Imaging of epileptic activity using EEG-correlated functional MRI.

This thesis describes the method of EEG-correlated fMRI and its application to patients with epilepsy. First, an introduction on MRI and functional imaging methods in the field of epilepsy is provided. Then, the present and future role of EEG-correlated fMRI in the investigation of the epilepsies is discussed. The fourth chapter reviews the important practicalities of EEG-correlated fMRI that were addressed in this project. These included patient safety, EEG quality and MRI artifacts during EEG-correlated fMRI. Technical solutions to enable safe, good quality EEG recordings inside the MR scanner are presented, including optimisation of the EEG recording techniques and algorithms for the on-line subtraction of pulse and image artifact. In chapter five, a study applying spike-triggered fMRI to patients with focal epilepsy (n = 24) is presented. Using statistical parametric mapping (SPM), cortical Blood Oxygen Level-Dependent (BOLD) activations corresponding to the presumed generators of the interictal epileptiform discharges (IED) were identified in twelve patients. The results were reproducible in repeated experiments in eight patients. In the remaining patients no significant activation (n = 10) was present or the activation did not correspond to the presumed epileptic focus (n = 2). The clinical implications of this finding are discussed. In a second study it was demonstrated that in selected patients, individual (as opposed to averaged) IED could also be associated with hemodynamic changes detectable with fMRI. Chapter six gives examples of combination of EEG-correlated fMRI with other modalities to obtain complementary information on interictal epileptiform activity and epileptic foci. One study compared spike-triggered fMRI activation maps with EEG source analysis based on 64-channel scalp EEG recordings of interictal spikes using co-registration of both modalities. In all but one patient, source analysis solutions were anatomically concordant with the BOLD activation. Further, the combination of spike- triggered fMRI with diffusion tensor and chemical shift imaging is demonstrated in a patient with localisation-related epilepsy. In chapter seven, applications of EEG-correlated fMRI in different areas of neuroscience are discussed. Finally, the initial imaging findings with the novel technique for the simultaneous and continuous acquisition of fMRI and EEG data are presented as an outlook to future applications of EEG-correlated fMRI. In conclusion, the technical problems of both EEG-triggered fMRI and simultaneous EEG-correlated fMRI are now largely solved. The method has proved useful to provide new insights into the generation of epileptiform activity and other pathological and physiological brain activity. Currently, its utility in clinical epileptology remains unknown

Coping with refractory epilepsy

AbstractWe investigated the coping behaviour and its correlation with demographic and illness-related data, depression, locus of control and psychosocial adaptation in 40 patients with intractable epilepsy with primarily or secondarily generalized tonic–clonic seizures. Three standardized self-reporting questionnaires were applied, which are the Freiburg Questionnaire of Coping with Illness (FKV), the von Zerssen Depression Scale (D-S), and the IPC-questionnaire measuring generalized locus of control beliefs; the Social Interview Schedule (SIS), a semi-structured interview, was used to measure the psychosocial adaptation. Active, problem-focused and compliance strategies were predominantly used and regarded as most helpful. Hence, the epileptic patients use similar coping patterns reported in patients with other non life-threatening chronic diseases. The level of depression was moderate and in the range of other chronic somatic diseases. The use of coping patterns, which are regarded as maladaptive, was correlated with distinct depression, a small degree of internal locus of control beliefs and poor psychosocial adaption. These results indicate the possibility to improve psychosocial adjustment by supporting effective strategies

Topiramate in add-on therapy: Results from an open-label, observational study

SummaryAn open-label, observational prospective study assessed the effectiveness of topiramate (TPM) as add-on therapy. A total of 450 patients aged 12 and above with a diagnosis of epilepsy and at least one epileptic seizure during the 12-week retrospective baseline were to be documented. After baseline evaluation, topiramate was added. Ninety-five percent of patients had at least one baseline AED, most commonly Carbamazepine (53%) or Valproate (34%). In 5% TPM was started in monotherapy. Topiramate dose titration and target dose was determined by clinical response and side effect profile. Patients were intended to be followed for a total of 1 year which included 6 visits during which seizure frequency, adverse events, weight as well as clinical global impression were recorded. During the 12 weeks retrospective baseline, a median of 2.8 seizures per month were recorded which reduced significantly to 0.7 per month during the complete treatment phase (p<0.0001). Seventy-two percent of patients had a ≥50% seizure reduction. Ten percent of patients were seizure free during the study. The most commonly reported adverse events were difficulties with memory (4.2%), somnolence (3.6%), and dizziness (2.7%). Overall, topiramate was well tolerated, and only 5% of patients discontinued treatment due to an adverse event. Retention in the study was higher than previously reported during randomized, dose controlled studies and is likely due to individualized doses as well as slower titration used

Free Energy Approach to the Formation of an Icosahedral Structure during the Freezing of Gold Nanoclusters

The freezing of metal nanoclusters such as gold, silver, and copper exhibits a novel structural evolution. The formation of the icosahedral (Ih) structure is dominant despite its energetic metastability. This important phenomenon, hitherto not understood, is studied by calculating free energies of gold nanoclusters. The structural transition barriers have been determined by using the umbrella sampling technique combined with molecular dynamics simulations. Our calculations show that the formation of Ih gold nanoclusters is attributed to the lower free energy barrier from the liquid to the Ih phases compared to the barrier from the liquid to the face-centered-cubic crystal phases

The Landscape of Connected Cancer Symptom Management in Rural America: A Narrative Review of Opportunities for Launching Connected Health Interventions

