The impact of one HF-rTMS session on mood and salivary cortisol in treatment resistant unipolar melancholic depressed patients

Left dorsolateral prefrontal cortex activation can accelerate stress recovery: A repetitive transcranial stimulation study

In this study, a single high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) session was applied over the left dorsolateral prefrontal cortex (DLPFC) after a moderate-to-intense stressor to investigate whether left DLPFC stimulation could regulate cortisol concentration after stress induction. Participants were randomly divided into three groups (stress-TMS, stress, and placebo-stress). Stress was induced in both the stress-TMS and stress groups using the Trier Social Stress Test (TSST). The placebo-stress group received a placebo TSST. In the stress-TMS group, a single HF-rTMS session was applied over the left DLPFC after TSST. Cortisol was measured across the different groups, and each group's responses to the stress-related questionnaire were recorded. After TSST, both the stress-TMS and stress groups reported increased self-reported stress, state anxiety, negative affect, and cortisol concentration compared with the placebo-stress group, indicating that TSST successfully induced a stress response. Compared with the stress group, the stress-TMS group exhibited reduced cortisol levels at 0, 15, 30, and 45 min after HF-rTMS. These results suggest that left DLPFC stimulation after stress induction might accelerate the stress recovery.

Effects of left anodal transcranial direct current stimulation on hypothalamic-pituitary-adrenal axis activity in depression: a randomized controlled pilot trial

The main objective of this study was to evaluate the effect of left anodal transcranial direct current stimulation (tDCS) on hypothalamic-pituitary-adrenal axis (HPAA) activity in individuals with depression. We conducted a 3-week, randomized, triple-blind pilot trial with 47 participants (dropout rate: 14.89%) randomly assigned to either the tDCS or control group (sham stimulation). Salivary cortisol was used as an HPAA activity marker since cortisol is the effector hormone of the HPAA. The primary outcome was the effect of tDCS on the diurnal cortisol pattern (DCP and area under the curve with respect to ground -AUCg-). Secondary outcomes included tDCS effects on cortisol awakening response (CAR) and cortisol decline (CD), as well as the variation of cortisol concentrations between the initiation of tDCS and 2 weeks later. Intention-to-treat and per-protocol analyses were conducted. Our primary outcome showed an absent effect of tDCS on DCP and AUCg. Additionally, tDCS had an absent effect on CAR, CD, and cortisol concentration variation before-after stimulation. Our pilot study suggests that anodal tDCS showed an absent effect on HPAA activity in individuals with depression. More studies are needed to confirm these findings.

Pre-frontal stimulation does not reliably increase reward responsiveness

Depression is the leading cause of disability worldwide and its effects can be fatal, with over 800,000 people dying by suicide each year. Neuromodulatory treatments such as transcranial magnetic stimulation (TMS) are being used to treat depression. Despite its endorsement by two regulatory bodies: NICE (2016) and the FDA (2008), there are major questions about the treatment efficacy and biological mechanisms of TMS. Ahn et al.'s (2013) justified the use of TMS in a clinical context in an important study indicating that excitatory TMS increases reward responsiveness. A pseudo-replication of this study by Duprat et al., (2016) also found a similar effect of active TMS, but only with the addition of an exploratory covariate to the analyses-trait reward responsiveness. Here we replicate Ahn et al.'s (2013) key study, and to test the reliability of the effects, and their dependency on trait reward responsiveness as described by Duprat et al., (2016). Using excitatory and sham TMS, we tested volunteers using the probabilistic learning task to measure their reward responsiveness both before and after stimulation. We also examined affect (positive, negative) following stimulation. Irrespective of TMS, the task was shown to be sensitive to reward responsiveness. However, we did not show TMS to be effective in increasing reward responsiveness and we did not replicate Ahn et al., (2013) or Duprat et al., (2016)'s key findings for TMS efficacy, where we provide evidence favouring the null. Moreover, exploratory analyses suggested following active stimulation, positive affect was reduced. Given our findings, we question the basic effects, which support the use of TMS for depression, particularly considering potential deleterious effects of reduced positive affect in patients with depression.

Repetitive Transcranial Magnetic Stimulation in Delirium: A Double-blind, Randomized, Sham-controlled, Pilot Study

INTRODUCTION

Delirium is a fatal but potentially reversible disorder of the central nervous system that imposes high costs on health systems. This study aims to evaluate the effect of intermittent theta-burst stimulation on the severity and course of delirium disorder.

METHODS

This is a double-blind, randomized, sham-controlled pilot study. The study participants were randomly allocated into the active (active intermittent theta-burst stimulation) and sham groups. The severity of delirium was assessed 15 minutes before the intervention and 15 minutes after that by the Neelon and Champagne (NEECHAM) confusion scale.

RESULTS

In the active group, total and subscale scores of NEECHAM significantly decreased after intervention (P<0.05). Although no statistical difference was found in the control group regarding the subscale scores of NEECHAM, the difference in the total scores before and after the sham intervention was statistically significant.

CONCLUSION

Carrying one session of repetitive transcranial magnetic stimulation on the left dorsolateral prefrontal cortex can reduce the delirium severity in a short period, although it will not decrease the number of delirium cases three days after the intervention.

HIGHLIGHTS

Delirium is a CNS disorder;Delirium treatment is based on pharmacological and non-pharmacological;rTMS is quasi-modern treatment of neurocognitive disorders.

PLAIN LANGUAGE SUMMARY

Delirium is fatal but reversible disorder. regarding the restrictions of routine treatments of delirium and by considering the cognition disturbances as the core symptom of delirium, and the positive effect of rTMS on cognition functions. we hypothesized that rTMS could be effective in the treatment of delirium.

Bilateral repetitive transcranial magnetic stimulation ameliorated sleep disorder and hypothalamic-pituitary-adrenal axis dysfunction in subjects with major depression

OBJECTIVE

In this study, we sought to explore the effectiveness of bilateral repetitive transcranial magnetic stimulation (rTMS) over the dorsolateral prefrontal cortex (DLPFC) on depressive symptoms and dysfunction of hypothalamic-pituitary-adrenal (HPA) axis in patients with major depressive disorder (MDD).

MATERIALS AND METHODS

One hundred and thirty-six adults with MDD were administrated drugs combined with 3 weeks of active rTMS (n = 68) or sham (n = 68) treatment. The 17-item Hamilton Depression Rating Scale for Depression (HAMD-17) was to elevate depression severity at baseline and weeks 4. To test the influence of rTMS on the HPA axis, plasma adrenocorticotropic hormone (ACTH) and serum cortisol (COR) were detected in pre- and post-treatment.

