Focal application of accelerated iTBS results in global changes in graph measures.

Graph analysis was used to study the effects of accelerated intermittent theta burst stimulation (aiTBS) on the brain's network topology in medication-resistant depressed patients. Anatomical and resting-state functional MRI (rs-fMRI) was recorded at baseline and after sham and verum stimulation. Depression severity was assessed using the Hamilton Depression Rating Scale (HDRS). Using various graph measures, the different effects of sham and verum aiTBS were calculated. It was also investigated whether changes in graph measures were correlated to clinical responses. Furthermore, by correlating baseline graph measures with the changes in HDRS in terms of percentage, the potential of graph measures as biomarker was studied. Although no differences were observed between the effects of verum and sham stimulation on whole-brain graph measures and changes in graph measures did not correlate with clinical response, the baseline values of clustering coefficient and global efficiency showed to be predictive of the clinical response to verum aiTBS. Nodal effects were found throughout the whole brain. The distribution of these effects could not be linked to the strength of the functional connectivity between the stimulation site and the node. This study showed that the effects of aiTBS on graph measures distribute beyond the actual stimulation site. However, additional research into the complex interactions between different areas in the brain is necessary to understand the effects of aiTBS in more detail.

Skills for Growing Up-Epilepsy: An exploratory mixed methods study into a communication tool to promote autonomy and empowerment of youth with epilepsy.

INTRODUCTION: The consequences of having epilepsy seriously hamper the development of autonomy for youth with epilepsy (YWE) and limit their social participation. This study was designed to provide insight into the impact of epilepsy on autonomy and empowerment and to evaluate the use of the Skills for Growing Up (SGU-Epilepsy) communication tool in pediatric epileptic care. METHODS: A mixed methods design was used to examine the impact of epilepsy on autonomy and empowerment and to evaluate the feasibility and use of the SGU-Epilepsy. Six focus groups with YWE and their parents were organized (N = 27), and the benefits of the SGU-Epilepsy were evaluated (N = 72). RESULTS: Youth with epilepsy struggled with social participation. Beliefs of YWE and their parents on managing daily life and taking medication were not always similar. Parents worried about the passive attitude of YWE, but autonomy of YWE seemed to be constrained by parents. The SGU-Epilepsy seemed to be feasible. It facilitated the communication on development and empowerment although it was sometimes confronting for parents. Not all YWE were motivated to use and discuss the tool. In the evaluation, no differences in perceived autonomy and empowerment between YWE who used SGU-Epilepsy and received usual care appeared. CONCLUSION: On the short-term, a beneficial effect of using the SGU-Epilepsy on autonomy and empowerment for YWE and their parents was not shown. The SGU-Epilepsy seemed to be a feasible instrument, however, to address nonmedical issues during pediatric consultations.

Chronic antiepileptic drug use and functional network efficiency: A functional magnetic resonance imaging study.

AIM: To increase our insight in the neuronal mechanisms underlying cognitive side-effects of antiepileptic drug (AED) treatment. METHODS: The relation between functional magnetic resonance-acquired brain network measures, AED use, and cognitive function was investigated. Three groups of patients with epilepsy with a different risk profile for developing cognitive side effects were included: A "low risk" category (lamotrigine or levetiracetam, n = 16), an "intermediate risk" category (carbamazepine, oxcarbazepine, phenytoin, or valproate, n = 34) and a "high risk" category (topiramate, n = 5). Brain connectivity was assessed using resting state functional magnetic resonance imaging and graph theoretical network analysis. The Computerized Visual Searching Task was used to measure central information processing speed, a common cognitive side effect of AED treatment. RESULTS: Central information processing speed was lower in patients taking AEDs from the intermediate and high risk categories, compared with patients from the low risk category. The effect of risk category on global efficiency was significant (P < 0.05, ANCOVA), with a significantly higher global efficiency for patient from the low category compared with the high risk category (P < 0.05, post-hoc test). Risk category had no significant effect on the clustering coefficient (ANCOVA, P > 0.2). Also no significant associations between information processing speed and global efficiency or the clustering coefficient (linear regression analysis, P > 0.15) were observed. CONCLUSION: Only the four patients taking topiramate show aberrant network measures, suggesting that alterations in functional brain network organization may be only subtle and measureable in patients with more severe cognitive side effects.

Wavelet entropy of BOLD time series: An application to Rolandic epilepsy.

