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1.
Laryngoscope Investig Otolaryngol ; 9(3): e1286, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38835333

ABSTRACT

Objective: To assess long-term safety and effectiveness of a multipoint, impedance-controlled, RF ablation device for treatment of chronic rhinitis through 12-month follow-up. Methods: A prospective, multicenter study. Bilateral posterior nasal nerve (PNN) ablation was performed on all participants. Assessments at 6-, 9-, and 12-month visits included Visual Analog Scale Nasal Symptom Score (VAS NSS), reflective Total Nasal Symptom Score (rTNSS), mini-Rhinoconjunctivitis Quality of Life Questionnaire (mini RQLQ), and adverse events. Results: Thirty-six participants were enrolled and 35 completed the 12-month follow-up. All 5 VAS NSS items demonstrated statistically significant improvement (p < .0001) over baseline at all 3 time points. The total rTNSS improved from 7.9 ± 1.8 at baseline to 4.3 ± 2.1 at 6-months, 3.8 ± 2.4 at 9-months, and 4.0 ± 2.1 at 12-months (all p < .0001). At 12-months, 91% (31/35) of participants had achieved the minimum clinically important difference (MCID) of a reduction from baseline of ≥1 point and 80% (28/35) of the participants met the responder criteria of ≥30% reduction from baseline. The total mean mini RQLQ was reduced from 3.0 ± 1.0 at baseline to 1.4 ± 0.8 at 6-months, 1.4 ± 1.0 at 9-months, and 1.3 ± 0.8 at 12-months (all p < .0001). At 12-months, 86% (30/35) of participants achieved the MCID of a reduction from baseline of ≥0.4 points for the mini RQLQ. No related serious adverse events occurred during the study. Conclusions: Impedance-controlled RF ablation of the PNN is safe and resulted in durable, significant improvement in rhinitis symptoms and quality of life through 12-month follow-up. Trial Registration: The study is registered at www.clinicaltrials.gov with the unique identifier of NCT05324397. Level of Evidence: 4.

2.
Laryngoscope Investig Otolaryngol ; 8(2): 367-372, 2023 Apr.
Article in English | MEDLINE | ID: mdl-37090860

ABSTRACT

Objective: Safety and efficacy of the NEUROMARK® system for treating chronic rhinitis. Methods: A prospective, single-arm, multicenter study was performed on adults with chronic rhinitis who underwent radiofrequency ablation to the posterior nasal nerves. Primary endpoints were device-related serious adverse events (SAEs) at 1 month and change from baseline in visual analog scale nasal symptom scale (VAS NSS) for rhinorrhea and nasal congestion at 3 months. Total nasal symptom score (rTNSS) and mini Rhinoconjunctivitis Quality of Life Questionnaire (mini RQLQ) score were also evaluated. Results: Thirty-six participants were enrolled and completed follow-up at 1 and 3 months. Mean VAS NSS scores for rhinorrhea and nasal congestion demonstrated significant improvement at 3 months (both p < .0001). The mean percent changes from baseline in VAS rhinorrhea and nasal congestion were 53% and 55%, respectively. Total scores and all individual rTNSS items significantly improved (all p < .001) over the measured interval. Percent responder rate (≥30% reduction from baseline in total rTNSS) at 3 months was 78%. The total mean mini RQLQ scores, as well as all subdomains, improved significantly (all p < .0001). At 3 months, 89% of participants reported a minimal clinically important difference of ≥0.4 point improvement in the mini RQLQ score. No SAEs occurred during the study. Conclusions: The NEUROMARK System is a novel radiofrequency ablation device that provides safe and effective treatment to the posterior nasal nerves for patients with chronic rhinitis. Study participants experienced statistically significant and clinically meaningful improvement in symptoms and quality of life assessments at 3 months post-procedure. Trial Registration: The study is registered at www.clinicaltrials.gov with the unique identifier of NCT05324397. Level of Evidence: 4.

