Deep transcranial magnetic stimulation for adolescents with treatment-resistant depression: A preliminary dose-finding study exploring safety and clinical effectiveness

BACKGROUND

Transcranial magnetic stimulation (TMS) is an intervention for treatment-resistant depression (TRD) that modulates neural activity. Deep TMS (dTMS) can target not only cortical but also deeper limbic structures implicated in depression. Although TMS has demonstrated safety in adolescents, dTMS has yet to be applied to adolescent TRD.

OBJECTIVE/HYPOTHESIS

This pilot study evaluated the safety, tolerability, and clinical effects of dTMS in adolescents with TRD. We hypothesized dTMS would be safe, tolerable, and efficacious for adolescent TRD.

METHODS

15 adolescents with TRD (Age, years: M = 16.4, SD = 1.42) completed a six-week daily dTMS protocol targeting the left dorsolateral prefrontal cortex (BrainsWay H1 coil, 30 sessions, 10 Hz, 3.6 s train duration, 20s inter-train interval, 55 trains; 1980 total pulses per session, 80 % to 120 % of motor threshold). Participants completed clinical, safety, and neurocognitive assessments before and after treatment. The primary outcome was depression symptom severity measured by the Children's Depression Rating Scale-Revised (CDRS-R).

RESULTS

14 out of 15 participants completed the dTMS treatments. One participant experienced a convulsive syncope; the other participants only experienced mild side effects (e.g., headaches). There were no serious adverse events and minimal to no change in cognitive performance. Depression symptom severity significantly improved pre- to post-treatment and decreased to a clinically significant degree after 10 treatment sessions. Six participants met criteria for treatment response.

LIMITATIONS

Main limitations include a small sample size and open-label design.

CONCLUSIONS

These findings provide preliminary evidence that dTMS may be tolerable and associated with clinical improvement in adolescent TRD.

Mitochondrial health, NLRP3 inflammasome activation, and white matter integrity in adolescent mood disorders: A pilot study

Adolescence is a particularly important period for brain development and is also when mood disorders typically emerge. Several psychiatric illnesses exhibit mitochondrial dysfunction, elevated inflammation, and impaired white matter integrity. This study explored the intersection of mitochondrial health, NLRP3 inflammasome activation, and white matter integrity in a small cohort of 29 adolescent patients with mood disorders (bipolar disorder (BD): n = 11, major depressive disorder (MDD): n = 19) and 19 healthy controls. In this sample, adolescents with mood disorders showed lower fractional anisotropy of the ventral cingulum bundle than healthy controls. Across all adolescents, we demonstrated a significant relationship between mitochondrial electron transport chain gene expression, and NLRP3 inflammasome gene expression and activation. Furthermore, circulating cell free mitochondrial DNA was associated with lower white matter integrity in the anterior thalamic radiation. Exploratory subgroup analyses revealed that adolescents with bipolar disorder exhibited lower levels of mitochondrial gene expression and volume, along with increased sensitivity to NLRP3 inflammasome activation compared to adolescents with unipolar depression. Overall, our results reveal relationships between peripherally-measured endpoints of mitochondrial health and NLRP3 inflammasome activation, and centrally measured endpoints of white matter integrity in adolescents. Together with subtle patterns of aberrant neural and biological structure and function in association with mood disorder diagnoses, these results may shed light on the pathophysiology of disease in this early phase of illness.

A Multilevel Examination of Cognitive Control in Adolescents With Nonsuicidal Self-injury

Background

Nonsuicidal self-injury (NSSI), a transdiagnostic behavior, often emerges during adolescence. This study used the Research Domain Criteria approach to examine cognitive control (CC) with a focus on response inhibition and urgency relative to NSSI severity in adolescents.

Methods

One hundred thirty-eight adolescents, assigned female sex at birth, with a continuum of NSSI severity completed negative and positive urgency measurements (self-report), an emotional Go/NoGo task within negative and positive contexts (behavioral), and structural and functional imaging during resting state and task (brain metrics). Cortical thickness, subcortical volume, resting-state functional connectivity, and task activation focused on an a priori-defined CC network. Eighty-four participants had all these main measures. Correlations and stepwise model selection followed by multiple regression were used to examine the association between NSSI severity and multiunit CC measurements.

