RESUMEN
Deep brain stimulation (DBS) of the subcallosal cingulate (SCC) can provide long-term symptom relief for treatment-resistant depression (TRD)1. However, achieving stable recovery is unpredictable2, typically requiring trial-and-error stimulation adjustments due to individual recovery trajectories and subjective symptom reporting3. We currently lack objective brain-based biomarkers to guide clinical decisions by distinguishing natural transient mood fluctuations from situations requiring intervention. To address this gap, we used a new device enabling electrophysiology recording to deliver SCC DBS to ten TRD participants (ClinicalTrials.gov identifier NCT01984710). At the study endpoint of 24 weeks, 90% of participants demonstrated robust clinical response, and 70% achieved remission. Using SCC local field potentials available from six participants, we deployed an explainable artificial intelligence approach to identify SCC local field potential changes indicating the patient's current clinical state. This biomarker is distinct from transient stimulation effects, sensitive to therapeutic adjustments and accurate at capturing individual recovery states. Variable recovery trajectories are predicted by the degree of preoperative damage to the structural integrity and functional connectivity within the targeted white matter treatment network, and are matched by objective facial expression changes detected using data-driven video analysis. Our results demonstrate the utility of objective biomarkers in the management of personalized SCC DBS and provide new insight into the relationship between multifaceted (functional, anatomical and behavioural) features of TRD pathology, motivating further research into causes of variability in depression treatment.
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Estimulación Encefálica Profunda , Depresión , Trastorno Depresivo Mayor , Humanos , Inteligencia Artificial , Biomarcadores , Estimulación Encefálica Profunda/métodos , Depresión/fisiopatología , Depresión/terapia , Trastorno Depresivo Mayor/fisiopatología , Trastorno Depresivo Mayor/terapia , Electrofisiología , Resultado del Tratamiento , Medición de Potencial de Campo Local , Sustancia Blanca , Lóbulo Límbico/fisiología , Lóbulo Límbico/fisiopatología , Expresión FacialRESUMEN
Subcallosal cingulate (SCC) deep brain stimulation (DBS) is an emerging therapy for refractory depression. Good clinical outcomes are associated with the activation of white matter adjacent to the SCC. This activation produces a signature cortical evoked potential (EP), but it is unclear which of the many pathways in the vicinity of SCC is responsible for driving this response. Individualized biophysical models were built to achieve selective engagement of two target bundles: either the forceps minor (FM) or cingulum bundle (CB). Unilateral 2 Hz stimulation was performed in seven patients with treatment-resistant depression who responded to SCC DBS, and EPs were recorded using 256-sensor scalp electroencephalography. Two distinct EPs were observed: a 120 ms symmetric response spanning both hemispheres and a 60 ms asymmetrical EP. Activation of FM correlated with the symmetrical EPs, while activation of CB was correlated with the asymmetrical EPs. These results support prior model predictions that these two pathways are predominantly activated by clinical SCC DBS and provide first evidence of a link between cortical EPs and selective fiber bundle activation.
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Estimulación Encefálica Profunda , Sustancia Blanca , Humanos , Estimulación Encefálica Profunda/métodos , Giro del Cíngulo/fisiología , Cuerpo Calloso , Potenciales EvocadosRESUMEN
Ongoing experimental studies of subcallosal cingulate deep brain stimulation (SCC DBS) for treatment-resistant depression (TRD) show a differential timeline of behavioral effects with rapid changes after initial stimulation, and both early and delayed changes over the course of ongoing chronic stimulation. This study examined the longitudinal resting-state regional cerebral blood flow (rCBF) changes in intrinsic connectivity networks (ICNs) with SCC DBS for TRD over 6 months and repeated the same analysis by glucose metabolite changes in a new cohort. A total of twenty-two patients with TRD, 17 [15 O]-water and 5 [18 F]-fluorodeoxyglucose (FDG) positron emission tomography (PET) patients, received SCC DBS and were followed weekly for 7 months. PET scans were collected at 4-time points: baseline, 1-month after surgery, and 1 and 6 months of chronic stimulation. A linear mixed model was conducted to examine the differential trajectory of rCBF changes over time. Post-hoc tests were also examined to assess postoperative, early, and late ICN changes and response-specific effects. SCC DBS had significant time-specific effects in the salience network (SN) and the default mode network (DMN). The rCBF in SN and DMN was decreased after surgery, but responder and non-responders diverged thereafter, with a net increase in DMN activity in responders with chronic stimulation. Additionally, the rCBF in the DMN uniquely correlated with depression severity. The glucose metabolic changes in a second cohort show the same DMN changes. The trajectory of PET changes with SCC DBS is not linear, consistent with the chronology of therapeutic effects. These data provide novel evidence of both an acute reset and ongoing plastic effects in the DMN that may provide future biomarkers to track clinical improvement with ongoing treatment.
