center. Intervention Crossover intervention with GH (0.67 mg/m2/d) and placebo, both over one year. Main Outcome Measures Apnea hypopnea index (AHI), obstructive apnea index (OAI), central apnea index (CAI), measured by polysomnography. Results Compared with placebo, GH did not increase AHI, CAI, or OAI (P > 0.35). The effect of GH vs placebo was neither different between men and women, nor between patients with a deletion or maternal uniparental disomy/imprinting center defect. After two years, there was no difference in AHI, CAI, or OAI compared with baseline (P > 0.18). Two patients (7%) fulfilled the criteria of obstructive sleep apnea regardless of GH or placebo. Conclusions GH compared with placebo does not cause a substantial increase in AHI, CAI, or OAI in adults with PWS who were treated with GH during childhood and have attained adult height. Our findings are reassuring and prove that GH can be administered safely.

During reactor operation the fission gases Kr and Xe are formed within the UO2 matrix of nuclear fuel. Their quantification is important to evaluate their impact on critical parameters regarding the fuel behaviour during irradiation and (long-term) interim storage, such as internal pressure of the fuel rod and fuel swelling. Moreover the content of Kr and Xe in the plenum of a fuel rod and their content in the UO2 fuel itself are widely used as indicators for the release properties of 129I, 137Cs, and other safety relevant radionuclides with respect to final disposal of spent nuclear fuel. The present study deals with the fission gas release from spent nuclear fuel exposed to simulated groundwater in comparison with the fission gas previously released to the fuel rod plenum during irradiation in reactor. In a unique approach we determined both the Kr and Xe inventories in the plenum by means of a puncturing test and in leaching experiments with a cladded fuel pellet and fuel fragments in bicarbonate water under 3.2 bar H2 overpressure. The fractional inventory of the fission gases released during irradiation into the plenum was (8.3 ± 0.9) %. The fraction of inventory of fission gases released during the leaching experiments was (17 ± 2) % after 333 days of leaching of the cladded pellet and (25 ± 2) % after 447 days of leaching of the fuel fragments, respectively. The relatively high release of fission gases in the experiment with fuel fragments was caused by the increased accessibility of water to the Kr and Xe occluded in the fuel.

Objective: Epilepsy, as a chronic and neurological disease. is generally associated with an increased risk for social and emotional behavior problems in children. These findings are mostly derived from studies on children with different epilepsy types. However, there is limited information about the associations between frontal lobe epilepsy (FLE) and cognitive and behavioral problems. The aim of this study was to examine relationships between FLE and executive and behavioral functioning reported by parents and teachers.Material and methods: Teachers and parents of 32 children (18 boys, 14 girls, mean age 9; 2 years +/- 1;6) with a confirmed diagnosis of FLE completed the Behavioral Rating Inventory of Executive Function (BRIEF), the Child Behavior Checklist (CBCL), and Teacher Report Form (TRF).Results: About 25 to 35% of the parents and teachers rated children in the abnormal range of the main scales of the BRIEF, CBCL, and TRF. Teachers tend to report more metacognition problems, whereas parents tend to report more behavior regulation problems. Children with left-sided FLE showed more problems than children with bilateral or right-sided FLE. The whole range of executive dysfunctioning is linked to behavioral dysfunctioning in RE, but ratings vary across settings and informants. The epilepsy variables age of onset, lateralization, drug load, and duration of epilepsy had only a small and scattered contribution.Conclusion: Ratings on the BRIEF, CBCL, and TRF are moderately to highly correlated, suggesting a (strong) link between executive and behavioral functioning. Subtle differences between parents and teachers ratings suggest different executive function demands in various settings. (C) 2018 Elsevier Inc. All rights reserved.

De heer A. is 25 jaar. Sinds zeven jaar heeft hij nachtelijke aanvallen die als epileptisch zijn geduid. De aanvallen komen vrijwel elke nacht voor.

Purpose Long-term video-EEG monitoring (LTM) is frequently used for diagnostic purposes and in the workup of epilepsy surgery to determine the seizure onset zone. Different strategies are applied to provoke seizures during LTM, of which withdrawal of anti-epileptic drugs (AED) is most effective. Remarkably, there is no standardized manner of AED withdrawal. For instance, the majority of clinics taper medication during clinical admission, whereas we prefer to taper medication at home prior to admission. Our aim was to study the advantages (efficiency and diagnostic yield) and disadvantages (safety and complication rates) of predominantly tapering of medication at home. Method We report a retrospective observational cohort of 273 patients who had a LTM at our tertiary epilepsy center from 2005 until 2011. Provocation methods to induce seizures were determined on individual basis. Success rate (duration of admittance, time to first seizure, efficiency and diagnostic yield) and complications and serious adverse events were assessed. Results AED were tapered in 180 (66%) patients, in 93 (24%) of these patients with additional (partial) sleep deprivation. In all of these patients tapering started at home one to four weeks prior to admission. In the other patients, only (partial) sleep deprivation or none provocation method at all was applied. Seizure recordings were successful in 79,9% of patients. Complications occurred in 19 patients (10.9%) of which 3 had (1.7%) serious adverse events (status epilepticus (SE)) with AED withdrawal. These complications only occurred during admittance, not at home. Conclusions AED withdrawal at home prior to LTM is an efficient and convenient method to increase the diagnostic yield of LTM and appears relatively safe.

