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A significant amount of European basic and clinical neuroscience research includes the use of transcranial magnetic stimulation (TMS) and low intensity transcranial electrical stimulation (tES), mainly transcranial direct current stimulation (tDCS). Two recent changes in the EU regulations, the introduction of the Medical Device Regulation (MDR) (2017/745) and the Annex XVI have caused significant problems and confusions in the brain stimulation field. The negative consequences of the MDR for non-invasive brain stimulation (NIBS) have been largely overlooked and until today, have not been consequently addressed by National Competent Authorities, local ethical committees, politicians and by the scientific communities. In addition, a rushed bureaucratic decision led to seemingly wrong classification of NIBS products without an intended medical purpose into the same risk group III as invasive stimulators. Overregulation is detrimental for any research and for future developments, therefore researchers, clinicians, industry, patient representatives and an ethicist were invited to contribute to this document with the aim of starting a constructive dialogue and enacting positive changes in the regulatory environment.
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Estimulación Transcraneal de Corriente Directa , Estimulación Magnética Transcraneal , Humanos , Investigación Biomédica , Aprobación de Recursos/legislación & jurisprudencia , Europa (Continente) , Unión Europea , Legislación de Dispositivos Médicos , Estimulación Magnética Transcraneal/métodosRESUMEN
Background: Posttraumatic stress disorder (PTSD) is a severe and frequent affection that is highly comorbid to major depressive disorder. Comorbid PTSD and depression are usually treatment-resistant, with a high risk of functional impairment and suicide. Esketamine nasal spray is a recent validated treatment for treatment-resistant depression (TRD), but its efficacy on comorbid TRD-PTSD remains insufficiently documented. In particular, flashbacks can occur during esketamine administration and their influence on clinical outcomes is unknown. Objectives: Our main objective was to describe esketamine-induced traumatic flashbacks and their impact on clinical trajectories within a sample of patients with comorbid TRD-PTSD. Methods: We retrospectively collected clinical data of patients receiving esketamine nasal spray for TRD with comorbid PTSD who experienced at least one flashback of their trauma during esketamine sessions across 11 psychiatric departments. Results: Between February 2020 and March 2023, 22 adult patients with TRD met inclusion criteria. In sixteen patients (72.7%) flashbacks disappeared as the sessions progressed. In six patients (27.3%), esketamine treatment was stopped because of persistent flashbacks. When esketamine was continued, clinical response was observed both for depression and PTSD (depression response rate: 45.5% and remission rate: 22.7%; PTSD response rate: 45.5% and remission: 18.2%). Limitations: The retrospective design of the study and the absence of a comparator group are the main limitations of our study. Conclusions: Our results suggest that the occurrence of esketamine-induced traumatic flashbacks does not hinder clinical response. On the contrary, when managed appropriately and combined with targeted psychotherapy, it could even contribute to positive outcomes.
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BACKGROUND: In 2008, the U.S. FDA approved rTMS as a treatment against medication-resistant depression. However, real-world rTMS outcomes remain understudied. This study investigates how rTMS for depression is delivered in routine clinical practice in France, and measures its effectiveness as well as its moderators. METHODS: Five centers provided retrospective data on patients who were treated with rTMS for treatment-resistant depression from January 2015 to December 2020. Patients were assessed twice using a hetero-questionnaire, with baseline and immediate post-treatment assessments. We conducted univariate analyses to study which factors were significantly associated with rTMS effectiveness. We then included age, gender, and significant factors in a multivariate model. RESULTS: We collected data from 435 patients with a mean age of 51.27 (14.91): 66 % were female, and 26 % suffered from bipolar depression. Stimulation was delivered using four different stimulation parameters: 1 Hz (7 % of the individuals), 10 Hz (43 %), 20 Hz (12 %), and 50 Hz (intermittent Theta Burst Stimulation, iTBS) (38 %). The mean improvement of depressive symptoms was 33 % (p < 0.001, effect-size: 0.79). Response and remission rates were of 31 % and 22.8 %, respectively. In the multivariate analysis, improvement in depressive symptoms was associated with higher baseline symptoms. CONCLUSION: This is one of the largest studies that investigates, with careful clinician-rated scales by trained psychiatrists, the effect of rTMS in naturalistic settings. Repetitive TMS appears to be effective in routine clinical practice, although its efficacy could be improved by analyzing predictors of response, as well as personalized targeting of specific brain areas.
