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Probing parietal-motor connectivity by means of intraoperative direct cortical stimulation
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Abstracts / Brain Stimulation 10 (2017) 346e540
16.08% (tDCSsham); for TUGcognitive was 21.74% (tDCSsitting), 24.10% (tDCSaerobic), 29.71% (tDCSWii), 21.9% (tDCSsham). Cognitive dual task cost for TUGcognitive was 19.96% (tDCSsitting), 7.91% (tDCSaerobic), 5.05% (tDCSWii), 19.92% (tDCSsham). PDQ-39 following each session, where a lower score reflects a greater quality of life, was 16.00 (tDCSsitting), 14.10 (tDCSaerobic), 16.47 (tDCSWii), and 15.58 (tDCSsham). Discussion: Our bilateral brain hemisphere tDCS did not lessen dual task cost when paired with concurrent activities in participants with PD. Fatigue from concurrent tasks (Wii and aerobic activity) may have limited physical performance. However, bilateral brain hemisphere tDCS paired with aerobic activity appeared to positively impact perceived quality of life and minimize cognitive dual task cost. Further investigation with a larger sample size is warranted. Keywords: Parkinson's disease, Gait, Executive Function, Transcranial Direct Current Stimulation [0294] ACUTE NEURAL IMAGING REACTION OF RTMS TO ESOPHAGEAL CANCER PATIENTS WITH DEPRESSION Q.W. Mu*, Z.W. Guo, J.Q. Yang, H.P. Chen. The Second Clinical Medical College of North Sichuan Medical College Nanchong Central Hospital, China Instruction: To investigate the alteration of the spontaneous neural activity and functional connectivity immediately after repetitive transcranial magnetic stimulation (rTMS) to esophageal cancer patients with depression using functional magnetic resonance imaging method. Methods: Eleven esophageal cancer patients with major depression were enrolled in this study. All of the patients received one time rTMS treatment with 10 Hz frequency and 100% resting motor threshold over the left dorsolateral prefrontal cortex involving 30 trains of 50 pulses with 25second intervals. Before and immediately after the treatment, the resting state functional magnetic resonance imaging examination was performed. The comparison of Hamilton Depression Scale (HAMD), amplitude of low frequency fluctuation (ALFF), and the functional connectivity of depression related brain regions before and after rTMS treatment were all conducted. Besides, the correlation between the alteration of ALFF in depression related brain regions and the HAMD changes were also calculated. Results: After one time rTMS treatment, the HAMD scores were significantly decreased. The depression related regions including right superior frontal cortex, inferior orbitofrontal gyrus, hippocampus, bilateral middle frontal cortices, anterior cingulate cortex (ACC), middle temporal gyri, and left inferior temporal gyrus all revealed significantly increased ALFF. The alteration of ALFF in the ACC was negative correlated with the alteration of HAMD. In addition, the limbic-cortical-striatal-thalamic network also increased in depression patients after rTMS treatment. Discussion: rTMS may achieve the rehabilitation of depression by improving the spontaneous neural activity of depression patients, and modulating the limbic-cortical-striatal-thalamic network. Keywords: Repetitive transcranial magnetic stimulation, Depression, Esophageal cancer, Functional magnetic resonance imaging [0297] PROBING PARIETAL-MOTOR CONNECTIVITY BY INTRAOPERATIVE DIRECT CORTICAL STIMULATION
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L. Cattaneo*, P. Meneghelli, V. Tramontano, F. Sala. University of Verona, Italy Introduction: according to influential models, based on monkey anatomy, the parietal cortex modulates motor output in an indirect way, by interposition of the premotor cortex. Conversely, in humans, some data from non-invasive brain stimulation suggest that the parietal cortex could be at the origin of direct cortico-cortical connections to the primary motor cortex (M1). Here we assessed the feasibility of investigating parietalmotor cortico-cortical connectivity by means of direct cortical stimulation in intraoperative settings with a conventional “conditioning / test stimulus” paradigm. Methods: we tested a single subject undergoing brain surgery for excision of a meningioma localized in the right postcentral region. Surgery was performed during general anesthesia. Direct electrical cortical stimulation was applied to M1 (test stimuli) in trains of 4 stimuli at 250 Hz. while EMG
