Correction: Cotovio et al. Regulatory Clearance and Approval of Therapeutic Protocols of Transcranial Magnetic Stimulation for Psychiatric Disorders. Brain Sci. 2023, 13, 1029

Missing Citation [...].

Reducing motor evoked potential amplitude variability through normalization

Background

Transcranial Magnetic Stimulation (TMS) is used for in vivo assessment of human motor cortical excitability, with application of TMS pulses over the motor cortex resulting in muscle responses that can be recorded with electromyography (EMG) as Motor Evoked Potentials (MEPs). These have been widely explored as potential biomarkers for neuropsychiatric disorders but methodological heterogeneity in acquisition, and inherent high variability, have led to constraints in reproducibility. Normalization, consisting in scaling the signal of interest to a known and repeatable measurement, reduces variability and is standard practice for between-subject comparisons of EMG. The effect of normalization on variability of MEP amplitude has not yet been explored and was assessed here using several methods.

Methods

Three maximal voluntary isometric contractions (MVICs) and 40 MEPs were collected from the right hand in healthy volunteers, with a retest session conducted 4 to 8 weeks later. MEP amplitude was normalized using either external references (MVICs) or internal references (extreme MEPs). Iterative re-sampling of 30 normalized MEPs per subject was repeated 5,000 times to define, for each normalization method, distributions for between-subject coefficients of variation (CV) of the mean MEP amplitude. Intra-class correlation coefficients (ICC) were used to assess the impact of normalization on test–retest stability of MEP amplitude measurements.

Results

In the absence of normalization, MEPs collected from the right hand of 47 healthy volunteers were within reported values regarding between-subject variability (95% confidence intervals for the CV: [1.0567,1.0577]) and showed good temporal stability (ICC = 0.77). Internal reference normalization substantially reduced between-subject variability, by values of up to 64%, while external reference normalization had no impact or increased between-subject variability. Normalization with the smallest references reduced test–retest stability, with use of the largest references resulting in slight reduction or improvement of ICCs. Internal reference normalization using the largest MEPs was found to be robust to several sensitivity analyses.

Conclusion

Internal, but not external, reference normalization reduces between-subject variability of MEP amplitude, and has a minimal impact on within-subject variability when conducted with the largest references. Additional research is necessary to further validate these normalization methods toward potential use of MEPs as biomarkers of neuropsychiatric disorders.

Regulatory Clearance and Approval of Therapeutic Protocols of Transcranial Magnetic Stimulation for Psychiatric Disorders

Non-invasive brain stimulation techniques (NIBS) have been widely used in both clinical and research contexts in neuropsychiatry. They are safe and well-tolerated, making NIBS an interesting option for application in different settings. Transcranial magnetic stimulation (TMS) is one of these strategies. It uses electromagnetic pulses for focal modulate ion of neuronal activity in brain cortical regions. When pulses are applied repeatedly (repetitive transcranial magnetic stimulation-rTMS), they are thought to induce long-lasting neuroplastic effects, proposed to be a therapeutic mechanism for rTMS, with efficacy and safety initially demonstrated for treatment-resistant depression (TRD). Since then, many rTMS treatment protocols emerged for other difficult to treat psychiatric conditions. Moreover, multiple clinical studies, including large multi-center trials and several meta-analyses, have confirmed its clinical efficacy in different neuropsychiatric disorders, resulting in evidence-based guidelines and recommendations. Currently, rTMS is cleared by multiple regulatory agencies for the treatment of TRD, depression with comorbid anxiety disorders, obsessive compulsive disorder, and substance use disorders, such as smoking cessation. Importantly, current research supports the potential future use of rTMS for other psychiatric syndromes, including the negative symptoms of schizophrenia and post-traumatic stress disorder. More precise knowledge of formal indications for rTMS therapeutic use in psychiatry is critical to enhance clinical decision making in this area.