Rationale Residual effects of hypnotics on driving performance have been mainly determined in studies using a standardized driving test with healthy good sleepers. Responses to effects may differ, however, between insomniacs and healthy volunteers due to the underlying sleep disorder. In addition, a majority of insomniacs uses hypnotics chronically resulting in the development of tolerance to impairing effects. Impaired driving performance in healthy volunteers may then be an overestimation of the actual effects in insomniacs. Objectives The present study aims to compare the residual effects of zopiclone 7.5 mg on on-the-road driving performance of 16 middle-aged insomniacs chronically using hypnotics (chronic users), 16 middle-aged insomniacs not or infrequently using hypnotics (infrequent users), and 16 healthy, age matched, good sleepers (controls). Methods The study was conducted according to a 3 × 2 double-blind, placebo controlled crossover design, with three groups and two treatment conditions. Treatments were single oral doses of zopiclone 7.5 mg and placebo administered at bedtime (2330 hours). Between 10 and 11 h after administration subjects performed a standardized highway driving test. Results Zopiclone 7.5 mg significantly impaired on-the-road driving performance in both insomnia groups and healthy controls. The magnitude of impairment was significantly less in the chronic users group as compared with the controls. Conclusions The smaller magnitude of effects suggests that investigating residual effects of hypnotics in healthy volunteers may yield a minor overestimation of the actual effects in insomnia patients

The Cold Finger Apparatus (KuhlFinger-Apparatur – KuFA) in operation at JRC-ITU is designed to experimentally examine the effects of Depressurization and LOss of Forced Circulation (DLOFC) accident scenarios on irradiated High Temperature Reactor (HTR) fuel pebbles. While remaining under an inert helium atmosphere, a HTR fuel pebble is subjected to heating schedules up to 1800 °C for several hundred hours. Fission gas release is monitored online during the experiment and volatile fission products are collected on condensation plates made of stainless steel positioned above the fuel sample on a “cold finger”, which is water-cooled to approximately 100 °C. Analysis of the substances deposited on the plates by means of gamma spectroscopy provides information on the fission product release as a function of time and temperature. The most recent KuFA test was performed on a fuel element irradiated in the High Flux Reactor (HFR) in Petten in the HFR-EU1bis campaign. The condensation plates feature dose rates up to 80 mSv/h and the lab background levels to some hundred μSv/h. Thus, effective collimation and background shielding is mandatory in order to perform a quantitatively accurate analysis of the samples by means of gamma spectroscopy. We present a detailed description of the experimental setup and the calibration procedure. The time-dependent fractional release of the volatile fission products 134Cs and 137Cs is shown. The results for the most recently tested fuel pebble HFR-EU1bis/5 are compared to data obtained for other fuel elements.

BACKGROUND: Cognitive behavioral therapy for insomnia (CBT-I) is a well-known, effective treatment for primary insomnia. However, the majority of sleeping problems occur in the presence of another medical or psychiatric disorder. Depression and general anxiety disorder (with a main feature of excessive generalized worrying) are disorders that frequently co-occur with insomnia. The purpose of this study is to evaluate whether depressive symptom severity or worrying influences the subjective effectiveness of CBT-I. METHODS: Patients with a complaint of insomnia received CBT-I. At the beginning of the therapy, patients completed a sleep evaluation list, the Beck Depression Inventory (BDI-II-NL, N = 92), and the Penn State Worry Questionnaire (PSWQ, N = 119). Based on the BDI and the PSWQ, the sample was divided into different groups: patients with low versus high depression scores, low worriers versus high worriers, and patients without depressive symptoms who were also classified as low worriers and patients with depressive symptoms who were also classified as high worriers. The sleep evaluation list was completed directly after the treatment and 6 months later. RESULTS: Sleep evaluation scores, subjective total sleep time, subjective sleep onset latency, and subjective wake after sleep onset all changed in a positive way after CBT-I and remained that way over the next 6 months for all patients. These positive effects of CBT-I did not differ between the subgroups. CONCLUSIONS: Results suggest that CBT-I improves subjective sleep experiences, regardless of depressive symptom severity or worrying. Language: en

Thanks to high frequency ultrasonic surface waves generated by specific focused transducers, a non destructive evaluation of the elastic moduli of very small or heterogeneous samples can be achieved. This method, called acoustic microscopy, was developed and tested for many years as cold and hot set-up; in 2011 an optimized version of the high frequency acoustic microscope has been definitively introduced in hot cell. This apparatus now constitutes a standard facility for irradiated fuels and materials characterization. This paper presents a review of the studies performed on different irradiated fuels in order to determine the elastic moduli. Behaviour laws are proposed in the burnup range up to ∼103 MWd kg −1 . The results, supported by benchmarking the outcome of acoustic measurements with other characterization techniques, indicate that the elastic modulus of irradiated fuel can be assessed without preliminary knowledge of density. Thus with a single non-destructive measurement it is possible to assess both the density and the Young's modulus with an acceptable precision.

