Quality of life and correlating factors in children, adolescents with epilepsy, and their caregivers: A cross-sectional multicenter study from Germany.

PURPOSE: To identify factors correlating with poorer quality of life (QoL) in children and adolescents with epilepsy and regarding QoL and depression of their caregivers in Germany. METHOD: A cross-sectional multicenter study on QoL and depression was performed in two representative German states (Hessen and Schleswig-Holstein). Variance analysis, linear regression, and bivariate correlation were used to identify correlating factors for poorer QoL and symptoms of depression. RESULTS: Data from 489 children and adolescents (mean age 10.4 ± 4.2 years, range 0.5-17.8; 54.0% male) and their caregivers were collected. We identified missing seizure freedom (p = 0.046), concomitant diseases (p = 0.007), hospitalization (p = 0.049), recent status epilepticus (p = 0.035), living in a nursing home or with foster parents (p = 0.049), and relevant degree of disability (p = 0.007) to correlate with poorer QoL in children and adolescents with epilepsy. Poorer QoL of caregivers was associated with longer disease duration (p = 0.004), non-idiopathic (mainly structural-metabolic) epilepsy (p = 0.003), ongoing seizures (p = 0.003), concomitant diseases (p = 0.003), relevant disability (p = 0.003), or status epilepticus (p = 0.003) as well as with unemployment of the primary caretaker (p = 0.010). Symptoms of depression of caregivers were associated with non-idiopathic epilepsy (p = 0.003), concomitant diseases (p = 0.003), missing seizure freedom (p = 0.007), status epilepticus (p = 0.004), or a relevant disability (p = 0.004) of their ward. A poorer QoL value of the children and adolescents correlated with a poorer QoL value of the caregivers (p < 0.001). CONCLUSIONS: Epilepsy shows a considerable impact on QoL and symptoms of depression. Early and effective therapy should focus on reduction of seizure frequency and the probability for developing status epilepticus. Furthermore, comprehensive care should pay attention at comorbidities, consequences of disability and dependency on others.

Multifocal epilepsy in children is associated with increased long-distance functional connectivity: An explorative EEG-fMRI study.

OBJECTIVE: Multifocal epileptic activity is an unfavourable feature of a number of epileptic syndromes (Lennox-Gastaut syndrome, West syndrome, severe focal epilepsies) which suggests an overall vulnerability of the brain to pathological synchronization. However, the mechanisms of multifocal activity are insufficiently understood. This explorative study investigates whether pathological connectivity within brain areas of the default mode network as well as thalamus, brainstem and retrosplenial cortex may predispose individuals to multifocal epileptic activity. METHODS: 33 children suffering from multifocal and monofocal (control group) epilepsies were investigated using EEG-fMRI recordings during sleep. The blood oxygenated level dependent (BOLD) signal of 15 regions of interest was extracted and temporally correlated (resting-state functional connectivity). RESULTS: Patients with monofocal epilepsies were characterized by strong correlations between the corresponding interhemispheric homotopic regions. This pattern of correlations with pronounced short-distance and weak long-distance functional connectivity resembles the connectivity pattern described for healthy children. Patients with multifocal epileptic activity, however, demonstrated significantly stronger correlations between a large number of regions of the default mode network as well as thalamus and brainstem, with a significant increase in long-distance connectivity compared to children with monofocal epileptic activity. In the group of patients with multifocal epilepsies there were no differences in functional connectivity between patients with or without Lennox-Gastaut syndrome. CONCLUSION: This explorative study shows that multifocal activity is associated with generally increased long-distance functional connectivity in the brain. It can be suggested that this pronounced connectivity may represent either a risk to pathological over-synchronization or a consequence of the multifocal epileptic activity.

De novo GABRG2 mutations associated with epileptic encephalopathies.

