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The neuroplastic effects of multisite stimulation - a continuous theta burst investigation
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Abstracts / Brain Stimulation 10 (2017) 346e540
meprobamate, propofol, a talking-through technique, an information leaflet, and animal-assisted therapy) have been proposed, but poorly researched. Conclusions: ECT-related anxiety is a highly prevalent phenomenon and the literature provides little guidance for its clinical management. Most studies are of a low methodological quality and suffer significant limitations thereby hampering conclusions. Given the clinical importance of ECT-related anxiety, further study on its nature and evolution through the course of treatment, and on anxiety-reducing interventions is warranted. Keywords: review, ECT, anxiety [0072] NETWORK MECHANISMS OF CLINICAL RESPONSE TO TMS POSTTRAUMATIC STRESS AND MAJOR DEPRESSIVE DISORDERS
IN
N.S. Philip*, J. Barredo, M. v 'ant Wout, J. Almeida, A.R. Tyrka, L.H. Price, L.L. Carpenter. Brown University, USA Introduction: Treatment with repetitive transcranial magnetic stimulation (TMS) can modulate pathological functional connectivity in patients with major depressive disorder (MDD). Posttraumatic stress disorder (PTSD) is often comorbid with MDD, and TMS can alleviate symptoms of PTSD. This is the first study to evaluate TMS-associated changes in connectivity, in patients with comorbid PTSD and MDD. Methods: Resting state functional connectivity was acquired on 33 participants, before and after 5Hz TMS therapy to left dorsolateral prefrontal cortex (DLPFC). Analyses used a priori seeds relevant to TMS, MDD or PTSD: the subgenual anterior cingulate cortex (sgACC), DLPFC, hippocampus (anterior and posterior), and basolateral amygdala (BLA). Seeds were used to evaluate predictors of response to TMS and to compare changes in pre- vs. post-treatment connectivity, adjusting for age and baseline symptom severity. Results were corrected using cluster-based FDR and leave-one-out cross-validation. Results: Several connectivity findings predicted TMS response, including anticorrelated connectivity between the sgACC and precuneus, increased connectivity between the DLPFC and anterior insula, and increased connectivity between the BLA and ventromedial prefrontal cortex (all corrected p<.001). Of the 33 participants, n¼25 had post-TMS data. These participants demonstrated greater anticorrelated connectivity between the sgACC and the precuneus/posterior cingulate and insula; DLPFC connectivity increased to right prefrontal cortex. Compared to positive connectivity at baseline, after TMS there was anticorrelated connectivity between the anterior hippocampus and the dorsal anterior cingulate cortex, and putamen (all corrected p<.001). Follow up analyses indicated that DLPFC changes were associated with improved depressive symptoms, whereas hippocampal uncoupling was uniquely associated with PTSD improvements. Conclusions: These results are consistent with prior work that implicated reduced default network with TMS in MDD, and indicate that TMS can uncouple hippocampal connectivity from PTSD-relevant salience network regions. Therefore TMS can correct clinically relevant network pathology, with changes relevant to commonly comorbid disorders. Keywords: resting state functional connectivity, 5 Hz, hippocampus, salience network [0073] ELECTROCONVULSIVE THERAPY FOR BEHAVIOURAL PROBLEMS IN DEMENTIA - A SYSTEMATIC REVIEW J.F. van den Berg, H.C. Kruithof, R.M. Kok, E. Spaans. Parnassia Psychiatric Institute, The Netherlands
Verwijk*,
H.P.
