- Email: [email protected]
O16 Shifts in mean peak oscillatory frequency during repetitive transcranial magnetic stimulation (rTMS) treatment of major depressive disorder
Abstracts / Clinical Neurophysiology 128 (2017) e178–e303
During the repeated treatment with tDCS the patient >65 yrs showed a significant improvement (onset of tDCS: 59.1 ± 12.2 s, the end of tDCS: 33.6 ± 8.1 p < 0.0001). Dual tests (counting back by 3 and 7 during walking) showed a similar improvement under regularly repeated tDCS stimulation during 2 years. The gender and duration of the disease did not influence on the development of the disease as strongly as age. The motor ability in PD can be maintained in the same level 665 yrs with rTMS (1 Hz) for the followed 3.5 years. Patients above 65 yrs deteriorated highly significantly compared with the group <65 yrs. The cognitive function was influenced by tDCS in the group >65 yrs where the results were significantly deteriorated compared with age match controls and patients with 665 yrs. The age is the main predictors for the effect of rTMS with 1 Hz. The progression rate was lower in both former groups than in our earlier study with dopa substitution only. Keywords: RTMS, TDCS, Parkinson’s disease, Progression of disease doi:10.1016/j.clinph.2017.07.026
O16 Shifts in mean peak oscillatory frequency during repetitive transcranial magnetic stimulation (rTMS) treatment of major depressive disorder—Andrew Leuchter, Juliane Corlier, Ian Cook (University of California Los Angeles, Semel Institute for Neuroscience and Human Behavior, Los Angeles, USA) Objectives: Repetitive Transcranial Magnetic Stimulation (rTMS) is an effective treatment for Major Depressive Disorder (MDD). Efficacy is variable and there are no reliable predictors of treatment outcome. This study aimed to identify a quantitative electroencephalography (qEEG) biomarker of rTMS treatment outcome. Methods: 59 subjects with MDD (mean baseline Inventory of Depressive Symptomatology – Self Rated [IDS-SR] score = 52) underwent rTMS treatment applied to left dorsolateral prefrontal cortex (DLPFC). Subjects were examined with a 64 channel TMScompatible qEEG system before, during, and after the initial treatment session. Changes in primary and secondary mean peak frequencies between 6 and 14 Hz were examined between pre- and post-treatment resting states. Clinical outcome was examined after two and six weeks of treatment, with response defined as a 50% reduction in IDS-SR and remission a final IDS-SR 11. Results: There was a significant association between changes in mean peak frequency and outcome. Early response and six -week remission were associated with acceleration and decreased variance of primary mean peak frequency, and emergence of higher frequency secondary peaks. Changes in mean peak frequency pre- to post- the initial rTMS treatment session predicted six-week clinical outcome. Discussion: Changes in mean peak frequency during the initial rTMS treatment session are a promising biomarker of clinical outcome. Conclusions: Future studies should examine shifts in frequency in relation to adjustment of rTMS parameters. Significance: qEEG studies performed during the initial rTMS treatment session may be a useful method for guiding decisions regarding the duration and parameters used for rTMS treatment. Keywords: rTMS, Major Depressive Disorder (MDD), clinical treatment, quantitative encephalography (qEEG), mean peak frequency doi:10.1016/j.clinph.2017.07.027
e185
O17 Controlled stimulation of deep brain areas using navigated TMS with a standard coil—Magnus Thordstein (University Hospital Linköping, Clinical Neurophysiology, Linkoping, Sweden) Introduction: TMS has mainly been used- and is often believed to only be suitable for stimulation of superficial cortical areas. However, standard coils have also been used to target deeper volumes, alternatively specially designed coils have been developed for this purpose. We aimed to validate the use of standard coils for the stimulation of deep volumes. We used a system for navigated TMS where the stimulus induced electrical field strength in any location of the brain can be estimated. In the process, we also studied if the use of a midline parieto-occipital location as site for shamstimulation could be justified. Methods: Healthy adults were stimulated using a standard figureof-eight coil in the Eximia system (Nexstim Ltd). The RMT for activation of the APB and AH muscles on the dominant side were defined. Four scalp locations were stimulated, each with three different intensities in relation to the RMTs: Three scalp locations with shortest Euclidian distance to dACC, insular and hippocampal cortices respectively, one location at the proposed site for sham-stimulation. Results: All locations could be stimulated in all subjects. The intensity at the superficial cortical area under the coil, needed to produce sufficient (as compared to the RMTs) electrical field strengths at the deep locations dACC and insula were within a reasonable range (1.5– 2 RMT), whereas hippocampal structures were not possible to stimulate using this set up. The sham stimulation location seems to be adequate in terms of not producing significant field strengths over motor cortices. Discussion: If navigated stimulation and estimation of electrical field strengths are utilised, a standard TMS setup can be used to stimulate deep structures such as the dACC and insular cortex in a biologically reasonable fashion. A midline parieto-occipital location may be used as a locus for sham-stimulation in studies investigating motor cortex stimulation.