3.
Neuropsychiatr ; 37(3): 115-121, 2023 Sep.
Article in English | MEDLINE | ID: mdl-36600105

ABSTRACT

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has resulted in significant upheaval in psychiatric care. Despite survey data collected from psychiatric patients and broad samples of individuals in single countries, there is little quantitative or qualitative data on changes to psychiatric care from the perspective of mental health providers themselves across developing countries. METHODS: To address this gap, we surveyed 27 practicing psychiatrists from Central and Eastern Europe, as well as Africa, the Middle East, and Latin America. RESULTS: Respondents observed a marked increase in anxiety in their patients, with increased (though less prominent) symptoms of depression, somatization, and addiction. They reported largescale changes in the structure of psychiatric treatment, chiefly a decline in psychiatric admissions and closing/repurposing of psychiatric beds. Results supported strong "buy in" from clinicians regarding the use of telehealth, though some clinicians perceived a reduction in the ability to connect with, and build alliances with, their patients. Finally, clinicians described an improvement in the image and meaning of psychiatry in society, increased awareness of mental illness, and greater value placed on mental health in the general population. CONCLUSIONS: These changes warrant further empirical study as to their potential long-term ramifications, particularly as the COVID-19 pandemic persists and new waves of infection occur periodically throughout the world. The increased psychiatric burden on the population coupled with the apparent salience of mental health and well-being in the public consciousness represents a global opportunity for psychiatry to advocate for further treatment, research, and education.


Subject(s)
COVID-19 , Psychiatry , Humans , Pandemics , SARS-CoV-2 , Surveys and Questionnaires , Internationality
4.
J ECT ; 38(3): 159-164, 2022 09 01.
Article in English | MEDLINE | ID: mdl-35704844

ABSTRACT

ABSTRACT: Electroconvulsive therapy (ECT) is a highly therapeutic and cost-effective treatment for severe and/or treatment-resistant major depression. However, because of the varied clinical practices, there is a great deal of heterogeneity in how ECT is delivered and documented. This represents both an opportunity to study how differences in implementation influence clinical outcomes and a challenge for carrying out coordinated quality improvement and research efforts across multiple ECT centers. The National Network of Depression Centers, a consortium of 26+ US academic medical centers of excellence providing care for patients with mood disorders, formed a task group with the goals of promoting best clinical practices for the delivery of ECT and to facilitate large-scale, multisite quality improvement and research to advance more effective and safe use of this treatment modality. The National Network of Depression Centers Task Group on ECT set out to define best practices for harmonizing the clinical documentation of ECT across treatment centers to promote clinical interoperability and facilitate a nationwide collaboration that would enable multisite quality improvement and longitudinal research in real-world settings. This article reports on the work of this effort. It focuses on the use of ECT for major depressive disorder, which accounts for the majority of ECT referrals in most countries. However, most of the recommendations on clinical documentation proposed herein will be applicable to the use of ECT for any of its indications.


Subject(s)
Depressive Disorder, Major , Depressive Disorder, Treatment-Resistant , Electroconvulsive Therapy , Depression , Documentation , Humans , Treatment Outcome
5.
Cell Rep ; 33(12): 108540, 2020 12 22.
Article in English | MEDLINE | ID: mdl-33357444

ABSTRACT

Resting-state functional magnetic resonance imaging (fMRI) is widely used in cognitive and clinical neuroscience, but long-duration scans are currently needed to reliably characterize individual differences in functional connectivity (FC) and brain network topology. In this report, we demonstrate that multi-echo fMRI can improve the reliability of FC-based measurements. In four densely sampled individual humans, just 10 min of multi-echo data yielded better test-retest reliability than 30 min of single-echo data in independent datasets. This effect is pronounced in clinically important brain regions, including the subgenual cingulate, basal ganglia, and cerebellum, and is linked to three biophysical signal mechanisms (thermal noise, regional variability in the rate of T2∗ decay, and S0-dependent artifacts) with spatially distinct influences. Together, these findings establish the potential utility of multi-echo fMRI for rapid precision mapping using experimentally and clinically tractable scan times and will facilitate longitudinal neuroimaging of clinical populations.


Subject(s)
Brain Mapping/methods , Echo-Planar Imaging/methods , Magnetic Resonance Imaging/methods , Precision Medicine/methods , Humans
6.
Nat Commun ; 11(1): 5290, 2020 10 20.
Article in English | MEDLINE | ID: mdl-33082311

ABSTRACT

Resting state functional connectivity magnetic resonance imaging (fMRI) is a tool for investigating human brain organization. Here we identify, visually and algorithmically, two prevalent influences on fMRI signals during 440 h of resting state scans in 440 healthy young adults, both caused by deviations from normal breathing which we term deep breaths and bursts. The two respiratory patterns have distinct influences on fMRI signals and signal covariance, distinct timescales, distinct cardiovascular correlates, and distinct tendencies to manifest by sex. Deep breaths are not sex-biased. Bursts, which are serial taperings of respiratory depth typically spanning minutes at a time, are more common in males. Bursts share features of chemoreflex-driven clinical breathing patterns that also occur primarily in males, with notable neurological, psychiatric, medical, and lifespan associations. These results identify common breathing patterns in healthy young adults with distinct influences on functional connectivity and an ability to differentially influence resting state fMRI studies.