Background: The 2016 President’s Cancer Panel called for projects focusing on improving cancer symptom management using connected health technologies (broadband and telecommunications). However, rural communities, like those in Appalachia, may experience a “double burden” of high cancer rates and lower rates of broadband access and adoption necessary for connected health solutions. Purpose: To better understand the current landscape of connected health in the management of cancer symptoms in rural America. Methods: A literature search was conducted using four academic databases (PubMed, CINAHL, MEDLINE, and PsycINFO) to locate articles published from 2010 to 2019 relevant to connected cancer symptom management in rural America. Text screening was conducted to identify relevant publications. Results: Among 17 reviewed studies, four were conducted using a randomized controlled trial; the remainder were formative in design or small pilot projects. Five studies engaged stakeholders from rural communities in designing solutions. Most commonly studied symptoms were psychological/emotional symptoms, followed by physical symptoms, particularly pain. Technologies used were primarily telephone-based; few were Internet-enabled video conferencing or web-based. Advanced mobile and Internet-based approaches were generally in the development phase. Overall, both rural patients and healthcare providers reported high acceptance, usage, and satisfaction of connected health technologies. Ten of the 17 studies reported improved symptom management outcomes. Methodological challenges that limited the interpretation of the findings were summarized. Implications: The review identified a need to engage rural stakeholders to develop and test connected cancer symptom management solutions that are based on advanced mobile and broadband Internet technologies

Causal hierarchy within the thalamo-cortical network in spike and wave discharges

Background: Generalised spike wave (GSW) discharges are the electroencephalographic (EEG) hallmark of absence seizures, clinically characterised by a transitory interruption of ongoing activities and impaired consciousness, occurring during states of reduced awareness. Several theories have been proposed to explain the pathophysiology of GSW discharges and the role of thalamus and cortex as generators. In this work we extend the existing theories by hypothesizing a role for the precuneus, a brain region neglected in previous works on GSW generation but already known to be linked to consciousness and awareness. We analysed fMRI data using dynamic causal modelling (DCM) to investigate the effective connectivity between precuneus, thalamus and prefrontal cortex in patients with GSW discharges. Methodology and Principal Findings: We analysed fMRI data from seven patients affected by Idiopathic Generalized Epilepsy (IGE) with frequent GSW discharges and significant GSW-correlated haemodynamic signal changes in the thalamus, the prefrontal cortex and the precuneus. Using DCM we assessed their effective connectivity, i.e. which region drives another region. Three dynamic causal models were constructed: GSW was modelled as autonomous input to the thalamus (model A), ventromedial prefrontal cortex (model B), and precuneus (model C). Bayesian model comparison revealed Model C (GSW as autonomous input to precuneus), to be the best in 5 patients while model A prevailed in two cases. At the group level model C dominated and at the population-level the p value of model C was ∼1. Conclusion: Our results provide strong evidence that activity in the precuneus gates GSW discharges in the thalamo-(fronto) cortical network. This study is the first demonstration of a causal link between haemodynamic changes in the precuneus - an index of awareness - and the occurrence of pathological discharges in epilepsy. © 2009 Vaudano et al

Emotion dysregulation mediates the relationship between nightmares and psychotic experiences: Results from a student population

Sleep-disruption is commonly associated with psychotic experiences. Whilst sparse, the literature to date highlights nightmares and related distress as prominent risk factors for psychosis in students. We aimed to further explore the relationship between specific nightmare symptoms and psychotic experiences in university students whilst examining the mediating role of emotion dysregulation. A sample (N=1273) of student respondents from UK universities completed measures of psychotic experiences, nightmare disorder symptomology, and emotion dysregulation. Psychotic experiences were significantly more prevalent in students reporting nightmares (n=757) relative to those who did not (n=516). Hierarchical linear regression analysis showed that psychotic experiences were significantly associated (Adjusted R2 = 32.4%) with perceived nightmare intensity, consequences and resulting awakenings, and with emotion regulation difficulties. Furthermore, multiple mediation analysis showed that the association between psychotic experiences and nightmare factors was mediated by emotion regulation difficulties. Adaptive regulation of dream content during rapid eye-movement sleep has previously been demonstrated to attenuate surges in affective arousal by controlling the intensity and variability of emotional content. Difficulties in emotion regulation may partially explain the experience of more intense and disruptive nightmares amongst individuals with psychotic experiences. Emotion regulation may represent an important control mechanism that safeguards dream content and sleep quality

Ciliary Abnormalities Due to Defects in the Retrograde Transport Protein DYNC2H1 in Short-Rib Polydactyly Syndrome

The short-rib polydactyly (SRP) syndromes are a heterogenous group of perinatal lethal skeletal disorders with polydactyly and multisystem organ abnormalities. Homozygosity by descent mapping in a consanguineous SRP family identified a genomic region that contained DYNC2H1, a cytoplasmic dynein involved in retrograde transport in the cilium. Affected individuals in the family were homozygous for an exon 12 missense mutation that predicted the amino acid substitution R587C. Compound heterozygosity for one missense and one null mutation was identified in two additional nonconsanguineous SRP families. Cultured chondrocytes from affected individuals showed morphologically abnormal, shortened cilia. In addition, the chondrocytes showed abnormal cytoskeletal microtubule architecture, implicating an altered microtubule network as part of the disease process. These findings establish SRP as a cilia disorder and demonstrate that DYNC2H1 is essential for skeletogenesis and growth