Keywords: Navigated brain stimulation, Deep stimulation, Sham stimulation doi:10.1016/j.clinph.2017.07.028
O18 Cathodal transcranial direct current stimulation reduces seizure frequency and modulates brain functional connectivity with drug-resistant temporal lobe epilepsy: A sham controlled study—Giovanni Assenza 1, Carlo Cottone 2, Franca Tecchio 2, Vincenzo Di Lazzaro 1 (1 Università Campus Bio-Medico di Roma, Neurology, Rome, Italy, 2 CNR, LET’S laboratory, Rome, Italy)
Purpose: One-third of epilepsy patients develop drug resistance epilepsy (DRE), and half of them can benefit from the surgical removal of epileptic focus (EF). Neuromodulation represents the only hope to ameliorate the quality of life of the remaining patients. Cathodal transcranial direct current stimulation (ctDCS) is a techniques able to non-invasively inhibit cortical excitability, which is abnormally increased in epilepsy, but its efficacy in reducing seizures and in modulating epileptic network is still under debate. We evaluated the efficacy of 20-min 1 mA ctDCS vs sham-tDCS in reducing seizure frequency and in modulating the functional connectivity (FC) between EF and the other cortical areas, in temporal DRE patients.
During the repeated treatment with tDCS the patient >65 yrs showed a significant improvement (onset of tDCS: 59.1 ± 12.2 s, the end of tDCS: 33.6 ± 8.1 p < 0.0001). Dual tests (counting back by 3 and 7 during walking) showed a similar improvement under regularly repeated tDCS stimulation during 2 years. The gender and duration of the disease did not influence on the development of the disease as strongly as age. The motor ability in PD can be maintained in the same level 665 yrs with rTMS (1 Hz) for the followed 3.5 years. Patients above 65 yrs deteriorated highly significantly compared with the group <65 yrs. The cognitive function was influenced by tDCS in the group >65 yrs where the results were significantly deteriorated compared with age match controls and patients with 665 yrs. The age is the main predictors for the effect of rTMS with 1 Hz. The progression rate was lower in both former groups than in our earlier study with dopa substitution only. Keywords: RTMS, TDCS, Parkinson’s disease, Progression of disease doi:10.1016/j.clinph.2017.07.026
O16 Shifts in mean peak oscillatory frequency during repetitive transcranial magnetic stimulation (rTMS) treatment of major depressive disorder—Andrew Leuchter, Juliane Corlier, Ian Cook (University of California Los Angeles, Semel Institute for Neuroscience and Human Behavior, Los Angeles, USA) Objectives: Repetitive Transcranial Magnetic Stimulation (rTMS) is an effective treatment for Major Depressive Disorder (MDD). Efficacy is variable and there are no reliable predictors of treatment outcome. This study aimed to identify a quantitative electroencephalography (qEEG) biomarker of rTMS treatment outcome. Methods: 59 subjects with MDD (mean baseline Inventory of Depressive Symptomatology – Self Rated [IDS-SR] score = 52) underwent rTMS treatment applied to left dorsolateral prefrontal cortex (DLPFC). Subjects were examined with a 64 channel TMScompatible qEEG system before, during, and after the initial treatment session. Changes in primary and secondary mean peak frequencies between 6 and 14 Hz were examined between pre- and post-treatment resting states. Clinical outcome was examined after two and six weeks of treatment, with response defined as a 50% reduction in IDS-SR and remission a final IDS-SR 11. Results: There was a significant association between changes in mean peak frequency and outcome. Early response and six -week remission were associated with acceleration and decreased variance of primary mean peak frequency, and emergence of higher frequency secondary peaks. Changes in mean peak frequency pre- to post- the initial rTMS treatment session predicted six-week clinical outcome. Discussion: Changes in mean peak frequency during the initial rTMS treatment session are a promising biomarker of clinical outcome. Conclusions: Future studies should examine shifts in frequency in relation to adjustment of rTMS parameters. Significance: qEEG studies performed during the initial rTMS treatment session may be a useful method for guiding decisions regarding the duration and parameters used for rTMS treatment. Keywords: rTMS, Major Depressive Disorder (MDD), clinical treatment, quantitative encephalography (qEEG), mean peak frequency doi:10.1016/j.clinph.2017.07.027
