Trigeminal Nerve Stimulation for Comorbid Posttraumatic Stress Disorder and Major Depressive Disorder

The efficacy of real versus sham external Trigeminal Nerve Stimulation (eTNS) in youth with Attention-Deficit/Hyperactivity Disorder (ADHD) over 4 weeks: a protocol for a multi-centre, double-blind, randomized, parallel-group, phase IIb study (ATTENS)

BACKGROUND

Attention Deficit/Hyperactivity Disorder (ADHD), if severe, is usually treated with stimulant or non-stimulant medication. However, users prefer non-drug treatments due to side effects. Alternative non-medication treatments have so far only shown modest effects. External trigeminal nerve stimulation (eTNS) is a minimal risk, non-invasive neuromodulation device, targeting the trigeminal system. It was approved for ADHD in 2019 by the USA Food and Drug administration (FDA) based on a small proof of concept randomised controlled trial (RCT) in 62 children with ADHD showing improvement of ADHD symptoms after 4 weeks of nightly real versus sham eTNS with minimal side effects. We present here the protocol of a larger confirmatory phase IIb study testing efficacy, longer-term persistency of effects and underlying mechanisms of action.

METHODS

A confirmatory, sham-controlled, double-blind, parallel-arm, multi-centre phase IIb RCT of 4 weeks of eTNS in 150 youth with ADHD, recruited in London, Portsmouth, and Southampton, UK. Youth with ADHD will be randomized to either real or sham eTNS, applied nightly for 4 weeks. Primary outcome is the change in the investigator-administered parent rated ADHD rating scale. Secondary outcomes are other clinical and cognitive measures, objective hyperactivity and pupillometry measures, side effects, and maintenance of effects over 6 months. The mechanisms of action will be tested in a subgroup of 56 participants using magnetic resonance imaging (MRI) before and after the 4-week treatment.

DISCUSSION

This multi-centre phase IIb RCT will confirm whether eTNS is effective in a larger age range of children and adolescents with ADHD, whether it improves cognition and other clinical measures, whether efficacy persists at 6 months and it will test underlying brain mechanisms. The results will establish whether eTNS is effective and safe as a novel non-pharmacological treatment for ADHD.

TRIAL REGISTRATION

ISRCTN82129325 on 02/08/2021, https://doi.org/10.1186/ISRCTN82129325 .

Modulating the default mode network: Antidepressant efficacy of transcutaneous electrical cranial-auricular acupoints stimulation targeting the insula

BACKGROUND

Transcutaneous electrical cranial-auricular acupoint stimulation (TECAS) is a novel non-invasive therapy for major depressive disorder (MDD) that stimulates acupoints innervated by the trigeminal and auricular vagus nerves. However, there are few neuroimaging studies involving the TECAS for the treatment of MDD. Therefore, this study aimed to investigate the treatment response and neurological effects of TECAS using resting-state functional magnetic resonance imaging (rs-fMRI).

METHOD

A total of 34 patients with mild-to-moderate MDD and 34 demographically matched healthy controls (HCs) were recruited. After an eight-week treatment the primary outcome was clinical response, defined as a baseline-to-endpoint ≥ 50 % reduction in the 17-item Hamilton Depression Rating Scale (HAMD-17). The low-frequency fluctuations (ALFF) method were used to investigate the brain abnormalities of MDD patients and HCs, and altered brain networks were analyzed between pre- and post-treatment using seed-based functional connectivity (FC) analysis.

RESULTS

We found no significant differences in terms of gender, age, and years of education between the two groups. After treatment, the response rate was 58.82 %. Compared to HCs, MDD patients showed lower ALFF values in the left insula(t = -4.298,P < 0.005), the insula-based FC revealed in the right middle frontal gyrus (MFG)/ right superior frontal gyrus, orbital part (ORBsupmed) (t = -5.29,P < 0.005) and the right anterior cingulate gyrus (ACC)were decreased (t = -6.08,P < 0.005). Furthermore, Compared to pre-treatment, abnormal FC values in the ACC /orbital superior frontal gyrus (SFG) (t = 3.42,P < 0.005) and left superior frontal gyrus (SFG)/ supplement motor area (SMA) were enhanced (t = 3.34,P < 0.005).

CONCLUSION

TECAS exhibits antidepressant efficacy, particularly influencing the insula-based functional connections within the Default Mode Network (DMN) related to emotion processing in individuals with MDD.

Traumatic Brain Injury and Neuromodulation Techniques in Rehabilitation: A Scoping Review

BACKGROUND AND OBJECTIVES

Traumatic Brain Injury (TBI) is a condition in which an external force, usually a violent blow to the head, causes functional impairment in the brain. Neuromodulation techniques are thought to restore altered function in the brain, resulting in improved function and reduced symptoms. Brain stimulation can alter the firing of neurons, boost synaptic strength, alter neurotransmitters and excitotoxicity, and modify the connections in their neural networks. All these are potential effects on brain activity. Accordingly, this is a promising therapy for TBI. These techniques are flexible because they can target different brain areas and vary in frequency and amplitude. This review aims to investigate the recent literature about neuromodulation techniques used in the rehabilitation of TBI patients.

MATERIALS AND METHODS

The identification of studies was made possible by conducting online searches on PubMed, Web of Science, Cochrane, Embase, and Scopus databases. Studies published between 2013 and 2023 were selected. This review has been registered on OSF (JEP3S).

RESULTS

We have found that neuromodulation techniques can improve the rehabilitation process for TBI patients in several ways. Transcranial Magnetic Stimulation (TMS) can improve cognitive functions such as recall ability, neural substrates, and overall improved performance on neuropsychological tests. Repetitive TMS has the potential to increase neural connections in many TBI patients but not in all patients, such as those with chronic diffuse axonal damage.

CONCLUSIONS

This review has demonstrated that neuromodulation techniques are promising instruments in the rehabilitation field, including those affected by TBI. The efficacy of neuromodulation can have a significant impact on their lives and improve functional outcomes for TBI patients.