Introduction: Many patients with dementia develop Behavioural and Psychological Symptoms of Dementia (BPSD) in the course of their disease. In some severe cases, behavioural, environmental, and pharmacological interventions are not sufficient to alleviate the potentially life-threatening symptoms. In those cases, electroconvulsive therapy (ECT) could be an option. This review aimed to summarize the scientific literature on ECT for BPSD. Methods: A search was conducted in Ovid MEDLINE, EMBASE, and PsycINFO. Two reviewers extracted the following data from the retrieved articles: number of patients and their age, gender, diagnoses, type of problem behaviour, which treatments were tried before ECT, specifications
of the ECT treatment, use of rating scales, treatment results, follow-up data, and possible side effects. Results: The initial search yielded 189 screened articles, of which 16 fulfilled the inclusion criteria. Of these 16 articles, one was a prospective cohort study, one was a case-control study, and the other studies were retrospective chart reviews, case series or case reports. In total, these studies reported on 94 patients. The number of ECT sessions ranged from 2 to 16 . Electrode placement was bilateral in 65 patients (69.1%). In 86 of the 94 described patients (91.4%), significant clinical improvement was observed, often early in the treatment course. Thirty-eight patients were referred for maintenance ECT. Adverse effects were most commonly mild, transient, or were not reported. Discussion: The reviewed articles suggest that ECT could be an effective treatment for severe BPSD, with few adverse consequences. However, because of the designs of the reviewed studies and their small number, and the substantial risk of selection bias, this review does not allow us to draw solid conclusions about the safety and effectiveness of ECT for problematic behaviour in dementia. Further prospective studies are needed to substantiate the preliminary positive results described in the reviewed articles. Keywords: ECT, Behavioural and Psychological Symptoms Dementia, Dementia, Review [0074] THE NEUROPLASTIC EFFECTS OF MULTISITE STIMULATION - A CONTINUOUS THETA BURST INVESTIGATION M. Do*, M. Kirkovski, C. Davies, P.G. Enticott, L.K. Byrne. Deakin University, Australia Continuous theta burst stimulation (cTBS) is a non-invasive brain stimulation technique which can induce neuroplastic changes within the human primary motor cortex (M1). The effects of cTBS on corticomotor excitability are not always homogenous with some authors noting a degree of interindividual variability. The current study investigated whether priming M1 intra- or inter-regionally with an additional bout of cTBS could reduce this variability. Using a conditioning-test protocol with a 10 min interval, active conditioning cTBS was applied to the dorsolateral prefrontal cortex (DLPFC-M1), the dorsal premotor cortex (dPMC-M1) or M1 (M1-M1) within the left hemisphere. Sham conditioning was also applied (ShamM1). Neuroplastic changes were indexed using peak-to-peak motorevoked potential (MEP) amplitudes recorded from the first dorsal interosseous muscle of the right hand elicited through single pulse TMS applied over the left-M1 ‘hotpot’. Nineteen right-handed healthy participants aged 19 to 33 (M ¼ 26.58, SD ¼ 3.10) underwent four randomised sessions separated by a minimum of five days. Overall, no significant between group differences were found. Single protocol analysis revealed that DLPFC-M1 stimulation induced facilitation of corticomotor excitability. Using individual response plots, and a criterion threshold of 20% change from baseline levels, participants were categorised as either responders (showing either facilitation or suppression) or non-responders. M1-M1 stimulation induced suppression of MEP responses in 47% of participants, whereas DLPFC-M1 stimulation induced facilitation in 42%. Sham-M1 stimulation was the least effective protocol with 58% showing no change. The results indicate that neuroplastic responses following intra- or interregional priming of M1 using cTBS