PURPOSE: To assess the wavelet entropy for the characterization of intrinsic aberrant temporal irregularities in the time series of resting-state blood-oxygen-level-dependent (BOLD) signal fluctuations. Further, to evaluate the temporal irregularities (disorder/order) on a voxel-by-voxel basis in the brains of children with Rolandic epilepsy. MATERIALS AND METHODS: The BOLD time series was decomposed using the discrete wavelet transform and the wavelet entropy was calculated. Using a model time series consisting of multiple harmonics and nonstationary components, the wavelet entropy was compared with Shannon and spectral (Fourier-based) entropy. As an application, the wavelet entropy in 22 children with Rolandic epilepsy was compared to 22 age-matched healthy controls. The images were obtained by performing resting-state functional magnetic resonance imaging (fMRI) using a 3T system, an 8-element receive-only head coil, and an echo planar imaging pulse sequence ( T2*-weighted). The wavelet entropy was also compared to spectral entropy, regional homogeneity, and Shannon entropy. RESULTS: Wavelet entropy was found to identify the nonstationary components of the model time series. In Rolandic epilepsy patients, a significantly elevated wavelet entropy was observed relative to controls for the whole cerebrum (P = 0.03). Spectral entropy (P = 0.41), regional homogeneity (P = 0.52), and Shannon entropy (P = 0.32) did not reveal significant differences. CONCLUSION: The wavelet entropy measure appeared more sensitive to detect abnormalities in cerebral fluctuations represented by nonstationary effects in the BOLD time series than more conventional measures. This effect was observed in the model time series as well as in Rolandic epilepsy. These observations suggest that the brains of children with Rolandic epilepsy exhibit stronger nonstationary temporal signal fluctuations than controls. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2017;46:1728-1737.

Abnormal Profiles of Local Functional Connectivity Proximal to Focal Cortical Dysplasias.

INTRODUCTION: Focal cortical dysplasia (FCD) is a congenital malformation of cortical development that often leads to medically refractory epilepsy. Focal resection can be an effective treatment, but is challenging as the surgically relevant abnormality may exceed the MR-visible lesion. The aim of the current study is to develop methodology to characterize the profile of functional connectivity around FCDs using resting-state functional MRI and in the individual patient. The detection of aberrant connectivity may provide a means to more completely delineate the clinically relevant lesion. MATERIALS AND METHODS: Fifteen FCD patients (age, mean±SD: 31±11 years; 11 males) and 16 matched healthy controls (35±9 years; 7 males) underwent structural and functional imaging at 3 Tesla. The cortical surface was reconstructed from the T1-weighted scan and the registered functional MRI data was spatially normalized to a common anatomical standard space employing the gyral pattern. Seed-based functional connectivity was determined in all subjects for all dysplasia locations. A single patient was excluded based on an aberrant FCD seed time series. Functional connectivity as a function of geodesic distance (along the cortical surface) was compared between the individual patients and the homotopic normative connectivity profiles derived from the controls. RESULTS: In 12/14 patients, aberrant profiles of functional connectivity were found, which demonstrated both hyper- and hypoconnectivity as well as combinations. Abnormal functional connectivity was typically found (also) beyond the lesion visible on structural MRI, while functional connectivity profiles not related to a lesion appeared normal in patients. CONCLUSION: This novel functional MRI technique has potential for delineating functionally aberrant from normal cortex beyond the structural lesion in FCD, which remains to be confirmed in future research.

Glutamate concentrations vary with antiepileptic drug use and mental slowing.

OBJECTIVE: Although antiepileptic drugs (AEDs) are effective in suppressing epileptic seizures, they also induce (cognitive) side effects, with mental slowing as a general effect. This study aimed to assess whether concentrations of MR detectable neurotransmitters, glutamate and GABA, are associated with mental slowing in patients with epilepsy taking AEDs. METHODS: Cross-sectional data were collected from patients with localization-related epilepsy using a variety of AEDs from three risk categories, i.e., AEDs with low, intermediate, and high risks of developing cognitive problems. Patients underwent 3T MR spectroscopy, including a PRESS (n=55) and MEGA-PRESS (n=43) sequence, to estimate occipital glutamate and GABA concentrations, respectively. The association was calculated between neurotransmitter concentrations and central information processing speed, which was measured using the Computerized Visual Searching Task (CVST) and compared between the different risk categories. RESULTS: Combining all groups, patients with lower processing speeds had lower glutamate concentrations. Patients in the high-risk category had a lower glutamate concentration and lower processing speed compared with patients taking low-risk AEDs. Patients taking intermediate-risk AEDs also had a lower glutamate concentration compared with patients taking low-risk AEDs, but processing speed did not differ significantly between those groups. No associations were found between the GABA concentration and risk category or processing speed. CONCLUSIONS: For the first time, a relation is shown between glutamate concentration and both mental slowing and AED use. It is suggested that the reduced excitatory action, reflected by lowered glutamate concentrations, may have contributed to the slowing of information processing in patients using AEDs with higher risks of cognitive side effects.

