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P19-15 Exploring neurovascular-neurometabolic couplings and activity-mediated water movements in the rodent cortex with an optical probe
S218 fMRI experiment showed that left frontal and middle frontal gyrus near BA 10 and BA 46 were activated. Furthermore, cingulate gyrus (BA 23) and corpus callosum (BA 29, 30), and so on were also activated. The reaction time of Yes response was a fairly shorter than that of No response about 50 ms in the MEG experiment. From the results of these experiments, it was estimated that the activation area of working memory was changing through cigulate gyrus to frontal area. It was also suggested that the difference of the reaction time (50 ms) for the judgment of Yes or No response could be affected by the priming effect. P19-15 Exploring neurovascular-neurometabolic couplings and activity-mediated water movements in the rodent cortex with an optical probe P. Marquet1,2 , E. Migacheva2,3 , S. Chamot3 , O. Seydoux3 , B. Weber4 , C. Depeursinge3 , P. Magistretti1,2 1 Centre des Neurosciences Psychiatriques, University of Lausanne; Lausanne, Switzerland, 2 Ecole Polytechnique Federale de Lausanne (EPFL), Brain Mind Institute, CH-1015 Lausanne, Switzerland, 3 Ecole Polytechnique Federale de Lausanne (EPFL), Advanced Photonics Lab., Microvision and Microdiagnosis Group CH-1015 Lausanne, Switzerland, 4 Division of Nuclear Medicine, University Hospital Zurich, Ramistrasse 100, CH-8091 Zurich, Switzerland Objective: Because the brain essentially lacks storage capacities for energy substrates, monitoring the local cerebral blood supply and energy metabolism allows the tracking of neuronal activity changes. However, currently many of the BOLD signals underlying mechanisms are only poorly understood. Furthermore, a new paradigm has emerged to look at brain activity through the observation with MRI of the molecular diffusion of water (Le Bihan Phys Med Biol 52, R57 90 (2007)). Thus, we have developed a novel optical method (optiprobe) aiming to explore the neurometabolic and neurovascular coupling mechanisms as well as activity mediated water movements in the rodent cortex. Methods: High resolution optical spectroscopy of blood oxygenation is used by several groups for investigating in vivo neuro-metabolic and neurovascular coupling mechanisms. However, significant uncertainties remain because accurate differentiation between scattering and absorption processes is not readily available with these techniques. Optiprobe allows, by recording spatially diffuse reflectance, to accurately monitor in laboratory animals the activation of discrete brain regions (~1 mm3 ) during specific tasks. Practically, based on photon migration theory in tissues, a separate measurement of the scattering and absorption spectra, corresponding to the activated brain areas can be obtained. Consequently, from absorption spectra, a direct and accurate monitoring of the local cerebral blood flow variations as well as blood oxygen level in microcirculation can be obtained. On the other hand, the scattering spectra could provide information concerning the local water diffusion, tightly related to neuronal electrical activity. Results: Preliminary results have demonstrated the optiprobe ability to record spatially diffuse reflectance variations and the dynamics of the corresponding absorption and scattering spectra during sensory tasks within the cortex of anaesthetic rats. Conclusion: Over-all, optiprobe allows an original analysis of the local intrinsic optical signals, which could provide new insights in the neurovascular-neurometabolic coupling and water movements accompanying neuronal activity. P19-16 Clinical utility of diffusion tensor imaging for evaluating patients with diffuse axonal injury and cognitive disorders K. Sugiyama1 , T. Kondo1 , Y. Oouchida1 , Y. Suzukamo1 , S.-I. Izumi1 1 Department of Physical Medicine and Rehabilitation, Tohoku University Graduate School of Medicine, Japan Objective: Although diffuse axonal injury (DAI) usually causes cognitive disorders, abnormal findings are generally undetected by conventional imaging techniques. The aim of this study was to evaluate the feasibility of using diffusion tensor imaging (DTI) to detect lesions in DAI patients and to investigate the correlation between DAI lesions and cognitive disorders. Methods: We examined 16 healthy controls and 11 patients with DAI. To assess their cognitive disorders, the DAI patients were subjected to various neuropsychological tests (MMSE, WAIS-R, TMT, PASAT, WMS-R, RBMT, WCST, and BADS). ADL and behavioral problems were evaluated
