FC42.4 Motion-onset visual evoked potentials II. – Pilot diagnostic studies Z. Kubova , M. Kuba, J. Kremlacek, J. Langrova, J. Szanyi Charles University, Faculty of Medicine in Hradec Kralove, Czech Republic Background: With respect to the existing way of visual motion processing system examination by the motion-onset VEPs (M-VEPs) (part I of our M-VEPs presentation), we tried to verify possible diagnostic utility of the M-VEPs. Aims: It was assumed that M-VEPs could help to increase sensitivity of VEP examination in neuro-ophthal- mological and CNS disorders with early or relatively selec- tive involvement of the magnocellular and/or dorsal stream of the visual pathway (Kubova, Kuba. Doc Ophthal 1992;81:209–18) in some patients. Methods: The contribution of the M-VEPs examination (indicating mainly magnocellular and dorsal stream activi- ty) compared to the standard pattern-reversal (PR-VEPs) examination (predominant parvocellular system and striate cortical activity) was tested in the following diagnoses: Multiple Sclerosis, Optic Neuritis, Neuroborreliosis, Glau- coma, Amblyopia, Dyslexia and Congenital Nyctalopia (see publications at http://www.lfhk.cuni.cz/elf). Results: The extended VEP examination increases sensi- tivity (in cases with pathological M-VEP and normal PR- VEPs latencies) for about 28% (data from about 3000 patients). The M-VEPs are well detectable in about 50° of the visual field, so they can be used for objective detec- tion of its reduction. In amblyopes with severe VA decrease (with abnormal PR-VEPs), M-VEPs can help to recognise additional pathology of the amblyopic eye. A distinct delay of the M-VEPs in some dyslexics can be interpreted as sign of supposed magnocellular deficit. Conclusion: On the basis of the presented pilot studies, we suggest that the M-VEPs should be more widely tested for a possibility to include them as a part of the electro- physiological examination in visual and CNS disorders. Such an extension of VEP examination need not prolong its total duration or expenses notably when suitable stimuli are used. Supported by Ministry of Health (NR8421-4/2005) and Ministry of Education (VZ 0021620816) of Czech Republic. doi:10.1016/j.clinph.2006.06.139 FC43.1 Is epilepsy related to the neural mechanisms under- lying consciousness? B. Evans Kings College Hospital, Department of Clinical Neurophys- iology, UK Background: Consciousness consists of three elements 1. Awareness 2. Memory (Working Memory WM and Episodic Memory EM) 3. Emotion. The anatomical arrangement of the Cortico Thalamic (CT) network is dual: One part is direct between the specific cortical functional areas and the associated specific thalamic nuclei, it uses Parvalbmin as the Ca 2+ binding protein. The other part is diffuse between all the areas of the cortex and all the tha- lamic nuclei, this uses Calbindin as the Ca 2+ binding pro- tein. EM is related to the Hippocampal structures and WM to the cortex. Emotion arises from nuclei near the Hippocampus. Epileptic discharges are focal, giving rise to Simple Partial Seizures (SPS) or Complex Partial Sei- zures (CPS) or generalised giving rise to primary or second- ary generalised seizures. Objectives: To determine if there is a relationship between the anatomical structures and clinical seizures. Methods: Evaluation of data. Results: The diffuse CT system probably underlies awareness. Generalised discharges here will result in Loss of awareness and hence loss of consciousness (LOC). Focal discharges leading to SPS without LOC may arise in the direct CT system. Focal discharges in or near the Hippo- campus may produce CPS with LOC from disturbance of EM rather than of awareness. Focal discharges that become generalised suggest spread from the direct to the diffuse CT system with consequent loss of awareness. Sin- gle focal discharges leading to transient cognitive impair- ment may disturb WM in the cortex. Conclusions: There is a relationship between the neural mechanisms of consciousness and clinical epilepsy. Epilep- sy may be a disorder of these mechanisms. doi:10.1016/j.clinph.2006.06.140 FC43.2 Vegetative coma with cognitive evoked potentials (CEPs) and fMRI: Implications for the consciousness model of Damasio and Guerit D. Debatisse 1 , E. Fornari 2 , E. Pralong 1 , P. Maeder 2 , M.H. Tetreault 1 , H. Foroglou 1 , J.G. Villemure 1 1 CHUV, NCH-UNN CHUV, Switzerland 2 CHUV, Neuroradiology CHUV, Switzerland Background: CEPs can predict comatose patient out- come. Positive predictive value exceeds by far their negative predictive value. The prognostic value can be improved by recording CEPs. Objectives: Medical, ethical, legal, and economic reasons justify the assessment of possible conscious remnants in comatose and vegetative patients. One of the issue as to whether it is possible to bypass communication and exam- ine consciousness thanks to the recording of scalp electrical brain activities with fMRI and P300 study. Methods: Four patients in a vegetative comatose state were confronted with a classical P300 design during the recording of ERPs and fMRI. ERPs and fMRI data were compared in order to assess whether a brain Oral Communications / Clinical Neurophysiology 117 (2006) S49–S111 S105