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Trastorno Depresivo Mayor , Humanos , Femenino , Persona de Mediana Edad , Masculino , Trastorno Depresivo Mayor/terapia , Trastorno Depresivo Mayor/etiología , Estimulación Magnética Transcraneal , Estudios Retrospectivos , Depresión/terapia , Encéfalo , Resultado del Tratamiento , Corteza Prefrontal/fisiologíaRESUMEN
At a time when innovations in psychiatry are booming, particularly in the field of medical devices, we thought it necessary, as members of French Society for Biological Psychiatry and Neuropsychopharmacology (AFPBN), to reconsider one of the oldest medical devices in psychiatry: the ECT apparatus. First, we recall the regulatory aspects of ECT. National guidelines define means of implementation and conditions of administration of ECT. Second, we remind of the indications and levels of evidence of ECT in the main psychiatric disorders, including catatonia. Then, we synthetize the place of ECT alongside other brain stimulation therapies, especially repetitive Trancranial Magnetic Stimulation (rTMS). Furthermore, we explain the general effects of ECT: increased neuronal plasticity and neurogenesis, enhancement of the stress axis, resistance to oxidative stress, improved vascular endothelial function, activation of microglia and astrocytes, decrease in inflammatory events by upregulation of neuroinflammatory cytokines, and production of mitochondrial ATP. These effects appear from the first sessions and continue during the course of ECT treatment, suggesting activation of endogenous neuroprotection. Finally, we remember that most patients perform as well or better on neuropsychological assessments after ECT, relative to pre-ECT results, and this improvement continues over the following months. Memory disorders reported post-ECT are not all attributable to ECT. They may be subjective in nature or linked to residual depressive (and possibly comorbid neurogenerative) symptoms later attributed to ECT, on the basis of preexisting negative representations. We urgently need to reemphasize the crucial role of ECT in psychiatric treatment strategies as well as the need to update ECT recommendations.
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Catatonia , Terapia Electroconvulsiva , Trastornos Mentales , Psiquiatría , Humanos , Terapia Electroconvulsiva/métodos , Trastornos Mentales/terapia , Estimulación Magnética Transcraneal/métodos , Catatonia/terapiaRESUMEN
BACKGROUND: One out of three patients with schizophrenia failed to respond adequately to antipsychotics and continue to experience debilitating symptoms such as auditory hallucinations and negative symptoms. The development of additional therapeutic approaches for these persistent symptoms constitutes a major goal for patients. Here, we develop a randomized-controlled trial testing the efficacy of high-frequency transcranial random noise stimulation (hf-tRNS) for the treatment of resistant/persistent symptoms of schizophrenia in patients with various profiles of symptoms, cognitive deficits and illness duration. We also aim to investigate the biological and cognitive effects of hf-tRNS and to identify the predictors of clinical response. METHODS: In a randomized, double-blind, 2-arm parallel-group, controlled, multicentre study, 144 patients with schizophrenia and persistent symptoms despite the prescription of at least one antipsychotic treatment will be randomly allocated to receive either active (n = 72) or sham (n = 72) hf-tRNS. hf-tRNS (100-500 Hz) will be delivered for 20 min with a current intensity of 2 mA and a 1-mA offset twice a day on 5 consecutive weekdays. The anode will be placed over the left dorsolateral prefrontal cortex and the cathode over the left temporoparietal junction. Patients' symptoms will be assessed prior to hf-tRNS (baseline), after the 10 sessions, and at 1-, 3- and 6-month follow-up. The primary outcome will be the number of responders defined as a reduction of at least 25% from the baseline scores on the Positive and Negative Syndrome Scale (PANSS) after the 10 sessions. Secondary outcomes will include brain activity and connectivity, source monitoring performances, social cognition, other clinical (including auditory hallucinations) and biological variables, and attitude toward treatment. DISCUSSION: The results of this trial will constitute a first step toward establishing the usefulness of hf-tRNS in schizophrenia whatever the stage of the illness and the level of treatment resistance. We hypothesize a long-lasting effect of active hf-tRNS on the severity of schizophrenia symptoms as compared to sham. This trial will also have implications for the use of hf-tRNS as a preventive intervention of relapse in patients with schizophrenia. TRIAL REGISTRATION: ClinicalTrials.gov NCT02744989. Prospectively registered on 20 April 2016.