In juvenile myoclonic epilepsy (JME), occurrence of seizures and epileptiform EEG discharges is influenced by internal and external factors. The most important internal factor is the chronodependency: the occurrence of myoclonic jerks in the early morning is one of the hallmarks of JME. Approximately two-thirds of the patients with JME report that seizures are provoked by a variety of general factors like stress, fatigue, fever, and sleep and more specific precipitants like flashing sunlight, music, reading, thinking, and excess alcohol. The prevalence rate of photosensitivity (photoparoxysmal EEG response) in patients with JME ranges from 8 to 90%; it is seen more often in females and adolescents and depends on drug use. Since both JME and photosensitivity are connected with generalized types of epilepsy and myoclonus, the two traits are comorbid for that reason. Epileptiform EEG discharges can be provoked by other activation methods: sleep, hyperventilation, and specific cognitive tasks. Attention seems to have a non-specific, inhibitory effect of the epileptiform discharges. Hyperventilation can induce absence seizures in patients with JME, while cognitive tasks are efficient in precipitating myoclonic seizures. This article is part of a supplemental special issue entitled Juvenile Myoclonic Epilepsy: What is it Really?

Objective This study aimed to (1) evaluate available systems and algorithms for ambulatory automatic seizure detection and (2) discuss benefits and disadvantages of seizure detection in epilepsy care. Methods PubMed and EMBASE were searched up to November 2014, using variations and synonyms of search terms “ seizure prediction ” OR “ seizure detection ” OR “ seizures ” AND “ alarm ”. Results Seventeen studies evaluated performance of devices and algorithms to detect seizures in a clinical setting. Algorithms detecting generalized tonic–clonic seizures (GTCSs) had varying sensitivities (11% to 100%) and false alarm rates (0.2–4/24 h). For other seizure types, detection rates were low, or devices produced many false alarms. Five studies externally validated the performance of four different devices for the detection of GTCSs. Two devices were promising in both children and adults: a mattress-based nocturnal seizure detector (sensitivity: 84.6% and 100%; false alarm rate: not reported) and a wrist-based detector (sensitivity: 89.7%; false alarm rate: 0.2/24 h). Significance Detection of seizure types other than GTCSs is currently unreliable. Two detection devices for GTCSs provided promising results when externally validated in a clinical setting. However, these devices need to be evaluated in the home setting in order to establish their true value. Automatic seizure detection may help prevent sudden unexpected death in epilepsy or status epilepticus, provided the alarm is followed by an effective intervention. Accurate seizure detection may improve the quality of life (QoL) of subjects and caregivers by decreasing burden of seizure monitoring and may facilitate diagnostic monitoring in the home setting. Possible risks are occurrence of alarm fatigue and invasion of privacy. Moreover, an unexpectedly high seizure frequency might be detected for which there are no treatment options. We propose that future studies monitor benefits and disadvantages of seizure detection systems with particular emphasis on QoL, comfort, and privacy of subjects and impact of false alarms.

Aim In female children with drug-resistant seizures and developmental delay from birth, atypical Rett syndrome caused by mutations in the CDKL5 gene should be considered. Several clinical features resemble classic Rett syndrome. Respiratory and sleep abnormalities are frequently present in Rett syndrome, whereas little is known in patients with CDKL5 mutations. Method In four genetically confirmed female patients with CDKL5 mutations (age range 2–15y), the presence of breathing and sleep abnormalities was evaluated using the validated Sleep Disturbance Scale for Children and polysomnography (PSG). Results The Sleep Disturbance Scale for Children indicated disorders of initiating and maintaining sleep, daytime somnolence, and sleep breathing disorders. In one patient, PSG showed central apnoeas during sleep: her total apnoea–hypopnoea index (AHI) was 4.9, of which the central AHI was 3.4/h. When awake, central apnoeas were present in two of the four female children (central AHI 28/h and 41/h respectively), all preceded by hyperventilation. PSG showed low rapid eye movement (REM) sleep (9.7–18.3%), frequent awakenings, and low sleep efficiency (range 59–78%). Interpretation Episodic hyperventilation followed by central apnoeas was present while awake in two of four patients. This may indicate failure of brainstem respiratory centres. In addition, low REM sleep, frequent arousals (not caused by apnoeas/seizures), and low sleep efficiency were present. Similar to Rett syndrome, in patients with CDKL5 mutations PSG seems warranted to evaluate breathing and sleep disturbances.

Several studies have shown that sleep and sleep restriction can influence epilepsy and trigger epileptic seizures. Circadian rhythmicity plays an important role in sleep physiology. Knowledge of the influence of circadian rhythmicity on epilepsy and seizures, and vice versa, is scarce. Greater knowledge of the interactions between circadian rhythm and epilepsy may be of value for understanding the pathophysiology of epilepsy, especially for the timing of diagnostic procedures and therapy to improve seizure control.

Almost one-third of epilepsy patients continue to have seizures despite adequate drug treatment. Chronotherapy (based on dynamic changes in drug pharmacology and disease-related processes) could be a promising treatment option. We aimed to explore whether different circadian types adjust administration times of anti-epileptic drugs (AEDs) as a step in exploring chronotherapeutic possibilities. We performed a questionnaire-based study to compare behavior of different circadian types in relation to times of taking drugs. Circadian type was determined by the Morningness-Eveningness Questionnaire. Results clearly show that morning types are taking their AEDs significantly earlier than do evening types on free days. Times of taking AEDs in the morning on work days also differ significantly between morning and evening types. Regardless of circadian type, drugs on free days are taken later than on working days. In conclusion, our study shows that patients adapt times of taking medication to their circadian type.