Subject(s)
Brain/diagnostic imaging , Respiration , Adult , Brain/physiology , Brain Mapping , Female , Humans , Magnetic Resonance Imaging , Male , Rest , Sex Factors , Young Adult
7.
Neuroimage ; 204: 116234, 2020 01 01.
Article in English | MEDLINE | ID: mdl-31589990

ABSTRACT

Breathing rate and depth influence the concentration of carbon dioxide in the blood, altering cerebral blood flow and thus functional magnetic resonance imaging (fMRI) signals. Such respiratory fluctuations can have substantial influence in studies of fMRI signal covariance in subjects at rest, the so-called "resting state functional connectivity" technique. If respiration is monitored during fMRI scanning, it is typically done using a belt about the subject's abdomen to record abdominal circumference. Several measures have been derived from these belt records, including the windowed envelope of the waveform (ENV), the windowed variance in the waveform (respiration variation, RV), and a measure of the amplitude of each breath divided by the cycle time of the breath (respiration volume per time, RVT). Any attempt to gauge respiratory contributions to fMRI signals requires a respiratory measure, but little is known about how these measures compare to each other, or how they perform beyond the small studies in which they were initially proposed. Here, we examine the properties of these measures in hundreds of healthy young adults scanned for an hour each at rest, a subset of the Human Connectome Project chosen for having high-quality physiological records. We find: 1) ENV, RV, and RVT are all correlated, and ENV and RV are more highly correlated to each other than to RVT; 2) respiratory events like deep breaths exhibit characteristic heart rate elevations, fMRI signal changes, head motions, and image quality abnormalities time-locked to large deflections in the belt traces; 3) all measures can "miss" deep breaths; 4) RVT "misses" deep breaths more than ENV or RV; 5) all respiratory measures change systematically over the course of a 14.4-min scan. We discuss the implications of these findings for the literature and ways to move forward in modeling respiratory influences on fMRI scans.


Subject(s)
Brain/diagnostic imaging , Brain/physiology , Connectome , Respiration , Respiratory Function Tests , Rest/physiology , Adult , Connectome/methods , Connectome/standards , Female , Humans , Magnetic Resonance Imaging/methods , Magnetic Resonance Imaging/standards , Male , Respiratory Function Tests/methods , Respiratory Function Tests/standards , Young Adult
8.
Neuroimage ; 201: 116041, 2019 11 01.
Article in English | MEDLINE | ID: mdl-31344484

ABSTRACT

Head motion estimates in functional magnetic resonance imaging (fMRI) scans appear qualitatively different with sub-second image sampling rates compared to the multi-second sampling rates common in the past. Whereas formerly the head appeared still for much of a scan with brief excursions from baseline, the head now appears to be in constant motion, and motion estimates often seem to divulge little information about what is happening in a scan. This constant motion has been attributed to respiratory oscillations that do not alias at faster sampling rates, and investigators are divided on the extent to which such motion is "real" motion or only "apparent" pseudomotion. Some investigators have abandoned the use of motion estimates entirely due to these considerations. Here we investigate the properties of motion in several fMRI datasets sampled at rates between 720 and 1160 ms, and describe 5 distinct kinds of respiratory motion: 1) constant real respiratory motion in the form of head nodding most evident in vertical position and pitch, which can be very large; 2) constant pseudomotion at the same respiratory rate as real motion, occurring only in the phase encode direction; 3) punctate real motions occurring at times of very deep breaths; 4) a low-frequency pseudomotion in only the phase encode direction at and after very deep breaths; 5) slow modulation of vertical and anterior-posterior head position by the respiratory envelope. We reformulate motion estimates in light of these considerations and obtain good concordance between motion estimates, physiologic records, image quality measures, and events evident in the fMRI signals. We demonstrate how variables describing respiration or body habitus separately scale with distinct kinds of head motion. We also note heritable aspects of respiration and motion.