Central effects of trigeminal electrical stimulation

This is a review of the literature on the main neuromodulation techniques, focusing on the possibility of introducing sensory threshold ULFTENS into them. Electro neuromodulation techniques have been in use for many years as promising methods of therapy for cognitive and emotional disorders. One of the most widely used forms of stimulation for orofacial pain is transcutaneous trigeminal stimulation on three levels: supraorbital area, dorsal surface of the tongue, and anterior skin area of the tragus. The purpose of this review is to trigger interest on using dental ULFTENS as an additional trigeminal neurostimulation and neuromodulation technique in the context of TMD. In particular, we point out the possibility of using ULFTENS at a lower activation level than that required to trigger a muscle contraction that is capable of triggering effects at the level of the autonomic nervous system, with extreme ease of execution and few side effects.

Clinical and cognitive effects of external trigeminal nerve stimulation (eTNS) in neurological and psychiatric disorders: a systematic review and meta-analysis

This pre-registered (CRD42022322038) systematic review and meta-analysis investigated clinical and cognitive outcomes of external trigeminal nerve stimulation (eTNS) in neurological and psychiatric disorders. PubMed, OVID, Web of Science, Chinese National Knowledge Infrastructure, Wanfang, and VIP database for Chinese technical periodicals were searched (until 16/03/2022) to identify trials investigating cognitive and clinical outcomes of eTNS in neurological or psychiatric disorders. The Cochrane Risk of Bias 2.0 tool assessed randomized controlled trials (RCTs), while the Risk of Bias of Non-Randomized Studies (ROBINS-I) assessed single-arm trials. Fifty-five peer-reviewed articles based on 48 (27 RCTs; 21 single-arm) trials were included, of which 12 trials were meta-analyzed (N participants = 1048; of which ~3% ADHD, ~3% Epilepsy, ~94% Migraine; age range: 10-49 years). The meta-analyses showed that migraine pain intensity (K trials = 4, N = 485; SMD = 1.03, 95% CI[0.84-1.23]) and quality of life (K = 2, N = 304; SMD = 1.88, 95% CI[1.22-2.53]) significantly improved with eTNS combined with anti-migraine medication. Dimensional measures of depression improved with eTNS across 3 different disorders (K = 3, N = 111; SMD = 0.45, 95% CI[0.01-0.88]). eTNS was well-tolerated, with a good adverse event profile across disorders. eTNS is potentially clinically relevant in other disorders, but well-blinded, adequately powered RCTs must replicate findings and support optimal dosage guidance.

Transcutaneous electrical cranial-auricular acupoint stimulation versus escitalopram for modulating the brain activity in mild to moderate major depressive disorder: An fMRI study

Transcutaneous electrical cranial-auricular acupoint stimulation (TECAS) is an innovative, non-invasive therapy for major depressive disorder (MDD). However, its effectiveness and underlying neural mechanisms remain not fully understood. This study aimed to investigate the treatment response and neurological effects of TECAS compared to escitalopram, a commonly used depression medication, using resting-state functional magnetic resonance imaging (rs-fMRI). Fifty-one patients with mild-to-moderate MDD (34 in the TECAS group and 17 in the Escitalopram group) and 51 healthy controls (HCs) participated in the study. We employed the low-frequency fluctuations (ALFF) and regional homogeneity (ReHo) methods to explore brain abnormalities in MDD patients and HCs. Additionally, seed-based functional connectivity (FC) analysis was conducted to examine altered brain networks before and after treatment.Compared to the HCs group, the MDD group exhibited lower ReHo and ALFF values in the right medial superior frontal gyrus (mSFG_R), indicating altered neural activity in this region. Furthermore, mSFG-based FC analysis revealed abnormal FC values in the right inferior occipital gyrus (IOG_R) and middle temporal gyrus (MTG) between after and before treatment in MDD patients. Interestingly, TECAS treatment was found to normalize these abnormal FC brain regions, suggesting its potential role in restoring neural connectivity in MDD patients. Notably, both TECAS and escitalopram demonstrated equivalent antidepressant efficacy, with both treatments showing modulatory effects on connectivity within the default mode network (DMN). The observed normalization of abnormal FC regions, including mSFG_R, IOG_R, and MTG, all belong to the DMN. In conclusion, this study sheds light on the neurological effects and treatment response of TECAS in MDD, highlighting its potential as a non-invasive therapeutic option for depressed patients.

Cognitive Functions following Trigeminal Neuromodulation

Vast scientific effort in recent years have been focused on the search for effective and safe treatments for cognitive decline. In this regard, non-invasive neuromodulation has gained increasing attention for its reported effectiveness in promoting the recovery of multiple cognitive domains after central nervous system damage. In this short review, we discuss the available evidence supporting a possible cognitive effect of trigeminal nerve stimulation (TNS). In particular, we ask that, while TNS has been widely and successfully used in the treatment of various neuropsychiatric conditions, as far as research in the cognitive field is concerned, where does TNS stand? The trigeminal nerve is the largest cranial nerve, conveying the sensory information from the face to the trigeminal sensory nuclei, and from there to the thalamus and up to the somatosensory cortex. On these bases, a bottom-up mechanism has been proposed, positing that TNS-induced modulation of the brainstem noradrenergic system may affect the function of the brain networks involved in cognition. Nevertheless, despite the promising theories, to date, the use of TNS for cognitive empowering and/or cognitive decline treatment has several challenges ahead of it, mainly due to little uniformity of the stimulation protocols. However, as the field continues to grow, standardization of practice will allow for data comparisons across studies, leading to optimized protocols targeting specific brain circuitries, which may, in turn, influence cognition in a designed manner.

Impact of psychiatric comorbidities on the treatment of epilepsies in adults

INTRODUCTION

Epilepsy is often accompanied by psychiatric comorbidities and the management of epilepsy in these patients presents unique challenges due to the interplay between the underlying neurological condition and the psychiatric symptoms and the combined use of multiple medications.

