Abstracts / Clinical Neurophysiology 128 (2017) e178–e303
O28 Advanced dynamic statistical parametric mapping (ADSPM) for focal cortical dysplasia at bottom of sulcus—Midori Nakajima, Hiroshi Otsubo (The Hospital for Sick Children, Department of Neurology, Toronto, Canada) Objective: To investigate whether our new technique of AdSPM for MEG could demonstrate epileptogenic focal cortical dysplasia at bottom of sulcus (FCDB). Methods: We analyzed 15 children (9 males; mean, 8.8 years) with FCDB, 3T MRI, scalp video EEG, and MEG. We compared spatial congruence between (1) FCDB and MEG cluster of single moving dipoles (SMD), (2) FCDB and spike volume in AdSPM. In SMD, we defined ‘‘Hit” when cluster overlapped FCDB. We defined ‘‘No hit” when cluster was remote from FCDB or when there was only scatter. In AdSPM, we analyzed each 100 ms segment around MEG spike dipole. We summated dSPM to estimate the source activity. The area with highest threshold was defined as spike volume location. We defined ‘‘Hit” when spike volume located in FCDB. Results: 12 children were diagnosed as FCD typeII in surgical specimen and the other 3 children were diagnosed as FCD type II on MRI. AdSPM hit FCDB in 12 of 15 children (80%) whereas MEG cluster hit 6 (33%). The detection ratio of FCDB was significantly higher in AdSPM than that of SMD (p = 0.03). Spike volume location was concordant within seizure onset zone in 9 (81%) of 11 children who underwent IVEEG. All 11 children with respective surgery and available follow-up achieved seizure freedom. Ten (90%) of the 11 children had spike volume in the resection area. Discussion: AdSPM estimates spike source of epileptogenic FCDB. Conclusion: AdSPM hit epileptogenic FCDB. Significance: AdSPM noninvasively and neurophysiologically demonstrates epileptogenic FCDB. Keywords: AdSPM, Focal cortical dysplasia at bottom of sulcus doi:10.1016/j.clinph.2017.07.039
O29 EEG criteria of non-convulsive status epilepticus—Sándor Beniczky (Danish Epilepsy Centre, Aarhus University, Aarhus, Denmark) Objectives: A panel of experts, in 2013, at the 4th Colloquium on Status Epilepticus in Salzburg, proposed a set of EEG criteria for nonconvulsive status epilepticus (NCSE), known as the Salzburg-criteria for NCSE. The objective was to validate these criteria. Methods: We did a diagnostic study where two raters blinded to all other patient data analysed EEG recordings from participants admitted three centres (n = 220). Participants were placed into one of two groups: the clinical validation group which consisted of consecutive patients with clinical suspicion of NCSE referred to EEG recording (n = 120), or the control group which consisted of consecutive patients with abnormal EEG-findings, but without clinical suspicion of NCSE (n = 100). The reference standard was inferred from all clinical and para-clinical data, therapeutic response, and final outcome, as evaluated by two raters who were blinded to diagnosis according to the Salzburg-criteria. Results: In the clinical validation group, sensitivity was 97.7% and specificity was 89.6% (overall accuracy: 92.5%). In the control group, specificity was 97%; sensitivity was not calculated in this group as the reference standard did not confirm NCSE in any of the control patients. Inter-rater agreement (IRA) was high, both for Salzburgcriteria (k = 0.87) and for the reference standard (k = 0.95). Therapeutic changes were seen significantly more often in the group
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of patients fulfilling Salzburg-criteria (84%) as compared to patients who did not (16%). Significance: Salzburg-criteria for NCSE have high diagnostic accuracy and excellent IRA, making them suitable for implementation in clinical practice. doi:10.1016/j.clinph.2017.07.040
Symposium I. – Updates on human brain connectome from physiology to disease S30 Behaviour performance in a cognitive-motor task during learning processes: Evidence from EEG network analysis—Fabrizio Vecchio (IRCCS San Raffaele Pisana, Brain Connectivity Laboratory, Rome, Italy) Objectives: Behavioral, cognitive, motor or learning acts require a finely tuned balance between triggering and blocking processes to provide appropriate preparation, initiation, on-line control, and timely inhibition of this act. Understanding the relation between structure and function of the brain is one of the basic questions of neuroscience. Although a large body of knowledge has been gathered over the last decades, we still have a poor understanding of their exact relationship. Methods: Human behavior and cognition are characterized by engagement of functional distributed networks within the brain. Such networks organization is especially significant in learning and for higher functions including abstract reasoning, memory and action planning and requires a high degree of intra-modal and inter-modal integration of information flow. These networks dynamically connect -with time-varying binding/unbinding mechanismsadjacent and/or remote cortical neuronal assemblies via corticocortical connections. Results: A novel approach, applying concepts from graph theory to neurophysiological data, is a promising new way to characterize brain activity. It provides a method to evaluate whether the functional connectivity patterns between brain areas resemble the organization of theoretically efficient, flexible or robust networks, based on the strength of synchronization of different brain regions. Discussion: During talks, it will be investigated brain connectivity in physiological aging by graph theoretical analysis of resting-state EEG recordings. Furthermore, evidences will be explained providing direct confirmation for a stochastic linking of cortical areas, as revealed by oscillatory synchronization of the two hemispheres, in determining behaviour performance in a cognitive-motor task during learning processes. Keywords: Functional coupling, Graph theory, EEG doi:10.1016/j.clinph.2017.07.041
S31 Structurally informed analyses of functional connectivity in stroke—Christian Gerloff (University Medical Center HamburgEppendorf, Department of Neurology, Hamburg, Germany) Objectives: Stroke is the leading cause of disability in industrialized countries, has a big impact on quality of life, and is of high socioeconomic relevance. Despite great advances of acute therapy – like thrombolysis and mechanical thrombectomy – approximately 50% of stroke survivors suffer from permanent neurological deficits, mostly because of structural and functional neural network failure. Methods: Review of own and published data on structural and functional connectivity in human stroke. Diffusion tensor imaging,