Replicability of motor cortex-excitability modulation by intermittent theta burst stimulation

OBJECTIVE

Transcranial Magnetic Stimulation (TMS) allows for cortical-excitability (CE) assessment and its modulation has been associated with neuroplasticity-like phenomena, thought to be impaired in neuropsychiatric disorders. However, the stability of these measures has been challenged, defying their potential as biomarkers. This study aimed to test the temporal stability of cortical-excitability modulation and study the impact of individual and methodological factors in determining within- and between-subject variability.

METHODS

We recruited healthy-subjects to assess motor cortex (MC) excitability modulation, collecting motor evoked potentials (MEP) from both hemispheres, before and after left-sided intermittent theta burst stimulation (iTBS), to obtain a measure of MEPs change (delta-MEPs). To assess stability across-time, the protocol was repeated after 6 weeks. Socio-demographic and psychological variables were collected to test association with delta-MEPs.

RESULTS

We found modulatory effects on left MC and not on right hemisphere following iTBS of left MC. Left delta-MEP was stable across-time when performed immediately after iTBS (ICC = 0.69), only when obtained first in left hemisphere. We discovered similar results in a replication cohort testing only left MC (ICC = 0.68). No meaningful associations were found between demographic and psychological factors and delta-MEPs.

CONCLUSIONS

Delta-MEP is stable immediately after modulation and not impacted by different individual factors, including expectation about TMS-effect.

SIGNIFICANCE

Motor cortex excitability modulation immediately after iTBS should be further explored as a potential biomarker for neuropsychiatric diseases.

Striatal dopamine D2-like receptors availability in obesity and its modulation by bariatric surgery: a systematic review and meta-analysis

There is significant evidence linking a 'reward deficiency syndrome' (RDS), comprising decreased availability of striatal dopamine D2-like receptors (DD2lR) and addiction-like behaviors underlying substance use disorders and obesity. Regarding obesity, a systematic review of the literature with a meta-analysis of such data is lacking. Following a systematic review of the literature, we performed random-effects meta-analyses to determine group differences in case-control studies comparing DD2lR between individuals with obesity and non-obese controls and prospective studies of pre- to post-bariatric surgery DD2lR changes. Cohen's d was used to measure effect size. Additionally, we explored factors potentially associated with group differences in DD2lR availability, such as obesity severity, using univariate meta-regression. In a meta-analysis including positron emission tomography (PET) and single-photon emission computed tomography (SPECT) studies, striatal DD2lR availability did not significantly differ between obesity and controls. However, in studies comprising patients with class III obesity or higher, group differences were significant, favoring lower DD2lR availability in the obesity group. This effect of obesity severity was corroborated by meta-regressions showing inverse associations between the body mass index (BMI) of the obesity group and DD2lR availability. Post-bariatric changes in DD2lR availability were not found, although a limited number of studies were included in this meta-analysis. These results support lower DD2lR in higher classes of obesity which is a more targeted population to explore unanswered questions regarding the RDS.

An Argument in Favor of Deep Brain Stimulation for Uncommon Movement Disorders: The Case for N-of-1 Trials in Holmes Tremor

Deep brain stimulation (DBS) is part of state-of-the-art treatment for medically refractory Parkinson’s disease, essential tremor or primary dystonia. However, there are multiple movement disorders that present after a static brain lesion and that are frequently refractory to medical treatment. Using Holmes tremor (HT) as an example, we discuss the effectiveness of currently available treatments and, performing simulations using a Markov Chain approach, propose that DBS with iterative parameter optimization is expected to be more effective than an approach based on sequential trials of pharmacological agents. Since, in DBS studies for HT, the thalamus is a frequently chosen target, using data from previous studies of lesion connectivity mapping in HT, we compared the connectivity of thalamic and non-thalamic targets with a proxy of the HT network, and found a significantly higher connectivity of thalamic DBS targets in HT. The understanding of brain networks provided by analysis of functional connectivity may thus provide an informed framework for proper surgical targeting of individual patients. Based on these findings, we argue that there is an ethical imperative to at least consider surgical options in patients with uncommon movement disorders, while simultaneously providing consistent information regarding the expected effectiveness and risks, even in a scenario of surgical-risk aversion. An approach based on n-of-1 DBS trials may ultimately significantly improve outcomes while informing on optimal therapeutic targets and parameter settings for HT and other disabling and rare movement disorders.