Posters using the functional assessment measure (FAM). Fractional anisotropy (FA) was examined using voxel-based DTI analysis with statistical parametric mapping. The two-sample t-test was applied to test the differences in FA between the DAI patients and healthy controls. Next, we used regression modeling to examine the covariate effects of all neuropsychological tests scores and FA images of the DAI patients. Moreover, we investigated the correlation of the total scores on the cognitive items of FAM with the number of lesions in the DAI patients. Results: Voxel-based DTI analysis revealed that compared to healthy controls, the brains of DAI patients had significantly more regions with decreased FA (p < 0.001), whereas few lesions were detected on conventional MRI. These findings appeared to depict DAI. There was a significant relationship between the results of the WAIS-R, TMT, and some indices of the WMS-R and the decreased FA observed in various areas of the brain (p < 0.001). Furthermore, the total cognitive scores on the FAM were correlated with cluster (number of DAI lesions, p = 0.007) and voxel numbers (total size of all DAI lesions, p = 0.001). Conclusion: Our results indicate that DTI is a useful technique not only for detecting DAI lesions but also for examining cognitive disorders in DAI patients. P19-17 Functional distribution of the palm sensory area using intraoperative intrinsic optical imaging T. Maehara1 , M. Inaji1 , T. Nariai1 , K. Sato2 , K. Ohno1 1 Department of Neurosurgery, Tokyo medical and dental University, Tokyo, Japan, 2 Department of Health and Nutrition Sciences Komazawa Women’s University Faculty of Human Health, Tokyo, Japan Objective: Intraoperative intrinsic optical imaging technique is important method to detect the precise functional distribution in the sensory cortex. Although several reports demonstrated that functional representation of the finger sensory area was aligned along the central sulcus, functional distribution of the palm sensory area has not been fully analyzed. We investigated the sensory area of the palm using this method. Method: We used intrinsic optical imaging for two patients with intractable epilepsy who had epileptic focus in and around the sensory cortex and one patient with a brain tumor extending from the insula cortex. One epileptic patient suffered from intractable simple partial seizures (SPSs) started from dysesthesia of the left palm, followed by secondarily generalization. Optical recording was performed following cortical recording of SSEPs. The cortical surface was illuminated with Xenon light, and the reflected light, which passed through a 605 nm bandpass filter, was detected by optical imaging system. Individual electrical stimulation of thumb, little finger and palm induced changes in the reflected light intensities. For the purpose of visualizing the intrinsic optical responses, we constructed maps on the sensory strip. Results: (1) In all three cases, the optical response area after electrical stimulation of the palm was defined in the sensory cortex between the finger areas and the postsensory sulcus. (2) We performed multiple subpial transection on the palm area in the patient suffered from SPSs with dysesthesia of the left palm. He complained of transient dysesthesia in the left palm that disappeared in a week. Conclusion: Using intraoperative intrinsic optical imaging, we suggested that the sensory area of the palm was located in the sensory cortex between the finger areas and the postsensory sulcus. P19-18 Spatiotemporal dynamics of neuromagnetic oscillatory changes during observation of actions Y. Tamura1 , M. Hirata1,2 , T. Goto1,2 , H. Onishi3 , H. Sugata1 , M. Inui1 , T. Saori1 , S. Yorifuji1 1 Division of Functional Diagnostic Science, Osaka University Graduate School of Medicine, Osaka, Japan, 2 Department of Neurosurgery, Osaka University Medical School, Osaka, Japan, 3 Department of Occupational Therapy, Osaka Prefecture University, Osaka, Japan Objective: Mirror neuron system (MNS) is known to be active during both observation and execution of actions, and involves inferior parietal lobule (IPL), inferior frontal gyrus (IFG) and ventral premotor cortex (vPM). However, the oscillatory changes and neural process of MNS are not fully understood. We aimed to delineate the oscillatory changes during observation of actions and the spatiotemporal profile of MNS.