RESUMEN
BACKGROUND: Prior trials suggest that intravenous racemic ketamine is a highly effective for treatment-resistant depression (TRD), but phase 3 trials of racemic ketamine are needed. AIMS: To assess the acute efficacy and safety of a 4-week course of subcutaneous racemic ketamine in participants with TRD. Trial registration: ACTRN12616001096448 at www.anzctr.org.au. METHOD: This phase 3, double-blind, randomised, active-controlled multicentre trial was conducted at seven mood disorders centres in Australia and New Zealand. Participants received twice-weekly subcutaneous racemic ketamine or midazolam for 4 weeks. Initially, the trial tested fixed-dose ketamine 0.5 mg/kg versus midazolam 0.025 mg/kg (cohort 1). Dosing was revised, after a Data Safety Monitoring Board recommendation, to flexible-dose ketamine 0.5-0.9 mg/kg or midazolam 0.025-0.045 mg/kg, with response-guided dosing increments (cohort 2). The primary outcome was remission (Montgomery-Åsberg Rating Scale for Depression score ≤10) at the end of week 4. RESULTS: The final analysis (those who received at least one treatment) comprised 68 in cohort 1 (fixed-dose), 106 in cohort 2 (flexible-dose). Ketamine was more efficacious than midazolam in cohort 2 (remission rate 19.6% v. 2.0%; OR = 12.1, 95% CI 2.1-69.2, P = 0.005), but not different in cohort 1 (remission rate 6.3% v. 8.8%; OR = 1.3, 95% CI 0.2-8.2, P = 0.76). Ketamine was well tolerated. Acute adverse effects (psychotomimetic, blood pressure increases) resolved within 2 h. CONCLUSIONS: Adequately dosed subcutaneous racemic ketamine was efficacious and safe in treating TRD over a 4-week treatment period. The subcutaneous route is practical and feasible.
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Trastorno Depresivo Resistente al Tratamiento , Ketamina , Humanos , Ketamina/efectos adversos , Depresión , Midazolam/efectos adversos , Australia , Trastorno Depresivo Resistente al Tratamiento/tratamiento farmacológicoRESUMEN
BACKGROUND: Sexual and/or gender minority (SGM) individuals experience higher rates and greater severity of depressive disorders than non-SGM persons. SGM individuals are more likely than non-SGM individuals to seek mental health treatment and to present to treatment with unique characteristics that should be accounted for when considering treatment recommendations. Patients seeking care for treatment-resistant depression (TRD) are offered a variety of evidence-based interventions ranging in modality and invasiveness (eg, psychotherapy and neuromodulation). METHODS: The current study used data from a TRD clinical research program to examine whether SGM (N = 52) and non-SGM (N = 202) patients differed in their clinical presentations and the treatment recommendations offered to them. RESULTS: We found that SGM patients were younger, had a more severe history of childhood trauma, and reported greater current suicidality than non-SGM patients. There were no significant differences in treatment recommendations between groups. CONCLUSIONS: This study adds to nascent literature investigating clinical characteristics of SGM populations seeking mental health care and provides foundational evidence for the unique treatment considerations necessary for SGM individuals seeking treatment for TRD. Research into whether treatment outcomes differ for SGM and non-SGM individuals with TRD is encouraged, given clinical differences in trauma history and suicidality.
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Identidad de Género , Minorías Sexuales y de Género , Humanos , Masculino , Femenino , Depresión , Conducta Sexual/psicología , Ideación SuicidaRESUMEN
BACKGROUND: The aims of this study were to evaluate the characteristics of patients and the pattern and rate of use of deep brain stimulation (DBS) for major depressive disorder (MDD) in the United States. METHODS: Data from the 2012-2014 Nationwide Inpatient Sample (NIS) included 116,890 patients. Patient variables included age, gender, race, median household income, insurance, primary diagnosis, primary procedure, length of stay, and total cost. Hospital variables included ownership, location, teaching status, bed size, and geographic region. RESULTS: Patients who received DBS for MDD were primarily high- income White females with private insurance. The mean age was 49.1 years (SD 7.85). The length of inpatient stay was 1 to 1.6 days. Total cost was highest in the West and lowest in the Northeast. Deep brain stimulation was mostly used by private nonprofit urban teaching hospitals in the South region of the United States. CONCLUSIONS: Deep brain stimulation was used in .03% of the total inpatient population with a primary diagnosis of MDD. If efficacy is established in definitive trials, DBS could fill a need for patients with treatment-resistant depression who do not respond to standard therapeutics or electro-convulsive therapy.