Translation and Validation of the Clinician Administered PTSD Scale (CAPS-CA-5) for Portuguese Children and Adolescents

INTRODUCTION

The aim of this study was to translate and validate into European Portuguese the CAPS-CA-5 (Clinician Administered PTSD Scale for Children and Adolescents), a semi-structured scale for the diagnosis of post-traumatic stress disorder in children and adolescents, according to the DSM-5 criteria.

MATERIAL AND METHODS

This study was developed in three stages. In the first stage, the translation and back-translation of CAPS-CA-5 into European Portuguese was carried out. In the second stage, the version obtained in the previous step was subjected to a pre-test. In the third stage, the final version of CAPS-CA-5, the KIDCOPE questionnaires and the Depression, Anxiety and Stress Scale-Children were applied to 101 children who had experienced at least one potentially traumatic event. The children included in this study were between seven and 18 years old and had a follow-up period in a Child Psychiatry or Pediatrics Clinic in one of the three hospitals involved in this project of at least one month.

RESULTS

Regarding the confirmatory factor analysis, our results show that the CAPS-CA-5 is a suitable psychometric instrument to assess the diagnosis and symptoms severity of post-traumatic stress disorder according to DSM-5. Convergent validity was comparable to its original version. Although there were negative relationships with almost all of its clusters, these were not statistically significant when applied with the positive coping strategies of the KIDCOPE. The European Portuguese version of the CAPS-CA-5 showed a good internal consistency (Cronbach's α for the total scale was 0.89).

CONCLUSION

The European Portuguese version of CAPS-CA-5 has similar psychometric properties to its original version.

Development of a Checklist of Potentially Traumatic Events in Children and Adolescents (CEPT-CA)

<b><i>Introduction:</i></b> Since exposure to potentially traumatic events during childhood and adolescence has been shown to be very common, its screening is very important. Our aim was to develop a self-assessment checklist to perform screening of potentially traumatic events in childhood and adolescence. <b><i>Methods:</i></b> The development of the Checklist of Potentially Traumatic Events in Children and Adolescents (CEPT-CA) was based on: (a) the structure of Life Events Checklist that has been translated, back-translated, and adapted; (b) recommendations of renowned entities about trauma in childhood; (c) particularities of potentially traumatic events in childhood; (d) adapting the language to the target population’s age group; (e) Portugal’s sociocultural context. The preliminary version of the CEPT-CA was again discussed with the Review Committee. Subsequently, a pre-test was carried out with 30 children/adolescents between the ages of 7 and 18 years. <b><i>Results:</i></b> The CEPT-CA includes the assessment of 16 potentially traumatic events. It also includes a 17th item, in which “any other very difficult/stressful event” may be added. Each event can be selected according to “It happened to me,” “I saw it happen to someone else,” “They told me,” “I’m not sure,” and “Not applicable.” The mean time to complete the questionnaire was 9 min. <b><i>Conclusion:</i></b> This pioneering study presents a checklist of potentially traumatic events in childhood/adolescence. This tool is useful for tracking these traumatic events, thereby allowing an early and specific assessment and intervention.

Hemispheric asymmetry of motor cortex excitability in mood disorders - Evidence from a systematic review and meta-analysis

OBJECTIVE

Mood disorders have been associated with lateralized brain dysfunction, on the left-side for depression and right-side for mania. Consistently, asymmetry of cortical excitability, as measured by transcranial magnetic stimulation (TMS) has been reported. Here, we reviewed and summarized work assessing such measures bilaterally in mood disorders.

METHODS

We performed a systematic review and extracted data to perform meta-analyses of interhemispheric asymmetry of motor cortex excitability, assessed with TMS, across different mood disorders and in healthy subjects. Additionally, potential predictors of interhemispheric asymmetry were explored.

