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Assessing stimulation effects induced by tDCS using MEG
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Abstracts / Brain Stimulation 10 (2017) 346e540
[0765] EFFECTS OF AURICULAR VAGUS NERVE STIMULATION ON BRAIN ACTIVITY, COGNITIVE PARAMETERS AND WELL-BEING T. Polak*, C. Stelzer, A. Katzorke, J.B.M. Zeller, M.J. Herrmann. University Clinic Würzburg, Germany Purpose: Auricular Vagus nerve stimulation (aVNS) in the region of the auricular branch of the Vagus nerve (ABVN) is an increasingly used noninvasive brain stimulation method. fMRI studies differ with respect to activation of the prefrontal cortex during aVNS. We now aimed to reappraise these findings by near-infrared spectroscopy (NIRS) as an independent method examining resting brain activity during aVNS in a shamecontrolled study. Methods: 42 healthy young subjects were allocated to aVNS (n¼20) or control stimulation at the ear lobe (sham, n¼22). aVNS was performed according to published procedures (intensity 8mA, frequency 25/s, pulse width 250ms). Brain activation was measured with NIRS in a region of interest covering prefrontal brain areas. Executive brain function was measured using the Trail Making Test and well-being using the german Scale of Well-being. Results: There was a significant change in resting brain activity in prefrontal brain areas over time during aVNS as indicated by a significant main effect for the inner subject factor “time” in ANOVA for repeated measurements (F(1,49)¼50,8, p<0.001). Post-hoc t-tests showed a significant decrease in oxygenated and an increase in deoxygenated hemoglobin. This pattern, however, did not differ significantly from that seen in the sham group. There was no change in cognitive performance nor in wellbeing in the subjects who underwent aVNS. Conclusions: Our preliminary results show a decrease in frontal brain activation upon aVNS as measured by NIRS. However, there was no statistically significant difference between aVNS and sham stimulation at the ear lobe. The results of this pilot study point to the possibility that there may be some overlap between stimulation in the region of the ABVN and stimulation at the ear lobe that is often used for sham stimulation of aVNS. Keywords: auricular vagus nerve stimulation, near-infrared spectroscopy, prefrontal cortex, auricular branch of vagus nerve
[0767] ASSESSING STIMULATION EFFECTS INDUCED BY TDCS USING MEG S. Jang*, D. Kim, H. Cho, M. Kwon, S.C. Jun. Gwangju Institute of Science and Technology, Republic of Korea Transcranial direct current stimulation (tDCS) has been used to modulate the neural activity, however, the effects of tDCS are inconsistent and quite dependent on target brain sites, stimulation duration time, intensity and so on. Thus, it is compelling to investigate stimulus-induced effects through the brain oscillatory changes. For this purpose, we recorded magnetoencephalography (MEG) before and after tDCS. Five healthy volunteers participated in this experiment consisting of three stimulation types d protocol 1 (anode: Cz and cathode: Fpz), protocol 2 (anode: Cz and cathode: POz), and sham; each protocol was conducted during one day. Stimulation was given at 1.5 mA for 15 min duration. Each During resting state (2 min) and go/no-go task before (5 min) and after (10 min) tDCS, MEG was recorded to investigate stimulation effects before and after stimulation. In behavior analysis, we found that button response time was shorter and task accuracy was higher in protocol 2 than others. Moreover, in MEG analysis, M200 and M300 of protocol 2 were larger in magnitude than others. Since go/no-go task performance was enhanced when current flow (forward direction: Cz to Fpz) was applied to the pre-frontal cortex, it may be inferred that protocol 2 may be related with improvement of cognitive ability. Protocol designing according to target sites may be important. Acknowledgement: This work was supported by the GIST Research Institute(GRI) in 2017. Keywords: tDCS, MEG, protocol