The Cognitive Profile of Ethosuximide in Children.

INTRODUCTION: Although ethosuximide is one of the oldest antiepileptic drugs (AEDs), little information is available about the cognitive side effects of ethosuximide. OBJECTIVE: The aim of this study was to investigate the cognitive profile of ethosuximide. METHODS: In this cross-sectional study, we used an extensive neuropsychological test battery in patients with epilepsy aged 6-16 years who were treated with monotherapy ethosuximide. We evaluated the efficacy of the drug by seizure frequency (seizure free or not). RESULTS: We included 61 patients with a mean age of 9.4 years [standard deviation (SD) 2.7] who used on average 686 mg/day (SD 245) ESM as monotherapy. ESM was effective in the majority of the patients (70 % were seizure free for at least 6 months at moment of inclusion). The total study population showed impairments of intelligence, visuomotor, and attentional function including activation/alertness. Comparisons between the well-controlled patients and patients who were not in remission showed significantly lower intelligence values and lower performance on the visual-perceptual and attentional tasks for the group with ongoing seizures. Our results suggested that the higher order cognitive dysfunctions (such as intelligence and visual-perceptual functions) may be regarded as seizure or aetiology effects and that the impaired fluid cognitive functions, such as activation/alertness, sustained auditory attention and attentional control or switching, were due to ESM. CONCLUSION: This study suggests the attentional dysfunction resulting in psychomotor slowing and alertness deficits may be regarded as effects of ethosuximide. Although no untreated baseline assessment was available, these effects are comparable to those of other AEDs, and ethosuximide may therefore be considered an AED with only mild effects on cognition. As ethosuximide is a first-line therapy for absence seizures in childhood, and drug-induced cognitive impairment may interfere with development, learning, and academic achievement, these findings are of interest to clinicians who prescribe this drug, especially when informing parents.

Delayed convergence between brain network structure and function in rolandic epilepsy.

INTRODUCTION: Rolandic epilepsy (RE) manifests during a critical phase of brain development, and has been associated with language impairments. Concordant abnormalities in structural and functional connectivity (SC and FC) have been described before. As SC and FC are under mutual influence, the current study investigates abnormalities in the SC-FC synergy in RE. METHODS: Twenty-two children with RE (age, mean ± SD: 11.3 ± 2.0 y) and 22 healthy controls (age 10.5 ± 1.6 y) underwent structural, diffusion weighted, and resting-state functional magnetic resonance imaging (MRI) at 3T. The probabilistic anatomical landmarks atlas was used to parcellate the (sub)cortical gray matter. Constrained spherical deconvolution tractography and correlation of time series were used to assess SC and FC, respectively. The SC-FC correlation was assessed as a function of age for the non-zero structural connections over a range of sparsity values (0.01-0.75). A modularity analysis was performed on the mean SC network of the controls to localize potential global effects to subnetworks. SC and FC were also assessed separately using graph analysis. RESULTS: The SC-FC correlation was significantly reduced in children with RE compared to healthy controls, especially for the youngest participants. This effect was most pronounced in a left and a right centro-temporal network, as well as in a medial parietal network. Graph analysis revealed no prominent abnormalities in SC or FC network organization. CONCLUSION: Since SC and FC converge during normal maturation, our finding of reduced SC-FC correlation illustrates impaired synergy between brain structure and function. More specifically, since this effect was most pronounced in the youngest participants, RE may represent a developmental disorder of delayed brain network maturation. The observed effects seem especially attributable to medial parietal connections, which forms an intermediate between bilateral centro-temporal modules of epileptiform activity, and bear relevance for language function.

Behavioral side-effects of levetiracetam in children with epilepsy: a systematic review.

PURPOSE: Children with epilepsy are more likely to have behavioral problems compared to children without epilepsy. Literature suggests that levetiracetam leads to behavioral side-effects in children with epilepsy. The objective of this study is to provide a better overview of the frequency and variety of behavioral side-effects, which can be initiated by levetiracetam therapy in children with epilepsy. METHOD: Electronic databases used in the search were PubMed, Medline, Cochrane and Embase. Studies were eligible for inclusion when they included children from one month to 18 years of age with a diagnosis of epilepsy, used levetiracetam, had other AEDs on a stable regimen for at least two months, reported about behavioral side-effects and had a follow-up of at least two weeks. Quality assessments and data collection were carried out for all eligible studies. RESULTS: Thirteen studies, including 727 patients using levetiracetam, were included in this systematic review. Three randomized controlled trials showed a total of 62 behavioral side-effects in 203 patients, effects which led to discontinuation of levetiracetam in only two of 102 patients (2.0%). Hostility, nervousness and aggression were reported mostly. Meta-analysis showed a statistically significant relative risk of 2.18 for the total number of behavioral side-effects for levetiracetam versus placebo. Observational studies showed mixed results with both behavioral deteriorations and improvements following levetiracetam. CONCLUSION: Based on the findings in this systematic review, children using levetiracetam have a risk of developing several behavioral side-effects such as aggression, hostility and nervousness compared to children who do not use levetiracetam.