Subject(s)
Head/physiology , Magnetic Resonance Imaging , Movement/physiology , Respiration , Adolescent , Artifacts , Child , Female , Humans , Male
9.
Article in English | MEDLINE | ID: mdl-31176387

ABSTRACT

BACKGROUND: Previously, we identified four depression subtypes defined by distinct functional connectivity alterations in depression-related brain networks, which in turn predicted clinical symptoms and treatment response. Optogenetic functional magnetic resonance imaging offers a promising approach for testing how dysfunction in specific circuits gives rise to subtype-specific, depression-related behaviors. However, this approach assumes that there are robust, reproducible correlations between functional connectivity and depressive symptoms-an assumption that was not extensively tested in previous work. METHODS: First, we comprehensively reevaluated the stability of canonical correlations between functional connectivity and symptoms (N = 220 subjects) using optimized approaches for large-scale statistical hypothesis testing, and we validated methods for improving estimation of latent variables driving brain-behavior correlations. Having confirmed this necessary condition, we reviewed recent advances in optogenetic functional magnetic resonance imaging and illustrated one approach to formulating hypotheses regarding latent subtype-specific circuit mechanisms and testing them in animal models. RESULTS: Correlations between connectivity features and clinical symptoms were robustly significant, and canonical correlation analysis solutions tested repeatedly on held-out data generalized. However, they were sensitive to data quality, preprocessing, and clinical heterogeneity, which can reduce effect sizes. Generalization could be markedly improved by adding L2 regularization, which decreased estimator variance, increased canonical correlations in left-out data, and stabilized feature selection. These improvements were useful for identifying candidate circuits for optogenetic interrogation in animal models. CONCLUSIONS: Multiview, latent-variable approaches such as canonical correlation analysis offer a conceptually useful framework for discovering stable patient subtypes by synthesizing multiple clinical and functional measures. Optogenetic functional magnetic resonance imaging holds promise for testing hypotheses regarding latent, subtype-specific mechanisms driving depressive symptoms and behaviors.


Subject(s)
Brain Mapping/methods , Brain/physiopathology , Depressive Disorder, Major/physiopathology , Neural Pathways/physiopathology , Adult , Female , Humans , Magnetic Resonance Imaging/methods , Male , Optogenetics/methods
10.
J Affect Disord ; 249: 286-293, 2019 Apr 15.
Article in English | MEDLINE | ID: mdl-30784726

ABSTRACT

BACKGROUND: Low field magnetic stimulation is a potentially rapid-acting treatment for depression with mood-enhancing effects in as little as one 20-min session. The most convincing data for LFMS has come from treating bipolar depression. We examined whether LFMS also has rapid mood-enhancing effects in treatment-resistant major depressive disorder, and whether these effects are dose-dependent. OBJECTIVE/HYPOTHESIS: We hypothesized that a single 20-min session of LFMS would reduce depressive symptom severity and that the magnitude of this change would be greater after three 20-min sessions than after a single 20-min session. METHODS: In a double-blind randomized controlled trial, 30 participants (age 21-65) with treatment-resistant depression were randomized to three 20-min active or sham LFMS treatments with 48 h between treatments. Response was assessed immediately following LFMS treatment using the 6-item Hamilton Depression Rating Scale (HAMD-6), the Positive and Negative Affect Scale (PANAS) and the Visual Analog Scale. RESULTS: Following the 3rd session of LFMS, the effect of LFMS on VAS and HAMD-6 was superior to sham (F (1, 24) = 7.45, p = 0.03, Bonferroni-Holm corrected; F (1, 22) = 6.92, p = 0.03, Bonferroni-Holm corrected, respectively). There were no differences between sham and LFMS following the initial or second session with the effect not becoming significant until after the third session. CONCLUSIONS: Three 20-min LFMS sessions were required for active LFMS to have a mood-enhancing effect for individuals with treatment-resistant depression. As this effect may be transient, future work should address dosing schedules of longer treatment courses as well as biomarker-based targeting of LFMS to optimize patient selection and treatment outcomes.