RESULTS

No statistical significance was found for the baseline of sociodemographic, characteristics of depression, and psychopharmaceutical dosages between sham and rTMS groups (p > 0.05). There was a significant difference in the HAMD-17 total score between the two groups at end of 4 weeks after treatment (p < 0.05). Compared to the sham group, the rTMS group demonstrated a more significant score reduction of HAMD-17 and sleep disorder factor (HAMD-SLD) including sleep onset latency, middle awakening, and early awakening items at end of 4-week after treatment (p < 0.05). Furthermore, total score reduction of HAMD-17 was correlated with a decrease in plasma ACTH, not in COR, by rTMS stimulation (p < 0.05).

CONCLUSION

Bilateral rTMS for 3 weeks palliated depression via improvement of sleep disorder, and plasma ACTH is a predictor for the efficacy of rTMS, especially in male patients with MDD.

Efficacy and Tolerability of Repetitive Transcranial Magnetic Stimulation on Suicidal Ideation: A Systemic Review and Meta-Analysis

OBJECTIVE

This study aimed to investigate the efficacy of repetitive transcranial magnetic stimulation (rTMS) in treating suicidal ideation in patients with mental illness.

METHOD

We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Major electronic databases were systematically searched from the time of their inception until July 22, 2021. The primary outcome was the mean change in the scores for suicidal ideation. The secondary outcome was the mean change in depression severity.

RESULTS

Ten randomized controlled trials were eligible with 415 participants in the active treatment group (mean age = 53.78 years; mean proportion of women = 54.5%) and 387 participants in the control group (mean age = 55.52 years; mean proportion of women = 51.78%). rTMS significantly reduced suicidal ideation (k = 10, n = 802, Hedges' g = -0.390, 95% confidence interval [CI] = -0.193 to -0.588, p <.001) and severity of depressive symptoms (k = 9, n = 761, Hedges' g = -0.698, 95% CI = -1.023 to -0.372, p < 0.001) in patients with major mental disorders. In the subgroup analysis, rTMS reduced suicidal ideation among patients with non-treatment-resistant depression (non-TRD) (-0.208) but not in those with TRD. rTMS as combination therapy had a larger effect than did monotherapy (-0.500 vs. -0.210). Suicidal ideation significantly reduced in patients receiving more than ten treatment sessions (-0.255). Importantly, the rTMS group showed favorable tolerability without major adverse events.

CONCLUSION

The study showed that rTMS was effective and well-tolerated in reducing suicidal ideation and depression severity in patients with major mental disorders.

Personalising transcranial magnetic stimulation for depression using neuroimaging: A systematic review

OBJECTIVES

Transcranial magnetic stimulation (TMS) is a well-established and effective treatment for depression, though response rates are suboptimal. Personalising TMS for depression with neuroimaging can take into account inter-individual differences in anatomical and electrophysiological characteristics; and thereby provide a potentially more efficacious form of treatment. The current systematic review aimed to critically appraise the literature relating to personalising TMS for depression with neuroimaging.

METHODS

PubMed, PsycINFO and Embase databases were used to identify relevant literature published up to November 2020.

RESULTS

A total of 37 studies were included in the review. Across these studies, a total of 1451 patients with depression received TMS that was personalised using neuroimaging. The majority of the studies used structural or functional neuroimaging to personalise treatment target (n = 30), primarily through neuronavigation methodologies. Fewer studies used electroencephalography to personalise treatment frequency or stimulus timing (n = 7). Only 6 studies directly compared neuroimaging-personalised TMS to standard TMS.

CONCLUSIONS

The findings from this review suggest that personalising TMS with neuroimaging may be more effective in the treatment of depression compared to standard TMS. Further research is required to directly compare neuroimaging-personalised TMS with standard TMS, and to identify the optimal parameters for treatment personalisation.

Assessment of multiple salivary biomarkers during repetitive transcranial magnetic stimulation (rTMS) treatment for major depression

Steroid hormones may serve as potential biomarkers of treatment response for major depressive disorder (MDD). Here, we assessed salivary levels of cortisol, dehydroepiandrosterone (DHEA), and DHEA sulfate (DHEA-S), as well as α-amylase activity, across 30 sessions of bilateral repetitive transcranial magnetic stimulation (rTMS) of the dorsolateral prefrontal cortex in MDD patients. While rTMS significantly improved symptoms as measured by three different symptom scales, salivary biomarker levels and their ratios showed no significant changes across sessions. These results do not support the routine clinical use of these biomarkers as reliable indicators of treatment outcome during rTMS administration for MDD.

Impact of one HF-rTMS session over the DLPFC and motor cortex on acute hormone dynamics and emotional state in healthy adults: a sham-controlled pilot study

Studies indicate that high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) can lower cortisol concentration or output, with some evidence suggesting a link to testosterone. Together, these stress and social hormones might help regulate the emotional response to HF-rTMS. This pilot study evaluated the effect of HF-rTMS on acute testosterone and cortisol dynamics and emotional state in eleven healthy adults. Using a sham-controlled, single-blind, crossover design, participants completed a HF-rTMS session targeting the dorsolateral prefrontal cortex (DLPFC) and motor cortex on separate days. Stimulation (250 total pulses) was applied at 90% of the resting motor threshold. Salivary testosterone and cortisol, mood, motivation, anxiety, and heart rate (HR) were assessed before (T₁) and 1 (T₂), 15 (T₃), and 30 min (T₄) after each session. There were no significant session differences in testosterone and cortisol concentration, mood, motivation, and HR. Although DLPFC stimulation produced less anxiety (vs. motor cortex), and testosterone output was stable across both treatments (vs. sham-related decline in testosterone), neither differed from the sham. Within-person fluctuations in testosterone, mood, motivation, and/or anxiety were significantly related across the DLPFC and motor cortex trials only. In conclusion, a single sub-maximal session of HF-rTMS did not affect the hormonal, emotional, or physiological state of healthy adults, relative to a sham. However, the emergence of stimulation-specific testosterone and/or emotional linkages suggests that the repeated effects of HF-rTMS may also manifest at the individual level. This offers another pathway to explain the therapeutic efficacy of rTMS and a model to explore interindividual variability in health-related outcomes.