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Esquizofrenia , Estimulación Transcraneal de Corriente Directa , Corteza Prefontal Dorsolateral , Método Doble Ciego , Alucinaciones/diagnóstico , Alucinaciones/terapia , Humanos , Estudios Multicéntricos como Asunto , Recurrencia Local de Neoplasia , Ensayos Clínicos Controlados Aleatorios como Asunto , Esquizofrenia/diagnóstico , Esquizofrenia/tratamiento farmacológico , Resultado del TratamientoRESUMEN
OBJECTIVES: Relapses and recurrence remain the greatest risks posed by patients with severe mood disorders after discontinuation of electroconvulsive therapy (ECT). To date, despite a wide range of literature on ECT, little is known about the rate of recurrence of depression after maintenance ECT (mECT) discontinuation specifically. This study sought to address this lacuna, confronting literature data to the results of a retrospective case study. METHODS: A comprehensive review was conducted, followed by a retrospective analysis of 18 cases of mECT discontinuation between January 2011 and June 2016 involving patients with affective disorders. RESULTS: The comprehensive review revealed that only 3 studies have assessed recurrence rate after c/mECT discontinuation. In our retrospective analysis, mean (SD) mECT duration was 12.69 (12.16) months. A new mood event (usually a depressive state) was observed in 50% of the cases, and 44% of those recurrences occurred during the first 6 months after discontinuation. DISCUSSION: Given that high recurrence rates are observed after mECT discontinuation, the authors discuss the advantages of long-term mECT and the choice of concomitant pharmacotherapy for severe and complex affective disorders.
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Terapia Electroconvulsiva , Trastornos del Humor/terapia , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Francia/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Trastornos del Humor/epidemiología , Recurrencia , Estudios RetrospectivosRESUMEN
The objective of this work was to study the impact of repetitive Transcranial Magnetic Stimulation (rTMS) on the EEG connectivity evaluated by indices based on graph theory, derived from Directed Transfer Function (DTF), in patients with major depressive disorder (MDD) or with bipolar disorder (BD). The results showed the importance of beta and gamma rhythms. The indices density, degree and clustering coefficient increased in MDD responders in beta and gamma bands after rTMS. Interestingly, the density and the degree changed in theta band in both groups of nonresponders (decreased in MDD nonresponders but increased in BD nonresponders). Moreover, both indices of integration (the characteristic path length and the global efficiency) as well as the clustering coefficient increased in BD nonresponders for gamma band. In BD responders, the activity increased in the frontal lobe, mainly in the left hemisphere, while in MDD responders in the central posterior part of brain. The fronto-posterior asymmetry decreased in both groups of responders in delta and beta bands. Changes in inter-hemispheric asymmetry were found only in BD nonresponders in all bands, except gamma band. Comparison between groups showed that the degree increased in delta band independently on disease (BD, MDD). These preliminary results showed that the DTF may be a useful marker allowing for evaluation of effectiveness of the rTMS therapy as well for group differentiation between MDD and BD considering separately groups of responders and nonresponders. However, further investigation should be performed over larger groups of patients to confirmed our findings.