AREAS COVERED

This paper aims to explore the complexities associated with managing epilepsy in the presence of psychiatric comorbidities, focusing on the impact of psychiatric disorders on epilepsy treatment strategies and the challenges posed by the simultaneous administration of multiple medications.

EXPERT OPINION

Patients with epilepsy and psychiatric comorbidities seem to present with a more severe form of epilepsy that is resistant to drug treatments and burdened by an increased morbidity and mortality. Whether prompt treatment of psychiatric disorders can influence the long-term prognosis of the epilepsy is still unclear as well as the role of specific treatment strategies, such as neuromodulation, in this group of patients. Clinical practice recommendations and guidelines will prompt the development of new models of integrated care to be implemented.

Trigeminal nerve stimulation for prolonged disorders of consciousness: A randomized double-blind sham-controlled study

BACKGROUND

Trigeminal nerve stimulation (TNS) has been proposed as a promising intervention for coma awakening. However, the effect of TNS on patients with prolonged disorders of consciousness (pDoC) is still unclear.

OBJECTIVE

This study aimed to investigate the therapeutic effects of TNS in pDoC caused by stroke, trauma, and anoxia.

METHODS

A total of 60 patients (male =25, female =35) aged over 18 who were in a vegetative state or minimally conscious state were randomly assigned to the TNS (N = 30) or sham TNS (N = 30) groups. 4 weeks of intervention and a followed up for 8 weeks were performed. The Glasgow Coma Scale (GCS) and Coma Recovery Scale-Revised (CRS-R) scores as primary outcomes were assessed at baseline and at 2, 4, 8, and 12 weeks.

RESULTS

The score changes in the TNS group over time for CRS-R (2-week: mean difference = 0.9, 95% CI = [0.3, 1.5], P = 0.006; 4-week: 1.6, 95% CI = [0.8, 2.5], P < 0.001; 8-week: mean difference = 2.4, 95% CI = [1.3, 3.5], P < 0.001; 12-week: mean difference = 2.3, 95% CI = [1.1, 3.4], P < 0.001) and GCS (4-week: mean difference = 0.7, 95% CI = [0.3, 1.2], P = 0.002; 8-week: mean difference = 1.1, 95% CI = [0.6, 1.7], P < 0.001; 12-week: 1.1, 95% CI = [0.5, 1.7], P = 0.003) were higher than those in the sham group. 18-Fluorodeoxyglucose Positron Emission Tomography (FDG-PET) revealed that the metabolism of the right parahippocampal cortex, right precuneus, and bilateral middle cingulate cortex was significantly increased in TNS group.

CONCLUSION

The results of this study indicate that TNS could increase local brain metabolism and may promote functional recovery in patients with prolonged disorders of consciousness.

REGISTRATION INFORMATION

Name of the registry: Chinese Clinical Trial Registry.

REGISTRATION NUMBER

ChiCTR1900025573. The date that the study was submitted to a registry: 2019-09-01. The date when the first patient was enrolled was 2021-01-20.

Transcutaneous electrical cranial-auricular acupoint stimulation versus escitalopram for mild-to-moderate depression: An assessor-blinded, randomized, non-inferiority trial

AIM

Transcutaneous electrical cranial-auricular acupoint stimulation (TECAS) is a novel non-invasive therapy that stimulates acupoints innervated by the trigeminal and auricular vagus nerves. An assessor-blinded, randomized, non-inferiority trial was designed to compare the efficacy of TECAS and escitalopram in mild-to-moderate major depressive disorder.

METHODS

468 participants received two TECAS sessions per day at home (n = 233) or approximately 10-13 mg/day escitalopram (n = 235) for 8 weeks plus 4-week follow-up. The primary outcome was clinical response, defined as a baseline-to-endpoint ≥50% reduction in Montgomery-Åsberg Depression Rating Scale (MADRS) score. Secondary outcomes included remission rate, changes in the severity of depression, anxiety, sleep and life quality.

RESULTS

The response rate was 66.4% on TECAS and 63.2% on escitalopram with a 3.2% difference (95% confidence interval [CI], -5.9% to 12.9%) in intention-to-treat analysis, and 68.5% versus 66.2% with a 2.3% difference (95% CI, -6.9% to 11.4%) in per-protocol analysis. The lower limit of 95% CI of the differences fell within the prespecified non-inferiority margin of -10% (P ≤ 0.004 for non-inferiority). Most secondary outcomes did not differ between the two groups. TECAS-treated participants who experienced psychological trauma displayed a markedly greater response than those without traumatic experience (81.3% vs 62.1%, P = 0.013). TECAS caused much fewer adverse events than escitalopram.

CONCLUSIONS

TECAS was comparable to escitalopram in improving depression and related symptoms, with high acceptability, better safety profile, and particular efficacy in reducing trauma-associated depression. It could serve an effective portable therapy for mild-to-moderate depression.

Short-term transcutaneous trigeminal nerve stimulation does not affect visual oddball task and paired-click paradigm ERP responses in healthy volunteers

Recent research suggests that transcutaneous trigeminal nerve stimulation (TNS) may positively affect cognitive function. However, no clear-cut evidence is available yet, since the majority of it derives from clinical studies, and the few data on healthy subjects show inconsistent results. In this study, we report the effects of short-term TNS on event-related potentials (ERP) recorded during the administration of a simple visual oddball task and a paired-click paradigm, both considered useful for studying brain information processing functions. Thirty-two healthy subjects underwent EEG recording before and after 20 min of sham- or real-TNS, delivered bilaterally to the infraorbital nerve. The amplitude and latency of P200 and P300 waves in the simple visual oddball task and P50, N100 and P200 waves in the paired-click paradigm were measured before and after treatment. Our results show that short-term TNS did not alter any of the ERP parameters measured, suggesting that in healthy subjects, short-term TNS may not affect brain processes involved in cognitive functions such as pre-attentional processes, early allocation of attention and immediate memory. The perspective of having an effective, non-pharmacological, non-invasive, and safe treatment option for cognitive decline is particularly appealing; therefore, more research on the positive effects on cognition of TNS is definitely needed.