The roles of caffeine and corticosteroids in modulating cortical excitability after paired associative stimulation (PAS) and transcranial alternating current stimulation (tACS) in caffeine-naïve and caffeine-adapted subjects

The modulatory effects of non-invasive brain stimulation (NIBS) are highly variable between subjects. This variability may be due to uncontrolled caffeine consumption and circadian rhythms. Therefore, here we studied if caffeine consumption, systemically available caffeine measured in saliva, and daytime have effects on the excitability and plasticity of the motor cortex. Since both, time of the day and caffeine may mediate their effects via cortisol, we also quantified corticosteroids in saliva. Experiment 1 was performed in caffeine-naïve participants (n = 30) and compared the effects of PAS or tACS with different stimulation intensities on the motor cortex with or without caffeine 200 mg administered in a double-blind fashion. Experiment 2 was performed in regular caffeine consumers (n = 30) and compared the influence of time of day on the effects of tACS (true or sham) on the motor cortex also with or without caffeine administered in a double-blind fashion. Caffeine increased the saliva corticosteroid concentrations in both experimental groups, and corticosteroid concentrations were higher in the morning in caffeine consumers. Gender also affected corticosteroid concentrations. There was a positive correlation between caffeine concentrations and baseline cortical excitability in caffeine-adapted participants, and a negative correlation between poststimulation caffeine concentrations and motor evoked potential (MEP) amplitudes after sham stimulation in caffeine-naïve subjects. No correlations were found between poststimulation caffeine or corticosteroid concentrations, and plasticity aftereffects. PAS and tACS did not elicit changes in the corticosteroid concentrations. We conclude that moderate caffeine consumption alters cortical excitability but not plasticity aftereffects. This study was registered in the ClinicalTrials.gov with these registration IDs: 1) NCT03720665 https://clinicaltrials.gov/ct2/results?cond=NCT03720665&term=&cntry=&state=&city=&dist= 2) NCT04011670 https://clinicaltrials.gov/ct2/results?cond=&term=NCT04011670&cntry=&state=&city=&dist=.

D-cycloserine normalizes long-term motor plasticity after transcranial magnetic intermittent theta-burst stimulation in major depressive disorder

OBJECTIVES

Major Depressive Disorder (MDD) is associated with glutamatergic alterations, including the N-methyl-D-aspartate receptor (NMDA-R). The NMDA-R plays an important role in synaptic plasticity, and individuals with MDD have been shown to have impairments in repetitive Transcranial Magnetic Stimulation (rTMS) motor plasticity. Here, we test whether D-cycloserine, a NMDA-R partial agonist, can rescue TMS motor plasticity in MDD.

METHODS

We conducted randomized double-blind placebo-controlled crossover studies in healthy (n = 12) and MDD (n = 12) participants. We stimulated motor cortex using TMS intermittent theta burst stimulation (iTBS) with placebo or D-cycloserine (100 mg). Motor evoked potentials (MEPs) were sampled before and after iTBS. Stimulus response curves (SRC) were characterized at baseline, +90 minutes, and the following day.

RESULTS

Acute iTBS MEP facilitation is reduced in MDD and is not rescued by D-cycloserine. After iTBS, SRCs shift to indicate sustained decrease in excitability in healthy participants, yet increased in excitability in MDD participants. D-cycloserine normalized SRC changes from baseline to the following day in MDD participants. In both healthy and MDD participants, D-cycloserine stabilized changes in SRC.

CONCLUSION

MDD is associated with alterations in motor plasticity that are rescued and stabilized by NMDA-R agonism.

SIGNIFICANCE

Agonism of NMDA receptors rescues iTBS motor plasticity in MDD.

Impact of bifrontal transcranial Direct Current Stimulation on decision-making and stress reactivity. A pilot study

Stress is an adaptive response with repercussions on the human health. The dorsolateral prefrontal cortex (DLPFC) is thought to be involved in stress regulation by contributing to limit its biological and behavioral pejorative consequences. Here, to investigate the contribution of the DLPFC in stress response, we applied transcranial Direct Current Stimulation (tDCS) over the DLPFC during acute stress exposure in healthy participants. We hypothesized that active tDCS compared to sham would impact top-down control of the DLPFC on goal-directed behavior and hypothalamo-pituitary-adrenal (HPA) axis activity. In a double-blind sham-controlled study, 30 healthy subjects were randomly allocated to receive either active (2 mA, n = 15) or sham tDCS (n = 15) with the anode over the left DLPFC and the cathode over the right DLFPC. During the 30-min stimulation period, participants faced an experimental acute stress paradigm. Changes in goal-directed behavior were measured with a decision-making task. HPA axis reactivity was assessed by repeated measures of salivary cortisol. Acute stress decreased appetite for immediate reward in the sham group (mean - 4.40%; p = 0.017) whereas no significant effect of stress was observed in the active group. During stress exposure, we observed a significant larger elevation of salivary cortisol (p = 0.045; Cohen's d = 0.431) in the sham tDCS group (+179.8%; Standard error of the mean (SEM) = 20.6) than in the active group (+138.5%; SEM = 14.2). Stimulating the DLPFC using bifrontal tDCS may prevent stress-induced acute effects on both biological and behavioral outcomes.

The effect of HF-rTMS over the left DLPFC on stress regulation as measured by cortisol and heart rate variability

The prefrontal cortex, and especially the Dorsolateral Prefrontal Cortex (DLPFC), plays an inhibitory role in the regulation of the Hypothalamic-Pituitary-Adrenal (HPA) axis under stressful situations. Moreover, recent evidence suggests that a sustained DLPFC activation is associated with adaptive stress regulation in anticipation of a stressful event, leading to a reduced stress-induced amygdala response, and facilitating the confrontation with the stressor. However, studies using experimental manipulation of the activity of the DLPFC before a stressor are scarce, and more research is needed to understand the specific role of this brain area in the stress-induced physiological response. This pre-registered study investigated the effect on stress regulation of a single excitatory high frequency (versus sham) repetitive transcranial magnetic stimulation (HF-rTMS) session over the left DLPFC applied before the Trier Social Stress Test in 75 healthy young women (M = 21.05, SD = 2.60). Heart rate variability (HRV) and salivary cortisol were assessed throughout the experimental protocol. The active HF-rTMS and the sham group showed a similar cognitive appraisal of the stress task. No differences in HRV were observed during both the anticipation and the actual confrontation with the stress task and therefore, our results did not reflect DLPFC-related adaptive anticipatory adjustments. Importantly, participants in the active HF-rTMS group showed a lower cortisol response to stress. The effect of left prefrontal HF-rTMS on the stress system provides further critical experimental evidence for the inhibitory role played by the DLPFC in the regulation of the HPA axis.