The interaction between epilepsy and sleep is thoroughly studied and is very complex. This review focuses on prevalence, impact on quality of life and effects of treatment of sleep disorders on the course of epilepsy. Self-reported sleep disturbances in people with epilepsy are about twice as prevalent as in healthy controls. People with epilepsy with sleep disturbances have a significant impairment of quality of life compared to those with no sleep disturbances. In children with epilepsy, sleep problems may lead to detrimental effects on daytime behavior and cognition. Most is known about obstructive sleep apnea syndrome (OSAS). Co-morbidity of epilepsy and OSAS is shown to be far higher than expected by chance. Treatment of OSAS significantly improves seizure control in people with epilepsy. More studies on the prevalence of other sleep disorders in people with epilepsy and the effect of treatment are required. Reports on the effect of treatment for other sleep disorders are scarce and not unequivocal.

There is strong evidence that epileptic seizures occur in diurnal or 24-h patterns. A study in rat models of partial epilepsy showed circadian seizure patterns, and in humans circadian rhythmicity in interictal discharges has been found, suggesting that circadian rhythm may play a role in epilepsy. Circadian influences on human seizure patterns have not been investigated. We performed a pilot study to ascertain influences of the circadian rhythm on seizure occurrence. We prospectively outlined circadian rhythms of patients admitted for long term EEG and video monitoring, using measurement of the dim light melatonin onset (DLMO). Seizures during admission were recorded with continuous EEG and video monitoring. The DLMO ranged from 18:46h to 23:13h (mean 21:22h). One hundred and twenty-four seizures of 21 patients were analysed. Seizures of temporal lobe origin occurred mainly between 11:00 and 17:00 h and frontal seizures were seen mostly between 23:00 and 05:00 h. When correlating seizure timing to the individual's circadian phase as measured by the DLMO, the following was seen: temporal seizures occurred most frequently in the 6 h before DLMO and frontal seizures mainly in 6-12 h after the DLMO. The results of this pilot study suggest that temporal and frontal seizures occur in a non-random fashion synchronized to a hormonal marker of the circadian timing system. (C) 2011 Elsevier B.V. All rights reserved.

Research on new sprout control methods led to the discovery of 1,4dimethylnaphthalene (1,4DMN) in the late 1970s. This compound has been registered in the USA since 1996 as a reduced risk chemical for use on stored potatoes for the purpose of sprout suppression. Relatively little is known about the levels of tuber residues required to maintain sprout suppression. The objective of this study was to identify the minimum 1,4DMN tuber residue levels above which sprout growth was inhibited. Using modified steel drums to store and treat potatoes, rates of 0 µL kg−1 to 56 µL kg−1 1,4DMN were applied to non-dormant, slightly “peeping” seed tubers of four different cultivars (Russet Burbank, Russet Norkotah, Shepody and FL1879) stored at 15 C ± 2C. Tubers were treated by dribbling 1,4DMN onto a gauze that was placed on top of a return air pipe that re-circulated forced air inside the drum. Higher application rates resulted in higher 1,4DMN residues and longer suppression of sprout growth. Sprout growth was controlled for more than 50 days for all cultivars in both years for tubers treated at the highest rate. The duration of sprout inhibition corresponded with the time it took for tuber residues to drop below an estimated residue level of 1.4–2.1 ppm, for R. Burbank, Shepody and FL1879, and 2.7 ppm for Russet Norkotah. Below these levels, sprouting was no longer suppressed and resumed for all cultivars.

Accumulating evidence suggests epilepsy and seizures may influence circadian rhythms and that circadian rhythms may influence epilepsy. It is also conceivable that seizure timing influences the timing of daily activities, sleeping, and wakefulness (i.e., chronotype). Only one group has studied the distribution of chronotypes of epileptics, showing significant differences between the diurnal activity patterns in two groups of patients with different epilepsy syndromes. The authors performed a questionnaire-based study of 200 epilepsy patients to compare the distribution of chronotypes and subjective sleep parameters of sleep duration and time of mid-sleep on free days to the distribution in the general population (n = 4042). Within this large group of epilepsy patients, we also compared the chronotypes of subsamples with well-defined epilepsy syndromes, i.e., temporal lobe epilepsy [TLE; n = 46], frontal lobe epilepsy [FLE; n = 30], and juvenile myoclonic epilepsy [JME; n = 38]. In addition, 27 patients who had had surgery for TLE were compared with those with TLE who had not had surgery. Both the Morningness-Eveningness Questionnaire and Munich Chronotype Questionnaire were used to determine chronotypes and subjective sleep parameters. Significant differences in morningness/eveningness distribution, timing of mid-sleep (corrected for sleep duration), and total sleep time on free days were found between epileptics and healthy controls. Those with epilepsy were more morning oriented, had earlier mid-sleep on free days, and longer sleep duration on free days (p

In a four-and-a-half year period, 19 patients with focal neurological deficits accompanied by a focal electrographic status epilepticus were encountered. Sixteen of these patients showed clouding of consciousness or confusion. Computed tomography of the brain revealed focal lesions in 15 patients. In 7 patients the lesions were the result of a recent cerebral event and in 8 patients they were long-standing. All patients were treated with anti-epileptic drugs. Ten of the 12 patients without an acute lesion showed a complete recovery in a few days. In these patients the symptoms may have been caused by the continuous seizure activity, classifying them as cases of non-convulsive focal status epilepticus. Only 2 of the 7 patients with an acute lesion had a full recovery. In patients with an acute lesion the part played by the electrographic status epilepticus in the acquired deficits is unclear. Continuous or frequent intermittent focal epileptic discharges on the EEG may warrant treatment with anti-epileptic drugs in patients with focal neurological deficits, even when one of the hallmarks of epilepsy, clonic movements, is absent.

