Improving BOLD sensitivity with real-time multi-echo echo-planar imaging - Towards a cleaner neurofeedback signal

Real-time functional magnetic resonance imaging (rtfMRI) suffers from known issues related to T2*-weighted single-echo echo-planar imaging (EPI). These include image dropout in areas with increased local magnetic susceptibility susceptibility gradients; suboptimal whole-brain blood oxygen level-dependent (BOLD) contrast due to average T2*-weighting; and confounders like subject motion and physiology. During fMRI neurofeedback a metric calculated from real-time brain activity is presented visually to the subject in the scanner. To prevent sham feedback, new methods should focus on improving BOLD signal quality in real-time. In this work, presented as a poster at the 11th annual meeting of the ISMRM Benelux chapter (17 January 2019), we present our work on real-time multi-echo fMRI and its usefulness in increasing the temporal signal-to-noise ratio (tSNR) of rtfMRI

Sudden unexpected death in epilepsy patients: Risk factors A systematic review

SummaryIntroductionSeveral risk factors for sudden unexplained death in epilepsy patients (SUDEP) have been proposed, but subsequent work has yielded conflicting data. The relative importance of various risk factors for SUDEP was never explored. The aim of this study is to review systematically risk factors for SUDEP and also to determine their relevance for SUDEP by calculating relative risk factor ratios.Methods and materialsAuthors performed a literature-search on “SUDEP” in Medline, the Cochrane Library and EMBASE. Studies with unknown number of SUDEP cases or with less than five SUDEP cases and reviews were excluded from further analysis. The value of each paper was assessed, based on the quality of the study and the reliability of the diagnosis of SUDEP. This value ranged from 1 (low quality) to 10 (high quality). Papers with a value below 7 were eliminated for further analysis. For each analysed factor, a risk factor ratio was determined, with a higher ratio for a stronger risk factor.ResultsA number of strong risk factors for SUDEP: young age, early onset of seizures, the presence of generalized tonic clonic seizures, male sex and being in bed. Weak risk factors for SUDEP: prone position, one or more subtherapeutic bloodlevels, being in the bedroom, a strucural brain lesion and sleeping.ConclusionsIn this study, authors have designed a quality scale to select papers. The relative importance of risk factors for SUDEP is demonstrated

Classification of intellectual disability according to domains of adaptive functioning and between-domains discrepancy in adults with epilepsy

Background In the Diagnostic and Statistical Manual of Mental Disorders-Fifth edition (DSM-5), the diagnostic criteria of intellectual disability (ID) include three domains of adaptive deficits: the conceptual, social and practical. Substantial intra-individual differences between domains can be considered an ID domain discrepancy. Method We explored the associations between ID domains, discrepancies and epilepsy in 189 adults (mean age = 47.9; SD = 15.6). Each DSM-5 ID domain was assessed separately, using subscales of the Vineland II for the social and practical domains, and psychological instruments, including intelligence tests, for the conceptual domain. A set of standardised criteria is proposed to identify an ID domain discrepancy. Results An ID domain discrepancy seemed to be present in about one-third of subjects and was particularly present in subjects with moderate ID (53.4%). Impairment in the social domain was most often the reason for the discrepancy. The presence of a discrepancy was significantly related to a focal (localised) epilepsy type (OR = 2.3, P = .028) and a mixed seizure type (OR = 1.4, P = .009). Epilepsy characteristics that are indicative of a more severe and refractory epilepsy, including various seizure types, a high seizure frequency, a combined epilepsy type (both focal and generalised epilepsy) and an early age at onset, were significantly related to more severe impairments in conceptual, social and practical adaptive behaviour (all P values <.01). Conclusions With a substantial proportion of the subjects who had both ID and epilepsy with an ID discrepancy, professionals should be aware of this and take all domains of ID into account when studying or working with this vulnerable population

Working memory deficits in high-functioning adolescents with autism spectrum disorders: neurpsychological and neuroimaging correlates

Working memory is a temporary storage system under attentional control. It is believed to play a central role in online processing of complex cognitive information and may also play a role in social cognition and interpersonal interactions. Adolescents with a disorder on the autism spectrum display problems in precisely these domains. Social impairments, communication difficulties, and repetitive interests and activities are core domains of autism spectrum disorders (ASD), and executive function problems are often seen throughout the spectrum. As the main cognitive theories of ASD, including the theory of mind deficit hypotheses, weak central coherence account, and the executive dysfunction theory, still fail to explain the broad spectrum of symptoms, a new perspective on the etiology of ASD is needed. Deficits in working memory are central to many theories of psychopathology, and are generally linked to frontal-lobe dysfunction. This article will review neuropsychological and (functional) brain imaging studies on working memory in adolescents with ASD. Although still disputed, it is concluded that within the working memory system specific problems of spatial working memory are often seen in adolescents with ASD. These problems increase when information is more complex and greater demands on working memory are made. Neuroimaging studies indicate a more global working memory processing or connectivity deficiency, rather than a focused deficit in the prefrontal cortex. More research is needed to relate these working memory difficulties and neuroimaging results in ASD to the behavioral difficulties as seen in individuals with a disorder on the autism spectru

Encoding order and developmental dyslexia:a family of skills predicting different orthographic components

We investigated order encoding in developmental dyslexia using a task that presented nonalphanumeric visual characters either simultaneously or sequentially—to tap spatial and temporal order encoding, respectively—and asked participants to reproduce their order. Dyslexic participants performed poorly in the sequential condition, but normally in the simultaneous condition, except for positions most susceptible to interference. These results are novel in demonstrating a selective difficulty with temporal order encoding in a dyslexic group. We also tested the associations between our order reconstruction tasks and: (a) lexical learning and phonological tasks; and (b) different reading and spelling tasks. Correlations were extensive when the whole group of participants was considered together. When dyslexics and controls were considered separately, different patterns of association emerged between orthographic tasks on the one side and tasks tapping order encoding, phonological processing, and written learning on the other. These results indicate that different skills support different aspects of orthographic processing and are impaired to different degrees in individuals with dyslexia. Therefore, developmental dyslexia is not caused by a single impairment, but by a family of deficits loosely related to difficulties with order. Understanding the contribution of these different deficits will be crucial to deepen our understanding of this disorder

Parent-completed scales for measuring seizure severity and severity of side-effects of antiepileptic drugs in childhood epilepsy: development and psychometric analysis.

We have developed two outcome measures for childhood epilepsy: a seizure severity (SS) scale and a side-effects (SE) scale. Both scales have been designed for completion by parents. The scales were tested in two pilot phases and the results of this stepwise analysis are described here. The final scales' psychometric properties were assessed in a group of 80 children with active epilepsy, representative of the population at whom the scales were aimed: children with chronic epilepsy, aged 4-16 years, including all seizure types and epilepsies, as well as children with neurological comorbidity. The SS scale and SE scale showed good internal consistency and test-retest stability. Although there was a significant positive correlation between the SS scale and the SE scale, this was low, indicating that the scales measure a different clinical trait. The SE scale consisted of two subscales: a Toxic subscale, measuring the severity of dose-related side-effects, and a Chronic subscale, measuring the severity of long-term behavioural and cognitive side-effects. These subscales for side-effects showed a high correlation and can be used as a joint scale. These scales have the potential to improve outcome assessment in childhood epilepsy and they can be used to assess important aspects of quality of life in this population

Kinderen met epileptiforme afwijkingen op het EEG: zelfs die behoeven aandacht

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