Epileptic encephalopathies are a devastating group of severe childhood onset epilepsies with medication-resistant seizures and poor developmental outcomes. Many epileptic encephalopathies have a genetic aetiology and are often associated with de novo mutations in genes mediating synaptic transmission, including GABAA receptor subunit genes. Recently, we performed next generation sequencing on patients with a spectrum of epileptic encephalopathy phenotypes, and we identified five novel (A106T, I107T, P282S, R323W and F343L) and one known (R323Q) de novo GABRG2 pathogenic variants (mutations) in eight patients. To gain insight into the molecular basis for how these mutations contribute to epileptic encephalopathies, we compared the effects of the mutations on the properties of recombinant α1ß2γ2L GABAA receptors transiently expressed in HEK293T cells. Using a combination of patch clamp recording, immunoblotting, confocal imaging and structural modelling, we characterized the effects of these GABRG2 mutations on GABAA receptor biogenesis and channel function. Compared with wild-type α1ß2γ2L receptors, GABAA receptors containing a mutant γ2 subunit had reduced cell surface expression with altered subunit stoichiometry or decreased GABA-evoked whole-cell current amplitudes, but with different levels of reduction. While a causal role of these mutations cannot be established directly from these results, the functional analysis together with the genetic information suggests that these GABRG2 variants may be major contributors to the epileptic encephalopathy phenotypes. Our study further expands the GABRG2 phenotypic spectrum and supports growing evidence that defects in GABAergic neurotransmission participate in the pathogenesis of genetic epilepsies including epileptic encephalopathies.

Neuronal networks in epileptic encephalopathies with CSWS.

OBJECTIVE: The aim of our study was to investigate the neuronal networks underlying background oscillations of epileptic encephalopathy with continuous spikes and waves during slow sleep (CSWS). METHODS: Sleep electroencephalography (EEG) studies before and after the treatment were investigated in 15 patients with CSWS. To investigate functional and effective connectivity within the network generating the delta activity in the background sleep EEG, the methods of dynamic imaging of coherent sources (DICS) and renormalized partial directed coherence (RPDC) were applied. RESULTS: Independent of etiology and severity of epilepsy, background EEG pattern in patients with CSWS before treatment is associated with the complex network of coherent sources in medial prefrontal cortex, somatosensory association cortex/posterior cingulate cortex, medial prefrontal cortex, middle temporal gyrus/parahippocampal gyrus/insular cortex, thalamus, and cerebellum. The analysis of information flow within this network revealed that the medial parietal cortex, the precuneus, and the thalamus act as central hubs, driving the information flow to other areas, especially to the temporal and frontal cortex. The described CSWS-specific pattern was no longer observed in patients with normalized sleep EEG. In addition, frequency of spiking showed a strong linear correlations with absolute source power, source coherence strength, and source RPDC strength at both time points: (1) Spike and wave index (SWI) versus absolute source power at EEG1 (r = 0.56; p = 0.008) and at EEG2 (r = 0.45; p = 0.009); (2) SWI versus source coherence strength at EEG1 (r = 0.71; p = 0.005) and at EEG2 (r = 0.52; p = 0.006); and (3) SWI versus source RPDC strength at EEG1 (r = 0.65; p = 0.003) and at EEG2 (r = 0.47; p = 0.009). SIGNIFICANCE: The leading role of the precuneus and thalamus in the hierarchical organization of the network underlying the background EEG points toward the significance of fluctuations of vigilance in the generation of CSWS. This hierarchical network organization appears to be specific for CSWS as it is resolved after successful treatment.

Costs of epilepsy and cost-driving factors in children, adolescents, and their caregivers in Germany.