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Estimulación Encefálica Profunda , Trastorno Depresivo Mayor , Estimulación Encefálica Profunda/métodos , Depresión , Trastorno Depresivo Mayor/etiología , Trastorno Depresivo Mayor/terapia , Femenino , Humanos , Pacientes Internos , Tiempo de Internación , Persona de Mediana Edad , Estados UnidosRESUMEN
BACKGROUND: Traditional rating scales for depression rely heavily on patient self-report, and lack detailed measurement of non-verbal behavior. However, there is evidence that depression is associated with distinct non-verbal behaviors, assessment of which may provide useful information about recovery. This study examines non-verbal behavior in a sample of patients receiving Deep Brain Stimulation (DBS) treatment of depression, with the purpose to investigate the relationship between non-verbal behaviors and reported symptom severity. METHODS: Videotaped clinical interviews of twelve patients participating in a study of DBS for treatment-resistant depression were analyzed at three time points (before treatment and after 3 months and 6 months of treatment), using an ethogram to assess the frequencies of 42 non-verbal behaviors. The Beck Depression Inventory (BDI) and Hamilton Depression Rating Scale (HDRS-17) were also collected at all time points. RESULTS: Factor analysis grouped non-verbal behaviors into three factors: react, engage/fidget, and disengage. Two-way repeated measures ANOVA showed that scores on the three factors change differently from each other over time. Mixed effects modelling assessed the relationship between BDI score and frequency of non-verbal behaviors, and provided evidence that the frequency of behaviors related to reactivity and engagement increase as BDI score decreases. LIMITATIONS: This study assesses a narrow sample of patients with a distinct clinical profile at limited time points. CONCLUSIONS: Non-verbal behavior provides information about clinical states and may be reliably quantified using ethograms. Non-verbal behavior may provide distinct information compared to self-report.
RESUMEN
Subcallosal cingulate cortex deep brain stimulation (SCC-DBS) is an experimental therapy for treatment-resistant depression (TRD). Refinement and optimization of SCC-DBS will benefit from increased study of SCC electrophysiology in context of ongoing high-frequency SCC-DBS therapy. The study objective was a 7-mo observation of frequency-domain 1/f slope in off-stimulation local field potentials (SCC-LFPs) alongside standardized measurements of depression severity in 4 patients undergoing SCC-DBS. SCC was implanted bilaterally with a combined neurostimulation-LFP recording system. Following a 1-mo off-stimulation postoperative phase with multiple daily recordings, patients received bilateral SCC-DBS therapy (130 Hz, 90 µs) and weekly resting-state SCC-LFP recordings over a 6-mo treatment phase. 1/f slopes for each time point were estimated via linear regression of log-transformed Welch periodograms. General linear mixed-effects models were constructed to estimate pretreatment sources of 1/f slope variance, and 95% bootstrap confidence intervals were constructed to estimate treatment phase 1/f slope association with treatment response (50% decrease in preimplantation symptom severity). Results show the time of recording was a prominent source of pretreatment 1/f slope variance bilaterally, with increased 1/f slope magnitude observed during night hours (2300-0659). Increase in right 1/f slope was observed in the setting of treatment response, with bootstrap analysis supporting this observation in 3 of 4 subjects. We conclude that 1/f slope can be measured longitudinally in a combined SCC-DBS/LFP recording system and likely conforms to known 1/f circadian variability. The preliminary evidence of 1/f slope increase during treatment response suggests a potential utility as a candidate biomarker for ongoing development of adaptive TRD-neuromodulation strategies.NEW & NOTEWORTHY In four patients with treatment-resistant depression undergoing therapeutic deep brain stimulation (DBS), we present the first longitudinal observations of local field potentials (LFP) from the subcallosal cingulate region outside the postoperative period. Specifically, our results demonstrate that frequency-domain 1/f activity is measurable in a combined DBS-LFP recording system and that right hemisphere recordings appear sensitive to mood state, thus suggesting a potential readout suitable for consideration in ongoing efforts to develop adaptive DBS delivery systems.