Subject(s)
Affect , Depressive Disorder, Treatment-Resistant/therapy , Magnetic Field Therapy , Adult , Aged , Depressive Disorder, Treatment-Resistant/psychology , Double-Blind Method , Female , Humans , Magnetic Field Therapy/methods , Male , Middle Aged , Patient Selection , Treatment Outcome , Young Adult
11.
Nat Microbiol ; 4(3): 396-403, 2019 03.
Article in English | MEDLINE | ID: mdl-30531975

ABSTRACT

The gut microbiota affects many important host functions, including the immune response and the nervous system1. However, while substantial progress has been made in growing diverse microorganisms of the microbiota2, 23-65% of species residing in the human gut remain uncultured3,4, which is an obstacle for understanding their biological roles. A likely reason for this unculturability is the absence in artificial media of key growth factors that are provided by neighbouring bacteria in situ5,6. In the present study, we used co-culture to isolate KLE1738, which required the presence of Bacteroides fragilis to grow. Bioassay-driven purification of B. fragilis supernatant led to the isolation of the growth factor, which, surprisingly, is the major inhibitory neurotransmitter GABA (γ-aminobutyric acid). GABA was the only tested nutrient that supported the growth of KLE1738, and a genome analysis supported a GABA-dependent metabolism mechanism. Using growth of KLE1738 as an indicator, we isolated a variety of GABA-producing bacteria, and found that Bacteroides ssp. produced large quantities of GABA. Genome-based metabolic modelling of the human gut microbiota revealed multiple genera with the predicted capability to produce or consume GABA. A transcriptome analysis of human stool samples from healthy individuals showed that GABA-producing pathways are actively expressed by Bacteroides, Parabacteroides and Escherichia species. By coupling 16S ribosmal RNA sequencing with functional magentic resonance imaging in patients with major depressive disorder, a disease associated with an altered GABA-mediated response, we found that the relative abundance levels of faecal Bacteroides are negatively correlated with brain signatures associated with depression.


Subject(s)
Bacteria/metabolism , Bacteroides/metabolism , Feces/microbiology , Gastrointestinal Microbiome , gamma-Aminobutyric Acid/metabolism , Adult , Aged , Bacteria/classification , Bacteroides/genetics , Brain/diagnostic imaging , Cohort Studies , Depression/microbiology , Depressive Disorder, Major/microbiology , Female , Gastrointestinal Tract/microbiology , Gene Expression Profiling , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Whole Genome Sequencing , Young Adult
14.
Brain Stimul ; 11(3): 575-581, 2018.
Article in English | MEDLINE | ID: mdl-29454551

ABSTRACT

BACKGROUND: Repetitive transcranial magnetic stimulation (rTMS) is an effective treatment for medication-refractory major depression, yet the mechanisms of action for this intervention are poorly understood. Here we investigate cerebral cortex thickness as a possible biomarker of rTMS treatment response. METHODS: Longitudinal change in cortical thickness is evaluated relative to clinical outcomes across 48 participants in 2 cohorts undergoing left dorsolateral prefrontal cortex rTMS as a treatment for depression. RESULTS: Our results reveal changes in thickness in a region of the left rostral anterior cingulate cortex that correlate with clinical response, with this region becoming thicker in patients who respond favorably to rTMS and thinner in patients with a less favorable response. Moreover, the baseline cortical thickness in this region correlates with rTMS treatment response - those patients with thinner cortex before treatment tended to have the most clinical improvement. CONCLUSIONS: This study is the first analysis of longitudinal cortical thickness change with rTMS as a treatment for depression with similar results across two cohorts. These results support further investigation into the use of structural MRI as a possible biomarker of rTMS treatment response.


Subject(s)
Depressive Disorder, Major/therapy , Depressive Disorder, Treatment-Resistant/therapy , Gyrus Cinguli/anatomy & histology , Prefrontal Cortex/physiology , Transcranial Magnetic Stimulation , Female , Humans , Hypertrophy , Magnetic Resonance Imaging , Male , Middle Aged , Neuroimaging , Treatment Outcome
15.
BMJ Case Rep ; 20182018 Jan 24.
Article in English | MEDLINE | ID: mdl-29367224

ABSTRACT

Lithium is a mood stabiliser used in the treatment of acute mania, bipolar disorder and as augmentation for unipolar major depression. Tremor is a common adverse effect associated with lithium at both therapeutic and toxic serum levels. We present a case of dose-dependent changes in the quality and intensity of a stroke-related, chronic cerebellar tremor with lithium treatment at serum levels within the therapeutic range. On admission, the patient in this case had a baseline fine, postural tremor, which increased in frequency and evolved to include myoclonic jerks once lithium therapy was initiated. Although the patient's serum lithium level was never in the toxic range, his tremor returned to baseline on reduction of his serum lithium level. This case highlights that a pre-existing, baseline tremor may lower the threshold for developing myoclonus. It also suggests that caution may be warranted with lithium therapy in the setting of known cerebellar disease.