RESULTS

Asymmetry of resting motor threshold (MT) among healthy volunteers was significant, favoring lower right relative to left-hemisphere excitability. MT was also significantly asymmetric in major depressive disorder (MDD), but with lower excitability of the left -hemisphere, when compared to the right, no longer observed in recovered patients. Findings on intracortical facilitation were similar. The few trials including bipolar depression revealed similar trends for imbalance, but with lower right hemisphere excitability, relative to the left.

CONCLUSIONS

There is interhemispheric asymmetry of motor cortical excitability in MDD, with lower excitability on left when compared to right-side. Interhemispheric asymmetry, with lower right relative to left-sided excitability, was found for bipolar depression and was also suggested for healthy volunteers, in a pattern that is clearly distinct from MDD.

SIGNIFICANCE

Mood disorders display asymmetric motor cortical excitability that is distinct from that found in healthy volunteers, supporting the presence of lateralized brain dysfunction in these disorders.

Functional neuroanatomy of mania

Mania, the diagnostic hallmark of bipolar disorder, is an episodic disturbance of mood, sleep, behavior, and perception. Improved understanding of the neurobiology of mania is expected to allow for novel avenues to address current challenges in its diagnosis and treatment. Previous research focusing on the impairment of functional neuronal circuits and brain networks has resulted in heterogenous findings, possibly due to a focus on bipolar disorder and its several phases, rather than on the unique context of mania. Here we present a comprehensive overview of the evidence regarding the functional neuroanatomy of mania. Our interpretation of the best available evidence is consistent with a convergent model of lateralized circuit dysfunction in mania, with hypoactivity of the ventral prefrontal cortex in the right hemisphere, and hyperactivity of the amygdala, basal ganglia, and anterior cingulate cortex in the left hemisphere of the brain. Clarification of dysfunctional neuroanatomic substrates of mania may contribute not only to improve understanding of the neurobiology of bipolar disorder overall, but also highlights potential avenues for new circuit-based therapeutic approaches in the treatment of mania.

Motor cortical inhibitory deficits in patients with obsessive-compulsive disorder-A systematic review and meta-analysis of transcranial magnetic stimulation literature

INTRODUCTION

Obsessive-compulsive disorder (OCD) is a highly prevalent chronic disorder, often refractory to treatment. While remaining elusive, a full understanding of the pathophysiology of OCD is crucial to optimize treatment. Transcranial magnetic stimulation (TMS) is a non-invasive technique that, paired with other neurophysiological techniques, such as electromyography, allows for in vivo assessment of human corticospinal neurophysiology. It has been used in clinical populations, including comparisons of patients with OCD and control volunteers. Results are often contradictory, and it is unclear if such measures change after treatment. Here we summarize research comparing corticospinal excitability between patients with OCD and control volunteers, and explore the effects of treatment with repetitive TMS (rTMS) on these excitability measures.

METHODS

We conducted a systematic review and meta-analysis of case-control studies comparing various motor cortical excitability measures in patients with OCD and control volunteers. Whenever possible, we meta-analyzed motor cortical excitability changes after rTMS treatment.

RESULTS

From 1,282 articles, 17 reporting motor cortex excitability measures were included in quantitative analyses. Meta-analysis regarding cortical silent period shows inhibitory deficits in patients with OCD, when compared to control volunteers. We found no statistically significant differences in the remaining meta-analyses, and no evidence, in patients with OCD, of pre- to post-rTMS changes in resting motor threshold, the only excitability measure for which longitudinal data were reported.

DISCUSSION

Our work suggests an inhibitory deficit of motor cortex excitability in patients with OCD when compared to control volunteers. Cortical silent period is believed to reflect activity of GABA_B receptors, which is in line with neuroimaging research, showing GABAergic deficits in patients with OCD. Regardless of its effect on OCD symptoms, rTMS apparently does not modify Resting Motor Threshold, possibly because this measure reflects glutamatergic synaptic transmission, while rTMS is believed to mainly influence GABAergic function. Our meta-analyses are limited by the small number of studies included, and their methodological heterogeneity. Nonetheless, cortical silent period is a reliable and easily implementable measurement to assess neurophysiology in humans, in vivo. The present review illustrates the importance of pursuing the study of OCD pathophysiology using cortical silent period and other easily accessible, non-invasive measures of cortical excitability.