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Estimulación Encefálica Profunda/métodos , Trastorno Depresivo Resistente al Tratamiento/terapia , Fenómenos Electrofisiológicos , Giro del Cíngulo , Evaluación de Procesos, Atención de Salud , Anciano , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana EdadRESUMEN
Deep brain stimulation (DBS) to the subcallosal cingulate cortex (SCC) is an emerging therapy for treatment resistant depression. Precision targeting of specific white matter fibers is now central to the model of SCC DBS treatment efficacy. A method to confirm SCC DBS target engagement is needed to reduce procedural variance across treatment providers and to optimize DBS parameters for individual patients. We examined the reliability of a novel cortical evoked response that is time-locked to a 2 Hz DBS pulse and shows the propagation of signal from the DBS target. The evoked response was detected in four individuals as a stereotyped series of components within 150 ms of a 6 V DBS pulse, each showing coherent topography on the head surface. Test-retest reliability across four repeated measures over 14 months met or exceeded standards for valid test construction in three of four patients. Several observations in this pilot sample demonstrate the prospective utility of this method to confirm surgical target engagement and instruct parameter selection. The topography of an orbital frontal component on the head surface showed specificity for patterns of forceps minor activation, which may provide a means to confirm DBS location with respect to key white matter structures. A divergent cortical response to unilateral stimulation of left (vs. right) hemisphere underscores the need for feedback acuity on the level of a single electrode, despite bilateral presentation of therapeutic stimulation. Results demonstrate viability of this method to explore patient-specific cortical responsivity to DBS for brain-circuit pathologies.
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Estimulación Encefálica Profunda/normas , Trastorno Depresivo Resistente al Tratamiento , Imagen de Difusión Tensora/métodos , Electroencefalografía/normas , Potenciales Evocados/fisiología , Giro del Cíngulo/fisiopatología , Sustancia Blanca/diagnóstico por imagen , Anciano , Estimulación Encefálica Profunda/métodos , Trastorno Depresivo Resistente al Tratamiento/diagnóstico por imagen , Trastorno Depresivo Resistente al Tratamiento/fisiopatología , Trastorno Depresivo Resistente al Tratamiento/terapia , Electroencefalografía/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto , Reproducibilidad de los ResultadosRESUMEN
OBJECTIVE: Refractory psychiatric disease is a major cause of morbidity and mortality worldwide, and there is a great need for new treatments. In the last decade, investigators piloted novel deep brain stimulation (DBS)-based therapies for depression and obsessive-compulsive disorder (OCD). Results from recent pivotal trials of these therapies, however, did not demonstrate the degree of efficacy expected from previous smaller trials. To discuss next steps, neurosurgeons, neurologists, psychiatrists and representatives from industry convened a workshop sponsored by the American Society for Stereotactic and Functional Neurosurgery in Chicago, Illinois, in June of 2016. DESIGN: Here we summarise the proceedings of the workshop. Participants discussed a number of issues of importance to the community. First, we discussed how to interpret results from the recent pivotal trials of DBS for OCD and depression. We then reviewed what can be learnt from lesions and closed-loop neurostimulation. Subsequently, representatives from the National Institutes of Health, the Food and Drug Administration and industry discussed their views on neuromodulation for psychiatric disorders. In particular, these third parties discussed their criteria for moving forward with new trials. Finally, we discussed the best way of confirming safety and efficacy of these therapies, including registries and clinical trial design. We close by discussing next steps in the journey to new neuromodulatory therapies for these devastating illnesses. CONCLUSION: Interest and motivation remain strong for deep brain stimulation for psychiatric disease. Progress will require coordinated efforts by all stakeholders.