are variable. Further work is required to identify the source of such variability and to evaluate the therapeutic and clinical potential of priming protocols. Keywords: Continuous theta burst stimulation, Transcranial magnetic stimulation, Priming, Plasticity [0076] RATIONAL TARGETING THALAMO-CORTICAL OSCILLATIONS WITH NONINVASIVE BRAIN STIMULATION F. Frohlich*. UNC at Chapel Hill, USA Introduction: Thalamo-cortical oscillations such as the alpha oscillation (8-12 Hz, wake state) and sleep spindles (11-16 Hz) are essential for cognition and behavior. Our long-term goal is to develop transcranial alternating current stimulation (tACS) paradigms for targeting
Abstracts / Brain Stimulation 10 (2017) 346e540
meprobamate, propofol, a talking-through technique, an information leaflet, and animal-assisted therapy) have been proposed, but poorly researched. Conclusions: ECT-related anxiety is a highly prevalent phenomenon and the literature provides little guidance for its clinical management. Most studies are of a low methodological quality and suffer significant limitations thereby hampering conclusions. Given the clinical importance of ECT-related anxiety, further study on its nature and evolution through the course of treatment, and on anxiety-reducing interventions is warranted. Keywords: review, ECT, anxiety [0072] NETWORK MECHANISMS OF CLINICAL RESPONSE TO TMS POSTTRAUMATIC STRESS AND MAJOR DEPRESSIVE DISORDERS
IN
N.S. Philip*, J. Barredo, M. v 'ant Wout, J. Almeida, A.R. Tyrka, L.H. Price, L.L. Carpenter. Brown University, USA Introduction: Treatment with repetitive transcranial magnetic stimulation (TMS) can modulate pathological functional connectivity in patients with major depressive disorder (MDD). Posttraumatic stress disorder (PTSD) is often comorbid with MDD, and TMS can alleviate symptoms of PTSD. This is the first study to evaluate TMS-associated changes in connectivity, in patients with comorbid PTSD and MDD. Methods: Resting state functional connectivity was acquired on 33 participants, before and after 5Hz TMS therapy to left dorsolateral prefrontal cortex (DLPFC). Analyses used a priori seeds relevant to TMS, MDD or PTSD: the subgenual anterior cingulate cortex (sgACC), DLPFC, hippocampus (anterior and posterior), and basolateral amygdala (BLA). Seeds were used to evaluate predictors of response to TMS and to compare changes in pre- vs. post-treatment connectivity, adjusting for age and baseline symptom severity. Results were corrected using cluster-based FDR and leave-one-out cross-validation. Results: Several connectivity findings predicted TMS response, including anticorrelated connectivity between the sgACC and precuneus, increased connectivity between the DLPFC and anterior insula, and increased connectivity between the BLA and ventromedial prefrontal cortex (all corrected p<.001). Of the 33 participants, n¼25 had post-TMS data. These participants demonstrated greater anticorrelated connectivity between the sgACC and the precuneus/posterior cingulate and insula; DLPFC connectivity increased to right prefrontal cortex. Compared to positive connectivity at baseline, after TMS there was anticorrelated connectivity between the anterior hippocampus and the dorsal anterior cingulate cortex, and putamen (all corrected p<.001). Follow up analyses indicated that DLPFC changes were associated with improved depressive symptoms, whereas hippocampal uncoupling was uniquely associated with PTSD improvements. Conclusions: These results are consistent with prior work that implicated reduced default network with TMS in MDD, and indicate that TMS can uncouple hippocampal connectivity from PTSD-relevant salience network regions. Therefore TMS can correct clinically relevant network pathology, with changes relevant to commonly comorbid disorders. Keywords: resting state functional connectivity, 5 Hz, hippocampus, salience network [0073] ELECTROCONVULSIVE THERAPY FOR BEHAVIOURAL PROBLEMS IN DEMENTIA - A SYSTEMATIC REVIEW J.F. van den Berg, H.C. Kruithof, R.M. Kok, E. Spaans. Parnassia Psychiatric Institute, The Netherlands
Verwijk*,
H.P.