recordings were made from distal upper limb muscles. In some trials, a brief train of two pulses at 250 Hz (conditioning stimulus) was delivered on the cortical surface along the intraparietal sulcus at 5 different positions separated by 1 cm, immediately prior to motor stimulation. Motor evoked potentials (MEPs) to conditioning stimuli alone, to test stimuli alone and to coupled conditioning and test stimuli, were recorded and compared. Results: stimulation of the intraparietal sulcus alone did not produce any MEP in any of the 5 spots. Stimulation of M1 alone produced stable MEPs. Conditioned M1 stimulation produced significantly smaller MEPs when parietal stimulation was applied to a specific spot, 1 cm posterior to the junction between the IPS and the postcentral sulcus. Conclusions: our preliminary data suggest that cortico-cortical connectivity can be tested with direct cortical stimulation. The data in our single subject seem to favor the hypothesis of direct connections between the cortex associated with the IPS and M1, though further investigations on a broader number of subjects are required. Keywords: Intraoperative, Connectivity, Motor cortex, direct cortical stimulation [0298] MEMORY ENCODING-RELATED ANTERIOR HIPPOCAMPAL POTENTIALS ARE MODULATED BY ELECTRIC DEEP BRAIN STIMULATION OF THE ENTORHINAL AREA N. Hansen*1, L. Chaieb 1, B. Staresina 2, K. Hampel 1, C.E. Elger 1, R. Surges 1, N. Axmacher 3, J. Fell 1. 1 University of Bonn, Germany; 2 University of Birmingham, UK; 3 Ruhr University Bochum, Germany Introduction: Deep brain stimulation (DBS) of the human entorhinal area with biphasic pulses of 50 Hz and stimulation amplitudes between 0.5 and 1.5 mA has been demonstrated to improve memory performance in a virtual navigation paradigm (Suthana et al., 2012). However, the impact of DBS on the entorhinal cortex and on memory-related hippocampal potentials has not yet been investigated. Methods: We used a DBS protocol with parameters similar to the study by Suthana and colleagues (2012) (50 Hz), but with a lower stimulation amplitude of 0.1 mA. We have to date recorded data from seven presurgical medial temporal lobe epilepsy patients implanted with mediotemporal depth electrodes. DBS was administered to the entorhinal area on the nonfocal side. The stimulation period consisted of alternating on- and off-cycles of 15 sec duration. During the stimulation period, patients learned objectcolour associations that were later tested (Staresina et al., 2012). Such associative memory paradigms are known to specifically depend upon the anterior hippocampus. We compared the mean amplitudes of event-related potentials elicited by the object/colour stimuli within the amygdala, anterior and medial hippocampus and parahippocampal cortex during on- and off-cycles, as well as between the focal and non-focal side. Results: For the anterior hippocampus, a two-way repeated measures ANOVA (factors: on/off, focal/non-focal) revealed a main effect for on-off, but no main effect for focal/non-focal, and no interaction. During DBS of the entorhinal cortex in an early time window (200-400ms),we observed more negative event-related potentials in conjunction with the on- than the offcondition on both the focal and non-focal side. For medial hippocampus, amygdala and parahippocampal cortex we observed no significant effects. Dicussion: Our results indicate that electrical DBS of the entorhinal area with a low amplitude has a significant impact on memory encodingrelated potentials within the anterior hippocampus. Keywords: Memory, event-related potentials, hippocampus, enthorinal area [0299] EXPERIENCE OF COMPLEX APPLICATION OF NEUROMODULATION TECHNOLOGIES IN CASES OF SEVERE CEREBRAL LESIONS V.P. Ilyichev 1, I.V. Martynov 2, A.L. Gorelik 3, 4, A.G. Naryshkin 5. 1 Voronezh State Medical University named after N.N. Burdenko, Voronezh, Russia; 2 The remedial treatment clinic, Voronezh, Russia; 3 The St. Petersburg Bekhterev Psychoneurological Research Institute, St. Petersburg, Russia; 4 Smirnov N.А. Neurosoft, Ivanovo, Russia; 5 North-Western State Medical University named after I.I.Mechnikov, St. Petersburg, Russia