Results

Higher NSSI severity correlated with higher negative urgency and lower accuracy during positive no-inhibition (Go). Brain NSSI severity correlates varied across modalities and valence. For right medial prefrontal cortex and right caudate, higher NSSI severity correlated with greater negative but lower positive inhibition (NoGo) activation. The opposite pattern was observed for the right dorsolateral prefrontal cortex. Higher NSSI severity correlated with lower left dorsal anterior cingulate cortex (ACC) negative inhibition activation and thicker left dorsal ACC, yet it was correlated with higher right rostral ACC positive inhibition activation and thinner right rostral ACC, as well as lower CC network resting-state functional connectivity.

Conclusions

Findings revealed multifaceted signatures of NSSI severity across CC units of analysis, confirming the relevance of this domain in adolescent NSSI and illustrating how multimodal approaches can shed light on psychopathology.

Behavioral Apophenia and Dimensions of Psychoticism in Adolescents with and without Mood Disorders

Apophenia is the tendency to falsely detect meaningful relationships and may indicate susceptibility to more extreme expressions on the psychotic spectrum. This pilot investigated the fragmented ambiguous object task (FAOT), a new measure designed to assess apophenia behaviorally in a sample of adolescents with and without mood disorders using an image recognition task. Our primary hypothesis was that increased image recognition would be associated with PID-5 psychoticism. Participants were 33 (79% female) adolescents with (n = 18) and without (n = 15) mood disorders. Consistent with predictions, increased recognition of ambiguous images correlated positively with psychoticism. There was also moderate evidence for long-term stability of FAOT apophenia scores over time (mean interval of approximately 10 months). These findings offer preliminary evidence that the FAOT may be reflective of underlying psychoticism in our target population.

Adolescent stress experience-expression-physiology correspondence: Links to depression, self-injurious thoughts and behaviors, and frontolimbic neural circuity

BACKGROUND

Dysregulated stress responsivity is implicated in adolescent risk for depression and self-injurious thoughts and behaviors (STBs). However, studies often examine levels of the stress response in isolation, precluding understanding of how coordinated disturbance across systems confers risk. The current study utilized a novel person-centered approach to identify stress correspondence profiles and linked them to depressive symptoms, STBs, and neural indices of self-regulatory capacity.

METHOD

Adolescents with and without a major depressive disorder diagnosis (N = 162, M_age = 16.54, SD = 1.96, 72.8% White, 66.5% female) completed the Trier Social Stress Test (TSST), questionnaires, and clinical interviews. Stress experience (self-report), expression (observed), and physiology (salivary cortisol) were assessed during the experimental protocol. Adolescents also underwent a magnetic resonance imaging scan.

RESULTS

Multitrajectory modeling revealed four profiles. High Experience-High Expression-Low Physiology (i.e., lower stress correspondence) adolescents were more likely to report depressive symptoms, lifetime nonsuicidal self-injury, and suicidal ideation relative to all other subgroups reflecting higher stress correspondence: Low Experience-Low Expression-Low Physiology, Moderate Experience-Moderate Expression-Moderate Physiology, High Experience-High Expression-High Physiology. High Experience-High Expression-Low Physiology adolescents also exhibited less positive amygdala-ventromedial prefrontal cortex resting state functional connectivity relative to Moderate Experience-Moderate Expression-Moderate Physiology.

LIMITATIONS

Data were cross-sectional, precluding inference about our profiles as etiological risk factors or mechanisms of risk.

CONCLUSIONS

Findings illustrate meaningful heterogeneity in adolescent stress correspondence with implications for multimodal, multilevel assessment and outcome monitoring in depression prevention and intervention efforts.

Adolescent cortisol and DHEA responses to stress as prospective predictors of emotional and behavioral difficulties: A person-centered approach

BACKGROUND

Well-orchestrated cortisol and DHEA stress responsivity is thought to support efficacious stressor management (i.e., coping) and reduce risk for psychopathology during adolescence. Evidence of these relations, however, is lacking empirically. This longitudinal investigation had three aims: 1) to identify within-adolescent profiles of joint cortisol-DHEA responsivity, 2) examine profiles as prospective predictors of adolescents' later emotional and behavioral difficulties, and 3) examine whether distraction coping helped buffer such prospective risk in each profile.