Antidepressant efficacy and immune effects of bilateral theta burst stimulation monotherapy in major depression: A randomized, double-blind, sham-controlled study

Inflammation theory has been consolidated by accumulating evidence, and many studies have suggested that the peripheral cytokine levels could be biomarkers for disease status and treatment outcome in major depressive disorder (MDD). Theta burst stimulation (TBS), a new form of repetitive transcranial magnetic stimulation (TMS) for MDD, has been demonstrated to improve depression via modulating dysfunctional neural network or hypothalamic–pituitary–adrenal axis hyperactivities in MDD. However, there is lack of exploratory studies investigating its effect on serum inflammatory cytokines. Here, we aimed to investigate the antidepressant efficacy of bilateral TBS monotherapy and its effects on the serum cytokine levels in MDD. We conducted a double-blind, randomized, sham-controlled trial, with 53 MDD patients who exhibited no responses to at least one adequate antidepressant treatment for the prevailing episode assigned randomly to one of two groups: bilateral TBS monotherapy (n = 27) or sham stimulation (n = 26). The TBS treatment period was 22 days. Blood samples from 31 study subjects were obtained for analyses. The bilateral TBS group exhibited significantly greater decreases in depression scores than the sham group at week 4 (56.5% vs. 33.1%; p < 0.001 [effect size (Cohen ’ s d) = 1.00]) and during the 20-week follow-up periods. Significantly more responders were also found at week 4 (70.3% vs. 23.1%, p = 0.001) and during the 20-week follow-up periods. However, we did not detect any significant effects of TBS on the cytokine panels or any correlations between improvement in depressive symptoms and changes in serum inflammatory markers. Our findings provided the first evidence that the antidepressant efficacy of bilateral TBS monotherapy might not work via immune-modulating mechanisms.

Endocrine and immune effects of non-convulsive neurostimulation in depression: A systematic review

BACKGROUND

Non-convulsive neurostimulation is a rapidly-developing alternative to traditional treatment approaches in depression. Modalities such as repetitive Transcranial Magnetic Stimulation (rTMS), transcranial Direct Current Stimulation (tDCS), Vagal Nerve Stimulation (VNS) and Deep Brain Stimulation (DBS) are now recognized as potential treatments. How non-convulsive neurostimulation interventions impact the neurohormonal and neuroimmune changes that accompany depression remains relatively unknown. If this type of intervention can drive endocrine, immune, as well symptom changes in depression, non-convulsive neurostimulation may represent a viable, multi-faceted treatment approach in depression. We were therefore interested to understand the state of the literature in this developing area.

METHODS

A systematic review of all studies that examined the impact of non-convulsive neurostimulation interventions on the hypothalamic-pituitary-adrenal (HPA) axis and immune function in the form of cytokine production in depression.

RESULTS

We identified 15 human studies, 9 that examined rTMS, 2 that examined tDCS, 2 that examined VNS and 2 that examined electroacupuncture. 11 animal studies were also identified, 3 that examined rTMS, 2 that examined DBS and 6 that examined electroacupuncture. All types of non-convulsive neurostimulation were able to revert the increases in cortisol, ACTH and other components of the HPA axis that are seen in depressed patients, as well as to modulate the levels of key cytokines known to be up-regulated in depression, such as IL-1β, IL-6 and TNF-α. Changes in the HPA axis and levels of cytokines in response to non-convulsive neurostimulation often did not correlate with change in depressive symptoms. Most studies were not controlled trials and thus, significant methodologic variability existed. Furthermore, many human studies lacked a sham stimulation comparator arm. We were unable to conduct relevant meta-analyses due to the design heterogeneities, heterogeneity in the reported outcome measures and the limited number of studies retrieved. Animal studies generally supported the findings of those in human, but again, significant variability in methodology and study design were evident.

CONCLUSIONS

Non-convulsive neurostimulation interventions show promise in their ability to alter the endocrine and immune disturbances that accompany depression. Further research, which includes blinded, sham-controlled comparator designs is required.

A Systematic Review of the Effectiveness of Non-Invasive Brain Stimulation Techniques to Reduce Violence Proneness by Interfering in Anger and Irritability

The field of neurocriminology has proposed several treatments (e.g., pharmacological, brain surgery, androgen-deprivation therapy, neurofeedback) to reduce violence proneness, but unfortunately, their effectiveness has been limited due to their side-effects. Therefore, it is necessary to explore alternative techniques to improve patients’ behavioural regulation with minimal undesirable effects. In this regard, non-invasive brain stimulation techniques, which are based on applying changing magnetic fields or electric currents to interfere with cortical excitability, have revealed their usefulness in alleviating the symptomatology of several mental disorders. However, to our knowledge, there are no reviews that assess whether these techniques are useful for reducing violence proneness. Therefore, we conducted a systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria using the following databases: PsycINFO, PubMed, Dialnet, Psicodoc, Web of Knowledge, and the Cochrane Library. We initially identified 3746 entries, and eventually included 56 publications. Most of the studies were unanimous in concluding that the application of these techniques over the prefrontal cortex (PFC) was not sufficient to promote anger and irritability reductions in euthymic individuals of both genders. Nevertheless, the application of non-invasive brain stimulation techniques, especially transcranial direct current stimulation, over the right PFC seemed to reduce violent reactions in these individuals by interfering with the interpretation of the unfavourable situations (e.g., threating signals) or inner states that evoked anger. In antisocial and pathological populations, the conclusions were provided by a few pilot studies with important methodological weaknesses. The main conclusion of these studies was that bilateral stimulation of the PFC satisfactorily reduced anger and irritability only in inmates, patients with autism spectrum disorders (ASD), people who suffered a closed-head injury, and agitated patients with Alzheimer’s disease. Moreover, combining these techniques with risperidone considerably reduced aggressiveness in these patients. Therefore, it is necessary to be cautious about the benefits of these techniques to control anger, due the methodological weaknesses of these studies. Nonetheless, they offer valuable opportunities to prevent violence by designing new treatments combining brain stimulation with current strategies, such as psychotherapy and psychopharmacology, in order to promote lasting changes.