OBJECTIVE: To provide first data on the cost of epilepsy and cost-driving factors in children, adolescents, and their caregivers in Germany. METHODS: A population-based, cross-sectional sample of consecutive children and adolescents with epilepsy was evaluated in the states of Hessen and Schleswig-Holstein (total of 8.796 million inhabitants) in all health care sectors in 2011. Data on socioeconomic status, course of epilepsy, and direct and indirect costs were recorded using patient questionnaires. RESULTS: We collected data from 489 children and adolescents (mean age ± SD 10.4 ± 4.2 years, range 0.5-17.8 years; 264 [54.0%] male) who were treated by neuropediatricians (n = 253; 51.7%), at centers for social pediatrics ("Sozialpaediatrische Zentren," n = 110, 22.5%) and epilepsy centers (n = 126; 25.8%). Total direct costs summed up to €1,619 ± €4,375 per participant and 3-month period. Direct medical costs were due mainly to hospitalization (47.8%, €774 ± €3,595 per 3 months), anticonvulsants (13.2%, €213 ± €363), and ancillary treatment (9.1%, €147 ± €344). The total indirect costs amounted to €1,231 ± €2,830 in mothers and to €83 ± €593 in fathers; 17.4% (n = 85) of mothers and 0.6% (n = 3) of fathers reduced their working hours or quit work because of their child's epilepsy. Independent cost-driving factors were younger age, symptomatic cause, and polytherapy with anticonvulsants. Older age, active epilepsy, symptomatic cause, and polytherapy were independent predictors of higher antiepileptic drug (AED) costs, whereas younger age, longer epilepsy duration, symptomatic cause, disability, and parental depression were independent predictors for higher indirect costs. SIGNIFICANCE: Treatment of children and adolescents with epilepsy is associated with high direct costs due to frequent inpatient admissions and high indirect costs due to productivity losses in mothers. Direct costs are age-dependent and higher in patients with symptomatic epilepsy and polytherapy. Indirect costs are higher in the presence of a child's disability and parental depression.

Analysis of epileptic seizure count time series by ensemble state space modelling.

We propose an approach for the analysis of epileptic seizure count time series within a state space framework. Time-dependent dosages of several simultaneously administered anticonvulsants are included as external inputs. The method aims at distinguishing which temporal correlations in the data are due to the medications, and which correspond to an unrelated background signal. Through this method it becomes possible to disentagle the effects of the individual anticonvulsants, i.e., to decide which anticonvulsant in a particular patient decreases or rather increases the number of seizures.

Altered information processing in children with focal epilepsies with and without intellectual disability.

The aim of this exploratory study was to investigate the relationship between focal interictal epileptiform discharges (IEDs), intellectual disability and cortical information processing in children with partial epilepsy. Two groups of patients--Group 1 (n = 9 patients) with focal IEDs and normal IQ and Group 2 (n = 10 patients) with focal IEDs and intellectual disability--were compared with 14 healthy control participants. A computerized choice reaction time task (go/no-go paradigm) was performed and event-related potentials (ERPs) were recorded. When an IED occurred during the period between the presentation of the stimulus and the response, the response was defined as a response with IED. Omission errors, commission errors and reaction time were evaluated in temporal relationship to IEDs. The Group 1 patients did not differ from the healthy children in neurophysiological functions and ERP amplitudes. The Group 2 children showed inferior Altered information processing in children with focal epilepsies with and without intellectual disability performances in verbal learning and memory, cognitive flexibility and selective attention, and were characterized by low ERP amplitudes compared with the epilepsy patients with normal IQ and the healthy children. We were not able to identify any significant relationship between IEDs and cognitive functions in either group of patients. Our findings suggest that the impact of IEDs on the overall intellectual abilities of epilepsy patients may not be as significant as previously thought. Moreover, it is likely that abnormalities in cognitive information processing as revealed by lower ERP amplitudes, occurrence of IEDs, and intellectual disabilities may represent common abnormal processes and may not be causally related to each other.

Evaluation of health-care utilization in patients with Dravet syndrome and on adjunctive treatment with stiripentol and clobazam.

Dravet syndrome (DS) is a rare, severe childhood epilepsy syndrome that imposes a substantial burden on patients and their caregivers. This study evaluated health-care utilization over a 2-year period in patients with DS at an outpatient clinic of a German epilepsy center. Data on the course of epilepsy, anticonvulsant treatment, and direct costs were recorded using the electronic seizure diary Epivista and patients' files. We enrolled 13 patients with DS (6 females, mean age: 12.3±7.5 years) between 2007 and 2010 and evaluated them during a 1-year baseline. All patients had drug-resistant epilepsy and their seizures failed to improve with a mean number of 6.7±3.4 anticonvulsants. They had an overall mean seizure frequency of 102.1 seizures per year (median: 31, range: 3-538) with 43.2 GTCSs per year (median: 14, range: 0-228). We estimated the annual total direct costs at €6506±3974 (range: €1174-11,783) per patient with hospitalization (68.9% of total direct costs) as the major cost factor ahead of costs for anticonvulsants (24.0%). For the 1-year follow-up period, less severely affected patients were continued on conventional anticonvulsants (n=4) or switched to adjunctive treatment with stiripentol and clobazam (n=9). In the latter group, six patients (67%) were long-term responders, with between 25% and 100% seizure reduction with respect to either GTCSs or the overall seizure frequency. This reduction in seizure frequency was associated with a shift in the distribution of cost components towards higher medication costs and decreased hospitalization costs. The total direct costs increased by 42.7%, mainly due to the newly introduced stiripentol, with an annual cost of €6610. This study showed that direct costs of patients with DS were above the average European costs of drug-resistant epilepsy in children. Treatment with new anticonvulsants resulted in reduction of seizures and inpatient admissions.