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Trastornos Mentales/cirugía , Neurocirugia , Procedimientos Neuroquirúrgicos/métodos , Humanos , Estados UnidosRESUMEN
OBJECTIVE: Create a software tool to facilitate tractography-based deep brain stimulation (DBS) electrode targeting within the patient-specific stereotactic coordinate system used in the operating room. APPROACH: StimVision was developed with Visualization Toolkit libraries and integrates four major components: 1) medical image visualization, 2) tractography visualization, 3) DBS electrode positioning, and 4) DBS activation volume calculation with tractography intersection. RESULTS: Initial applications of StimVision are focused on the study of subcallosal cingulate (SCC) DBS for the treatment of depression. Retrospective modeling results on SCC DBS have suggested that direct stimulation of a specific collection of tractographic pathways are necessary for therapeutic benefit; thereby creating a tractography-based DBS surgical targeting hypotheses. StimVision is the tool we created to facilitate prospective clinical evaluation of that hypothesis. SIGNIFICANCE: Retrospective tractography-based analyses are common in DBS research; however, intraoperative software tools for interactive selection of a tractography-based DBS target are not readily available. StimVision provides an academic research tool to assist clinical implementation of new DBS targeting strategies and postoperative evaluation of targeting outcome.
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Estimulación Encefálica Profunda/instrumentación , Estimulación Encefálica Profunda/métodos , Depresión/terapia , Lóbulo Límbico/fisiología , Programas Informáticos , Flujo de Trabajo , Mapeo Encefálico , Imagen de Difusión Tensora , Electrodos Implantados , Femenino , Humanos , Imagenología Tridimensional , Masculino , Estudios RetrospectivosRESUMEN
PURPOSE OF REVIEW: The purpose of this paper is to provide a review of the use of ketamine as an antidepressant for treatment-resistant depression (TRD) in the geriatric population. Available treatment options for late-life treatment-resistant depression are limited and include electroconvulsive therapy and transcranial magnetic stimulation as well as possible pharmacologic augmentation. Ketamine has been shown to be a promising treatment in TRD; however, data regarding the use of ketamine in the elderly includes only five case reports. RECENT FINDINGS: We discuss the use of ketamine for late-life TRD and present two cases where ketamine led to a significant and sustained improvement in depressive symptoms. Ketamine is a promising treatment for geriatric patients with TRD. Further studies in the elderly will provide valuable insights into the use of ketamine for a population much in need of safe and effective treatments for TRD.
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Antidepresivos/uso terapéutico , Trastorno Depresivo Resistente al Tratamiento/tratamiento farmacológico , Ketamina/uso terapéutico , Anciano , Trastorno Depresivo Resistente al Tratamiento/psicología , Humanos , Resultado del TratamientoRESUMEN
Deep brain stimulation (DBS) of the subcallosal cingulate cortex (SCC) is an experimental therapy for treatment-resistant depression (TRD). Chronic SCC DBS leads to long-term changes in the electrophysiological dynamics measured from local field potential (LFP) during wakefulness, but it is unclear how it impacts sleep-related brain activity. This is a crucial gap in knowledge, given the link between depression and sleep disturbances, and an emerging interest in the interaction between DBS, sleep, and circadian rhythms. We therefore sought to characterize changes in electrophysiological markers of sleep associated with DBS treatment for depression. We analyzed key electrophysiological signatures of sleep-slow-wave activity (SWA, 0.5-4.5 Hz) and sleep spindles-in LFPs recorded from the SCC of 9 patients who responded to DBS for TRD. This allowed us to compare the electrophysiological changes before and after 24 weeks of therapeutically effective SCC DBS. SWA power was highly correlated between hemispheres, consistent with a global sleep state. Furthermore, SWA occurred earlier in the night after chronic DBS and had a more prominent peak. While we found no evidence for changes to slow-wave power or stability, we found an increase in the density of sleep spindles. Our results represent a first-of-its-kind report on long-term electrophysiological markers of sleep recorded from the SCC in patients with TRD, and provides evidence of earlier NREM sleep and increased sleep spindle activity following clinically effective DBS treatment. Future work is needed to establish the causal relationship between long-term DBS and the neural mechanisms underlying sleep.