Subject(s)
Antidepressive Agents/adverse effects , Bipolar Disorder/drug therapy , Lithium Compounds/adverse effects , Tremor/chemically induced , Cerebellar Diseases/complications , Dose-Response Relationship, Drug , Drug Substitution , Humans , Male , Myoclonus/chemically induced , Stroke/complications
16.
Am J Geriatr Psychiatry ; 26(3): 334-346, 2018 Mar.
Article in English | MEDLINE | ID: mdl-29111132

ABSTRACT

OBJECTIVE: The aims of the current review were to: 1) examine whether the rTMS effects on executive function increase as age advances; 2) to examine the potential of rTMS to remediate executive function in older depressed patients; and 3) to assess the relationship between the executive function and mood benefits from rTMS in depression. METHODS: Randomized or matched-groups, blind, sham-controlled studies (12 studies, 347 participants) on excitatory rTMS applied to left DLPFC in depression were reviewed. RESULTS: A series of meta-regressions found no evidence of greater rTMS effects on executive functions as age advances. Similarly, meta-analyses showed no significant rTMS effects on executive functions in older depressed individuals. However, meta-regression analyses showed that the size of the executive function benefits from rTMS in depression are positively related to the effect size of mood symptom reduction. Despite its correlational nature, this finding is consistent with the idea that improvement in executive function may play a critical role in depression recovery. CONCLUSIONS: The authors consider these findings preliminary because of the modest number of available studies. Based on a qualitative review, the authors describe methodologic modifications that may increase rTMS efficacy for both executive functions and mood in late-life depression.


Subject(s)
Aging , Cognitive Dysfunction/therapy , Depressive Disorder/complications , Executive Function , Transcranial Magnetic Stimulation/methods , Cognitive Dysfunction/etiology , Humans
17.
J Clin Psychiatry ; 79(1)2018.
Article in English | MEDLINE | ID: mdl-28541649

ABSTRACT

OBJECTIVE: To provide expert recommendations for the safe and effective application of repetitive transcranial magnetic stimulation (rTMS) in the treatment of major depressive disorder (MDD). PARTICIPANTS: Participants included a group of 17 expert clinicians and researchers with expertise in the clinical application of rTMS, representing both the National Network of Depression Centers (NNDC) rTMS Task Group and the American Psychiatric Association Council on Research (APA CoR) Task Force on Novel Biomarkers and Treatments. EVIDENCE: The consensus statement is based on a review of extensive literature from 2 databases (OvidSP MEDLINE and PsycINFO) searched from 1990 through 2016. The search terms included variants of major depressive disorder and transcranial magnetic stimulation. The results were limited to articles written in English that focused on adult populations. Of the approximately 1,500 retrieved studies, a total of 118 publications were included in the consensus statement and were supplemented with expert opinion to achieve consensus recommendations on key issues surrounding the administration of rTMS for MDD in clinical practice settings. CONSENSUS PROCESS: In cases in which the research evidence was equivocal or unclear, a consensus decision on how rTMS should be administered was reached by the authors of this article and is denoted in the article as "expert opinion." CONCLUSIONS: Multiple randomized controlled trials and published literature have supported the safety and efficacy of rTMS antidepressant therapy. These consensus recommendations, developed by the NNDC rTMS Task Group and APA CoR Task Force on Novel Biomarkers and Treatments, provide comprehensive information for the safe and effective clinical application of rTMS in the treatment of MDD.