[0768] EFFECTIVENESS AND ACCEPTABILITY OF INTENSIVE REPETITIVE TRANSCRANIAL MAGNETIC STIMULATION (I-RTMS) IN NEGATIVE SYMPTOMS OF SCHIZOPHRENIA T. Sverak*1, 2, L. Albrechtova 1, L. Ustohal 1, 2. 1 Masaryk University and University Hospital Brno, Czech Republic; 2 Central European Institute of Technology, Masaryk University, Czech Republic Introduction: Negative symptoms in schizophrenia are disabling and do not respond adequately to antipsychotic or psychosocial treatment. Some meta-analyses suggest efficacy of repetitive transcranial magnetic stimulation (rTMS) for the treatment of them. Usually patients have a not really good compliance and attend three weeks of the treatment is very difficult for them. Using more intensive stimulation protocol might hold promise as a valuable alternative and may be more bearable for the patients. Methods: Open label study which observe the effect of I-rTMS. Investigators examined 8 patients with schizophrenia with predominant negative symptoms and with a high-degree of illness severity. Patients were treated with 10-Hz rTMS applied 4 times per day for 4 days to the left dorsolateral prefrontal cortex. They received total 32000 pulses. Effects on negative symptoms was measured by Positive and negative syndrome scale (PANSS) before the treatment, immediately after the treatment and after 14 days. The results were compared by Wilcoxon's non-parametric test. Results: Negative scale in PANSS was improved by 22% after the I-rTMS and by 16% 14 days after the treatment but these results was not statistically significant (p¼ 0,12). No serious adverse events occurred and no patient discontinued the treatment. Discussion: I-rTMS treatment in negative symptoms was found to be safe with excellent acceptability and may have the potential to decrease negative symptoms. The benefit of your design appears to be a rapid onset of the effect. Although, the effect was slightly decreased 14 days after the treatment, so it is questionable, how long this effect of I-rTMS design will last in time. However, the efficacy of our I-rTMS design has not yet been proven on this small sample and further sham- controlled studies including longer follow-up is needed. Keywords: Transcranial magnetic stimulation, Intensive treatment, Schizophrenia, Negative symptoms [0769] DEEP BRAIN STIMULATION OF HUMAN NUCLEUS ACCUMBENS MODULATES PARIETO-FRONTAL ACTIVITY AND INDUCES BEHAVIOURAL CHANGES RELATED TO SUSTAINED ATTENTION AND EXECUTIVE CONTROL J.J. Gonzalez-Rosa*1, B. Reneses 2, N. Parashkev 3, F. Lopez-Sosa 1, M. J. Garcia-Albea 2, A. Oliviero 4, J.A. Barcia 2, B.A. Yebra 1, Strange 1, 5. 1 Technical University of Madrid, Spain; 2 Hospital Clínico San n Sanitaria San Carlos (IdISSC), Spain; Carlos - Instituto de Investigacio 3 Institute of Neurology - UCL, UK; 4 Hospital Nacional de Parapl ejicos, Spain; 5 Alzheimer’s Disease Research Centre & Reina Sofia-CIEN Foundation, Spain Deep brain stimulation (DBS) is currently being successfully employed to alleviate symptoms of severe psychiatric conditions. In this respect, DBS of the nucleus accumbens (NAcc) has been recently introduced to treat treatment-refractory obsessive compulsive disease (OCD). Despite its known effectiveness in the reduction of symptom severity, the operating mechanisms and its effect on pathophysiological brain activity and cognitive functioning remain unclear. Here, we investigated the underlying electrophysiological characteristics of DBS treatment targeting the NAcc using scalp EEG during the performance of a sustained attention task. Thus, we aimed to study the specific effects of NAcc-DBS on EEG activity and task performance by comparing the results of patients with the stimulator turned “ON” and “OFF”. Five patients undergoing NAcc-DBS for treatment of refractory OCD engaged in an AX-CPT paradigm (with equiprobable Go/NoGo conditions) during the recording of scalp event-related potentials (ERP) and simultaneous DBS.