Structural genomic variation in childhood epilepsies with complex phenotypes.

A genetic contribution to a broad range of epilepsies has been postulated, and particularly copy number variations (CNVs) have emerged as significant genetic risk factors. However, the role of CNVs in patients with epilepsies with complex phenotypes is not known. Therefore, we investigated the role of CNVs in patients with unclassified epilepsies and complex phenotypes. A total of 222 patients from three European countries, including patients with structural lesions on magnetic resonance imaging (MRI), dysmorphic features, and multiple congenital anomalies, were clinically evaluated and screened for CNVs. MRI findings including acquired or developmental lesions and patient characteristics were subdivided and analyzed in subgroups. MRI data were available for 88.3% of patients, of whom 41.6% had abnormal MRI findings. Eighty-eight rare CNVs were discovered in 71 out of 222 patients (31.9%). Segregation of all identified variants could be assessed in 42 patients, 11 of which were de novo. The frequency of all structural variants and de novo variants was not statistically different between patients with or without MRI abnormalities or MRI subcategories. Patients with dysmorphic features were more likely to carry a rare CNV. Genome-wide screening methods for rare CNVs may provide clues for the genetic etiology in patients with a broader range of epilepsies than previously anticipated, including in patients with various brain anomalies detectable by MRI. Performing genome-wide screens for rare CNVs can be a valuable contribution to the routine diagnostic workup in patients with a broad range of childhood epilepsies.

Atypical vitamin B6 deficiency: a rare cause of unexplained neonatal and infantile epilepsies.

ALDH7A1 and PNPO deficiencies are rare inborn errors of vitamin B6 metabolism causing perinatal seizure disorders. The phenotypic variability, however, is broad. To assess the frequency of these deficiencies in unexplained infantile epilepsy, we screened 113 patients for mutations in both genes. We identified 1 patient with an epilepsy phenotype resembling Dravet syndrome and likely pathogenic mutations in ALDH7A1. Presenting features were highly atypical of pyridoxine-dependent epilepsy, including febrile seizures, response to anticonvulsive drugs, and periods of seizure freedom without pyridoxine treatment. "Hidden" vitamin B6 deficiencies might be rare but treatable causes of unexplained epilepsy extending beyond the classical phenotypes.

Mutations in GRIN2A cause idiopathic focal epilepsy with rolandic spikes.

Idiopathic focal epilepsy (IFE) with rolandic spikes is the most common childhood epilepsy, comprising a phenotypic spectrum from rolandic epilepsy (also benign epilepsy with centrotemporal spikes, BECTS) to atypical benign partial epilepsy (ABPE), Landau-Kleffner syndrome (LKS) and epileptic encephalopathy with continuous spike and waves during slow-wave sleep (CSWS). The genetic basis is largely unknown. We detected new heterozygous mutations in GRIN2A in 27 of 359 affected individuals from 2 independent cohorts with IFE (7.5%; P = 4.83 × 10(-18), Fisher's exact test). Mutations occurred significantly more frequently in the more severe phenotypes, with mutation detection rates ranging from 12/245 (4.9%) in individuals with BECTS to 9/51 (17.6%) in individuals with CSWS (P = 0.009, Cochran-Armitage test for trend). In addition, exon-disrupting microdeletions were found in 3 of 286 individuals (1.0%; P = 0.004, Fisher's exact test). These results establish alterations of the gene encoding the NMDA receptor NR2A subunit as a major genetic risk factor for IFE.

Everolimus in tuberous sclerosis patients with intractable epilepsy: a treatment option?