The effect of neurostimulation applied to the left dorsolateral prefrontal cortex on post-stress adaptation as a function of depressive brooding

Depressive brooding following a stressful event predicts negative affect and neuroendocrine responses related to psychological stress. The dorsolateral prefrontal cortex (DLPFC) has been associated with the top-down regulation of thoughts and emotions, and abnormal neural activity within this region has been associated with increased psychological stress and ruminative thinking. The aim of this study was to investigate whether the modulation of the DLPFC could have beneficial effects on ruminative thoughts and the endocrine response following a self-relevant stressor. Using a sham-controlled within-subjects crossover-design, two sessions of intermittent theta-burst stimulation (iTBS) were administered over the left DLPFC to thirty-eight healthy-volunteers after they were confronted with a social-evaluative stressor, the Trier Social Stress Test. To assess stress recovery, momentary rumination was measured before and after a resting period subsequent to the encounter with the stressor. In addition, cortisol levels were measured between and after the two iTBS sessions that were applied during the stress recovery phase. Overall, iTBS did not significantly influence ruminative thinking and cortisol secretion during the stress recovery phase. However, taking into account participants ruminative tendencies, our results revealed that for participants with higher levels of brooding ruminative thinking remained stable after iTBS, whereas in the sham condition there was a marginal significant increase in ruminative thinking. Moreover, only after iTBS, there was a significant reduction in cortisol secretion (i.e. a faster return to baseline as compared to sham) for high brooders during the recovery from the stressor. These results show that the prefrontal cortex plays a role in stress recovery mechanisms in individuals who are more vulnerable for psychopathology.

The influence of personality on the effect of iTBS after being stressed on cortisol secretion

Over the last years, individualization of repetitive Transcranial Magnetic Stimulation (rTMS) parameters has been a focus of attention in the field of non-invasive stimulation. It has been proposed that in stress-related disorders personality characteristics may influence the clinical outcome of rTMS. However, the underlying physiological mechanisms as to how personality may affect the rTMS response to stress remains to be clarified. In this sham-controlled crossover study, after being stressed by the Trier Social Stress Test, 38 healthy females received two sessions of intermittent theta burst stimulation (iTBS) applied to the left dorsolateral prefrontal cortex. To take possible personality influences into account, they also completed the Temperament and Character Inventory. Mood and salivary cortisol were assessed throughout the experimental protocol. Overall, two iTBS sessions did not significantly alter mood or influenced cortisol secretion. When taking into account personality features, higher scores on the character dimension Cooperativeness was related to decreased cortisol output, only when active iTBS was administered after the social stressor. In line with other studies, personality features such as the character dimension Cooperativeness may be of particular interest to explain individual neurobiological responses to neurostimulation.

The Abnormal Functional Connectivity between the Hypothalamus and the Temporal Gyrus Underlying Depression in Alzheimer's Disease Patients

Hypothalamic communication with the rest of the brain is critical for accomplishing a wide variety of physiological and psychological functions, including the maintenance of neuroendocrine circadian rhythms and the management of affective processes. Evidence has shown that major depressive disorder (MDD) patients exhibit increased functioning of the hypothalamic-pituitary-adrenal (HPA) axis. Neurofibrillary tangles are also found in the hypothalamus of Alzheimer’s disease (AD) patients, and AD patients exhibit abnormal changes in the HPA. However, little is known of how the hypothalamus interacts with other brain regions in AD patients with depression (D-AD). Functional connectivity (FC) analysis explores the connectivity between brain regions that share functional properties. Here, we used resting-state (rs) magnetic resonance imaging (MRI) technology and the FC method to measure hypothalamic connectivity across the whole brain in 22 D-AD patients and 21 non-depressed AD patients (nD-AD). Our results showed that D-AD patients had reduced FC among the hypothalamus, the right middle temporal gyrus (MTG) and the right superior temporal gyrus (STG) compared with the FC of nD-AD patients, suggesting that the abnormal FC between the hypothalamus and the temporal lobe may play a key role in the pathophysiology of depression in AD patients.

Affective Processing in Non-invasive Brain Stimulation Over Prefrontal Cortex

The prefrontal cortex (PFC) is the most frequently targeted brain region by non-invasive brain stimulation (NBS) studies. Non-invasively stimulating the PFC has been shown to both modulate affective processing and improve the clinical symptoms of several psychiatric disorders, such as depression and schizophrenia. The magnitude of the modulation depends on several factors, including the stimulation frequency, the number of stimulation sessions, and the specific sub-region of the PFC that is stimulated. Although some of the potential underlying mechanisms have been identified, the exact mechanisms that underlie these cognitive and affective changes remain unclear. The present review aims to summarize recent advances in the study of affective processing using NBS over the PFC. We will provide a theoretical framework for better understanding how affective processing changes are induced by NBS, with the goal of providing testable hypotheses for future studies.

Treatment-refractory substance use disorder: Focus on alcohol, opioids, and cocaine

Substance use disorders are common, but only a small minority of patients receive adequate treatment. Although psychosocial therapies are effective, relapse is common. This review focusses on novel pharmacological and other treatments for patients with alcohol, opioid, or cocaine use disorders who do not respond to conventional treatments. Disulfiram, acamprosate, and the opioid antagonist naltrexone have been approved for the treatment of alcoholism. A novel, "as needed" approach is the use of the mu-opioid antagonist and partial kappa agonist nalmefene to reduce alcohol consumption. Other novel pharmacological approaches include the GABA-B receptor agonist baclofen, anticonvulsants such as topiramate and gabapentin, the partial nicotine receptor agonist varenicline, and other drugs. For opioid dependence, opioid agonist therapy with methadone or buprenorphine is the first-line treatment option. Other options include oral or depot naltrexone, morphine sulfate, depot or implant formulations, and heroin (diacetylmorphine) in treatment-refractory patients. To date, no pharmacological treatment has been approved for cocaine addiction; however, 3 potential pharmacological treatments are being studied, disulfiram, methylphenidate, and modafinil. Pharmacogenetic approaches may help to optimize treatment response in otherwise treatment-refractory patients and to identify which patients are more likely to respond to treatment, and neuromodulation techniques such as repeated transcranial magnetic stimulation and deep brain stimulation also may play a role in the treatment of substance use disorders. Although no magic bullet is in sight for treatment-refractory patients, some novel medications and brain stimulation techniques have the potential to enrich treatment options at least for some patients.