Abstracts / Brain Stimulation 10 (2017) 346e540
[0765] EFFECTS OF AURICULAR VAGUS NERVE STIMULATION ON BRAIN ACTIVITY, COGNITIVE PARAMETERS AND WELL-BEING T. Polak*, C. Stelzer, A. Katzorke, J.B.M. Zeller, M.J. Herrmann. University Clinic Würzburg, Germany Purpose: Auricular Vagus nerve stimulation (aVNS) in the region of the auricular branch of the Vagus nerve (ABVN) is an increasingly used noninvasive brain stimulation method. fMRI studies differ with respect to activation of the prefrontal cortex during aVNS. We now aimed to reappraise these findings by near-infrared spectroscopy (NIRS) as an independent method examining resting brain activity during aVNS in a shamecontrolled study. Methods: 42 healthy young subjects were allocated to aVNS (n¼20) or control stimulation at the ear lobe (sham, n¼22). aVNS was performed according to published procedures (intensity 8mA, frequency 25/s, pulse width 250ms). Brain activation was measured with NIRS in a region of interest covering prefrontal brain areas. Executive brain function was measured using the Trail Making Test and well-being using the german Scale of Well-being. Results: There was a significant change in resting brain activity in prefrontal brain areas over time during aVNS as indicated by a significant main effect for the inner subject factor “time” in ANOVA for repeated measurements (F(1,49)¼50,8, p<0.001). Post-hoc t-tests showed a significant decrease in oxygenated and an increase in deoxygenated hemoglobin. This pattern, however, did not differ significantly from that seen in the sham group. There was no change in cognitive performance nor in wellbeing in the subjects who underwent aVNS. Conclusions: Our preliminary results show a decrease in frontal brain activation upon aVNS as measured by NIRS. However, there was no statistically significant difference between aVNS and sham stimulation at the ear lobe. The results of this pilot study point to the possibility that there may be some overlap between stimulation in the region of the ABVN and stimulation at the ear lobe that is often used for sham stimulation of aVNS. Keywords: auricular vagus nerve stimulation, near-infrared spectroscopy, prefrontal cortex, auricular branch of vagus nerve
[0767] ASSESSING STIMULATION EFFECTS INDUCED BY TDCS USING MEG S. Jang*, D. Kim, H. Cho, M. Kwon, S.C. Jun. Gwangju Institute of Science and Technology, Republic of Korea Transcranial direct current stimulation (tDCS) has been used to modulate the neural activity, however, the effects of tDCS are inconsistent and quite dependent on target brain sites, stimulation duration time, intensity and so on. Thus, it is compelling to investigate stimulus-induced effects through the brain oscillatory changes. For this purpose, we recorded magnetoencephalography (MEG) before and after tDCS. Five healthy volunteers participated in this experiment consisting of three stimulation types d protocol 1 (anode: Cz and cathode: Fpz), protocol 2 (anode: Cz and cathode: POz), and sham; each protocol was conducted during one day. Stimulation was given at 1.5 mA for 15 min duration. Each During resting state (2 min) and go/no-go task before (5 min) and after (10 min) tDCS, MEG was recorded to investigate stimulation effects before and after stimulation. In behavior analysis, we found that button response time was shorter and task accuracy was higher in protocol 2 than others. Moreover, in MEG analysis, M200 and M300 of protocol 2 were larger in magnitude than others. Since go/no-go task performance was enhanced when current flow (forward direction: Cz to Fpz) was applied to the pre-frontal cortex, it may be inferred that protocol 2 may be related with improvement of cognitive ability. Protocol designing according to target sites may be important. Acknowledgement: This work was supported by the GIST Research Institute(GRI) in 2017. Keywords: tDCS, MEG, protocol