Aberrant functional connectivity between motor and language networks in rolandic epilepsy.

INTRODUCTION: Rolandic epilepsy (RE) is an idiopathic focal childhood epilepsy with a well-established neuropsychological profile of language impairment. The aim of this study is to provide a functional correlate that links rolandic (sensorimotor) pathology to language problems using functional MRI. MATERIALS AND METHODS: Twenty-three children with RE (8-14 years old) and 21 matched controls underwent extensive language assessment (Clinical Evaluation of Language Fundamentals). fMRI was performed at rest and using word generation, reading, and finger tapping paradigms. Since no activation group differences were found, regions of interest (ROIs) were defined at pooled (patients and controls combined) activation maxima and in contralateral homotopic cortex, and used to assess language lateralization as well as for a resting-state connectivity analysis. Furthermore, the association between connection strength and language performance was investigated. RESULTS: Reduced language performance was found in the children with RE. Bilateral activation was found for both language tasks with some predominance of the left hemisphere in both groups. Compared to controls, patient connectivity was decreased between the left sensorimotor area and right inferior frontal gyrus (p<0.01). For this connection, lower connectivity was associated with lower language scores in the patient group (r=0.49, p=0.02), but not in the controls. CONCLUSION: Language laterality analysis revealed bilateral language representation in the age range under study (8-14 years). As a consequence, the connection of reduced functional connectivity we found represents an impaired interplay between motor and language networks, and aberrant functional connectivity associated with poorer language performance. These findings provide a first neuronal correlate in terms of aberrant resting-state functional connectivity for language impairment in RE.

Visual Analogue Scale to score the effects of Botulinum Toxin A treatment in children with cerebral palsy in daily clinical practice.

OBJECTIVE: This study examined the reliability and efficiacy of the Visual Analogue Scale (VAS) in evaluating spasticity treatment in an outpatient setting. PATIENTS AND METHODS: We used a parent-reported VAS device for evaluating the effects of Botulinum Toxin A (BTX-A). Data were collected on 55 children with cerebral palsy. Individual goals of treatment were formulated in close consultation with the caregivers. The categories of treatment options were improvement of pain, problems with nursing, sitting position, standing and walking. RESULTS: Seventy-four interventions were performed in 55 children. A statistically significant effect was found for improvement of nursing, standing and walking. No statistically significant effect for pain was found, probably because of small numbers. In seven children there was no effect at all. Side effects were observed in five children. CONCLUSION: In using a VAS instrument, beneficial effects were found for nursing, standing and walking after BTX-A treatment. A positive (not significant) correlation was found between the VAS and the Modified Tardieu for those children who also underwent a gait analysis. Evaluating spasticity treatment with the use of the VAS has an important advantage because it is a quick and easy method for evaluating individually defined treatment goals in an outpatient setting, in which time-consuming evaluations are not an option.

Pulsed and continuous radiofrequency current adjacent to the cervical dorsal root ganglion of the rat induces late cellular activity in the dorsal horn.

BACKGROUND: Pulsed radiofrequency treatment has recently been described as a non-neurodestructive or minimally neurodestructive alternative to radiofrequency heat lesions. In clinical practice long-lasting results of pulsed radiofrequency treatment adjacent to the cervical dorsal root ganglion for the management of chronic radicular spinal pain have been reported without neurologic complications. However, the mode of action is unclear. An early (3 h) effect of pulsed radiofrequency as measured by an increase of c-Fos in the pain-processing neurons of the dorsal horn of rats has been described in the literature. This effect was not mediated by tissue heating. The authors investigated a possible late or long-term effect of three different radiofrequency modalities. METHODS: Cervical laminectomy was performed in 19 male Wistar rats. The cervical dorsal root ganglion was randomly exposed to one of the four interventions: sham, continuous radiofrequency current at 67 centigrades, or pulsed radiofrequency current for 120 s or 8 min. The animals were sacrificed and the spinal cord was prepared for c-Fos labeling 7 days after the intervention. RESULTS: The number of c-Fos immunoreactive cells in the dorsal horn was significantly increased in the three different radiofrequency modalities as compared with sham. No significant difference was demonstrated between the three active intervention groups. CONCLUSIONS: The authors demonstrated a late neuronal activity in the dorsal horn after exposure of the cervical dorsal root ganglion to different radiofrequency modalities, which was not temperature dependent.