Repetitive transcranial magnetic stimulation for treatment resistant depression: Re-establishing connections

Repetitive transcranial magnetic stimulation (rTMS) is a relatively recent addition to the neurostimulation armamentarium for treating individuals suffering from treatment refractory depression and has demonstrated efficacy in clinical trials. One of the proposed mechanisms of action underlying the therapeutic effects of rTMS for depression involves the modulation of depression-associated dysfunctional activity in distributed brain networks involving frontal cortical and subcortical limbic regions, via changes to aberrant functional and structural connectivity. Although there is currently a paucity of published data, we review changes to functional and structural connectivity following rTMS for depression. Current evidence suggests an rTMS-induced normalisation of depression-associated dysfunction within and between large scale functional networks, including the default mode, central executive and salience networks, associated with an amelioration of depressive symptoms. Additionally, changes to measures of white matter microstructure, primarily in the dorsolateral prefrontal cortex, have also been reported following rTMS for depression, possibly reversing depression-associated abnormalities. We argue that measures of functional and structural connectivity can be used to optimise rTMS targeting within the dorsolateral prefrontal cortex and also to explore novel rTMS targets for depression. Finally, we discuss the utility of measures of brain connectivity as predictive biomarkers of rTMS treatment response in guiding therapeutic decisions.

A Randomised Controlled Trial of Neuronavigated Repetitive Transcranial Magnetic Stimulation (rTMS) in Anorexia Nervosa

Background

Anorexia nervosa (AN) is associated with morbid fear of fatness, extreme food restriction and altered self-regulation. Neuroimaging data implicate fronto-striatal circuitry, including the dorsolateral prefrontal cortex (DLPFC).

Methods

In this double-blind parallel group study, we investigated the effects of one session of sham-controlled high-frequency repetitive transcranial magnetic stimulation (rTMS) to the left DLPFC (l-DLPFC) in 60 individuals with AN. A food exposure task was administered before and after the procedure to elicit AN-related symptoms.

Outcomes

The primary outcome measure was ‘core AN symptoms’, a variable which combined several subjective AN-related experiences. The effects of rTMS on other measures of psychopathology (e.g. mood), temporal discounting (TD; intertemporal choice behaviour) and on salivary cortisol concentrations were also investigated. Safety, tolerability and acceptability were assessed.

Results

Fourty-nine participants completed the study. Whilst there were no interaction effects of rTMS on core AN symptoms, there was a trend for group differences (p = 0.056): after controlling for pre-rTMS scores, individuals who received real rTMS had reduced symptoms post-rTMS and at 24-hour follow-up, relative to those who received sham stimulation. Other psychopathology was not altered differentially following real/sham rTMS. In relation to TD, there was an interaction trend (p = 0.060): real versus sham rTMS resulted in reduced rates of TD (more reflective choice behaviour). Salivary cortisol concentrations were unchanged by stimulation. rTMS was safe, well–tolerated and was considered an acceptable intervention.

Conclusions

This study provides modest evidence that rTMS to the l-DLPFC transiently reduces core symptoms of AN and encourages prudent decision making. Importantly, individuals with AN considered rTMS to be a viable treatment option. These findings require replication in multiple-session studies to evaluate therapeutic efficacy.

Trial Registration

www.Controlled-Trials.comISRCTN22851337

Noninvasive brain stimulation to suppress craving in substance use disorders: Review of human evidence and methodological considerations for future work

Substance use disorders (SUDs) can be viewed as a pathology of neuroadaptation. The pharmacological overstimulation of neural mechanisms of reward, motivated learning and memory leads to drug-seeking behavior. A critical characteristic of SUDs is the appearance of craving, the motivated desire and urge to use, which is a main focus of current pharmacological and behavioral therapies. Recent proof-of-concept studies have tested the effects of noninvasive brain stimulation on craving. Although its mechanisms of action are not fully understood, this approach shows interesting potential in tuning down craving and possibly consumption of diverse substances. This article reviews available results on the use of repetitive transcranial magnetic stimulation (rTMS) and transcranial electrical stimulation (tES) in SUDs, specifically tobacco, alcohol and psychostimulant use disorders. We discuss several important factors that need to be addressed in future works to improve clinical assessment and effects of noninvasive brain stimulation in SUDs. Factors discussed include brain stimulation devices and parameters, study designs, brain states and subjects' characteristics.

Neurobiological mechanisms of repetitive transcranial magnetic stimulation of the dorsolateral prefrontal cortex in depression: a systematic review

Depression is one of the most prevalent mental illnesses worldwide and a leading cause of disability, especially in the setting of treatment resistance. In recent years, repetitive transcranial magnetic stimulation (rTMS) has emerged as a promising alternative strategy for treatment-resistant depression and its clinical efficacy has been investigated intensively across the world. However, the underlying neurobiological mechanisms of the antidepressant effect of rTMS are still not fully understood. This review aims to systematically synthesize the literature on the neurobiological mechanisms of treatment response to rTMS in patients with depression. Medline (1996-2014), Embase (1980-2014) and PsycINFO (1806-2014) were searched under set terms. Three authors reviewed each article and came to consensus on the inclusion and exclusion criteria. All eligible studies were reviewed, duplicates were removed, and data were extracted individually. Of 1647 articles identified, 66 studies met both inclusion and exclusion criteria. rTMS affects various biological factors that can be measured by current biological techniques. Although a number of studies have explored the neurobiological mechanisms of rTMS, a large variety of rTMS protocols and parameters limits the ability to synthesize these findings into a coherent understanding. However, a convergence of findings suggest that rTMS exerts its therapeutic effects by altering levels of various neurochemicals, electrophysiology as well as blood flow and activity in the brain in a frequency-dependent manner. More research is needed to delineate the neurobiological mechanisms of the antidepressant effect of rTMS. The incorporation of biological assessments into future rTMS clinical trials will help in this regard.

Self-directedness: an indicator for clinical response to the HF-rTMS treatment in refractory melancholic depression

Although well-defined predictors of response are still unclear, clinicians refer a variety of depressed patients for a repetitive Transcranial Magnetic Stimulation (rTMS) treatment. It has been suggested that personality features such as Harm Avoidance (HA) and self-directedness (SD) might provide some guidance for a classical antidepressant treatment outcome. However, to date no such research has been performed in rTMS treatment paradigms. In this open study, we wanted to examine whether these temperament and character scores in particular would predict clinical outcome in refractory unipolar depressed patients when a typical high-frequency (HF)-rTMS treatment protocol is applied. Thirty six unipolar right-handed antidepressant-free treatment resistant depressed (TRD) patients, all of the melancholic subtype, received 10 HF-rTMS sessions applied to the left dorsolateral prefrontal cortex (DLPFC). All patients were classified as at least stage III TRD and were assessed with the Temperament and Character Inventory (TCI) before a HF-rTMS treatment. Only the individual scores on SD predicted clinical outcome. No other personality scales were found to be a predictor of this kind of application. Our results suggest that refractory MDD patients who score higher on the character scale SD may be more responsive to the HF-rTMS treatment.