Asunto(s)
Estimulación Encefálica Profunda , Trastorno Depresivo Resistente al Tratamiento , Humanos , Giro del Cíngulo/fisiología , Depresión , Estimulación Encefálica Profunda/métodos , Sueño , Trastorno Depresivo Resistente al Tratamiento/terapiaRESUMEN
BACKGROUND: RECOVER is a randomized sham-controlled trial of vagus nerve stimulation and the largest such trial conducted with a psychiatric neuromodulation intervention. OBJECTIVE: To describe pre-implantation baseline clinical characteristics and treatment history of patients with unipolar, major depressive disorder (MDD), overall and as a function of exposure to interventional psychiatric treatments (INTs), including electroconvulsive therapy, transcranial magnetic stimulation, and esketamine. METHODS: Medical, psychiatric, and treatment records were reviewed by study investigators and an independent Study Eligibility Committee prior to study qualification. Clinical characteristics and treatment history (using Antidepressant Treatment History [Short] Form) were compared in those qualified (N = 493) versus not qualified (N = 228) for RECOVER, and among the qualified group as a function of exposure to INTs during the current major depressive episode (MDE). RESULTS: Unipolar MDD patients who qualified for RECOVER had marked TRD (median of 11.0 lifetime failed antidepressant treatments), severe disability (median WHODAS score of 50.0), and high rate of baseline suicidality (77% suicidal ideation, 40% previous suicide attempts). Overall, 71% had received at least one INT. Compared to the no INT group, INT recipients were younger and more severely depressed (QIDS-C, QIDS-SR), had greater suicidal ideation, earlier diagnosis of MDD, and failed more antidepressant medication trials. CONCLUSIONS: RECOVER-qualified unipolar patients had marked TRD and marked treatment resistance with most failing one or more prior INTs. Treatment with ≥1 INTs in the current MDE was associated with earlier age of MDD onset, more severe clinical presentation, and greater treatment resistance relative to patients without a history of INT. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT03887715.
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Trastorno Depresivo Mayor , Trastorno Depresivo Resistente al Tratamiento , Estimulación Magnética Transcraneal , Humanos , Masculino , Femenino , Trastorno Depresivo Mayor/terapia , Persona de Mediana Edad , Adulto , Trastorno Depresivo Resistente al Tratamiento/terapia , Terapia Electroconvulsiva , Estimulación del Nervio Vago , Antidepresivos/uso terapéutico , Ketamina , Resultado del TratamientoRESUMEN
OBJECTIVE: This study began as a single-blind randomized controlled trial (RCT) to investigate the efficacy and safety of electroconvulsive therapy (ECT) for severe treatment-refractory agitation in advanced dementia. The aims are to assess agitation reduction using the Cohen-Mansfield Agitation Inventory (CMAI), evaluate tolerability and safety outcomes, and explore the long-term stability of agitation reduction and global functioning. Due to challenges encountered during implementation, including recruitment obstacles and operational difficulties, the study design was modified to an open-label format and other protocol amendments were implemented. METHODS: Initially, the RCT randomized participants 1:1 to either ECT plus usual care or simulated ECT plus usual care (S-ECT) groups. As patients were enrolled, data were collected from both ECT and simulated ECT (S-ECT) patients. The study now continues in an open-label study design where all patients receive actual ECT, reducing the targeted sample size from 200 to 50 participants. RESULTS: Study is ongoing and open to enrollment. CONCLUSION: The transition of the ECT-AD study design from an RCT to open-label design exemplifies adaptive research methodologies in response to real-world challenges. Data from both the RCT and open-label phases of the study will provide a unique perspective on the role of ECT in managing severe treatment-refractory agitation in dementia, potentially influencing future clinical practices and research approaches.
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Demencia , Terapia Electroconvulsiva , Agitación Psicomotora , Humanos , Terapia Electroconvulsiva/métodos , Agitación Psicomotora/terapia , Demencia/terapia , Demencia/complicaciones , Método Simple Ciego , Femenino , Masculino , Resultado del Tratamiento , Anciano , Conducta Motora Aberrante en la DemenciaRESUMEN
Deep brain stimulation (DBS) devices capable of measuring differential local field potentials ( ∂ LFP) enable neural recordings alongside clinical therapy. Efforts to identify oscillatory correlates of various brain disorders, or disease readouts, are growing but must proceed carefully to ensure readouts are not distorted by brain environment. In this report we identified, characterized, and mitigated a major source of distortion in ∂ LFP that we introduce as mismatch compression (MC). Using in vivo, in silico, and in vitro models of MC, we showed that impedance mismatches in the two recording electrodes can yield incomplete rejection of stimulation artifact and subsequent gain compression that distorts oscillatory power. We then developed and validated an opensource mitigation pipeline that mitigates the distortions arising from MC. This work enables more reliable oscillatory readouts for adaptive DBS applications.