Abstracts / Brain Stimulation 10 (2017) 346e540
16.08% (tDCSsham); for TUGcognitive was 21.74% (tDCSsitting), 24.10% (tDCSaerobic), 29.71% (tDCSWii), 21.9% (tDCSsham). Cognitive dual task cost for TUGcognitive was 19.96% (tDCSsitting), 7.91% (tDCSaerobic), 5.05% (tDCSWii), 19.92% (tDCSsham). PDQ-39 following each session, where a lower score reflects a greater quality of life, was 16.00 (tDCSsitting), 14.10 (tDCSaerobic), 16.47 (tDCSWii), and 15.58 (tDCSsham). Discussion: Our bilateral brain hemisphere tDCS did not lessen dual task cost when paired with concurrent activities in participants with PD. Fatigue from concurrent tasks (Wii and aerobic activity) may have limited physical performance. However, bilateral brain hemisphere tDCS paired with aerobic activity appeared to positively impact perceived quality of life and minimize cognitive dual task cost. Further investigation with a larger sample size is warranted. Keywords: Parkinson's disease, Gait, Executive Function, Transcranial Direct Current Stimulation [0294] ACUTE NEURAL IMAGING REACTION OF RTMS TO ESOPHAGEAL CANCER PATIENTS WITH DEPRESSION Q.W. Mu*, Z.W. Guo, J.Q. Yang, H.P. Chen. The Second Clinical Medical College of North Sichuan Medical College Nanchong Central Hospital, China Instruction: To investigate the alteration of the spontaneous neural activity and functional connectivity immediately after repetitive transcranial magnetic stimulation (rTMS) to esophageal cancer patients with depression using functional magnetic resonance imaging method. Methods: Eleven esophageal cancer patients with major depression were enrolled in this study. All of the patients received one time rTMS treatment with 10 Hz frequency and 100% resting motor threshold over the left dorsolateral prefrontal cortex involving 30 trains of 50 pulses with 25second intervals. Before and immediately after the treatment, the resting state functional magnetic resonance imaging examination was performed. The comparison of Hamilton Depression Scale (HAMD), amplitude of low frequency fluctuation (ALFF), and the functional connectivity of depression related brain regions before and after rTMS treatment were all conducted. Besides, the correlation between the alteration of ALFF in depression related brain regions and the HAMD changes were also calculated. Results: After one time rTMS treatment, the HAMD scores were significantly decreased. The depression related regions including right superior frontal cortex, inferior orbitofrontal gyrus, hippocampus, bilateral middle frontal cortices, anterior cingulate cortex (ACC), middle temporal gyri, and left inferior temporal gyrus all revealed significantly increased ALFF. The alteration of ALFF in the ACC was negative correlated with the alteration of HAMD. In addition, the limbic-cortical-striatal-thalamic network also increased in depression patients after rTMS treatment. Discussion: rTMS may achieve the rehabilitation of depression by improving the spontaneous neural activity of depression patients, and modulating the limbic-cortical-striatal-thalamic network. Keywords: Repetitive transcranial magnetic stimulation, Depression, Esophageal cancer, Functional magnetic resonance imaging [0297] PROBING PARIETAL-MOTOR CONNECTIVITY BY INTRAOPERATIVE DIRECT CORTICAL STIMULATION
MEANS
OF
L. Cattaneo*, P. Meneghelli, V. Tramontano, F. Sala. University of Verona, Italy Introduction: according to influential models, based on monkey anatomy, the parietal cortex modulates motor output in an indirect way, by interposition of the premotor cortex. Conversely, in humans, some data from non-invasive brain stimulation suggest that the parietal cortex could be at the origin of direct cortico-cortical connections to the primary motor cortex (M1). Here we assessed the feasibility of investigating parietalmotor cortico-cortical connectivity by means of direct cortical stimulation in intraoperative settings with a conventional “conditioning / test stimulus” paradigm. Methods: we tested a single subject undergoing brain surgery for excision of a meningioma localized in the right postcentral region. Surgery was performed during general anesthesia. Direct electrical cortical stimulation was applied to M1 (test stimuli) in trains of 4 stimuli at 250 Hz. while EMG