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Trastorno Bipolar/fisiopatología , Ondas Encefálicas/fisiología , Conectoma/métodos , Trastorno Depresivo Mayor/fisiopatología , Electroencefalografía/métodos , Estimulación Magnética Transcraneal , Adulto , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
A group of European experts reappraised the guidelines on the therapeutic efficacy of repetitive transcranial magnetic stimulation (rTMS) previously published in 2014 [Lefaucheur et al., Clin Neurophysiol 2014;125:2150-206]. These updated recommendations take into account all rTMS publications, including data prior to 2014, as well as currently reviewed literature until the end of 2018. Level A evidence (definite efficacy) was reached for: high-frequency (HF) rTMS of the primary motor cortex (M1) contralateral to the painful side for neuropathic pain; HF-rTMS of the left dorsolateral prefrontal cortex (DLPFC) using a figure-of-8 or a H1-coil for depression; low-frequency (LF) rTMS of contralesional M1 for hand motor recovery in the post-acute stage of stroke. Level B evidence (probable efficacy) was reached for: HF-rTMS of the left M1 or DLPFC for improving quality of life or pain, respectively, in fibromyalgia; HF-rTMS of bilateral M1 regions or the left DLPFC for improving motor impairment or depression, respectively, in Parkinson's disease; HF-rTMS of ipsilesional M1 for promoting motor recovery at the post-acute stage of stroke; intermittent theta burst stimulation targeted to the leg motor cortex for lower limb spasticity in multiple sclerosis; HF-rTMS of the right DLPFC in posttraumatic stress disorder; LF-rTMS of the right inferior frontal gyrus in chronic post-stroke non-fluent aphasia; LF-rTMS of the right DLPFC in depression; and bihemispheric stimulation of the DLPFC combining right-sided LF-rTMS (or continuous theta burst stimulation) and left-sided HF-rTMS (or intermittent theta burst stimulation) in depression. Level A/B evidence is not reached concerning efficacy of rTMS in any other condition. The current recommendations are based on the differences reached in therapeutic efficacy of real vs. sham rTMS protocols, replicated in a sufficient number of independent studies. This does not mean that the benefit produced by rTMS inevitably reaches a level of clinical relevance.
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Trastornos Mentales/terapia , Enfermedades del Sistema Nervioso/terapia , Guías de Práctica Clínica como Asunto , Estimulación Magnética Transcraneal/métodos , Medicina Basada en la Evidencia/normas , Humanos , Estimulación Magnética Transcraneal/efectos adversos , Estimulación Magnética Transcraneal/normasRESUMEN
The safety and efficacy of neuronavigated intermittent theta burst stimulation (iTBS) in patients with bipolar depression has not yet been investigated. We hypothesized the superiority of active iTBS over sham. Twenty-six patients were randomly allocated to receive either active (n=12) or sham (n=14) iTBS. Response and remission rates according to changes in depression MADRS score were high following active iTBS (72% and 42% for response and remission rates, respectively), but no significant difference was found after sham stimulation (42%and 25%). No adverse events were observed. This study revealed the safety and tolerability of twice daily iTBS in patients with bipolar depression. Larger controlled studies are warranted to prove iTBS superiority in treatment-resistant bipolar depression.
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Trastorno Bipolar/fisiopatología , Trastorno Depresivo Mayor/fisiopatología , Trastorno Depresivo Resistente al Tratamiento/fisiopatología , Adulto , Femenino , Humanos , Masculino , Proyectos Piloto , Corteza Prefrontal/fisiología , Estimulación Magnética Transcraneal/métodos , Resultado del Tratamiento , Adulto JovenRESUMEN
Repeated transcranial magnetic stimulation (rTMS) is still a recent treatment in psychiatry. This article aims at updating the clinicians'knowledge about rTMS in the treatment of mood disorders (uni and bipolar depressive disorders, manic/mixed states, suicidal risk, catatonia). It is intended for clinicians who are required to indicate and/or use rTMS in their current practice. rTMShas the highest level of evidence for the treatment of unipolar depression, provided that effective parameters are used, that is to say, for classical high frequency protocols: 20 to 30 sessions, 1000 pulses/session, 5 to 20Hz, and 110 % of the motor threshold. Low frequency protocol are also efficient and well tolerated. The duration of the efficacy varies with relapses rates around 50 % at one year. Pharmacological treatment generally remains associated. With regard to manic states, and mixed states the results are preliminary and limited to a possible reduction in symptoms. In the suicidal risk associated with mood disorders, the interest of rTMS is still to demonstrate, as well as in catatonia. The current place of the rTMS is no longer disputed in the curative treatment of major depressive disorder, preferentially used after one or two lines of antidepressants upstream. Further studies are needed to confirm preliminary positive findings in other aspects of mood disorders.