[0768] EFFECTIVENESS AND ACCEPTABILITY OF INTENSIVE REPETITIVE TRANSCRANIAL MAGNETIC STIMULATION (I-RTMS) IN NEGATIVE SYMPTOMS OF SCHIZOPHRENIA T. Sverak*1, 2, L. Albrechtova 1, L. Ustohal 1, 2. 1 Masaryk University and University Hospital Brno, Czech Republic; 2 Central European Institute of Technology, Masaryk University, Czech Republic Introduction: Negative symptoms in schizophrenia are disabling and do not respond adequately to antipsychotic or psychosocial treatment. Some meta-analyses suggest efficacy of repetitive transcranial magnetic stimulation (rTMS) for the treatment of them. Usually patients have a not really good compliance and attend three weeks of the treatment is very difficult for them. Using more intensive stimulation protocol might hold promise as a valuable alternative and may be more bearable for the patients. Methods: Open label study which observe the effect of I-rTMS. Investigators examined 8 patients with schizophrenia with predominant negative symptoms and with a high-degree of illness severity. Patients were treated with 10-Hz rTMS applied 4 times per day for 4 days to the left dorsolateral prefrontal cortex. They received total 32000 pulses. Effects on negative symptoms was measured by Positive and negative syndrome scale (PANSS) before the treatment, immediately after the treatment and after 14 days. The results were compared by Wilcoxon's non-parametric test. Results: Negative scale in PANSS was improved by 22% after the I-rTMS and by 16% 14 days after the treatment but these results was not statistically significant (p¼ 0,12). No serious adverse events occurred and no patient discontinued the treatment. Discussion: I-rTMS treatment in negative symptoms was found to be safe with excellent acceptability and may have the potential to decrease negative symptoms. The benefit of your design appears to be a rapid onset of the effect. Although, the effect was slightly decreased 14 days after the treatment, so it is questionable, how long this effect of I-rTMS design will last in time. However, the efficacy of our I-rTMS design has not yet been proven on this small sample and further sham- controlled studies including longer follow-up is needed. Keywords: Transcranial magnetic stimulation, Intensive treatment, Schizophrenia, Negative symptoms [0769] DEEP BRAIN STIMULATION OF HUMAN NUCLEUS ACCUMBENS MODULATES PARIETO-FRONTAL ACTIVITY AND INDUCES BEHAVIOURAL CHANGES RELATED TO SUSTAINED ATTENTION AND EXECUTIVE CONTROL J.J. Gonzalez-Rosa*1, B. Reneses 2, N. Parashkev 3, F. Lopez-Sosa 1, M. J. Garcia-Albea 2, A. Oliviero 4, J.A. Barcia 2, B.A. Yebra 1, Strange 1, 5. 1 Technical University of Madrid, Spain; 2 Hospital Clínico San n Sanitaria San Carlos (IdISSC), Spain; Carlos - Instituto de Investigacio 3 Institute of Neurology - UCL, UK; 4 Hospital Nacional de Parapl ejicos, Spain; 5 Alzheimer’s Disease Research Centre & Reina Sofia-CIEN Foundation, Spain Deep brain stimulation (DBS) is currently being successfully employed to alleviate symptoms of severe psychiatric conditions. In this respect, DBS of the nucleus accumbens (NAcc) has been recently introduced to treat treatment-refractory obsessive compulsive disease (OCD). Despite its known effectiveness in the reduction of symptom severity, the operating mechanisms and its effect on pathophysiological brain activity and cognitive functioning remain unclear. Here, we investigated the underlying electrophysiological characteristics of DBS treatment targeting the NAcc using scalp EEG during the performance of a sustained attention task. Thus, we aimed to study the specific effects of NAcc-DBS on EEG activity and task performance by comparing the results of patients with the stimulator turned “ON” and “OFF”. Five patients undergoing NAcc-DBS for treatment of refractory OCD engaged in an AX-CPT paradigm (with equiprobable Go/NoGo conditions) during the recording of scalp event-related potentials (ERP) and simultaneous DBS.