METHOD

At Time 1, boys (n = 110) and girls (n = 105) between 11 and 16 years of age with varied levels of risk for psychopathology completed a lab-based socio-evaluative stressor and questionnaires (e.g., coping, internalizing and externalizing problems). Emotional and behavioral adjustment was assessed again at Time 2 (2 years later).

RESULTS

Multi-trajectory modeling of adolescents' cortisol and DHEA within the context of the stressor revealed three groups: Normative (n = 107; 49.8%), Hyperresponsive (n = 64; 29.8%), Hyporesponsive (n = 44; 20.5%). Relative to Normative, Hyperresponsive and Hyporesponsive adolescents were more and less advanced in pubertal status, respectively. Hyperresponsive adolescents, but not Hyporesponsive, reported greater emotional and behavioral problems at Time 2, relative to Normative adolescents. Links between distraction coping and Time 2 adjustment varied across the groups. Specifically, distraction coping was associated with fewer Time 2 emotional and behavioral problems for Normative adolescents. However, the converse was true for Hyporesponsive adolescents, with distraction associated with greater Time 2 emotional and behavioral problems. Distraction was not associated with Time 2 emotional and behavioral problems for Hyperresponsive adolescents (i.e., elevated levels irrespective of distraction coping utilization).

CONCLUSION

Our results strengthen inference about the role neuroendocrine coordination plays in risk for psychopathology. Findings also help to clarify inconsistent distraction coping-psychopathology linkages, illustrating different patterns of cortisol-DHEA responsivity that support as well as thwart the use of this potentially efficacious strategy.

Cortical thickness and resting-state cardiac function across the lifespan: A cross-sectional pooled mega-analysis

Understanding the association between autonomic nervous system [ANS] function and brain morphology across the lifespan provides important insights into neurovisceral mechanisms underlying health and disease. Resting-state ANS activity, indexed by measures of heart rate [HR] and its variability [HRV] has been associated with brain morphology, particularly cortical thickness [CT]. While findings have been mixed regarding the anatomical distribution and direction of the associations, these inconsistencies may be due to sex and age differences in HR/HRV and CT. Previous studies have been limited by small sample sizes, which impede the assessment of sex differences and aging effects on the association between ANS function and CT. To overcome these limitations, 20 groups worldwide contributed data collected under similar protocols of CT assessment and HR/HRV recording to be pooled in a mega-analysis (N = 1,218 (50.5% female), mean age 36.7 years (range: 12-87)). Findings suggest a decline in HRV as well as CT with increasing age. CT, particularly in the orbitofrontal cortex, explained additional variance in HRV, beyond the effects of aging. This pattern of results may suggest that the decline in HRV with increasing age is related to a decline in orbitofrontal CT. These effects were independent of sex and specific to HRV; with no significant association between CT and HR. Greater CT across the adult lifespan may be vital for the maintenance of healthy cardiac regulation via the ANS-or greater cardiac vagal activity as indirectly reflected in HRV may slow brain atrophy. Findings reveal an important association between CT and cardiac parasympathetic activity with implications for healthy aging and longevity that should be studied further in longitudinal research.

International Consensus Based Review and Recommendations for Minimum Reporting Standards in Research on Transcutaneous Vagus Nerve Stimulation (Version 2020)

Given its non-invasive nature, there is increasing interest in the use of transcutaneous vagus nerve stimulation (tVNS) across basic, translational and clinical research. Contemporaneously, tVNS can be achieved by stimulating either the auricular branch or the cervical bundle of the vagus nerve, referred to as transcutaneous auricular vagus nerve stimulation(VNS) and transcutaneous cervical VNS, respectively. In order to advance the field in a systematic manner, studies using these technologies need to adequately report sufficient methodological detail to enable comparison of results between studies, replication of studies, as well as enhancing study participant safety. We systematically reviewed the existing tVNS literature to evaluate current reporting practices. Based on this review, and consensus among participating authors, we propose a set of minimal reporting items to guide future tVNS studies. The suggested items address specific technical aspects of the device and stimulation parameters. We also cover general recommendations including inclusion and exclusion criteria for participants, outcome parameters and the detailed reporting of side effects. Furthermore, we review strategies used to identify the optimal stimulation parameters for a given research setting and summarize ongoing developments in animal research with potential implications for the application of tVNS in humans. Finally, we discuss the potential of tVNS in future research as well as the associated challenges across several disciplines in research and clinical practice.