Anti-depressive mechanism of repetitive transcranial magnetic stimulation in rat: the role of the endocannabinoid system

Repetitive transcranial magnetic stimulation (rTMS) to treat depression has been thoroughly investigated in recent years. However, the underlying mechanisms are not fully understood. In this study, a chronic unpredictable mild stress (CUMS) paradigm was applied to male Sprague Dawley rats. Then rTMS was performed for 7 consecutive days, and the anti-depressive effects were evaluated by the sucrose preference test (SPT), the forced swimming test (FST), and the open-field test (OFT). Hippocampal cannabinoid type I receptor (CB1) expression was measured, and the expression levels of brain-derived neurotrophic factor (BDNF), Bcl-2, and Bax and the number of bromodeoxyuridine (BrdU)-positive cells were also investigated. These parameters were also observed after the selective CB1 receptor antagonist AM251 was used as a blocking agent. The results showed that CUMS induced a significant decrease in sucrose preference, a significant increase in immobility time in the FST, and a significantly decreased horizontal distance in the OFT. In addition, reduced hippocampal CB1 receptor, BDNF, and Bcl-2/Bax protein expression levels in CUMS rats, as well as decreased cell proliferation were also observed in the dentate gyrus. Meanwhile, rTMS treatment up-regulated cell proliferation; elevated CB1 receptor, BDNF, and Bcl-2/Bax expression levels in the hippocampus; and ameliorated depressive-like behaviors. All of these beneficial effects were abolished by AM251. These results indicate that rTMS increases BDNF production and hippocampal cell proliferation to protect against CUMS-induced changes through its effect on CB1 receptors.

Polarity- and valence-dependent effects of prefrontal transcranial direct current stimulation on heart rate variability and salivary cortisol

Recent evidence has supported the notion that the hypothalamic-pituitary-adrenal (HPA) and the sympatho-adreno-medullary (SAM) systems are modulated by cortical structures such as the prefrontal cortex. This top-down modulation may play a major role in the neuroendocrine changes associated with stressful events. We aimed to investigate further this hypothesis by modulating directly prefrontal cortex excitability using transcranial direct current stimulation (tDCS) - a non-invasive, neuromodulatory tool that induces polarity-dependent changes in cortical excitability - and measuring effects on salivary cortisol and heart rate variability as proxies of the HPA and SAM systems. Twenty healthy participants with no clinical and neuropsychiatric conditions were randomized to receive bifrontal tDCS (left anodal/right cathodal or left cathodal/right anodal) or sham stimulation, in a within-subject design. During each stimulation session, after a resting period, subjects were shown images with neutral or negative valence. Our findings showed that excitability enhancing left anodal tDCS induced a decrease in cortisol levels. This effect is more pronounced during emotional negative stimuli. Moreover, vagal activity was higher during left anodal tDCS and emotional negative stimuli, as compared to sham stimulation and neutral images. We also observed an association between higher mood scores, higher vagal activation and lower cortisol levels for anodal stimulation. Subjective mood and anxiety evaluation revealed no specific changes after stimulation. Our findings suggest that tDCS induced transient, polarity specific modulatory top-down effects with anodal tDCS leading to a down-regulation of HPA and SAM systems. Further research using tDCS and neuroendocrine markers should explore the mechanisms of stress regulation in healthy and clinical samples.

A systematic review of non-invasive brain stimulation therapies and cardiovascular risk: implications for the treatment of major depressive disorder

Major depressive disorder (MDD) and cardiovascular diseases are intimately associated. Depression is an independent risk factor for mortality in cardiovascular samples. Neuroendocrine dysfunctions in MDD are related to an overactive hypothalamus-pituitary-adrenal (HPA) axis and increased sympathetic activity. Novel intervention strategies for MDD include the non-invasive brain stimulation (NIBS) techniques such as repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS). In fact, although these techniques have being increasingly used as a treatment for MDD, their cardiovascular effects were not sufficiently investigated, which would be important considering the dyad MDD/cardiovascular disorders. We investigated this issue through a systematic review for published articles from the first date available to May 2012 in MEDLINE and other databases, looking for main risk factors and surrogate markers for cardiovascular disease such as: cortisol, heart rate variability (HRV), alcohol, smoking, obesity, hypertension, glucose. We identified 37 articles (981 subjects) according to our eligibility criteria. Our main findings were that NIBS techniques might be effective strategies for down-regulating HPA activity and regulating food, alcohol, and cigarette consumption. NIBS's effects on HRV and blood pressure presented mixed findings, with studies suggesting that HRV values can decrease or remain unchanged after NIBS, while one study found that rTMS increased blood pressure levels. Also, a single study showed that glucose levels decrease after tDCS. However, most studies tested the acute effects after one single session of rTMS/tDCS; therefore further studies are necessary to investigate whether NIBS modifies cardiovascular risk factors in the long-term. In fact, considering the burden of cardiac disease, further trials in cardiovascular, depressed, and non-depressed samples using NIBS should be performed.

Increased cortical excitability with prefrontal high-frequency repetitive transcranial magnetic stimulation in adolescents with treatment-resistant major depressive disorder

OBJECTIVE

To examine changes in motor cortical excitability in adolescent subjects receiving 30 sessions of high-frequency prefrontal repetitive transcranial magnetic stimulation (rTMS).

METHODS

Eight adolescents with treatment-resistant major depressive disorder (MDD) enrolled in an open augmentation trial of 10 Hz rTMS. Resting motor thresholds were obtained by the visualization of movement method with a maximum likelihood threshold hunting computer algorithm at baseline and after every five sessions of rTMS. Motor threshold was recorded as the percentage of total machine output at each measurement.

RESULTS

Motor threshold data from baseline, weeks 2, 4, and 5 were included in a mixed model repeated measure analysis to examine a change in least square mean effect over time. The omnibus effect did not reach statistical significance (F=1.25, p=0.32). However, multiple comparisons from the overall model demonstrated a decrease in the least square mean motor threshold. The mean contrast from baseline to week 5 approached significance (p=0.07). Moreover, a post-hoc analysis with a Wilcoxon signed ranks test demonstrated a significant decrease at week 5 (p=0.03).