Subject(s)
Depressive Disorder, Major/therapy , Transcranial Magnetic Stimulation/methods , Consensus , Contraindications , Humans , Transcranial Magnetic Stimulation/adverse effects
18.
Brain Stimul ; 10(5): 919-925, 2017.
Article in English | MEDLINE | ID: mdl-28747260

ABSTRACT

BACKGROUND: Repetitive transcranial magnetic stimulation (TMS) is a non-invasive, safe, and efficacious treatment for depression. TMS has been shown to normalize abnormal functional connectivity of cortico-cortical circuits in depression and baseline functional connectivity of these circuits predicts treatment response. Less is known about the relationship between functional connectivity of frontostriatal circuits and treatment response. OBJECTIVE/HYPOTHESIS: We investigated whether baseline functional connectivity of distinct frontostriatal circuits predicted response to TMS. METHODS: Resting-state fMRI (rsfMRI) was acquired in 27 currently depressed subjects with treatment resistant depression and 27 healthy controls. Depressed subjects were treated with 5 weeks of daily TMS over the left dorsolateral prefrontal cortex (DLPFC). The functional connectivity between limbic, executive, rostral motor, and caudal motor regions of frontal cortex and their corresponding striatal targets were determined at baseline using an existing atlas based on diffusion tensor imaging. TMS treatment response was measured by percent reduction in the 24-item Hamilton Depression Rating Scale (HAMD24). In an exploratory analysis, correlations were determined between baseline functional connectivity and TMS treatment response. RESULTS: Seven cortical clusters belonging to the executive and rostral motor frontostriatal projections had reduced functional connectivity in depression compared to healthy controls. No frontostriatal projections showed increased functional connectivity in depression (voxel-wise p < 0.01, family-wise α < 0.01). Only baseline functional connectivity between the left DLPFC and the striatum predicted TMS response. Higher baseline functional connectivity correlated with greater reductions in HAMD24 (Pearson's R = 0.58, p = 0.002). CONCLUSION(S): In an exploratory analysis, higher functional connectivity between the left DLPFC and striatum predicted better treatment response. Our findings suggest that the antidepressant mechanism of action of TMS may require connectivity from cortex proximal to the stimulation site to the striatum.


Subject(s)
Depressive Disorder, Treatment-Resistant/physiopathology , Depressive Disorder, Treatment-Resistant/therapy , Frontal Lobe/physiology , Neostriatum/physiology , Nerve Net/physiology , Transcranial Magnetic Stimulation/methods , Adult , Depressive Disorder, Treatment-Resistant/diagnostic imaging , Diffusion Tensor Imaging/methods , Female , Frontal Lobe/diagnostic imaging , Humans , Magnetic Resonance Imaging/methods , Male , Middle Aged , Neostriatum/diagnostic imaging , Nerve Net/diagnostic imaging , Predictive Value of Tests , Treatment Outcome
19.
Int Rev Psychiatry ; 29(2): 89-97, 2017 04.
Article in English | MEDLINE | ID: mdl-28420271

ABSTRACT

With the antidepressant efficacy of Transcranial Magnetic Stimulation well-established by several meta-analyses, there is growing interest in its mechanism of action. TMS has been shown to engage, and in some cases, normalize functional connectivity and neurotransmitter levels within networks dysfunctional in the depressed state. In this review, I will suggest candidate biomarkers, based on neuroimaging, that may be predictive of response to TMS. I will then review the effects of TMS on networks and neurotransmitter systems involved in depression. Throughout, I will also discuss how our current understanding of response predication and network engagement may be used to personalize treatment and optimize its efficacy.


Subject(s)
Connectome , Depressive Disorder, Major , Neurotransmitter Agents/metabolism , Transcranial Magnetic Stimulation/methods , Depressive Disorder, Major/diagnostic imaging , Depressive Disorder, Major/metabolism , Depressive Disorder, Major/physiopathology , Depressive Disorder, Major/therapy , Humans
20.
Curr Behav Neurosci Rep ; 4(1): 70-77, 2017 03.
Article in English | MEDLINE | ID: mdl-28316903

ABSTRACT

PURPOSE OF REVIEW: First, we will identify candidate predictive biomarkers of antidepressant response of TMS based on the neuroimaging literature. Next, we will review the effects of TMS on networks involved in depression. Finally, we will discuss ways in which our current understanding of network engagement by TMS may be used to optimize its antidepressant effect. RECENT FINDINGS: The past few years has seen significant interest in the antidepressant mechanisms of TMS. Studies using functional neuroimaging and neurochemical imaging have demonstrated engagement of networks known to be important in depression. Current evidence supports a model whereby TMS normalizes network function gradually over the course of several treatments. This may, in turn, mediate its antidepressant effect. SUMMARY: One strategy to optimize the antidepressant effect of TMS is to more precisely target networks relevant in depression. We propose methods to achieve this using functional and neurochemical imaging.

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