Editorial: The Ups and Downs of Mind-Wandering in Adolescents

The human brain is always active; it wanders freely during rest as well as when we lose focus during tasks. Mind-wandering encompasses spontaneous thinking, such as processing recent experiences, problem solving, and achieving insights. Understanding this unconstrained brain activity may lead to clues about the neural mechanisms of mental health problems. Brain networks implicated in mind-wandering include the default mode network (DMN), the salience network, and task-positive networks including the frontoparietal control network and dorsal attention network.¹ Given that these networks mature during adolescence, coinciding with a time notable for the emergence of mental health problems, quantifying and examining the neural correlates of mind-wandering in adolescents with psychopathology may shed light on how the healthy and pathological brain functions and point to possible methods of intervening.

Coordination between frontolimbic resting state connectivity and hypothalamic-pituitary-adrenal axis functioning in adolescents with and without depression

Depression is associated with abnormalities in Hypothalamic-Pituitary-Adrenal (HPA) axis functioning and neural circuitry that underlie the stress response. Resting-state functional connectivity (RSFC) between frontolimbic brain regions captures intrinsic connections that may set the stage for the rallying and regulating of the HPA axis system. This study examined the association between cortisol stress response and frontolimbic (amygdala and ventral and dorsal medial prefrontal cortex [vmPFC and dmPFC respectively]) RSFC in 88 (Age: M = 15.95, SD = 2.04; 71.60% female) adolescents with (N = 55) and without (N = 33) major depressive disorder (MDD). We collected salivary cortisol in the context of a modified Trier Social Stress Test (TSST) paradigm. Key findings were that adolescents with depression and healthy controls showed different patterns of association between amygdala and vmPFC RSFC and HPA functioning: while healthy controls showed a positive relationship between frontolimbic connectivity and cortisol levels that may indicate coordination across neural and neuroendocrine systems, adolescents with depression showed a minimal or inverse relationship, suggesting poor coordination of these systems. Results were similar when examining non-suicidal self-injury subgroups within the MDD sample. These findings suggest that the intrinsic quality of this frontolimbic connection may be related to HPA axis functioning. In MDD, inverse associations may represent a compensatory response in one system in response to dysfunction in the other. Longitudinal multilevel research, however, is needed to disentangle how stress system coordination develops in normal and pathological contexts and how these systems recover with treatment.

Brain entropy and neurotrophic molecular markers accompanying clinical improvement after ketamine: Preliminary evidence in adolescents with treatment-resistant depression

BACKGROUND

Current theory suggests that treatment-resistant depression (TRD) involves impaired neuroplasticity resulting in cognitive and neural rigidity, and that clinical improvement may require increasing brain flexibility and adaptability.

AIMS

In this hypothesis-generating study, we sought to identify preliminary evidence of brain flexibility correlates of clinical change within the context of an open-label ketamine trial in adolescents with TRD, focusing on two promising candidate markers of neural flexibility: (a) entropy of resting-state functional magnetic resonance imaging (fMRI) signals; and (b) insulin-stimulated phosphorylation of mammalian target of rapamycin (mTOR) and glycogen synthase-3-beta (GSK3β) in peripheral blood mononuclear cells.

METHODS

We collected resting-state functional magnetic resonance imaging data and blood samples from 13 adolescents with TRD before and after a series of six ketamine infusions over 2 weeks. Usable pre/post ketamine data were available from 11 adolescents for imaging and from 10 adolescents for molecular signaling. We examined correlations between treatment response and changes in the central and peripheral flexibility markers.

RESULTS

Depression reduction correlated with increased nucleus accumbens entropy. Follow-up analyses suggested that physiological changes were associated with treatment response. In contrast to treatment non-responders (n=6), responders (n=5) showed greater increase in nucleus accumbens entropy after ketamine, together with greater post-treatment insulin/mTOR/GSK3β signaling.