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Trastornos del Humor/terapia , Estimulación Magnética Transcraneal , Humanos , Estimulación Magnética Transcraneal/métodos , Estimulación Magnética Transcraneal/estadística & datos numéricosRESUMEN
Aim: The aim of this work was to study the neurophysiological effect of repetitive transcranial magnetic stimulation (rTMS) applied to the left dorsolateral prefrontal cortex (DLPFC) in 8 patients with major depression disorder (MDD) and 10 patients with bipolar disorder (BP), considering separately responders and non-responders to rTMS therapy in each of both groups. Methods: The Higuchi's Fractal Dimension (FD) was analyzed from 64-channels EEG signals in five physiological frequency bands and every channel separately. Changes of FD were analyzed before and after 1st, 10th, and 20th session of rTMS. Results: Some differences in response to the rTMS therapy was found across individual groups. In MDD responders, FD decreased in all bands after longer stimulation (20th session). Whereas, in BP non-responders, FD decreased after 1st session in all bands as well as after 10th session in lower frequencies (delta and theta). In MDD non-responders and BP responders FD increased at the beginning of the therapy (1st and 10th session, respectively), but the final FD value did not changed in comparison to the initial FD value, except the FD decrease for theta band in BP responders. Comparison between groups showed a higher FD in MDD responders than in MDD non-responders in every band before as well as after stimulation. In contrast to MDD patients, FD was lower in BP responders than in BP non-responders in higher frequency bands (alpha, beta, and gamma) in both conditions as well as in lower frequency bands (delta and theta) after stimulation. Comparing both groups of responders, FD was lower in MDD than in BP in every band, except alpha. In case of non-responders, FD was higher in BP than in MDD in all bands in both conditions. Conclusion: The results showed that FD may be useful marker for evaluation of the rTMS effectiveness and the therapy progress as well as for group differentiation between MDD and BP or between responders and non-responders. The changes of FD under the influence of rTMS allow to unambiguously conclude whether the effect of stimulation is positive or negative as well as allow to evaluate an optimal time of rTMS.
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Aim: The main objective of this work was to study the impact of repetitive Transcranial Magnetic Stimulation (rTMS) treatment on brain activity in 8 patients with major depressive disorder (MDD) and 10 patients with bipolar disorder (BP). Changes due to rTMS stimulation of the left dorsolateral prefrontal cortex (DLPFC) were investigated considering separately responders and non-responders to therapy in each of both groups. The aim of the research is to determine whether non-responders differ from responders suffered from both diseases, as well as if any change occurred due to rTMS across consecutive rTMS sessions. Methods: The graph-theory-based connectivity analysis of non-linearity measure of phase interdependencies-Phase Locking Value (PLV)-was examined from EEG data. The approximately 15-min EEG recordings from each of participants were recorded before and after 1st, 10th, and 20th session, respectively. PLV calculated from data was analyzed using principal graph theory indices (strength and degree) within five physiological frequency bands and in individual channels separately. The impact of rTMS on the EEG connectivity in every group of patients evaluated by PLV was assessed. Results: Each of four groups reacted differently to rTMS treatment. The strength and degree of PLV increased in gamma band in both groups of responders. Moreover, an increase of indices in beta band for BP-responders was observed. While, in MDD-non-responders the indices decreased in gamma band and increased in beta band. Moreover, the index strength was lower in alpha band for BP- non-responders. The rTMS stimulation caused topographically specific changes, i.e., the increase of the activity in the left DLPFC as well as in other brain regions such as right parieto-occipital areas. Conclusions: The analysis of PLV allowed for evaluation of the rTMS impact on the EEG activity in each group of patients. The changes of PLV under stimulation might be a good indicator of response to depression treatment permitting to improve the effectiveness of therapy.