SYSTEMATIC REVIEW REGISTRATION

[https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020201764], identifier [CRD42020201764].

Symptom provocation for treatment of obsessive-compulsive disorder using transcranial magnetic stimulation: A step-by-step guide for professional training

Transcranial Magnetic Stimulation (TMS) is a non-invasive brain stimulation technique that was cleared by the Food and Drug Administration (FDA) for the treatment of Obsessive-Compulsive Disorder (OCD) in 2018. The approved protocol includes individualized symptom provocation before each stimulation session, to elicit a moderate level of obsessional distress. Although symptom provocation can be a delicate, demanding, and uncomfortable procedure, structured training methods for those who are going to apply it are not available. Here, we describe a model for training in symptom provocation for TMS technicians, developed at the Champalimaud Clinical Centre in Lisbon, Portugal. Our programme includes two-sessions dedicated to clinical communication and symptom provocation techniques from a theoretical and practical perspective. Additionally, supervision meetings are conducted during treatment of patients, allowing regular case discussion and redefinition of symptom provocation hierarchy, as needed. In addition to having a strong practical component, our training program is short and pragmatic, allowing for easy implementation and fluid transition to clinical practice. By sharing our experience, we hope to contribute to systematize training procedures required for symptom provocation in the context of TMS, and to qualitatively describe a methodology that can be used for implementation of TMS programmes for the treatment of OCD.

In Older Adults the Antidepressant Effect of Repetitive Transcranial Magnetic Stimulation Is Similar but Occurs Later Than in Younger Adults

Background

Treatment resistant depression is common in older adults and treatment is often complicated by medical comorbidities and polypharmacy. Repetitive transcranial magnetic stimulation (rTMS) is a treatment option for this group due to its favorable profile. However, early influential studies suggested that rTMS is less effective in older adults. This evidence remains controversial.

Methods

Here, we evaluated the rTMS treatment outcomes in a large international multicenter naturalistic cohort of >500 patients comparing older vs. younger adults.

Results

We show that older adults, while having similar antidepressant response to younger adults, respond more slowly, which may help to explain differences from earlier studies when the duration of a treatment course was shorter.

Conclusions

Such evidence helps to resolve a long-standing controversy in treating older depressed patients with rTMS. Moreover, these findings provide an important data point in the call to revise policy decisions from major insurance providers that have unfairly excluded older adults.

Repetitive Transcranial Magnetic Stimulation for Major Depressive Disorder in Older Adults: Systematic Review and Meta-Analysis

BACKGROUND

Major Depressive Disorder (MDD) in older adults is a serious public health concern. Repetitive transcranial magnetic stimulation (rTMS) is a non-pharmacological intervention approved for Major Depressive Disorder (MDD) treatment in adults, but its value in older adults remains unknown. The present study aims to systematically review and meta-analyze evidence of rTMS efficacy in MDD treatment among older adults.

METHODS

We systematically reviewed the literature for randomized controlled trials (RCTs) and open-label studies assessing rTMS for the treatment of MDD in patients older than 50 years-old, published until June 2020. Random-effects meta-analyses using standardized mean differences (SMD) were conducted to assess change in depression severity score (primary outcome), while odds-ratios (OR) were used to assess secondary categorical outcomes (response and remission). Additionally, univariate meta-regression analyses were performed to identify potential predictors of change in depression severity scores.