BACKGROUND: Tuberous Sclerosis Complex (TSC) is an often severe neurodevelopmental disorder caused by overactivation of the mTOR pathway due to mutations in either the TSC1 or TSC2 genes. Seizures are the primary cause of neurologic morbidity and often refractory. The mTOR inhibitor everolimus was recently approved for the treatment of giant cell astrocytomas and renal angiomyolipomas in TSC. Whether everolimus has any direct effect on epilepsy in TSC is not known. METHODS: Within the framework of a compassionate use trial, we evaluated the safety and efficacy of everolimus in seven patients with TSC and intractable epilepsy. We evaluated seizure frequency, seizure-free days and adverse effects including standard laboratory parameters. Seizure frequency was analysed in each patient using a non-parametric test for trend and using a Generalized Estimating Equations Model in the total patient group. The observation period was continued for nine months. RESULTS: One patient discontinued the medication at the beginning of the observation period due to side effects (flushing). In the remaining 6 patients, we observed a reduction of seizures in 4/6 patients with a reduction of 25-100%. In addition, the percentage of seizure-free days increased in 3/4 of these patients. In 2/6 patients, no alteration of seizure frequency was noted. We observed an increase of mild infections and an increase of triglycerides and various liver function tests. We did not encounter life-threatening infections or other side effects of everolimus. INTERPRETATION: In some patients with TSC, everolimus may have an anticonvulsant effect with a reduction in seizure frequency and increase of seizure-free days. Everolimus was well tolerated, with adverse effects similar to those reported in previous studies.

EEG-fMRI in atypical benign partial epilepsy.

Atypical benign partial epilepsy (ABPE) is a subgroup among the idiopathic focal epilepsies of childhood. Aim of this study was to investigate neuronal networks underlying ABPE and compare the results with previous electroencephalography (EEG)-functional magnetic resonance imaging (fMRI) studies of related epilepsy syndromes. Ten patients with ABPE underwent simultaneous EEG-fMRI recording. In all 10 patients several types of interictal epileptiform discharges (IEDs) were recorded. Individual IED-associated blood oxygen level-dependent (BOLD) signal changes were analyzed in a single subject analysis for each IED type (33 studies). A group analysis was also performed to determine common BOLD signal changes across the patients. IED-associated BOLD signal changes were found in 31 studies. Focal BOLD signal changes concordant with the spike field (21 studies) and distant cortical and subcortical BOLD signal changes (31 studies) were detected. The group analysis revealed a thalamic activation. This study demonstrated that ABPE is characterized by patterns similar to studies in rolandic epilepsy (focal BOLD signal changes in the spike field) as well as patterns observed in continuous spikes and waves during slow sleep (CSWS) (distant BOLD signal changes in cortical and subcortical structures), thereby underscoring that idiopathic focal epilepsies of childhood form a spectrum of overlapping syndromes.

Variability of EEG-fMRI findings in patients with SCN1A-positive Dravet syndrome.

PURPOSE: Dravet syndrome (DS) or severe myoclonic epilepsy of infancy is an intractable epileptic encephalopathy of early childhood that is caused by a mutation in the SCN1A gene in most patients. The aim of this study was to identify a syndrome-specific epileptic network underlying interictal epileptiform discharges (IEDs) in patients with DS. METHODS: Ten patients with the diagnosis of DS associated with mutations in the SCN1A gene were investigated using simultaneous recording of electroencephalography and functional magnetic resonance imaging ((EEG-fMRI). Time series of IEDs were used as regressors for the statistical fMRI analysis. KEY FINDINGS: In nine patients with DS, individual blood oxygenation level-dependent (BOLD) signal changes were seen. In three patients the thalamus was involved. Furthermore, regions of the default mode network were activated in seven patients. However, a common activation pattern associated with IEDs could not be detected. SIGNIFICANCE: The study demonstrates that, despite a common genetic etiology in DS, different neuronal networks underlie the individual IEDs.

Neuronal networks in west syndrome as revealed by source analysis and renormalized partial directed coherence.