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BACKGROUND: Major depressive disorder (MDD) and bipolar disorder (BP) are two different types of mood disorders, sometimes difficult to distinguish from their depressive symptoms, and for which repetitive transcranial magnetic stimulation (rTMS) of the dorsolateral prefrontal cortex (DLPFC) has been proposed to treat refractory patients. Here we studied whether the electroencephalogram (EEG) at rest could be used to predict the therapeutic response to left DLPFC 10 Hz rTMS, and to which extent BP and MDD patients show similar correlation between the clinical response and the cortical networks at rest. METHODS: Eight MDD (6 females) and 10 BP patients (6 females) were included. The rTMS therapy consisted of 10 to 20 neuronavigated sessions, with 2000 pulses continuously applied at 120% motor threshold for each session. RTMS sessions at the beginning, middle and end of the therapy were performed while recording EEG signals. EEG spectral power was partitioned using the common physiological frequency bands and was statistically analysed at the scalp level and after cortical source reconstruction. RESULTS: We found significantly higher power in theta and beta bands in BP patients than in MDD patients, mainly localised in the prefrontal cortex. In addition, responders showed higher power in delta and theta bands in parietal regions and weaker frontal alpha power, when compared to non-responders. DISCUSSION: These preliminary findings on a small cohort suggest that pre-treatment EEG oscillatory patterns may have some predictive value regarding rTMS therapy, both for MDD and BP disorders.
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Trastorno Bipolar/fisiopatología , Ondas Encefálicas/fisiología , Trastorno Depresivo Mayor/fisiopatología , Corteza Prefrontal/fisiopatología , Adulto , Trastorno Bipolar/diagnóstico , Trastorno Depresivo Mayor/diagnóstico , Electroencefalografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Lóbulo Parietal , Estimulación Magnética Transcraneal/métodos , Adulto JovenRESUMEN
The study assumed that the antisaccade (AS) task is a relevant psychophysical tool to assess (i) short-term neuromodulation of the dorsolateral prefrontal cortex (DLPFC) induced by intermittent theta burst stimulation (iTBS); and (ii) mood change occurring during the course of the treatment. Saccadic inhibition is known to strongly involve the DLPFC, whose neuromodulation with iTBS requires less stimulation time and lower stimulation intensity, as well as results in longer aftereffects than the conventional repetitive transcranial magnetic stimulation (rTMS). Active or sham iTBS was applied every day for 3 weeks over the left DLPFC of 12 drug-resistant bipolar depressed patients. To assess the iTBS-induced short-term neuromodulation, the saccadic task was performed just before (S1) and just after (S2) the iTBS session, the first day of each week. Mood was evaluated through Montgomery and Asberg Depression Rating Scale (MADRS) scores and the difference in scores between the beginning and the end of treatment was correlated with AS performance change between these two periods. As expected, only patients from the active group improved their performance from S1 to S2 and mood improvement was significantly correlated with AS performance improvement. In addition, the AS task also discriminated depressive bipolar patients from healthy control subjects. Therefore, the AS task could be a relevant and useful tool for clinicians to assess if the Transcranial magnetic stimulation (TMS)-induced short-term neuromodulation of the DLPFC occurs as well as a "trait vs. state" objective marker of depressive mood disorder.