[Involvement of the trigeminal nerve system in the sense of smell]

A systematic review of literature on the issue of involvement in the sense of smell, as well as the interaction between the trigeminal and olfactory nerves, was carried out. The article discusses the features of the chemical perception systems, as well as the treatment of olfactory disorders using transcranial electrical stimulation of the trigeminal nerve.

Electrical stimulation of the trigeminal nerve improves olfaction in healthy individuals: A randomized, double-blind, sham-controlled trial

BACKGROUND

Both activated by environmental odorants, there is a clear role for the intranasal trigeminal and olfactory nerves in smell function. Unfortunately, our ability to perceive odorants decreases with age or with injury, and limited interventions are available to treat smell loss.

OBJECTIVE

We investigated whether electrical stimulation of the trigeminal nerve via trigeminal nerve stimulation (TNS) or transcranial direct current stimulation (tDCS) modulates odor sensitivity in healthy individuals.

METHODS

We recruited 20 healthy adults (12 Female, mean age = 27) to participate in this three-visit, randomized, double-blind, sham-controlled trial. Participants were randomized to receive one of three stimulation modalities (TNS, tDCS, or sham) during each of their visits. Odor detection thresholds were obtained at baseline, immediately post-intervention, and 30-min post-intervention. Furthermore, participants were asked to complete a sustained attention task and mood assessments before odor detection testing.

RESULTS

Findings reveal a timeXcondition interaction for guaiacol (GUA) odorant detection thresholds (F (3.188, 60.57) = 3.833, P = 0.0125), but not phenyl ethyl alcohol (PEA) odorant thresholds. At 30-min post-stimulation, both active TNS and active tDCS showed significantly increased sensitivity to GUA compared to sham TNS (Sham TNS = -8.30% vs. Active TNS = 9.11%, mean difference 17.43%, 95% CI 5.674 to 29.18, p = 0.0044; Sham TNS = -8.30% vs. Active tDCS = 13.58%, mean difference 21.89%, 95% CI 10.47 to 33.32, p = 0.0004).

CONCLUSION

TNS is a safe, simple, noninvasive method for boosting olfaction. Future studies should investigate the use of TNS on smell function across different stimulation parameters, odorants, and patient populations.

The Effectiveness of Trigeminal Nerve Stimulation on Traumatic Brain Injury

OBJECTIVES

Trigeminal nerve stimulation (TNS) is a promising strategy in treating diseases of the nervous system. In this study, the effects of TNS on traumatic brain injury (TBI) were investigated in a mouse model.

MATERIALS AND METHODS

TBI was induced using a weight-drop device, and TNS treatment was delivered in the first hour after the TBI. Twenty-four hours later, the mice's behavior, brain edema, and expression of inflammatory factors were tested. Functional magnetic resonance imaging also was used to explore the possible effects of TNS on brain activity.

RESULTS

TNS alleviates TBI-induced neurological dysfunction in animal behavior tests, besides protecting the blood-brain barrier and reducing the level of brain edema. TNS also effectively reduces the level of tumor necrosis factor-α and interleukin 6 and downregulates the cleaved caspase-3 signaling pathway. A series of brain areas was found to be possibly regulated by TNS, thus affecting the neural functions of animals.

CONCLUSION

This study elucidates the role of TNS as an effective treatment for TBI by inhibiting the occurrence of a secondary brain injury.

Neuro-Cardiac-Guided TMS (NCG TMS): A replication and extension study

Neuro-Cardiac-Guided Transcranial Magnetic Stimulation (NCG-TMS) was studied for its potential to specifically target the frontal-vagal network. Previous research demonstrated that prefrontal stimulation led to significant heartrate slowing. We aimed to replicate these results in a larger sample and extend the findings to investigate dose-response relationships, reproducibility and stimulation frequency (10 Hz and intermittent theta burst (iTBS)). Data of forty-five healthy controls were analyzed, of which 28 received 10 Hz TMS (NCG-TMS) and 27 iTBS (NCG-iTBS; 10 received both protocols) at different stimulation sites according to the 10-20-EEG system. NCG-TMS yielded a relative heartrate deceleration at the F3/4 coil position replicating earlier studies. Both internal consistency and dose-response relationships were found. For NCG-iTBS adverse events were reported and topography for frontal-vagal activation was more lateralised relative to NCG-TMS. These results indicate that we were able to transsynaptically stimulate the frontal-vagal network and that excitability thresholds for the prefrontal cortex may differ relative to motor cortex.

SPECT imaging of cerebral blood flow changes induced by acute trigeminal nerve stimulation in drug-resistant epilepsy. A pilot study

OBJECTIVE

To explore the cortical areas targeted by acute transcutaneous trigeminal nerve stimulation (TNS) in patients with drug-resistant epilepsy (DRE) using single photon emission computed tomography (SPECT).

METHODS

Ten patients with DRE underwent brain SPECT at baseline and immediately after a 20-minute TNS (0.25 ms; 120 Hz; 30 s ON and 30 s OFF) applied bilaterally to the infraorbital nerve. The French Color Standard International Scale was used for qualitative analyses and z-scores were used to calculate the Odds Ratio (OR).

RESULTS

At baseline global hypoperfusion (mainly in temporo-mesial, temporo-parietal and fronto-temporal and temporo-occipital areas) was detected in all patients. Following TNS, a global increase in cortical tracer uptake and a significant decrease in median hypoperfusion score were observed. A significant effect favoring a general TNS-induced increase in cortical perfusion (OR = 4.96; p = 0.0005) was detected in 70% of cases, with significant effects in the limbic (p = 0.003) and temporal (p = 0.003) lobes. Quantitative analyses of z-scores confirmed significant TNS-induced increases in perfusion in the temporal (+0.59 SDs; p = 0.001), and limbic (+0.43 SDs; p = 0.03) lobes.