RESULTS

Fourteen RCTs were included in meta-analyses and 26 studies (10 RCTs and 16 open-label studies) in meta-regression. Active rTMS was significantly superior to sham-treatment for reduction of severity (SMD=0.36; 95%CI=0.13-0.60), as well as response (OR=3.26; 95%CI=2.11-5.04) and remission (OR=4.63; 95%CI=2.24-9.55). Studies were of moderate to high quality, with funnel plots and Egger's regression test not suggestive of publication bias. In meta-regressions, higher mean age and number of sessions were significantly associated to greater improvement.

CONCLUSIONS

Our results support that rTMS is an effective, safe and well-tolerated treatment for MDD in older adults, and that it should be considered in the treatment of this vulnerable population.

Day-to-day variability in motor threshold during rTMS treatment for depression: Clinical implications

BACKGROUND

When repetitive transcranial magnetic stimulation (rTMS) is used to treat medication refractory depression, the treatment pulse intensity is individualized according to motor threshold (MT). This measure is often acquired only on the first day of treatment, as per the protocol currently approved by Food and Drug Administration.

OBJECTIVE

Here, we aimed to assess daily MT variability across an rTMS treatment course and simulate the effects of different schedules of MT assessment on treatment intensity.

METHODS

We conducted a naturalistic retrospective study with 374 patients from a therapeutic rTMS program for depression that measures MT daily.

RESULTS

For each patient, in almost half the TMS sessions, MT varied on average more than 5% as compared to the baseline MT acquired in the first treatment day. Such variability was only minimally impacted by having different TMS technicians acquiring MT in different days. In a smaller cohort of healthy individuals, we confirmed that the motor hotspot localization method, a critical step for accurate MT assessment, was stable in different days, arguing that daily MT variability reflects physiological variability, rather than an artifact of measurement error. Finally, in simulations of the effect of one-time MT measurement, we found that half of sessions would have been 5% or more above or below target intensity, with almost 5% of sessions 25% above target intensity. The simulated effects of weekly MT measurements were significantly improved.

CONCLUSIONS

In conclusion, MT varies significantly across days, not fully dependent on methods of MT acquisition. This finding may have important implications for therapeutic rTMS practice regarding safety and suggests that regular MT assessments, daily or at least weekly, would ameliorate the effect.

Diagnosis and Treatment of Neuroleptic Malignant Syndrome in the Intensive Care Unit: A Case Report

Neuroleptic malignant syndrome is a neurological emergency caused by dysregulation of dopaminergic neurotransmission. While it is typically characterized by muscle rigidity, fever and altered mental status, it may have a heterogeneous and non-specific presentation, leading to delays in diagnosis and treatment. Treatment involves cessation of dopamine-receptor antagonists and supportive measures, but in more severe cases, bromocriptine, dantrolene, benzodiazepines and/or electroconvulsive therapy should be considered. We present the case of a 66-year-old man with severe neuroleptic malignant syndrome, diagnosed due to need for continuous invasive ventilation in an Intensive Care Unit, after successful treatment for respiratory sepsis. The patient recovered after electroconvulsive therapy and administration of bromocriptine. This unusually severe case illustrates the need for a high level of suspicion for neuroleptic malignant syndrome in critically ill patients with malignant catatonic syndromes, allowing for an early diagnosis and potentially lifesavingtreatment.

Cortical excitability and its modulation in obsessive-compulsive disorder - a systematic review

Introduction

Obsessive-Compulsive Disorder (OCD) is an incapacitating Neuropsychiatric condition characterized by the presence of obsessions and/or compulsions. Although the disorder’s phenotype is well described, its pathophysiology remains elusive (Aouizerate et al, 2004). Over the last decade, techniques to noninvasively study the brain’s neurophysiology, such as Transcranial Magnetic Stimulation (TMS), have found widespread use in psychiatric research. For OCD, single- and paired-pule TMS protocols have been used to explore abnormalities in motor cortex excitability and cortical neuroplasticity. Here we propose to systematically review and, where possible, metanalyse existing case-control studies that compared such measures in patients and healthy subjects.

Objectives

To systematically review and meta-analyse published case-control studies comparing cortical excitability measures, as measured by single- or paired-pulse TMS, in subjects with OCD and healthy controls.