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CONTEXT: The aim of this study was to assess whether the combination of low frequency repetitive transcranial magnetic stimulation (rTMS) and venlafaxine (150-225 mg/day) is effective and safe for treatment-resistant unipolar depression (TRD). METHOD: In a multicenter (18 centers) randomized double blind controlled trial with three arms, 170 patients were allocated to receive active rTMS combined with active venlafaxine (n = 55), active rTMS combined with placebo venlafaxine (n = 60) or sham rTMS combined with active venlafaxine (n = 55). The patients received once daily sessions of active or sham 1 Hz rTMS applied over the right dorsolateral prefrontal cortex (360 pulses/day delivered at 120% of the resting motor threshold) for two to six weeks; rTMS was combined with active or sham venlafaxine (mean dose: 179.0 ± 36.6 mg/day). The primary outcome was the number of patients who achieved remission, which was defined as an HDRS17 score <8. RESULTS: We reported a similar significant antidepressant effect in the 3 groups (P < 10(-6)), with a comparable delay of action and a comparable number of remitters at the endpoint (28% in the combination group, 41% in the rTMS group and 43% in the venlafaxine group; P = 0.59). CONCLUSION: Low frequency rTMS appears to be as effective as venlafaxine and as effective as the combination of both treatments for TRD. Because of its short session duration (the duration of one session was 8.5 min) and its safety, slow rTMS might be a useful alternative treatment for patients with TRD.
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Trastorno Depresivo Resistente al Tratamiento/terapia , Corteza Prefrontal/fisiología , Estimulación Magnética Transcraneal/efectos adversos , Antidepresivos/efectos adversos , Antidepresivos/uso terapéutico , Terapia Combinada , Ciclohexanoles/efectos adversos , Ciclohexanoles/uso terapéutico , Trastorno Depresivo Resistente al Tratamiento/tratamiento farmacológico , Método Doble Ciego , Femenino , Francia , Humanos , Masculino , Persona de Mediana Edad , Factores de Tiempo , Clorhidrato de VenlafaxinaRESUMEN
Repetitive transcranial magnetic stimulation (rTMS) modulates brain activity in different ways according to the stimulation parameters. Although the after-effects of rTMS over motor cortex are well documented in healthy individuals, less is known about the stimulation of dorso-lateral prefrontal cortex (DLPFC). Here, we studied in 20 healthy subjects how cortical oscillations are modulated by four different active rTMS protocols (1Hz, 10Hz, continuous and intermittent theta bursts - cTBS and iTBS) of the left DLPFC, and by a sham protocol used as a control condition, by comparing the spectral power of pre- and post-rTMS electroencephalographic (EEG) recordings of 15min duration. EEG spectrum was estimated with the fast Fourier transform (FFT) and partitioned using the common physiological frequency bands: delta (1-4Hz), theta (3.5-7Hz), alpha (7.5-13Hz), low beta (14-22Hz), high beta (22-30Hz) and gamma (30-45Hz). Statistical analyses of EEG changes induced by rTMS were computed with Statistical Parametric Mapping (SPM) for EEG, in every frequency band, at the scalp level and at the cortex level. We found for every active protocol a significant decrease of delta and theta power on left prefrontal electrodes, mainly localised in the left DLPFC. In higher frequency bands (beta and gamma), the decrease of power in the DLPFC was also observed contralaterally. Protocol-specific amplitude effects were found in the prefrontal cortex bilaterally in all frequency bands, but also in parietal and temporal regions in low EEG frequencies. In high frequencies, EEG power in the prefrontal cortex increased after rTMS for 10Hz and iTBS protocols, but this effect did not survive the comparison to Sham responses. Because large delta and theta activity is usually associated with cortical inhibition, observed rTMS-induced EEG changes in low frequencies suggest that rTMS of DLPFC transiently decreases local cortical inhibition. Importantly, local responses take place in association with other unknown mechanisms that modulate inter-hemispheric connectivity between homologous regions, resulting in the increase or decrease of fast activity in each prefrontal lobe, depending on the stimulation protocol. Only decreases of fast activity following active rTMS could be detected as significant when compared to Sham stimulation.
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Electroencefalografía/métodos , Corteza Prefrontal/fisiología , Estimulación Magnética Transcraneal/métodos , Adulto , Femenino , Voluntarios Sanos , Humanos , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
Eight patients with major depression, included in a double-blind study, performed an antisaccade task. Results suggested a link between antisaccade performances and clinical scale scores in patients who respond to therapy. Moreover, error rates may well predict response from day of inclusion, thus serving as a state-marker for mood disorders.