CONCLUSIONS

These data provide preliminary evidence that changes in neural flexibility may underlie symptom relief in adolescents with TRD following ketamine. Future research with adequately powered samples is needed to confirm resting-state entropy and insulin-stimulated mTOR and GSK3β as brain flexibility markers and candidate targets for future clinical trials.

CLINICAL TRIAL NAME

Ketamine in adolescents with treatment-resistant depressionURL: https://clinicaltrials.gov/ct2/show/NCT02078817Registration number: NCT02078817.

Transcendental meditation and hypothalamic-pituitary-adrenal axis functioning: a pilot, randomized controlled trial with young adults

Transcendental meditation (TM) is effective in alleviating stress and anxiety and promoting well-being. While the underlying biological mechanisms of TM are not yet fully explored, the hypothalamic-pituitary-adrenal (HPA) axis represents an index providing important clues embodying the stress system cascade. In this pilot study, young adults were randomly assigned to TM training followed by 8 weeks of meditation practice or a wait-list control condition. TM was conducted over 8 weeks. Thirty-four young adult participants were randomized; 27 participants completed the HPA outcome assessments (41% male). To assess HPA axis functioning, salivary samples to assess cortisol awakening response (CAR) that were collected in the morning, both at baseline and at week-4. Salivary cortisol in the context of a social stressor using the Trier Social Stress Test (TSST) was collected at week-8. The results indicate that participants who were randomly assigned to TM had lower awakening salivary cortisol levels and a greater drop in CAR from baseline to week-4 than the control group. There were no significant differences in HPA axis functioning in the context of the TSST. Primary limitations of this randomized controlled trial were the small sample size, the use of a wait-list as opposed to an active control, and the limited scope of HPA axis assessments. The results of this pilot study provide tentative evidence that TM may impact biological stress system functioning and suggests that this may be a worthwhile avenue to continue to examine. It will also be useful to extend these findings to a broader array of meditative and mindful practices, particularly for those who are experiencing more distress.

Neural and Behavioral Correlates of Clinical Improvement to Ketamine in Adolescents With Treatment Resistant Depression

Treatment-resistant depression (TRD) is a serious problem in adolescents. Development and optimization of novel interventions for these youth will require a deeper knowledge of the neurobiology of depression. A well-established phenomenon of depression is an attention bias toward negativity and away from positivity that is evidenced behaviorally and neurally, but it is unclear how symptom reduction is related to changes to this bias. Neurobiological research using a treatment probe has promise to help discover the neural changes that accompany symptom improvement. Ketamine has utility for such research because of its known rapid and strong antidepressant effects in the context of TRD. Our previous study of six open-label ketamine infusions in 11 adolescents with TRD showed variable response, ranging from full remission, partial response, non-response, or clinical worsening. In this study, we examined the performance of these participants on Word Face Stroop (WFS) fMRI task where they indicated the valence of affective words superimposed onto either congruent or incongruent emotional faces before and after the ketamine infusions. Participants also completed a clinical assessment (including measurement of depression symptomology and anhedonia/pleasure) before and after the ketamine infusions. Following ketamine treatment, better WFS performance correlated with self-reported decreased depressive symptoms and increased pleasure. Analyses of corticolimbic, corticostriatal and default mode (DMN) networks showed that across networks, decreased activation during all conditions (congruent negative, congruent positive, incongruent negative, and incongruent positive) correlated with decreases in depressive symptoms and with increases in pleasure. These findings suggest that in adolescents with TRD, clinical improvement may require an attenuation of the negativity bias and re-tuning of these three critical neural networks to attenuate DMN and limbic regions activation and allow more efficient recruitment of the reward network. Lower activation across conditions may facilitate shifting across different salient emotional stimuli rather than getting trapped in downward negative spirals.