Few studies have evaluated human seizure occurrence over the 24-hour day, and only one group has employed intracranial electrocorticography monitoring to record seizures. Circadian patterns in seizures may have important implications in diagnosis and therapy and provide opportunities in research. We have analyzed spontaneous seizures in 33 consecutive patients with long-term intracranial EEG and video monitoring. Several aspects of seizures were noted, including time of day, origin, type, and behavioral state (sleeping/awake). We recorded 450 seizures that showed an uneven distribution over the day, depending on lobe of origin: temporal lobe seizures occurred preferentially between 1100 and 1700 hours, frontal seizures between 2300 and 0500 hours, and parietal seizures between 1700 and 2300 hours. In the awake state, larger proportions of clinical seizures were seen from 0500 to 1100 hours and from 1700 to 2300 hours. During sleep, larger proportions occurred from 1100 to 1700 hours and from 2300 to 0500 hours. Our results suggest that seizures from different brain regions have a strong tendency to occur in different diurnal patterns.

It is well known that seizures of some types of epilepsy tend to occur in patterns. The circadian rhythm may play a significant role in this phenomenon. In animal studies it has been found that seizures in experimental partial epilepsy are probably under the influence of the biological clock. In this review an introduction to the influence of the human circadian rhythm in epilepsy is given. Furthermore, the methodology of measuring the circadian rhythm in humans is explored. An overview of widely used methods includes protocols used to desynchronize circadian rhythm, and sleep–wake and biological markers such as the dim light melatonin onset, core body temperature, and cortisol that are employed to determine the phase of the circadian rhythm. Finally, the use of sleep parameters, actigraphy, and questionnaires is discussed. These are also important in assessment of the circadian rhythm.

Item does not contain fulltext Prader-Willi syndrome (PWS) is a neurogenetic disorder with hypotonia, psychomotor delay, obesity, short stature, and sleep-related breathing disorders. The aim of this study was to evaluate the association between psychomotor development and sleep-related breathing disorders in PWS infants. Bayley Scales of Infant Development were performed in 22 PWS infants, with a median (interquartile range, IQR) age of 1.8 (1.1-3.4) y, and a body mass index SD score (BMISDS) of -0.5 (-1.3 to 1.6). We evaluated psychomotor development in relation to results of polysomnography. Median (IQR) mental and motor development was 73.1% (64.3-79.6%) and 55.2% (46.5-63.1%) of normal children, respectively. All infants had sleep-related breathing disorders, mostly of central origin. The apnea hypopnea index was not associated with psychomotor development. Only four infants had obstructive sleep apnea syndrome (OSAS). They had a significantly delayed mental development of 65.5% (60.0-70.3%) of normal. They had a median BMISDS of 1.4 (0.1-1.6), which tended to be higher than in those without OSAS. Our data indicate that psychomotor development in PWS infants is not related to central sleep-related breathing disorders, but infants with OSAS have more severely delayed mental development, suggesting that PWS infants should be screened for OSAS.

Item does not contain fulltext This is the second report of a family with a recurrence of a CDKL5 mutation (c. 283-3_290del) in 2 sisters. Both parents tested negative for the mutation in all tissues, but germline mosaicism is likely. Clinically CDKL5 patients resemble those with Rett syndrome, caused by a MECP2 mutation, who experience a regression, after an initial normal development. Even though both siblings showed a typical CDKL5 phenotype, their presentation is different. From birth, the oldest daughter had a severe developmental delay, feeding problems, and hypotonia and experienced daily refractory seizures. The youngest daughter appeared to be normal until age 3 months. At that age seizures started, deterioration and regression became evident, and an epileptic encephalopathy developed. This report of familial recurrence, with suspected germline mosaicism in a healthy parent, has important consequences for genetic counseling. Although it is not possible to predict an exact recurrence risk, it is likely to be increased.

The reliability of visual interpretation of electroencephalograms (EEG) is of great importance in assessing the value of this diagnostic tool. We prospectively obtained 50 standard EEGs and 61 EEGs after partial sleep deprivation from 93 children (56 males, 37 females) with a mean age of 6 years 10 months (SE 5mo; range 4mo-15y 7mo) with one or more newly diagnosed, unprovoked seizures. Two clinical neurophysiologists independently classified the background pattern and the presence of epileptiform discharges or focal non-epileptiform abnormalities of each EEG. The agreement was substantial for the interpretation of the EEG as normal or abnormal (kappa 0.66), almost perfect for the presence of epileptiform discharges (kappa 0.83), substantial for the occurrence of an abnormal background pattern (kappa 0.73), and moderate for the presence of focal non-epileptiform discharges (kappa 0.54). In conclusion, the reliability of the visual interpretation of EEGs in children is almost perfect as regards the presence of epileptiform, abnormalities, and moderate to substantial for the presence of other abnormalities.