Methods

We have conducted a systematic review of published literature (PROSPERO registration CRD42020201764) reporting measures of cortical excitability as measured by single or paired-pulse TMS, in patients with OCD and healthy controls. We searched 4 different electronic libraries (PubMed, Web of Science, EMBASE, PsycINFO). The resulting list of articles was reviewed, separately, by two researchers. Disagreements were discussed and resolved by consensus, until a final list of eligible articles was obtained.

Results

13 studies reporting motor cortex excitability measures were included in our final list. The total number of participants included in our analyses is 615 (349 OCD; 180 healthy subjects; 86 other conditions)

Conclusions

A sufficient number of studies was found to allow for metanalyses, currently ongoing.

Reward-related gustatory and psychometric predictors of weight loss following bariatric surgery: a multicenter cohort study

BACKGROUND

Reward sensitivity has been proposed as a potential mediator of outcomes for bariatric surgery.

OBJECTIVES

We aimed to determine whether gustatory and psychometric measures of reward-related feeding are predictors of bariatric-induced weight loss.

METHODS

A multicenter longitudinal cohort study was conducted in patients scheduled for bariatric surgery (surgical group), assessed at baseline and 2 follow-up assessments. Predictions of % weight loss from baseline (%WL) according to baseline gustatory measures, including intensity and pleasantness ratings of sweet and other tastants, and psychometric measures of reward-related feeding behavior, including hedonic hunger scores, were assessed with multivariable linear regression. Exploratory analyses were conducted to test for associations between %WL and changes in gustatory and psychophysical measures, as well as for comparisons with data from patients on the surgery waiting list (control group).

RESULTS

We included 212 patients, of whom 96 in the surgical group and 50 in the control group were prospectively assessed. The groups were similar at baseline and, as expected, bariatric surgery resulted in higher %WL (BTreatment-Time  = 2.4; 95% CI: 2.1-2.8; P  < 0.0001). While variation in gustatory measures did not differ between groups, in the surgery group baseline sweet intensity predicted %WL at the primary endpoint (11 to 18 months postoperatively; β = 0.2; B = 0.2, 95% CI: 0.02 to 0.3; P  = 0.02), as did hedonic hunger scores (β = -0.2; B = -2.0, 95% CI: -3.8 to -0.3; P  = 0.02). Furthermore, at this endpoint, postsurgical reduction of sweet taste intensity and acceptance of sweet foods were associated with %WL (β = -0.3; B = -3.5, 95% CI: -5.8 to -1.3; P  = 0.003, and β = -0.2; B = -4.7, 95% CI: -8.5 to -0.8; P  = 0.02, respectively). The use of sweet intensity as a predictor of weight change was confirmed in another bariatric cohort.

CONCLUSIONS

Sweet intensity ratings and hedonic hunger scores predict %WL after surgery. The variability of sweet intensity ratings is also associated with %WL, further suggesting they may reflect physiological processes that are variably modulated by bariatric surgery, influencing clinical outcomes.

Mapping mania symptoms based on focal brain damage

BACKGROUNDAlthough mania is characteristic of bipolar disorder, it can also occur following focal brain damage. Such cases may provide unique insight into brain regions responsible for mania symptoms and identify therapeutic targets.METHODSLesion locations associated with mania were identified using a systematic literature search (n = 41) and mapped onto a common brain atlas. The network of brain regions functionally connected to each lesion location was computed using normative human connectome data (resting-state functional MRI, n = 1000) and contrasted with those obtained from lesion locations not associated with mania (n = 79). Reproducibility was assessed using independent cohorts of mania lesions derived from clinical chart review (n = 15) and of control lesions (n = 490). Results were compared with brain stimulation sites previously reported to induce or relieve mania symptoms.RESULTSLesion locations associated with mania were heterogeneous and no single brain region was lesioned in all, or even most, cases. However, these lesion locations showed a unique pattern of functional connectivity to the right orbitofrontal cortex, right inferior temporal gyrus, and right frontal pole. This connectivity profile was reproducible across independent lesion cohorts and aligned with the effects of therapeutic brain stimulation on mania symptoms.CONCLUSIONBrain lesions associated with mania are characterized by a specific pattern of brain connectivity that lends insight into localization of mania symptoms and potential therapeutic targets.FUNDINGFundação para a Ciência e Tecnologia (FCT), Harvard Medical School DuPont-Warren Fellowship, Portuguese national funds from FCT and Fundo Europeu de Desenvolvimento Regional, Child Neurology Foundation Shields Research, Sidney R. Baer, Jr. Foundation, Nancy Lurie Marks Foundation, Mather's Foundation, and the NIH.