Hypothalamic-pituitary-adrenal axis dysregulation in depressed adolescents with non-suicidal self-injury

Non-suicidal self-injury (NSSI) is characterized by causing harm to one's own body without the intent of suicide. While major depressive disorder (MDD) has been associated with elevated cortisol (at least in some subgroups), prior studies in NSSI have suggested that NSSI is associated with blunted reactivity to stress of the hypothalamic-pituitary-adrenal (HPA) axis, possibly consistent with an allostatic load model. The present study used a multi-level approach to examine salivary cortisol in the context of a social stressor in 162 adolescents (ages 12 to 19 years old) with MDD with a history of repeated engagement in NSSI (MDD/NSSI) versus MDD without repeated NSSI (MDD), and healthy controls (HC). Observed (expressed) and self-reported (experienced) ratings of stress were also obtained during the social stress paradigm. The results showed that MDD/NSSI exhibited lower salivary cortisol levels and differed in cortisol trajectories in the context of a social stressor compared to HC and MDD. Observed stress, but not self-reported stress, during the social stress paradigm was greater for the MDD/NSSI than HC. Follow-up analyses suggested the possibility that this pattern of lower cortisol for those who engage in NSSI was present in females and males, and was more pronounced in those with repeated NSSI (but not subthreshold NSSI) and those with a history of NSSI and suicide attempts. Overall, these findings add to the prior literature and begin to show a consistent pattern for how stress is processed in atypical ways for those who engage in repeated NSSI. Importantly, these results suggest that some of the heterogeneity across adolescent depression may be better represented by these underlying biological processes, perhaps even representing subgroups that will benefit from different types of intervention. Hypothalamic-Pituitary-Adrenal Axis Dysregulation in Depressed Adolescents with Non-Suicidal Self-Injury.

Neural and neuroendocrine predictors of pharmacological treatment response in adolescents with depression: A preliminary study

OBJECTIVE

Typically, about 30 to 50% of adolescents with depression fail to respond to evidence-based treatments, including antidepressant medications such as selective serotonin reuptake inhibitors (SSRIs). Efforts for identifying predictors and moderators of treatment response are needed to begin to address critical questions relevant to personalized care in adolescent depression. In this pilot study, we aim to identify biological predictors of response to antidepressant treatment.

METHOD

We used a multiple levels of analysis approach to evaluate threat system functioning (fronto-limbic system and the associated hormonal cascade) to determine if key biological indexes at baseline could predict improvement in depressive symptoms after eight weeks of antidepressant treatment in adolescents with depression.

RESULTS

Neural predictors of favorable treatment response included lower amygdala connectivity with left supplementary motor area and with right precentral gyrus, and greater amygdala connectivity with right central opercular cortex and Heschl's gyrus connectivity during rest. During an emotion task, neural predictors of treatment response were greater activation of the bilateral anterior cingulate cortex and left medial frontal gyrus. Additionally, different patterns of salivary cortisol obtained in the context of a modified Trier Social Stress Test were associated with those whose depressive symptoms remitted as compared to those whose symptoms persisted.

CONCLUSIONS

This approach shows significant promise for identifying predictors of treatment response in adolescents with depression. Future work is needed that incorporates sufficiently powered, randomized control trials to provide the basis by which both predictors and moderators of treatment response are identified. The hope is that this work will inform the development of methods that can guide clinician decision-making in assigning beneficial treatments for adolescents who are suffering from depression.

Trauma Sequelae are Uniquely Associated with Components of Self-Reported Sleep Dysfunction in OEF/OIF/OND Veterans