West syndrome is a severe epileptic encephalopathy of infancy with a poor developmental outcome. This syndrome is associated with the pathognomonic EEG feature of hypsarrhythmia. The aim of the study was to describe neuronal networks underlying hypsarrhythmia using the source analysis method (dynamic imaging of coherent sources or DICS) which represents an inverse solution algorithm in the frequency domain. In order to investigate the interaction within the detected network, a renormalized partial directed coherence (RPDC) method was also applied as a measure of the directionality of information flow between the source signals. Both DICS and RPDC were performed for EEG delta activity (1-4 Hz) in eight patients with West syndrome and in eight patients with partial epilepsies (control group). The brain area with the strongest power in the given frequency range was defined as the reference region. The coherence between this reference region and the entire brain was computed using DICS. After that, the RPDC was applied to the source signals estimated by DICS. The results of electrical source imaging were compared to results of a previous EEG-fMRI study which had been carried out using the same cohort of patients. As revealed by DICS, delta activity in hypsarrhythmia was associated with coherent sources in the occipital cortex (main source) as well as the parietal cortex, putamen, caudate nucleus and brainstem. In patients with partial epilepsies, delta activity could be attributed to sources in the occipital, parietal and sensory-motor cortex. In West syndrome, RPDC showed the strongest and most significant direction of ascending information flow from the brainstem towards the putamen and cerebral cortex. The neuronal network underlying hypsarrhythmia in this study resembles the network which was described in previous EEG-fMRI and PET studies with involvement of the brainstem, putamen and cortical regions in the generation of hypsarrhythmia. The RPDC suggests that brainstem could have a key role in the pathogenesis of West syndrome. This study supports the theory that hypsarrhythmia results from ascending brainstem pathways that project widely to basal ganglia and cerebral cortex.

CDKL5 mutations as a cause of severe epilepsy in infancy: clinical and electroencephalographic long-term course in 4 patients.

CDKL5 mutations cause severe epilepsy in infancy with subsequent epileptic encephalopathy. As yet, few studies report on long-term observations in patients with CDKL5-related epileptic encephalopathy. In this study, we describe the evolution of the epilepsy phenotype and the electroencephalographic (EEG) features in 4 patients during a maximum observation period of 22 years. All 4 patients had epilepsy starting with focal seizures in the first 3 months of life, evolving to epileptic spasms between the ages of 2 and 6 years and later on to tonic seizures. In 3 patients, epilepsy was resistant to antiepileptic therapy. Although there was no common EEG pattern in all patients, late hypsarrhythmia until the age of 9 years was observed in 2 patients. CDKL5-related epileptic encephalopathies are a group of refractory seizure disorders starting in early infancy. The phenomenon of late hypsarrhythmia may help define a subgroup of patients with severe and adverse outcomes.

Myoclonic astatic epilepsy (Doose syndrome) - a lamotrigine responsive epilepsy?

PURPOSE: Myoclonic astatic epilepsy (MAE, Doose syndrome) is a difficult to treat idiopathic generalized epilepsy of early childhood. MAE frequently shows the course of an epileptic encephalopathy and may result in permanent cognitive impairment. Systematic analyses on clinical effects of different AED combinations are still needed. The purpose of our study was to analyze the therapeutic effect of adjunctive lamotrigine (LTG) in pharmacoresistant MAE patients. PATIENTS AND METHODS: In an exploratory, retrospective study, 10 pharmacoresistant MAE patients were included who had been admitted to the Northern German Epilepsy Center between 07/2007 and 12/2010 and had been treated with LTG. Documentation was performed with the electronic seizure diary Epivista. A total observation period of 32 weeks was defined: 8-week 'pre LTG treatment phase' (before starting with LTG), 16-week 'titration phase' (starting with very low LTG doses), 8-week 'follow-up phase'. Seizure frequency, medication and adverse events were extracted from the electronic diary and evaluated in each particular patient. The individual reduction of seizure frequency per day was defined as primary outcome variable. Additionally, a dose-effect-relationship was analyzed for each patient. RESULTS: Six out of ten patients were seizure free during the follow-up phase. Statistical analysis indicated a significant seizure reduction in seven patients at follow-up compared to the pre LTG treatment phase. Seizure frequency did not significantly decrease in two patients and increased in one patient. A significant relationship between seizure frequency per day and LTG dosage during titration and follow-up phase could be demonstrated in nine patients. Group statistics using the exact Wilcoxon test revealed a significant reduction in seizure frequency (p = 0.049, two-sided). CONCLUSION: Our data provide evidence that adjunctive LTG is an eligible therapeutic option for the treatment of pharmacoresistant MAE and encourage further prospective studies to verify this observation.