recordings were made from distal upper limb muscles. In some trials, a brief train of two pulses at 250 Hz (conditioning stimulus) was delivered on the cortical surface along the intraparietal sulcus at 5 different positions separated by 1 cm, immediately prior to motor stimulation. Motor evoked potentials (MEPs) to conditioning stimuli alone, to test stimuli alone and to coupled conditioning and test stimuli, were recorded and compared. Results: stimulation of the intraparietal sulcus alone did not produce any MEP in any of the 5 spots. Stimulation of M1 alone produced stable MEPs. Conditioned M1 stimulation produced significantly smaller MEPs when parietal stimulation was applied to a specific spot, 1 cm posterior to the junction between the IPS and the postcentral sulcus. Conclusions: our preliminary data suggest that cortico-cortical connectivity can be tested with direct cortical stimulation. The data in our single subject seem to favor the hypothesis of direct connections between the cortex associated with the IPS and M1, though further investigations on a broader number of subjects are required. Keywords: Intraoperative, Connectivity, Motor cortex, direct cortical stimulation [0298] MEMORY ENCODING-RELATED ANTERIOR HIPPOCAMPAL POTENTIALS ARE MODULATED BY ELECTRIC DEEP BRAIN STIMULATION OF THE ENTORHINAL AREA N. Hansen*1, L. Chaieb 1, B. Staresina 2, K. Hampel 1, C.E. Elger 1, R. Surges 1, N. Axmacher 3, J. Fell 1. 1 University of Bonn, Germany; 2 University of Birmingham, UK; 3 Ruhr University Bochum, Germany Introduction: Deep brain stimulation (DBS) of the human entorhinal area with biphasic pulses of 50 Hz and stimulation amplitudes between 0.5 and 1.5 mA has been demonstrated to improve memory performance in a virtual navigation paradigm (Suthana et al., 2012). However, the impact of DBS on the entorhinal cortex and on memory-related hippocampal potentials has not yet been investigated. Methods: We used a DBS protocol with parameters similar to the study by Suthana and colleagues (2012) (50 Hz), but with a lower stimulation amplitude of 0.1 mA. We have to date recorded data from seven presurgical medial temporal lobe epilepsy patients implanted with mediotemporal depth electrodes. DBS was administered to the entorhinal area on the nonfocal side. The stimulation period consisted of alternating on- and off-cycles of 15 sec duration. During the stimulation period, patients learned objectcolour associations that were later tested (Staresina et al., 2012). Such associative memory paradigms are known to specifically depend upon the anterior hippocampus. We compared the mean amplitudes of event-related potentials elicited by the object/colour stimuli within the amygdala, anterior and medial hippocampus and parahippocampal cortex during on- and off-cycles, as well as between the focal and non-focal side. Results: For the anterior hippocampus, a two-way repeated measures ANOVA (factors: on/off, focal/non-focal) revealed a main effect for on-off, but no main effect for focal/non-focal, and no interaction. During DBS of the entorhinal cortex in an early time window (200-400ms),we observed more negative event-related potentials in conjunction with the on- than the offcondition on both the focal and non-focal side. For medial hippocampus, amygdala and parahippocampal cortex we observed no significant effects. Dicussion: Our results indicate that electrical DBS of the entorhinal area with a low amplitude has a significant impact on memory encodingrelated potentials within the anterior hippocampus. Keywords: Memory, event-related potentials, hippocampus, enthorinal area [0299] EXPERIENCE OF COMPLEX APPLICATION OF NEUROMODULATION TECHNOLOGIES IN CASES OF SEVERE CEREBRAL LESIONS V.P. Ilyichev 1, I.V. Martynov 2, A.L. Gorelik 3, 4, A.G. Naryshkin 5. 1 Voronezh State Medical University named after N.N. Burdenko, Voronezh, Russia; 2 The remedial treatment clinic, Voronezh, Russia; 3 The St. Petersburg Bekhterev Psychoneurological Research Institute, St. Petersburg, Russia; 4 Smirnov N.А. Neurosoft, Ivanovo, Russia; 5 North-Western State Medical University named after I.I.Mechnikov, St. Petersburg, Russia