Background: A study was undertaken to evaluate the efficacy of dexamethasone in patients mechanically ventilated for lower respiratory infection caused by respiratory syncytial virus (RSV-LRTI). Methods: In a multicentre randomised controlled trial patients were randomised to receive either intravenous dexamethasone (0.15 mg/kg 6 hourly for 48 hours) or placebo. End points were the duration of mechanical ventilation, length of stay (LOS) in the pediatric intensive care unit (PICU) and in hospital, and the duration of supplemental oxygen administration. Results: Thirty seven patients received dexamethasone and 45 received placebo. There was no significant difference in any of the end points between the two groups. In a post hoc analysis patients were stratified into those with mild gas exchange anomalies ( PaO2/FiO(2) > 200 mm Hg and/or mean airway pressure 10 cm H2O, pneumonia group). In the 39 patients with bronchiolitis the duration of mechanical ventilation was 4.3 days shorter in the dexamethasone group than in the placebo group (4.9 v 9.2 days, 95% CI - 7.8 to - 0.8, p= 0.02) and the duration of supplemental oxygen was 3.6 days shorter (7.7 v 11.3 days, 95% CI - 8.0 to - 0.1, p= 0.048). No differences in end points were found in the pneumonia group. Conclusions: Dexamethasone had no beneficial effect in patients mechanically ventilated for RSV-LRTI but was found to have a beneficial effect in patients with bronchiolitis

The gold standards for measurement of sleep and wake are polysomnography (PSG) and the multiple sleep latency test (MSLT) and will remain so. Actigraphy is cheap, less labor intensive for the sleep laboratory and gives no burden for the patient. Major features of sleep (time in bed, total sleep time, sleep onset latency, wake after sleep onset and naps during the day) are easily quantified. If done over at least five days the results are in a reasonable way comparable to those of PSG. Obviously, actigraphy provides less details of sleep and the way it is disturbed. From the combination of PSG and one week actigraphy, one gets all details of sleep and wake and their fluctuations over time. As “stand alone” technique, actigraphy is indicated in young children, mentally handicapped patients and in the assessment of therapy for sleep disorders. In our opinion assessment of sleep disorders in children should include actigraphy over at least 5-7 24 hour days, if possible combined with one or two nights PSG. As there are no strict rules and normal values for MSLT in children, actigraphy is also helpful as tool for global assessment of hypersomnia in young patients.

As early as in 1898, it was noted that there was a need to find "a plausible explanation of the long recognized affinities of migraine and epilepsy". However, results of recent studies are clearly conflicting on this matter. In this cross-sectional study, we aimed to define the prevalence and characteristics of both seizure-related and interictal headaches in patients with epilepsy (5-75years) seeking help in the tertiary epilepsy clinic SEIN in Zwolle. Using a questionnaire, subjects were surveyed on the existence of headaches including characteristics, duration, severity, and accompanying symptoms. Furthermore, details on epilepsy were retrieved from medical records (e.g., syndrome, seizure frequency, and use of drugs). Diagnoses of migraine, tension-type headache, or unclassifiable headache were made based on criteria of the International Classification of Headache Disorders. Between March and December 2013, 29 children and 226 adults were evaluated, 73% of whom indicated having current headaches, which is significantly more often when compared with the general population (p

Many older adults report sleep problems and use of hypnotics. Several studies have shown that hypnotics can have acute adverse effects on driving the next morning. It is unclear however whether driving of chronic hypnotic users is impaired. Therapeutic effects on insomnia and development of tolerance may reduce the residual effects on driving.The present study aimed to compare actual driving performance and driving-related skills of chronic hypnotic users to good sleepers. To determine whether insomnia itself affects driving performance, driving and driving-related skills were compared between insomnia patients who do not or infrequently use hypnotics and good sleepers.Twenty-two frequent users of hypnotics (using hypnotics a parts per thousand yen4 nights per week for more than 3 months), 20 infrequent users (using hypnotics a parts per thousand currency sign3 nights per week), and 21 healthy, age-matched controls participated in this study. On the night before testing, all subjects were hospitalized for an 8-h sleep recorded by polysomnography. Frequent hypnotic users used their regular medication at bedtime (2330 hours), while infrequent users and controls received no medication. Cognitive performance (word learning, digit span, tracking, divided attention, vigilance, and inhibitory control) was assessed 8.5 h and driving performance between 10 and 11 h after bedtime and dosing.Polysomnographic recordings did not significantly differ between the groups, but the insomnia patients, treated or untreated, still reported subjective sleep complaints. Results show no differences in driving performance and driving-related skills between both groups of insomnia patients and controls.Driving performance in chronic users of hypnotics and untreated insomnia patients is not impaired. For chronic users, this may be due to prescription of relatively safe drugs and low doses. For untreated insomniacs, this corroborates previous findings showing an absence of neuropsychological deficits in this group of patients.

Background - Studies on determinants of quality of life (QOL) after a stroke focus on one aspect (most important: neurological deficit, mood disorders or cognitivc failure) and as such provide no insight in the relative contribution of each factor on QOL. The groups of patients studied often contain victims of different types of stroke. This inhomogenity in patients leads to further confusion about QOL aftcr stroke. Objective - To evaluate in one study factors important for QOL in the period 3-12 months after a first one-sided ischemic stroke in the region of the middle cerebral artery. Design - Measurcs for QOL (Sickness Impact Profile, SIP), cognitive status (Wechsler Adult Intelligence Scale revised), mood and neurological deficit were scored 3, 6 and 12 months after the stroke. Setting - Successive patients admitted to a general hospital and rehabilitation clinic in The Hague, The Netherlands. Patients - A complete examination was performed three times in 35 patients. The results were compared to those of 20 controls matched for age, last occupation and educational level. Results - There was no significant neurological improvement between 3 and 12 months after the stroke. Cognition was impaired when compared to the estimated premorbid level and to the controls. There was incomplete recovery over the study interval. The patients as a group were depressed and remained so over the period of the study. The resulting quality of life scores were abnormal at 3 months and improved only slightly. Stepwise regression analysis revealed that depression and degree of paresis were the most important variables for the SIP total outcome. Conclusions - In a homogenous group of stroke patients the QOL improved somewhat in the period 3 to 12 months after the stroke but was still highly abnormal after 1 year. The decrease in QOL was correlated with depression and - to some degrec - with neurological deficit, but not to cognitive disturbances.