CONCLUSION

Short-term TNS is followed a global increase in cortical perfusion, namely in the temporal and limbic lobes.

SIGNIFICANCE

The TNS-induced perfusion increase may reflect neurons' activity changes in cortical areas implicated in the epilepsy network.

A device review of Relivion®: an external combined occipital and trigeminal neurostimulation (eCOT-NS) system for self-administered treatment of migraine and major depressive disorder

Introduction: Many patients with migraine are non-responsive or intolerant to pharmaceutical or surgical interventions. Peripheral nerve stimulation (PNS) offers a potential solution for these patients. This review discusses the external combined occipital and trigeminal neurostimulation (eCOT-NS) provided by the Relivion®, a multi-channel head-mounted device for self-administered PNS.Areas covered: Challenges and advantages of PNS systems for the treatment of migraine and depression are introduced, followed by an overall review of clinical evidence of the efficacy of the Relivion® system in treating migraine. The supporting smartphone app and cloud-based analytics which enable remote treatment management by the health care provider are also discussed. Recent empirical indications for the potency of this PNS combination for the treatment of depression are also summarized.Expert opinion: Relivion® is an eCOT-NS system, featuring Food and Drug Administration-approved, noninvasive, self-administered, customizable, multi-focal PNS for the treatment of migraine. In accordance with current telehealth trends, the Relivion® also enhances remote disease management and personalization using digital-monitoring, cloud-based technology, and artificial intelligence. As research on this system progresses, it may become the preferred treatment for the management of a number of neurological and psychiatric diseases, with migraine and major depressive disorders as precedents.

Trigeminal nerve electrical stimulation: An effective arousal treatment for loss of consciousness

BACKGROUND

To determine if trigeminal nerve electrical stimulation (TNS) would be an effective arousal treatment for loss of consciousness (LOC), we applied neuroscientific methods to investigate the role of potential brain circuit and neuropeptide pathway in regulating level of consciousness.

METHODS

Consciousness behavioral analysis, Electroencephalogram (EEG) recording, Chemogenetics, Microarray analysis, Milliplex MAP rat peptide assay, Chromatin immune-precipitation (ChIP), Dual-luciferase reporter experiment, Western blot, PCR and Fluorescence in situ hybridization (FISH).

RESULTS

TNS can markedly activate the neuronal activities of the lateral hypothalamus (LH) and the spinal trigeminal nucleus (Sp5), as well as improve rat consciousness level and EEG activities. Then we proved that LH activation and upregulated neuropeptide hypocretin are beneficial for promotion of consciousness recovery. We then applied gene microarray experiment and found hypocretin might be mediated by a well-known transcription factor Early growth response gene 1 (EGR1), and the results were confirmed by ChIP and Dual-luciferase reporter experiment.

CONCLUSION

This study illustrates that TNS is an effective arousal strategy Treatment for LOC state via the activation of Sp5 and LH neurons and upregulation of hypocretin expression.

Bimodal neuromodulation combining sound and tongue stimulation reduces tinnitus symptoms in a large randomized clinical study

Tinnitus is a phantom auditory perception coded in the brain that can be bothersome or debilitating, affecting 10 to 15% of the population. Currently, there is no clinically recommended drug or device treatment for this major health condition. Animal research has revealed that sound paired with electrical somatosensory stimulation can drive extensive plasticity within the brain for tinnitus treatment. To investigate this bimodal neuromodulation approach in humans, we evaluated a noninvasive device that delivers sound to the ears and electrical stimulation to the tongue in a randomized, double-blinded, exploratory study that enrolled 326 adults with chronic subjective tinnitus. Participants were randomized into three parallel arms with different stimulation settings. Clinical outcomes were evaluated over a 12-week treatment period and a 12-month posttreatment phase. For the primary endpoints, participants achieved a statistically significant reduction in tinnitus symptom severity at the end of treatment based on two commonly used outcome measures, Tinnitus Handicap Inventory (Cohen’s d effect size: −0.87 to −0.92 across arms; P < 0.001) and Tinnitus Functional Index (−0.77 to −0.87; P < 0.001). Therapeutic improvements continued for 12 months after treatment for specific bimodal stimulation settings, which had not previously been demonstrated in a large cohort for a tinnitus intervention. The treatment also achieved high compliance and satisfaction rates with no treatment-related serious adverse events. These positive therapeutic and long-term results motivate further clinical trials toward establishing bimodal neuromodulation as a clinically recommended device treatment for tinnitus.

Electroacupuncture trigeminal nerve stimulation plus body acupuncture for chemotherapy-induced cognitive impairment in breast cancer patients: An assessor-participant blinded, randomized controlled trial

Chemotherapy causes various side effects, including cognitive impairment, known as 'chemobrain'. In this study, we determined whether a novel acupuncture mode called electroacupuncture trigeminal nerve stimulation plus body acupuncture (EA/TNS + BA) could produce better outcomes than minimum acupuncture stimulation (MAS) as controls in treating chemobrain and other symptoms in breast cancer patients. In this assessor- and participant-blinded, randomized controlled trial, 93 breast cancer patients under or post chemotherapy were randomly assigned to EA/TNS + BA (n = 46) and MAS (n = 47) for 2 sessions per week over 8 weeks. The Montreal Cognitive Assessment (MoCA) served as the primary outcome. Digit span test was the secondary outcomes for attentional function and working memory. The quality of life and multiple functional assessments were also evaluated. EA/TNS + BA treated group had much better performance than MAS-treated group on reverse digit span test at Week 2 and Week 8, with medium effect sizes of 0.53 and 0.48, respectively, although no significant differences were observed in MoCA score and prevalence of chemobrain between the two groups. EA/TNS + BA also markedly reduced incidences of diarrhoea, poor appetite, headache, anxiety, and irritation, and improved social/family and emotional wellbeing compared to MAS. These results suggest that EA/TNS + BA may have particular benefits in reducing chemotherapy-induced working memory impairment and the incidence of certain digestive, neurological, and distress-related symptoms. It could serve as an effective intervention for breast cancer patients under and post chemotherapy (trial registration: https://www.clinicaltrials.gov: NCT02457039).