While the associations between psychological distress (e.g., posttraumatic stress disorder [PTSD], depression) and sleep dysfunction have been demonstrated in trauma-exposed populations, studies have not fully explored the associations between sleep dysfunction and the wide range of common physical and physiological changes that can occur after trauma exposure (e.g., pain, cardiometabolic risk factors). We aimed to clarify the unique associations of psychological and physical trauma sequelae with different aspects of self-reported sleep dysfunction. A comprehensive psychological and physical examination was administered to 283 combat-deployed trauma-exposed Operation Enduring Freedom/Operation Iraqi Freedom/Operation New Dawn (OEF/OIF/OND) veterans. The Pittsburgh Sleep Quality Index (PSQI) and PSQI Addendum for PSTD (PSQI-A) were administered along with measures of PTSD, depression, anxiety, pain, traumatic brain injury, alcohol use, nicotine dependence, and cardiometabolic symptoms. We first performed a confirmatory factor analysis of the PSQI and then conducted regressions with the separate PSQI factors as well as the PSQI-A to identify unique associations between trauma-related measures and the separate aspects of sleep. We found that the PSQI global score was composed of three factors: Sleep Efficiency (sleep efficiency/sleep duration), Perceived Sleep Quality (sleep quality/sleep latency/sleep medication) and Daily Disturbances (sleep disturbances/daytime dysfunction). Linear regressions demonstrated that PTSD symptoms were uniquely associated with the PSQI global score and all three factors, as well as the PSQI-A. For the other psychological distress variables, anxiety was independently associated with PSQI global as well as Sleep Efficiency, Perceived Sleep Quality, and PSQI-A, whereas depression was uniquely associated with Daily Disturbances and PSQI-A. Notably, cardiometabolic symptoms explained independent variance in PSQI global and Sleep Efficiency. These findings help lay the groundwork for further investigations of the mechanisms of sleep dysfunction in trauma-exposed individuals and may help in the development of more effective, individualized treatments.

Network-targeted cerebellar transcranial magnetic stimulation improves attentional control

Developing non-invasive brain stimulation interventions to improve attentional control is extremely relevant to a variety of neurological and psychiatric populations, yet few studies have identified reliable biomarkers that can be readily modified to improve attentional control. One potential biomarker of attention is functional connectivity in the core cortical network supporting attention - the dorsal attention network (DAN). We used a network-targeted cerebellar transcranial magnetic stimulation (TMS) procedure, intended to enhance cortical functional connectivity in the DAN. Specifically, in healthy young adults we administered intermittent theta burst TMS (iTBS) to the midline cerebellar node of the DAN and, as a control, the right cerebellar node of the default mode network (DMN). These cerebellar targets were localized using individual resting-state fMRI scans. Participants completed assessments of both sustained (gradual onset continuous performance task, gradCPT) and transient attentional control (attentional blink) immediately before and after stimulation, in two sessions (cerebellar DAN and DMN). Following cerebellar DAN stimulation, participants had significantly fewer attentional lapses (lower commission error rates) on the gradCPT. In contrast, stimulation to the cerebellar DMN did not affect gradCPT performance. Further, in the DAN condition, individuals with worse baseline gradCPT performance showed the greatest enhancement in gradCPT performance. These results suggest that temporarily increasing functional connectivity in the DAN via network-targeted cerebellar stimulation can enhance sustained attention, particularly in those with poor baseline performance. With regard to transient attention, TMS stimulation improved attentional blink performance across both stimulation sites, suggesting increasing functional connectivity in both networks can enhance this aspect of attention. These findings have important implications for intervention applications of TMS and theoretical models of functional connectivity.

[AORTOENTERIC FISTULA, A POOR PROGNOSIS FINDING]

We report the case of a patient admitted with upper gastrointestinal bleeding. The CT scan revealed an aorto-duodenal fistula. This case highlights the progression of radiological imaging in parallel with the clinical course. We take this opportunity to write a brief literature review mainly focused on the description and diagnostic modalities of aortoenteric fistulas.

Frontal eye field involvement in sustaining visual attention: evidence from transcranial magnetic stimulation

The frontal eye field (FEF), particularly the right FEF, is broadly implicated in top-down control of transient acts of attention, but less is known about its involvement in sustained attention. Although neuroimaging studies of sustained attention tasks commonly find FEF activation, it is unclear how this region contributes to moment-to-moment fluctuations in sustained performance. We sought to determine if the FEF plays a critical role in sustained attention, and if that role differs between periods of worse performance (out-of-the-zone) and periods of better performance (in-the-zone). We used offline 1 Hz repetitive transcranial magnetic stimulation (TMS) to temporarily attenuate either right or left FEF excitability while participants performed a go/no-go sustained attention task (the gradual onset continuous performance task). The results demonstrate that following TMS to the right FEF, sustained attention during in-the-zone periods significantly worsened both in terms of lower accuracy and increased reaction time variability. In contrast, applying TMS to the left FEF did not significantly affect accuracy or variability. These results demonstrate that the right FEF plays a crucial role in supporting optimal sustained attention.