CONCLUSIONS

This suggests that high-frequency rTMS may increase cortical excitability in adolescents with treatment-resistant MDD.

Melancholia

PURPOSE OF REVIEW

The key question for melancholia is whether it should have status as a separate disorder and the literature of the last 12-24 months is surveyed largely from that perspective.

RECENT FINDINGS

A number of interesting findings have appeared across a broad range of issues, but, with the possible exception of some large clinical trials, remain largely unreplicated.

SUMMARY

Supporters of melancholia as a distinct entity will find little comfort in the recent literature.

Repetitive transcranial magnetic stimulation in anorexia nervosa: a pilot study

The search for new treatments to improve outcome in people with anorexia nervosa continues. This pilot study investigated whether one session of high frequency repetitive transcranial magnetic stimulation (rTMS) delivered to the left dorsolateral prefrontal cortex reduces eating disorder related symptoms following exposure to visual and real food stimuli. Safety and tolerability were also assessed. Ten right-handed people with anorexia nervosa underwent one session of rTMS. Subjective experiences related to the eating disorder (e.g. urge to restrict, feeling full etc.) were assessed before and after rTMS. Non-parametric repeated measures tests were used. rTMS was safe and well-tolerated, and resulted in reduced levels of feeling full, feeling fat and feeling anxious. Thus, rTMS may reduce core symptoms of anorexia nervosa. Future research should establish the therapeutic potential of rTMS in anorexia nervosa.

Repetitive transcranial magnetic stimulation reduces cortisol concentrations in bulimic disorders

BACKGROUND

In people with bulimic eating disorders, exposure to high-calorie foods can result in increases in food craving, raised subjective stress and salivary cortisol concentrations. This cue-induced food craving can be reduced by repetitive transcranial magnetic stimulation (rTMS). We investigated whether rTMS has a similar effect on salivary cortisol concentrations, a measure of hypothalamic-pituitary-adrenal axis (HPAA) activity.

METHOD

We enrolled twenty-two female participants who took part in a double-blind randomized sham-controlled trial on the effects of rTMS on food craving. Per group, eleven participants were randomized to the real or sham rTMS condition. The intervention consisted of one session of high-frequency rTMS delivered to the left dorsolateral prefrontal cortex (DLPFC). Salivary cortisol concentrations were assessed at four time points throughout the 90-min trial. To investigate differences in post-rTMS concentrations between the real and sham rTMS groups, a random-effects model including the pre-rTMS cortisol concentrations as covariates was used.

RESULTS

Salivary cortisol concentrations following real rTMS were significantly lower compared with those following sham rTMS. In this sample, there was also a trend for real rTMS to reduce food craving more than sham rTMS.

CONCLUSIONS

These results suggest that rTMS applied to the left DLPFC alters HPAA activity in people with a bulimic disorder.

Neurobiological mechanisms of repetitive transcranial magnetic stimulation on the underlying neurocircuitry in unipolar depression

For nearly two decades now, transcranial magnetic stimulation (TMS) has been available as a noninvasive clinical tool to treat patients suffering from major depression. In this period, a bulk of animal and human studies examined TMS parameters to improve clinical outcome. However, the neurobiological mechanisms underlying mood changes remain an important focus of research. In addition to having an effect on neuroendocrinological processes, neurotransmitter systems, and neurotrophic factors, TMS may not only affect the stimulated cortical regions, but also those connected to them. Therefore, we will review current human data on possible neurobiological mechanisms of repetitive (r) TMS implicated in the deregulated neurocircuitry present in unipolar depression. Furthermore, as the rTMS application can be considered as a “top-down” neuronal intervention, we will focus on the neuronal pathways linked with the stimulated area and we will present an integrative model of action.

Repetitive transcranial magnetic stimulation reduces cue-induced food craving in bulimic disorders

BACKGROUND

Craving or the "urge to consume" is a characteristic of bulimic eating disorders and addictions. Dysfunction of the dorsolateral prefrontal cortex (DLPFC) is associated with craving. We investigated whether stimulation of the DLPFC reduces food craving in people with a bulimic-type eating disorder.

METHODS

Thirty-eight people with bulimic-type eating disorders were randomly allocated to receive one session of real or sham high-frequency repetitive transcranial magnetic stimulation (rTMS) to the left DLPFC in a double-blind procedure. Outcome measures included self-reported food craving immediately after the stimulation session and frequency of bingeing over a 24-hour follow-up period.

RESULTS

Compared with sham control, real rTMS was associated with decreased self-reported urge to eat and fewer binge-eating episodes over the 24 hours following stimulation.

CONCLUSIONS

High-frequency rTMS of the left DLPFC lowers cue-induced food cravings in people with a bulimic eating disorder and may reduce binge eating. These results provide a rationale for exploring rTMS as a treatment for bulimic eating disorders.

Carbonic anhydrase I, II, and VI, blood plasma, erythrocyte and saliva zinc and copper increase after repetitive transcranial magnetic stimulation

INTRODUCTION

Repetitive transcranial magnetic stimulation (rTMS) has been used to treat symptoms from many disorders; biochemical changes occurred with this treatment. Preliminary studies with rTMS in patients with taste and smell dysfunction improved sensory function and increased salivary carbonic anhydrase (CA) VI and erythrocyte CA I, II. To obtain more information about these changes after rTMS, we measured changes in several CA enzymes, proteins, and trace metals in their blood plasma, erythrocytes, and saliva.

METHODS

Ninety-three patients with taste and smell dysfunction were studied before and after rTMS in an open clinical trial. Before and after rTMS, we measured erythrocyte CA I, II and salivary CA VI, zinc and copper in parotid saliva, blood plasma, and erythrocytes, and appearance of novel salivary proteins by using mass spectrometry.

RESULTS

After rTMS, CA I, II and CA VI activity and zinc and copper in saliva, plasma, and erythrocytes increased with significant sensory benefit. Novel salivary proteins were induced at an m/z value of 21.5K with a repetitive pattern at intervals of 5K m/z.

CONCLUSIONS

rTMS induced biochemical changes in specific enzymatic activities, trace metal concentrations, and induction of novel salivary proteins, with sensory improvement in patients with taste and smell dysfunction. Because patients with several neurologic disorders exhibit taste and smell dysfunction, including Parkinson disease, Alzheimer disease, and multiple sclerosis, and because rTMS improved their clinical symptoms, the biochemical changes we observed may be relevant not only in our patients with taste and smell dysfunction but also in patients with neurologic disorders with these sensory abnormalities.