Electrical stimulation of cranial nerves in cognition and disease

The cranial nerves are the pathways through which environmental information (sensation) is directly communicated to the brain, leading to perception, and giving rise to higher cognition. Because cranial nerves determine and modulate brain function, invasive and non-invasive cranial nerve electrical stimulation methods have applications in the clinical, behavioral, and cognitive domains. Among other neuromodulation approaches such as peripheral, transcranial and deep brain stimulation, cranial nerve stimulation is unique in allowing axon pathway-specific engagement of brain circuits, including thalamo-cortical networks. In this review we amalgamate relevant knowledge of 1) cranial nerve anatomy and biophysics; 2) evidence of the modulatory effects of cranial nerves on cognition; 3) clinical and behavioral outcomes of cranial nerve stimulation; and 4) biomarkers of nerve target engagement including physiology, electroencephalography, neuroimaging, and behavioral metrics. Existing non-invasive stimulation methods cannot feasibly activate the axons of only individual cranial nerves. Even with invasive stimulation methods, selective targeting of one nerve fiber type requires nuance since each nerve is composed of functionally distinct axon-types that differentially branch and can anastomose onto other nerves. None-the-less, precisely controlling stimulation parameters can aid in affecting distinct sets of axons, thus supporting specific actions on cognition and behavior. To this end, a rubric for reproducible dose-response stimulation parameters is defined here. Given that afferent cranial nerve axons project directly to the brain, targeting structures (e.g. thalamus, cortex) that are critical nodes in higher order brain networks, potent effects on cognition are plausible. We propose an intervention design framework based on driving cranial nerve pathways in targeted brain circuits, which are in turn linked to specific higher cognitive processes. State-of-the-art current flow models that are used to explain and design cranial-nerve-activating stimulation technology require multi-scale detail that includes: gross anatomy; skull foramina and superficial tissue layers; and precise nerve morphology. Detailed simulations also predict that some non-invasive electrical or magnetic stimulation approaches that do not intend to modulate cranial nerves per se, such as transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS), may also modulate activity of specific cranial nerves. Much prior cranial nerve stimulation work was conceptually limited to the production of sensory perception, with individual titration of intensity based on the level of perception and tolerability. However, disregarding sensory emulation allows consideration of temporal stimulation patterns (axon recruitment) that modulate the tone of cortical networks independent of sensory cortices, without necessarily titrating perception. For example, leveraging the role of the thalamus as a gatekeeper for information to the cerebral cortex, preventing or enhancing the passage of specific information depending on the behavioral state. We show that properly parameterized computational models at multiple scales are needed to rationally optimize neuromodulation that target sets of cranial nerves, determining which and how specific brain circuitries are modulated, which can in turn influence cognition in a designed manner.

Human cerebrovascular responses to diving are not related to facial cooling

NEW FINDINGS

What is the central question of this study? Does facial cooling-mediated stimulation of cutaneous trigeminal afferents associated with the diving response increase cerebral blood flow or are factors associated with breath-holding (e.g. arterial carbon dioxide accumulation, pressor response) more important in humans? What is the main finding and its importance? Physiological factors associated with breath-holding such as arterial carbon dioxide accumulation and the pressor response, but not facial cooling (trigeminal nerve stimulation), make the predominant contribution to diving response-mediated increases in cerebral blood flow in humans.

ABSTRACT

Diving evokes a pattern of physiological responses purported to preserve oxygenated blood delivery to vital organs such as the brain. We sought to uncouple the effects of trigeminal nerve stimulation on cerebral blood flow (CBF) from other modifiers associated with the diving response, such as apnoea and changes in arterial carbon dioxide tension. Thirty-seven young healthy individuals participated in separate trials of facial cooling (FC, 3 min) and cold pressor test (CPT, 3 min) under poikilocapnic (Protocol 1) and isocapnic conditions (Protocol 2), facial cooling while either performing a breath-hold (FC +BH) or breathing spontaneously for a matched duration (FC -BH) (Protocol 3), and BH during facial cooling (BH +FC) or without facial cooling (BH -FC) (Protocol 4). Under poikilocapnic conditions neither facial cooling nor CPT evoked a change in middle cerebral artery blood flow velocity (MCA v_mean ; transcranial Doppler) (P > 0.05 vs. baseline). Under isocapnic conditions, facial cooling did not change MCA v_mean (P > 0.05), whereas CPT increased MCA v_mean by 13% (P < 0.05). Facial cooling with a concurrent BH markedly increased MCA v_mean (Δ23%) and internal carotid artery blood flow (ICA_Q ; duplex Doppler ultrasound) (Δ26%) (P < 0.001), but no change in MCA v_mean and ICA_Q was observed when facial cooling was accompanied by spontaneous breathing (P > 0.05). Finally, MCA v_mean and ICA_Q were similarly increased by BH either with or without facial cooling. These findings suggest that physiological factors associated with BH, and not facial cooling (i.e. trigeminal nerve stimulation) per se, make the predominant contribution to increases in CBF during diving in humans.

Assessor- and participant-blinded, randomized controlled trial of dense cranial electroacupuncture stimulation plus body acupuncture for neuropsychiatric sequelae of stroke

AIM

Acupuncture has benefits in the rehabilitation of neuropsychiatric sequelae of stroke. This study was aimed to evaluate the effectiveness of dense cranial electroacupuncture stimulation plus body acupuncture (DCEAS+BA) in treating poststroke depression (PSD), functional disability, and cognitive deterioration.