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Estimulación Encefálica Profunda , Humanos , EncéfaloRESUMEN
Ongoing experimental studies of subcallosal cingulate deep brain stimulation (SCC DBS) for treatment-resistant depression (TRD) show a differential timeline of behavioral effects with rapid changes after initial stimulation, and both early and delayed changes over the course of ongoing chronic stimulation. This study examined the longitudinal resting-state regional cerebral blood ow (rCBF) changes in intrinsic connectivity networks (ICNs) with SCC DBS for TRD over 6 months and repeated the same analysis by glucose metabolite changes in a new cohort. A total of twenty-two patients with TRD, 17 [15O]-water and 5 [18]-Fluorodeoxyglucose (FDG) positron emission tomography (PET) patients, received SCC DBS and were followed weekly for 7 months. PET scans were collected at 4-time points: baseline, 1-month after surgery, and 1 and 6 months of chronic stimulation. A linear mixed model was conducted to examine the differential trajectory of rCBF changes over time. Post-hoc tests were also examined to assess postoperative, early, and late ICN changes and response-specific effects. SCC DBS had significant time-specific effects in the salience network (SN) and the default mode network (DMN). The rCBF in SN and DMN was decreased after surgery, but responder and non-responders diverged thereafter, with a net increase in DMN activity in responders with chronic stimulation. Additionally, the rCBF in the DMN uniquely correlated with depression severity. The glucose metabolic changes in a second cohort show the same DMN changes. The trajectory of PET changes with SCC DBS is not linear, consistent with the chronology of therapeutic effects. These data provide novel evidence of both an acute reset and ongoing plastic effects in the DMN that may provide future biomarkers to track clinical improvement with ongoing treatment.
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Background: A critical advance in depression research is to clarify the hypothesized role of interoceptive processing in neural mechanisms of treatment efficacy. This study tests whether cortical interoceptive processing, as indexed by the heartbeat-evoked potential (HEP), is modulated by deep brain stimulation (DBS) to the subcallosal cingulate (SCC) for treatment resistant depression (TRD). Methods: Eight patients with TRD were enrolled in a study of SCC DBS safety and efficacy. Electroencephalography (EEG) and symptom severity measures were sampled in a laboratory setting over the course of a six-month treatment protocol. The primary outcome measure was an EEG-derived HEP, which reflects cortical processing of heartbeat sensation. Cluster-based permutation analyses were used to test the effect of stimulation and time in treatment on the HEP. The change in signal magnitude after treatment was correlated with change in depression severity as measured by the 17-item Hamilton Depression Rating Scale. Results: HEP amplitude was greater after 24 weeks of treatment ( t (7)=-4.40, p =.003, g= -1.38, 95% Cl [-2.3, -0.42]), and this change was inversely correlated with latency of treatment response (rho = -0.75, 95% Cl [-0.95, -0.11], p= .03). An acute effect of DBS was also observed, but as a decrease in HEP amplitude ( t (6) =6.66, p <.001, g= 2.19, 95% Cl [0.81, 3.54]). HEP differences were most pronounced over left posterior sensors from 405-425 ms post-stimulus. Conclusion: Brain-based evidence substantiates a theorized link between interoception and depression, and suggests an interoceptive contribution to the mechanism of treatment efficacy with deep brain stimulation for severe depression.
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BACKGROUND: Past research has established that adverse childhood experiences (ACE) are correlated with depression severity. The purpose of the present study was to examine how the number and nature of ACE exposure is associated with symptomatology and treatment outcomes in adult patients with treatment resistant depression (TRD). METHODS: Participants include 454 patients with a diagnosis of major depression or persistent depressive disorder. A one-way analysis of variance (ANOVA) was used to assess whether number of ACEs was associated with certain outcomes. Linear regression analyses were performed to model the associations between the five ACE subtypes (e.g., sexual abuse, physical violence, injury/illness, childhood grief, and parental upheaval) and symptom severity. Logistic regression analyses were then used to model the association between ACE subtypes and history of lifetime suicide attempt(s) and inpatient admission(s). RESULTS: Greater ACE exposure was associated with more severe symptomatology and treatment outcomes, but these differences were only seen between patients reporting no ACEs versus 3+ ACEs. Only the subtypes of violence and illness/injury were significant predictors of more severe symptomatology. The ACE subtypes of sexual trauma and violence uniquely predicted a lifetime suicide attempt(s), and only the subtype of sexual trauma predicted lifetime inpatient admission(s). LIMITATIONS: Limitations of the present study include retrospective adult assessments of childhood trauma, lack of data on ACE severity and timing, and the cross-sectional reporting of multiple study measures. CONCLUSIONS: Exposure to multiple ACE subtypes, particularly sexual and physical trauma, is associated with depression symptom severity, and history of suicidality, and inpatient admission(s).