Introduction: Many patients with dementia develop Behavioural and Psychological Symptoms of Dementia (BPSD) in the course of their disease. In some severe cases, behavioural, environmental, and pharmacological interventions are not sufficient to alleviate the potentially life-threatening symptoms. In those cases, electroconvulsive therapy (ECT) could be an option. This review aimed to summarize the scientific literature on ECT for BPSD. Methods: A search was conducted in Ovid MEDLINE, EMBASE, and PsycINFO. Two reviewers extracted the following data from the retrieved articles: number of patients and their age, gender, diagnoses, type of problem behaviour, which treatments were tried before ECT, specifications
of the ECT treatment, use of rating scales, treatment results, follow-up data, and possible side effects. Results: The initial search yielded 189 screened articles, of which 16 fulfilled the inclusion criteria. Of these 16 articles, one was a prospective cohort study, one was a case-control study, and the other studies were retrospective chart reviews, case series or case reports. In total, these studies reported on 94 patients. The number of ECT sessions ranged from 2 to 16 . Electrode placement was bilateral in 65 patients (69.1%). In 86 of the 94 described patients (91.4%), significant clinical improvement was observed, often early in the treatment course. Thirty-eight patients were referred for maintenance ECT. Adverse effects were most commonly mild, transient, or were not reported. Discussion: The reviewed articles suggest that ECT could be an effective treatment for severe BPSD, with few adverse consequences. However, because of the designs of the reviewed studies and their small number, and the substantial risk of selection bias, this review does not allow us to draw solid conclusions about the safety and effectiveness of ECT for problematic behaviour in dementia. Further prospective studies are needed to substantiate the preliminary positive results described in the reviewed articles. Keywords: ECT, Behavioural and Psychological Symptoms Dementia, Dementia, Review [0074] THE NEUROPLASTIC EFFECTS OF MULTISITE STIMULATION - A CONTINUOUS THETA BURST INVESTIGATION M. Do*, M. Kirkovski, C. Davies, P.G. Enticott, L.K. Byrne. Deakin University, Australia Continuous theta burst stimulation (cTBS) is a non-invasive brain stimulation technique which can induce neuroplastic changes within the human primary motor cortex (M1). The effects of cTBS on corticomotor excitability are not always homogenous with some authors noting a degree of interindividual variability. The current study investigated whether priming M1 intra- or inter-regionally with an additional bout of cTBS could reduce this variability. Using a conditioning-test protocol with a 10 min interval, active conditioning cTBS was applied to the dorsolateral prefrontal cortex (DLPFC-M1), the dorsal premotor cortex (dPMC-M1) or M1 (M1-M1) within the left hemisphere. Sham conditioning was also applied (ShamM1). Neuroplastic changes were indexed using peak-to-peak motorevoked potential (MEP) amplitudes recorded from the first dorsal interosseous muscle of the right hand elicited through single pulse TMS applied over the left-M1 ‘hotpot’. Nineteen right-handed healthy participants aged 19 to 33 (M ¼ 26.58, SD ¼ 3.10) underwent four randomised sessions separated by a minimum of five days. Overall, no significant between group differences were found. Single protocol analysis revealed that DLPFC-M1 stimulation induced facilitation of corticomotor excitability. Using individual response plots, and a criterion threshold of 20% change from baseline levels, participants were categorised as either responders (showing either facilitation or suppression) or non-responders. M1-M1 stimulation induced suppression of MEP responses in 47% of participants, whereas DLPFC-M1 stimulation induced facilitation in 42%. Sham-M1 stimulation was the least effective protocol with 58% showing no change. The results indicate that neuroplastic responses following intra- or interregional priming of M1 using cTBS are variable. Further work is required to identify the source of such variability and to evaluate the therapeutic and clinical potential of priming protocols. Keywords: Continuous theta burst stimulation, Transcranial magnetic stimulation, Priming, Plasticity [0076] RATIONAL TARGETING THALAMO-CORTICAL OSCILLATIONS WITH NONINVASIVE BRAIN STIMULATION F. Frohlich*. UNC at Chapel Hill, USA Introduction: Thalamo-cortical oscillations such as the alpha oscillation (8-12 Hz, wake state) and sleep spindles (11-16 Hz) are essential for cognition and behavior. Our long-term goal is to develop transcranial alternating current stimulation (tACS) paradigms for targeting