METHODS

In this assessor- and participant-blinded, randomized controlled trial, 91 stroke patients who initially had PSD were randomly assigned to either DCEAS+BA (n = 45) or minimum acupuncture stimulation as controls (n = 46) for three sessions per week over 8 consecutive weeks. The primary outcome was baseline-to-end-point change in score of the 17-item Hamilton Depression Rating Scale. Secondary outcomes included the Montgomery-Åsberg Depression Rating Scale for depressive symptoms, the Barthel Index for functional disability, and the Montreal Cognitive Assessment for cognitive function.

RESULTS

DCEAS+BA-treated patients showed strikingly greater end-point reduction than MAS-treated patients in scores of the three symptom domains. The clinical response rate, defined as an at least 50% baseline-to-end-point reduction in 17-item Hamilton Depression Rating Scale score, was markedly higher in the DCEAS+BA-treated group than that of controls (40.0% vs 17.4%, P = 0.031). Incidence of adverse events was not different in the two groups. Subgroup analysis revealed that DCEAS+BA with electrical stimulation on forehead acupoints was more apparent in reducing Barthel-Index-measured disability than that without electrical stimulation.

CONCLUSION

DCEAS+BA, particularly with electrical stimulation on forehead acupoints, reduces PSD, functional disability, and cognitive deterioration of stroke patients. It can serve as an effective rehabilitation therapy for neuropsychiatric sequelae of stroke.

Neurostimulation in Anxiety Disorders, Post-traumatic Stress Disorder, and Obsessive-Compulsive Disorder

Many pharmacological treatments were proved effective in the treatment of panic disorder (PD), generalized anxiety disorder (GAD), social anxiety disorder (SAD), post-traumatic stress disorder (PTSD), and obsessive-compulsive disorder (OCD); still many patients do not achieve remission with these treatments. Neurostimulation techniques have been studied as promising alternatives or augmentation treatments to pharmacological and psychological therapies. The most studied neurostimulation method for anxiety disorders, PTSD, and OCD was repetitive transcranial magnetic stimulation (rTMS). This neurostimulation technique had the highest level of evidence for GAD. There were also randomized sham-controlled trials indicating that rTMS may be effective in the treatment of PTSD and OCD, but there were conflicting findings regarding these two disorders. There is indication that rTMS may be effective in the treatment of panic disorder, but the level of evidence is low. Deep brain stimulation (DBS) was most studied for treatment of OCD, but the randomized sham-controlled trials had mixed findings. Preliminary findings indicate that DBS could be affective for PTSD. There is weak evidence indicating that electroconvulsive therapy, transcranial direct current stimulation, vagus nerve stimulation, and trigeminal nerve stimulation could be effective in the treatment of anxiety disorders, PTSD, and OCD. Regarding these disorders, there is no support in the current literature for the use of neurostimulation in clinical practice. Large high-quality studies are warranted.

Neurostimulation Therapies

Depression is one of the most disabling conditions in the world. In many cases patients continue to suffer with depressive disorders despite a series of adequate trials of medication and psychotherapy. Neuromodulation treatments offer a qualitatively different modality of treatment that can frequently prove efficacious in these treatment-refractory patients. The field of neuromodulation focuses on the use of electrical/electromagnetic energy, both invasively and noninvasively, to interface with and ultimately alter activity within the human brain for therapeutic purposes. These treatments provide another set of options to offer patients when clinically indicated, and knowledge of their safety, risks and benefits, and appropriate clinical application is essential for modern psychiatrists and other mental health professionals. Although neuromodulation techniques hold tremendous promise, only three such treatments are currently approved by the United States Food and Drug Administration (FDA) for the treatment of major depressive disorder: electroconvulsive therapy (ECT), vagus nerve stimulation (VNS), and repetitive transcranial magnetic stimulation (rTMS). Additionally, numerous other neurostimulation modalities (deep brain stimulation [DBS], magnetic seizure therapy [MST], transcranial electric stimulation [tES], and trigeminal nerve stimulation [TNS]), though currently experimental, show considerable therapeutic promise. Researchers are actively looking for ways to optimize outcomes and clinical benefits by making neuromodulation treatments safer, more efficacious, and more durable.

Possible association between photic sneeze syndrome and migraine and psychological distress

Background

Photic sneeze syndrome (PSS) is a condition that causes sneezing when the eye is exposed to sudden bright light. Because alterations in the parasympathetic and trigeminal nerve systems have been implicated in PSS, and such systems are involved in migraine and stress‐related disorders, we examined the possible associations of PSS with migraine and psychological distress.

Methods

The presence of PSS and migraine was examined in 11 840 participants from the general population using a self‐report questionnaire. Psychological distress was assessed by the 6‐item Kessler Psychological Distress Scale (K6).

Results

The overall prevalence of PSS was 3.1%. Individuals with PSS were more likely to suffer from migraine (odds ratio = 1.97, P = 2.18 × 10^–9), clinically relevant psychological distress (K6 score ≥ 5: odds ratio = 1.40, P = 0.00143), and severe psychological distress (K6 score ≥ 13: odds ratio = 1.49, P = 0.0486). Overall, K6 scores were significantly higher in those with PSS than in those without (P = 0.000013). Analysis controlling for sex and the presence of migraine showed that PSS was associated with higher K6 scores irrespective of sex or the presence of migraine.

Conclusions

The low prevalence of PSS identified in the present study may be due to the inadequate ability of the self‐report questionnaire to identify PSS. Despite such limitation, the present study suggests that individuals with PSS are more likely to suffer from migraine and psychological distress than those without PSS. PSS may be a potential target for the research of migraine and stress‐related disorders.

Our data obtained through a self‐report questionnaire administered to 11,840 participants showed that individuals with photic sneeze syndrome were more likely to suffer from migraine and psychological distress than those without photic sneeze syndrome. Photic sneeze syndrome may be a potential target for the research of migraine and stress‐related disorders.