A ventilator-dependent child had been in the paediatric intensive care unit (PICU) ever since birth. As a result, she had fallen behind considerably in her development.After 18 months, continuous positive airway tracheostomy tube with a novel lightweight device device, the child was discharged home where pressure was successfully administered via a. This enabled her to walk in the PICU. With this she could walk with an action range of 10 m. Subsequently, her psychornotor development improved remarkably.To the authors' knowledge, this is the first case report of a patient, adult or paediatric, who could actually walk with a sufficient radius of action while receiving long-term respiratory support.

Summary: Purpose: To assess the diagnostic yield of a repeated EEG (REPEEG) after partial sleep deprivation (SD) in children and adolescents with one or more seizures who previously had had a standard EEG (STDEEG) without epileptiform abnormalities (EAs). In the literature, 32–75% of such REPEEGs after SD were reported to show EA. Methods: In a prospective, multicentred study, we selected children aged 1 month to 16 years with one or more idiopathic or remote symptomatic newly diagnosed seizures. A REPEEG was recorded in children without EAs in their STDEEG. Results: Of 552 children and adolescents who entered the study, 243 (44%) had a STDEEG without EAs. In 177 (73% of eligible children), REPEEGs were recorded after SD. We found EAs in 61 (34.5%) REPEEGs and new nonepileptiform abnormalities in five (1%). In 552 children in the total cohort, the REPEEG thus added 11% with EAs to the 56% with EAs in the STDEEG. Of REPEEGs, 81% included sleep compared with 20% of STDEEGs. In about half the REPEEGs, EAs occurred during sleep only. One child had tonic-clonic seizures probably related to the SD. Conclusions: One third of REPEEGs yielded new diagnostic information. Partial, age-dependent SD was highly effective in inducing sleep, which is important because in many cases EAs were found only during EEG recording in sleep. The procedure was safe and convenient.

Cognitive behavioral therapy for insomnia (CBT-I) is a well-known, effective treatment for primary insomnia. However, the majority of sleeping problems occur in the presence of another medical or psychiatric disorder. Depression and general anxiety disorder (with a main feature of excessive generalized worrying) are disorders that frequently co-occur with insomnia. The purpose of this study is to evaluate whether depressive symptom severity or worrying influences the subjective effectiveness of CBT-I.Patients with a complaint of insomnia received CBT-I. At the beginning of the therapy, patients completed a sleep evaluation list, the Beck Depression Inventory (BDI-II-NL, N = 92), and the Penn State Worry Questionnaire (PSWQ, N = 119). Based on the BDI and the PSWQ, the sample was divided into different groups: patients with low versus high depression scores, low worriers versus high worriers, and patients without depressive symptoms who were also classified as low worriers and patients with depressive symptoms who were also classified as high worriers. The sleep evaluation list was completed directly after the treatment and 6 months later.Sleep evaluation scores, subjective total sleep time, subjective sleep onset latency, and subjective wake after sleep onset all changed in a positive way after CBT-I and remained that way over the next 6 months for all patients. These positive effects of CBT-I did not differ between the subgroups.Results suggest that CBT-I improves subjective sleep experiences, regardless of depressive symptom severity or worrying.

There are many different types of sleep disorders. The majority of sleep-related breathing disorders can be attributed to sleep apnoea syndrome. Nocturnal choking sensation is a different symptom, for which we present two cases. Nocturnal choking sensation is a terrifying symptom for the patient and the diagnostic approach can be challenging. Aside from sleep choking syndrome, this symptom may appear with nocturnal laryngospasm, insular epilepsy and nocturnal gastro-oesophageal reflux. A thorough patient history and observation of the nocturnal event, sometimes supported by EEG findings, may provide the clue to the diagnosis. These kinds of nocturnal symptoms are best analyzed in a clinic specialized in both epilepsy and sleep disorders.

Sleep deprivation is common in intensive care unit (ICU) patients. The criterion standard for sleep monitoring, polysomnography, is impractical in ICU. Actigraphy (a wrist watch indicating amount of sleep) proved to be a good alternative in non-ICU patients, but not in prolonged mechanically ventilated patients, probably due to ICU-acquired weakness. Short-stay ICU patients do not suffer from ICU-acquired weakness. However, the accuracy of actigraphy is unknown in these patients. Therefore, we compared actigraphy to polysomnography in short-stay ICU patients. Sleep measurements were conducted in 7 postcardiothoracic surgery patients. The sensitivity (percentage of actigraphy data that agreed with sleep determined using polysomnography) and specificity (percentage of actigraphy data that agreed with awake determined using polysomnography) were calculated. The result showed that actigraphy underestimated the amount of wake time and overestimated the amount of sleep. The median specificity for actigraphy was always less than 19% and sensitivity more than 94%. Therefore, actigraphy is not reliable for sleep monitoring in short-stay ICU patients. Copyright © 2013 Wolters Kluwer Health | Lippincott Williams and Wilkins.