Posters using the functional assessment measure (FAM). Fractional anisotropy (FA) was examined using voxel-based DTI analysis with statistical parametric mapping. The two-sample t-test was applied to test the differences in FA between the DAI patients and healthy controls. Next, we used regression modeling to examine the covariate effects of all neuropsychological tests scores and FA images of the DAI patients. Moreover, we investigated the correlation of the total scores on the cognitive items of FAM with the number of lesions in the DAI patients. Results: Voxel-based DTI analysis revealed that compared to healthy controls, the brains of DAI patients had significantly more regions with decreased FA (p < 0.001), whereas few lesions were detected on conventional MRI. These findings appeared to depict DAI. There was a significant relationship between the results of the WAIS-R, TMT, and some indices of the WMS-R and the decreased FA observed in various areas of the brain (p < 0.001). Furthermore, the total cognitive scores on the FAM were correlated with cluster (number of DAI lesions, p = 0.007) and voxel numbers (total size of all DAI lesions, p = 0.001). Conclusion: Our results indicate that DTI is a useful technique not only for detecting DAI lesions but also for examining cognitive disorders in DAI patients. P19-17 Functional distribution of the palm sensory area using intraoperative intrinsic optical imaging T. Maehara1 , M. Inaji1 , T. Nariai1 , K. Sato2 , K. Ohno1 1 Department of Neurosurgery, Tokyo medical and dental University, Tokyo, Japan, 2 Department of Health and Nutrition Sciences Komazawa Women’s University Faculty of Human Health, Tokyo, Japan Objective: Intraoperative intrinsic optical imaging technique is important method to detect the precise functional distribution in the sensory cortex. Although several reports demonstrated that functional representation of the finger sensory area was aligned along the central sulcus, functional distribution of the palm sensory area has not been fully analyzed. We investigated the sensory area of the palm using this method. Method: We used intrinsic optical imaging for two patients with intractable epilepsy who had epileptic focus in and around the sensory cortex and one patient with a brain tumor extending from the insula cortex. One epileptic patient suffered from intractable simple partial seizures (SPSs) started from dysesthesia of the left palm, followed by secondarily generalization. Optical recording was performed following cortical recording of SSEPs. The cortical surface was illuminated with Xenon light, and the reflected light, which passed through a 605 nm bandpass filter, was detected by optical imaging system. Individual electrical stimulation of thumb, little finger and palm induced changes in the reflected light intensities. For the purpose of visualizing the intrinsic optical responses, we constructed maps on the sensory strip. Results: (1) In all three cases, the optical response area after electrical stimulation of the palm was defined in the sensory cortex between the finger areas and the postsensory sulcus. (2) We performed multiple subpial transection on the palm area in the patient suffered from SPSs with dysesthesia of the left palm. He complained of transient dysesthesia in the left palm that disappeared in a week. Conclusion: Using intraoperative intrinsic optical imaging, we suggested that the sensory area of the palm was located in the sensory cortex between the finger areas and the postsensory sulcus. P19-18 Spatiotemporal dynamics of neuromagnetic oscillatory changes during observation of actions Y. Tamura1 , M. Hirata1,2 , T. Goto1,2 , H. Onishi3 , H. Sugata1 , M. Inui1 , T. Saori1 , S. Yorifuji1 1 Division of Functional Diagnostic Science, Osaka University Graduate School of Medicine, Osaka, Japan, 2 Department of Neurosurgery, Osaka University Medical School, Osaka, Japan, 3 Department of Occupational Therapy, Osaka Prefecture University, Osaka, Japan Objective: Mirror neuron system (MNS) is known to be active during both observation and execution of actions, and involves inferior parietal lobule (IPL), inferior frontal gyrus (IFG) and ventral premotor cortex (vPM). However, the oscillatory changes and neural process of MNS are not fully understood. We aimed to delineate the oscillatory changes during observation of actions and the spatiotemporal profile of MNS.