UNCORRECTED PROOF Abstract — WCN 2013 No: 1302 Topic: 36 — Other Topic Evaluating variability of fMRI in the sensorimotor cortex—A multicenter study* M. Wurnig a,b,c , J. Rath a,b,c , N. Klinger a,b,c , I. Höllinger a,b,c , A. Geissler a,b,c , F.P. Fischmeister a,b,c , M. Aichhorn d , T. Foki a,b,c , M. Kronbichler d , J. Nickel e , C. Siedentopf f , W. Staffen g , M. Verius f , S. Golaszewski g , F. Koppelstätter f , E. Knosp h , E. Auff b , S. Felber i , R.J. Seitz e , R. Beisteiner a,b,c . a Department of Neurology, Study Group Clinical fMRI, Vienna, Austria; b Department of Neurology, Medical University Vienna, Vienna, Austria; c High Field MR Center of Excellence, Medical University Vienna, Vienna, Austria; d Department of Psychology and Centre for Neurocognitive Research, University of Salzburg, Salzburg, Austria; e Department of Neurology, Heirnich-Heine-Universität Düsseldorf, Düsseldorf, Germany; f Department of Radiology, Medical University of Innsbruck, Innsbruck, Austria; g Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria; h Department of Neurosurgery, Medical University Vienna, Vienna, Austria; i Institute for Diagnostic Radiology, Stiftungsklinikum Mittelrhein, Koblenz, Germany Background: More and more patients with planned neurosurgical interventions undergo fMRI-scans with localization of the primary sensorimotor cortex being one of the most frequently requested clinical tasks. Reliability of fMRI-localization is an important issue since changing the resection margins in the range of millimeters might dramatically change the functional outcome of surgery. Up to now dependence of fMRI-localization on the investigating site was only assessed in healthy volunteers, but is not known for patients with pathological brains. Objective: To evaluate between-site-variability of fMRI in the sensorimotor cortex using a somatosensory and a motor task. Methods: 15 patients with planned neurosurgical intervention due to unilateral brain pathology underwent fMRI-scans at 3 experienced clinical sites. fMRI-scans included a motor (fist clenching of hand contralateral to pathology) and a somatosensory task (vibrotactile stimulation of digitus 2/3 contralateral to pathology). fMRI-variability was assessed with (1) center-of-activation (COA) variability, (2) activation-size-ratio (SR), (3) activation-overlap-ratio (OR) and (4) intraclass-correlation-coefficients (ICC). Results: Median COA variability was 5.7 mm (IQR 3.2–7.9 mm, maximum 16.5 mm) for the motor task and 5.8 mm (IQR 3.4– 8.0 mm, maximum 12.0 mm) for the sensorimotor task. Median SR was 48.7% (IQR 40.8–66.1%; motor) and 30.8% (IQR 14.0–39.3%; somatosensory) respectively. The figures for OR were 33.0% (IQR 26.6–43.2%; motor) and 4.0% (IQR 1.1–10.2%; somatosensory). ICC was 0.23 (motor) and 0.20 (somatosensory). Conclusion: Correspondence of fMRI-localizations is quite good between centers. In single patients localization differences can amount up to 16.5 mm. This figure needs to be considered in clinical practice and for clinical studies with multicentric designs. *A full manuscript has been accepted for publication in Radiology (doi: http://dx.doi.org/10.1148/radiol.13121357). doi:10.1016/j.jns.2013.07.2292 Abstract — WCN 2013 No: 2174 Topic: 36 — Other Topic Effects of aging on supraspinal motor control of ankle movements P. Linortner a , M. Jehna b , H. Johansen-Berg c , P.M. Matthews d , R. Schmidt a , F. Fazekas a , C. Enzinger a,b . a Department of Neurology, Medical University of Graz, Graz, Austria; b Department of Radiology, Medical University of Graz, Graz, Austria; c Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK; d Department of Medicine, Imperial College London, London, UK Background: Age-effects on functional Magnetic Resonance Imaging (fMRI) activation obtained by hand/finger movements have been reported previously in healthy subjects. However, despite the importance of changing gait capacities with age, analog studies for lower limb movements are scarce. Objective: The purpose of this study was to explore the effects of age on motor control of ankle movements, aggregating data from several studies. Patients and methods: We analyzed the fMRI data of 102 right-foot dominant healthy subjects aged 20–83 years, obtained during ankle movements. We both used FSL higher level analyses as standard approach and a meta-analysis employing coordinate-based activa- tion likelihood estimation (ALE). Results: Unilateral ankle movements elicited activation in the primary motor cortices and supplementary motor areas bilaterally (with contralateral peaks), the contralateral somatosensory cortices and the ipsilateral cerebellum. With increasing age, increasing cerebellar and precuneus activity was observed. Conclusion: Similar to previous findings for fine motor skills of the upper limb, the BOLD-response associated with ankle movement scales with age. However, these changes predominantly concerned the precuneus, an area that has been implicated in neurodegenera- tive disorders like Alzheimer's disease. doi:10.1016/j.jns.2013.07.2293 Abstract — WCN 2013 No: 2140 Topic: 36 — Other Topic The phenomenology and epistemology of konzo: Readings from the Kahemba Outbreak, Democratic Republic of Congo. Part I: Socioeconomic aspects D. Okitundu a , M.-T. Sombo a , J. Kabamle b , N. Mashukanu c , T. Kazadi a , D. Mumba d , M. Boivin e , D. Tshala-Katumbay f . a Neurology, University of Kinshasa, Kinshasa, Congo; b Sciences de Base, University of Kinshasa, Kinshasa, Congo; c Programme National de Nutrition, Ministère de la Santé, Kinshasa, Congo; d Tropical Medicine, University of Kinshasa, Kinshasa, Congo; e Neurology, Michigan State University, Michigan, MI, USA; f Neurology, Center for Research on Occupational and Environmental Toxicology, Oregon Health & Science University, Portland, OR, USA Objectives: To determine the demographic characteristics of house- holds affected by konzo; quantify the level of economic distress associated with konzo and elucidate the relationship between economic distress and cyanide poisoning. Subjects and methods: 210 children aged 8.83 ± 2.57 years, 123 konzo and 87 non-konzo according to WHO criteria, were recruited in sectional study on demographic and economic profiles of patients affected by konzo. The work had included a literature review, a survey by structured interviews, observations and sampling of cassava flour and urine samples for biochemical analyzes in search of markers of cyanide poisoning. The socio-economic profile was evaluated by the Home. All children were tested negative for HIV and HTLV-1. Results: The frequency of konzo was 79.47% for children aged b 15 years and 56.9%. for females. Exposure to HCN cassava flour is equivalent konzo children and non-konzo (p = 0.503), the severity of konzo was proportional to the poverty of the family socio- economic environment overall (p = 0.008). The nutritional status of Abstracts / Journal of the Neurological Sciences e629 (2013) e629–e678 e662