e185
O17 Controlled stimulation of deep brain areas using navigated TMS with a standard coil—Magnus Thordstein (University Hospital Linköping, Clinical Neurophysiology, Linkoping, Sweden) Introduction: TMS has mainly been used- and is often believed to only be suitable for stimulation of superficial cortical areas. However, standard coils have also been used to target deeper volumes, alternatively specially designed coils have been developed for this purpose. We aimed to validate the use of standard coils for the stimulation of deep volumes. We used a system for navigated TMS where the stimulus induced electrical field strength in any location of the brain can be estimated. In the process, we also studied if the use of a midline parieto-occipital location as site for shamstimulation could be justified. Methods: Healthy adults were stimulated using a standard figureof-eight coil in the Eximia system (Nexstim Ltd). The RMT for activation of the APB and AH muscles on the dominant side were defined. Four scalp locations were stimulated, each with three different intensities in relation to the RMTs: Three scalp locations with shortest Euclidian distance to dACC, insular and hippocampal cortices respectively, one location at the proposed site for sham-stimulation. Results: All locations could be stimulated in all subjects. The intensity at the superficial cortical area under the coil, needed to produce sufficient (as compared to the RMTs) electrical field strengths at the deep locations dACC and insula were within a reasonable range (1.5– 2 RMT), whereas hippocampal structures were not possible to stimulate using this set up. The sham stimulation location seems to be adequate in terms of not producing significant field strengths over motor cortices. Discussion: If navigated stimulation and estimation of electrical field strengths are utilised, a standard TMS setup can be used to stimulate deep structures such as the dACC and insular cortex in a biologically reasonable fashion. A midline parieto-occipital location may be used as a locus for sham-stimulation in studies investigating motor cortex stimulation.
Keywords: Navigated brain stimulation, Deep stimulation, Sham stimulation doi:10.1016/j.clinph.2017.07.028
O18 Cathodal transcranial direct current stimulation reduces seizure frequency and modulates brain functional connectivity with drug-resistant temporal lobe epilepsy: A sham controlled study—Giovanni Assenza 1, Carlo Cottone 2, Franca Tecchio 2, Vincenzo Di Lazzaro 1 (1 Università Campus Bio-Medico di Roma, Neurology, Rome, Italy, 2 CNR, LET’S laboratory, Rome, Italy)
Purpose: One-third of epilepsy patients develop drug resistance epilepsy (DRE), and half of them can benefit from the surgical removal of epileptic focus (EF). Neuromodulation represents the only hope to ameliorate the quality of life of the remaining patients. Cathodal transcranial direct current stimulation (ctDCS) is a techniques able to non-invasively inhibit cortical excitability, which is abnormally increased in epilepsy, but its efficacy in reducing seizures and in modulating epileptic network is still under debate. We evaluated the efficacy of 20-min 1 mA ctDCS vs sham-tDCS in reducing seizure frequency and in modulating the functional connectivity (FC) between EF and the other cortical areas, in temporal DRE patients.