With advancing physiological age of potato tubers an increase in electrolyte leakage from tuber tissue was observed for various seed lots. This increase was most marked after tubers exhibited sprout growth and corresponded with a decline in tuber water content. Leakage increased minimally with storage time when sprouting was prevented or limited by either dormancy, low storage temperature, or frequent desprouting. Sprouting capacity of tubers increased to a maximum and then declined with storage time. This decline coincided with the increase in electrolyte leakage, suggesting that membrane integrity was one determinant in vigour of seed potato tubers. The pattern of electrolytes leaking from tuber tissue could be described by a function composed of a saturable and a linear component, suggesting two different sources contributing to the leakage. The saturable component, expected to reflect membrane integrity, was most responsive to aging treatments.

In female children with drug-resistant seizures and developmental delay from birth, atypical Rett syndrome caused by mutations in the CDKL5 gene should be considered. Several clinical features resemble classic Rett syndrome. Respiratory and sleep abnormalities are frequently present in Rett syndrome, whereas little is known in patients with CDKL5 mutations.In four genetically confirmed female patients with CDKL5 mutations (age range 2-15 y), the presence of breathing and sleep abnormalities was evaluated using the validated Sleep Disturbance Scale for Children and polysomnography (PSG).The Sleep Disturbance Scale for Children indicated disorders of initiating and maintaining sleep, daytime somnolence, and sleep breathing disorders. In one patient, PSG showed central apnoeas during sleep: her total apnoea-hypopnoea index (AHI) was 4.9, of which the central AHI was 3.4/h. When awake, central apnoeas were present in two of the four female children (central AHI 28/h and 41/h respectively), all preceded by hyperventilation. PSG showed low rapid eye movement (REM) sleep (9.7-18.3%), frequent awakenings, and low sleep efficiency (range 59-78%).Episodic hyperventilation followed by central apnoeas was present while awake in two of four patients. This may indicate failure of brainstem respiratory centres. In addition, low REM sleep, frequent arousals (not caused by apnoeas/seizures), and low sleep efficiency were present. Similar to Rett syndrome, in patients with CDKL5 mutations PSG seems warranted to evaluate breathing and sleep disturbances.

Behavioural episodes of staring in children are difficult to distinguish from epileptic seizures, especially in children with developmental disorders such as ADHD, autism spectrum disorders and intellectual disabilities. We discuss two patients with staring episodes who were using anti-epileptic drugs. In both patients, EEG with video monitoring showed that the staring was non-epileptic. The first is an 8-year-old boy, who developed severe motor problems and ataxia during treatment with valproate. His staring episodes were behavioural, caused by his intellectual disability, and the motor problems resolved after discontinuation of valproate. The second patient is a 10-year-old boy with known autism, ADHD and infantile seizures, who developed staring for which he was using valproate. Again, video-EEG monitoring during staring showed no abnormalities and in this case the staring was caused by his intellectual disability and autism. We discuss the differential diagnosis of staring episodes in children with developmental disorders and present the pitfalls of the diagnostic process.

A new furnace for accident condition testing of spherical high temperature reactor fuel elements has been installed and now operates in the hot cells of the Institute for Transuranium Elements (ITU) Karlsruhe. The recent apparatus was constructed on the basis of a former development by Forschungszentrum Jülich (Schenk, Pitzer, and Nabielek, 1988, “Fission Product Release Profiles From Spherical HTR Fuel Elements at Accident Temperatures,” Jülich Report No. 2234), where it was named KüFA, the German acronym for cold finger apparatus. In a preceding publication (Kostecka, Ejton, de Weerd, and Toscano, 2004, “Post-Irradiation Testing of HTR-Fuel Elements Under Accident Conditions, Part 1 and 2,” Second International Topical Meeting on High Temperature Reactor Technology, Beijing, China) the general concept and details of the device were described. The present paper reports on the first operation under hot conditions, and the calibration of the fission gas measurement and of the efficiency of the cold finger, which is used to plate out solid fission products. Finally the results of fission product release and analysis of two heating tests on two fuel elements from the high temperature reactor K6 irradiation experiment (Nabielek, Conrad, Roellig, and Meyers, 1993, “Fuel Irradiation Experiments on HFR-K6 and HFR-B1 With Intermittent Water Vapour Injections,” Technical Committee Meeting on Response of Fuel, Fuel Elements and Gas Cooled Reactor Cores Under Accidental Air or Water Ingress Conditions, Beijing, China, Oct. 25–27) are presented and discussed.

A group of 121 patients, 22 with a preterminal chronic renal insufficiency (PCRI), 74 on chronic haemodialysis (CHD), and 25 on continuous ambulatory peritoneal dialysis (CAPD), was evaluated by means of neurophysiological and neuropsychological studies to detect signs of central nervous system dysfunction. CHD patients were studied the day before dialysis treatment. In each patient the neurophysiological and neuropsychological studies were performed on the same day. The same overall result emerged from the neurophysiological and neuropsychological studies: all three patient groups showed significant deviations from the values obtained from a healthy reference group, whereas no differences were found between the three patient groups. Biochemical variables (a.o. PTH, Al, PO4) showed inconsistent or only minor correlations with the encephalopathic parameters. Apparently traditional biochemical variables are not a reliable measure to safeguard renal patients from neurotoxic damage. With respect to central nervous system dysfunction CAPD appears to be as 'safe' as CHD.