Right-sided brain lesions predominate among patients with lesional mania: evidence from a systematic review and pooled lesion analysis

Despite claims that lesional mania is associated with right-hemisphere lesions, supporting evidence is scarce, and association with specific brain areas has not been demonstrated. Here, we aimed to test whether focal brain lesions in lesional mania are more often right- than left-sided, and if lesions converge on areas relevant to mood regulation. We thus performed a systematic literature search (PROSPERO registration CRD42016053675) on PubMed and Web-Of-Science, using terms that reflect diagnoses and structures of interest, as well as lesional mechanisms. Two researchers reviewed the articles separately according to PRISMA Guidelines, selecting reports of adult-onset hypomania, mania or mixed state following a focal brain lesion, for pooled-analyses of individual patient data. Eligible lesion images were manually traced onto the corresponding MNI space slices, and lesion topography analyzed using standard brain atlases. Using this approach, data from 211 lesional mania patients was extracted from 114 reports. Among 201 cases with focal lesions, more patients had lesions involving exclusively the right (60.7%) than exclusively the left (11.4%) hemisphere. In further analyses of 56 eligible lesion images, while findings should be considered cautiously given the potential for selection bias of published lesion images, right-sided predominance of lesions was confirmed across multiple brain regions, including the temporal lobe, fusiform gyrus and thalamus. These, and several frontal lobe areas, were also identified as preferential lesion sites in comparisons with control lesions. Such pooled-analyses, based on the most comprehensive dataset of lesional mania available to date, confirm a preferential association with right-hemisphere lesions, while suggesting that several brain areas/circuits, relevant to mood regulation, are most frequently affected.

Durability of antidepressant response to repetitive transcranial magnetic stimulation: Systematic review and meta-analysis

BACKGROUND

The therapeutic options for treatment-resistant depression (TRD) encompass a range of neuromodulatory techniques, including repetitive transcranial magnetic stimulation (rTMS). While rTMS is safe and has documented short-term efficacy, durability of antidepressant effects is poorly established.

OBJECTIVE

Assess existing evidence regarding durability of rTMS-induced antidepressant response.

METHODS

We performed a systematic review of studies reporting antidepressant outcome measures collected three or more months after the end of an induction course of rTMS for depression. Among responders to the induction course, we used a meta-analytic approach to assess response rates at 3 (m3), 6 (m6) or 12 (m12) months after induction, and studied predictors of responder rates using meta-regression.

RESULTS

Nineteen studies published between 2002 and 2018 were included. Eighteen were eligible for analysis at m3 (732 patients) and m6 (695 patients) and 9 at m12 (247 patients). Among initial responders, 66.5% sustained response at m3 (95% CI = 57.1-74.8%, I² = 27.6%), 52.9% at m6 (95% CI = 40.3-65%, I² = 0%), and 46.3% at m12 (95% CI = 32.6-60.7%, I² = 0%), in the absence of any major bias. Random-effects meta-regressions further demonstrated that a higher proportion of women, as well as receipt of maintenance treatment, predicted higher responder rates at specific time-points.

CONCLUSIONS

rTMS is a durable treatment for depression, with sustained responder rates of 50% up to 1 year after a successful induction course of treatment. Maintenance treatment may enhance the durability of the antidepressant effects of rTMS, and should be considered in clinical practice, as well as systematically explored in future clinical trials.