Concentrations of stiripentol in children and adults with epilepsy: the influence of dose, age, and comedication.

BACKGROUND: Stiripentol (STP) was approved as an orphan drug in 2007 in Europe as adjunctive therapy with valproic acid (VPA) and clobazam (CLB) for Dravet syndrome. Dravet syndrome is a highly pharmacoresistant form of epilepsy, which starts in early childhood. Data about STP pharmacokinetics and interactions are still limited and in part inconsistent. The aim of our study was to analyze the effect of age, gender, daily STP dose per body weight (milligrams per kilogram), VPA, CLB, and enzyme-inducing antiepileptic drugs on STP concentration-to-dose ratio (CDR), STP clearance, and STP trough concentrations. METHODS: Retrospectively, 220 STP serum concentrations in 75 patients from 3 German Epilepsy Centers were analyzed. Analysis of variance, regression analysis, and generalized estimating equations were used for statistical analysis. RESULTS: Our findings confirm the nonlinear STP pharmacokinetics. At steady state, STP CDR increased with daily STP doses. Compared with patients older than 12 years, STP concentrations were decreased by 39.6% in children aged 6-12 years (P < 0.001) and by 57.5% in children younger than 6 years (P < 0.001). Phenobarbital and phenytoin decreased STP concentrations by 63.2%. This effect was highly significant (P < 0.001), despite the small number of patients (n = 7) treated with phenobarbital or phenytoin. VPA had no significant effect on STP serum concentrations, whereas STP serum concentrations were moderately but significantly increased by CLB (24.6%, P = 0.011). CONCLUSIONS: Therapeutic drug monitoring of STP seems to be useful because of the wide variation of STP CDR, the nonlinear concentration-to-dose relationship, age-dependent pharmacokinetics, and drug-drug interactions.

Beneficial prenatal levodopa therapy in autosomal recessive guanosine triphosphate cyclohydrolase 1 deficiency.

OBJECTIVE: To report the first prenatal dopaminergic replacement therapy in autosomal recessive (AR) guanosine triphosphate cyclohydrolase 1 (GTPCH) deficiency without hyperphenylalaninemia. DESIGN: Case reports, literature review, and video presentation. SETTING: University of Lübeck, Lübeck, Germany. PATIENTS: Two boys from a consanguineous family. MAIN OUTCOME MEASURES: Physical and mental development as a function of replacement initiation. RESULTS: The older sibling presented with typical features of AR GTPCH deficiency due to a homozygous mutation in the GCH1 gene with proven pathogenicity. Levodopa treatment was initiated at age 10 months and resulted in a distinct motor improvement. However, mental development was delayed. In the younger sibling, prenatal replacement therapy was initiated after a prenatal diagnosis of AR GTPCH deficiency was made. At age 17 months, both motor and mental development were normal for his age. CONCLUSIONS: This report highlights the importance of an early diagnosis, including prenatal diagnosis, of complex dopa-responsive extrapyramidal syndromes. Prenatally initiated dopaminergic replacement therapy is beneficial and thus justified in AR GTPCH deficiency, allowing prevention of significant impairment of mental abilities.

Improving sensitivity of EEG-fMRI studies in epilepsy: the role of sleep-specific activity.

Using simultaneous recordings of EEG and functional MRI (EEG-fMRI) in patients with focal epilepsy, recent studies have revealed insufficient sensitivity and a lack of correspondence between epileptic EEG foci and activation patterns in some patients. In this study of children with focal epilepsy, we explore whether sleep-specific activity (sleep spindles, k-complexes and vertex sharp waves) may increase the sensitivity of EEG-fMRI of interictal epileptiform discharges (IED). When considering the sleep-specific activity in a statistical model, it was possible to increase the statistical significance of the activated voxels inside of the expected source of the IED and to reduce the number of activated voxels outside of it. According to this study, it could be worthwhile to include sleep-specific activity into the model by analyzing EEG-fMRI data in epilepsy.