Neuromodulatory treatments for post-traumatic stress disorder (PTSD)

Electroconvulsive therapy has been used successfully in some individuals with posttraumatic stress disorder (PTSD) whose symptoms have not improved with other treatments. But there are only a few reports. Meanwhile, an array of new neuromodulation strategies, including repetitive transcranial magnetic stimulation, transcranial direct current stimulation, vagus nerve stimulation, trigeminal nerve stimulation, and deep brain stimulation have been developed and applied experimentally in the treatment of other psychiatric disorders. This article will review the clinical evidence and mechanistic basis for their use in PTSD.

Double-Blind, Sham-Controlled, Pilot Study of Trigeminal Nerve Stimulation for Attention-Deficit/Hyperactivity Disorder

OBJECTIVE

Trigeminal nerve stimulation (TNS), a minimal-risk noninvasive neuromodulation method, showed potential benefits for attention-deficit/hyperactivity disorder (ADHD) in an unblinded open study. The present blinded sham-controlled trial was conducted to assess the efficacy and safety of TNS for ADHD and potential changes in brain spectral power using resting-state quantitative electroencephalography.

METHOD

Sixty-two children 8 to 12 years old, with full-scale IQ of at least 85 and Schedule for Affective Disorders and Schizophrenia-diagnosed ADHD, were randomized to 4 weeks of nightly treatment with active or sham TNS, followed by 1 week without intervention. Assessments included weekly clinician-administered ADHD Rating Scales (ADHD-RS) and Clinical Global Impression (CGI) scales and quantitative electroencephalography at baseline and week 4.

RESULTS

ADHD-RS total scores showed significant group-by-time interactions (F1,228 = 8.12, p = .005; week 4 Cohen d = 0.5). CGI-Improvement scores also favored active treatment (χ21,168 = 8.75, p = .003; number needed to treat = 3). Resting-state quantitative electroencephalography showed increased spectral power in the right frontal and frontal midline frequency bands with active TNS. Neither group had clinically meaningful adverse events.

CONCLUSION

This study demonstrates TNS efficacy for ADHD in a blinded sham-controlled trial, with estimated treatment effect size similar to non-stimulants. TNS is well tolerated and has minimal risk. Additional research should examine treatment response durability and potential impact on brain development with sustained use.

CLINICAL TRIAL REGISTRATION INFORMATION

Trigeminal Nerve Stimulation for ADHD; http://clinicaltrials.gov/; NCT02155608.

The latent structure of major depressive symptoms and its relationship with somatic disorder symptoms among Filipino female domestic workers in China

Emerging research have investigated the factor structure of major depressive disorder (MDD) symptoms based on DSM-5 nomenclature. However, to date, results have been inconsistent on what symptom-structure best represent MDD. This study examines the best fitting MDD among four competing models in a sample of overseas Filipino domestic helpers (N = 232). The results show that a two-factor model (Model 2b; Krause et al., 2010) provided the best fit. The model consist of two factors: somatic and non-somatic/affective symptoms. Somatic component includes sleep difficulties, fatigue, appetite changes, concentration difficulties, and psychomotor agitation/retardation while non-somatic/affective component covers anhedonia, depressed mood, feelings of worthlessness, and thoughts of death. Further, the results reveal a pattern where PHQ-15 somatic symptom-items have a higher significant relationship with MDD's somatic symptoms than with the MDD's non-somatic/affective symptoms. These findings suggest that the items of model 2b are appropriately embedded in their respective factors. Differentiating MDD factors have important clinical implications, particularly in the diagnosis and treatment of depression among overseas Filipino domestic helpers.

Double Blinded Randomized Trial of Subcutaneous Trigeminal Nerve Stimulation as Adjuvant Treatment for Major Unipolar Depressive Disorder

BACKGROUND

More than 30% of major depressive disorder patients fail to respond to adequate trials of medications and psychotherapy. While modern neuromodulation approaches (ie, vagal nerve stimulation, deep brain stimulation) are yet to prove their efficacy for such cases in large randomized controlled trials, trigeminal nerve stimulation (TNS) has emerged as an alternative with promising effects on mood disorders.

OBJECTIVE

To assess efficacy, safety, tolerability, and placebo effect duration of continuous subcutaneous TNS (sTNS) in treatment-resistant depression (TRD).

METHODS

The TREND study is a single-center, double-blind, randomized, controlled, phase II clinical trial. Twenty unipolar TRD patients will receive V1 sTNS as adjuvant to medical therapy and randomized to active vs sham stimulation throughout a 24-wk period. An additional 24-wk open-label phase will follow. Data concerning efficacy, placebo response, relapse, and side effects related to surgery or electrical stimulation will be recorded. We will use the HDRS-17, BDI-SR, IDS_SR30, and UKU scales.

EXPECTED OUTCOMES

The main outcome measure is improvement in depression scores using HAM-17 under continuous sTNS as adjuvant to antidepressants. Active stimulation is expected to significantly impact response and remission rates. Minor side effects are expected due to the surgical procedure and electrical stimulation. The open-label phase should further confirm efficacy and tolerability.

DISCUSSION

This study protocol is designed to define efficacy of a novel adjuvant therapy for TRD. We must strive to develop safe, reproducible, predictable, and well-tolerated neuromodulation approaches for TRD patients impaired to manage their lives and contribute with society.

Efficacy and mode of action of external trigeminal neurostimulation in migraine

INTRODUCTION

Available preventive drug treatments for migraine lack complete efficacy and often have unpleasant adverse effects. Hence, their clinical utility and therapeutic adherence are limited. Noninvasive neurostimulation methods applied over various peripheral sites (forehead, mastoid, upper arm, cervical vagus nerve) have raised great interest because of their excellent efficacy/tolerance profile. Among them external trigeminal nerve stimulation (eTNS) was first to obtain FDA approval for migraine therapy. Areas covered: All clinical trials of eTNS as preventive or acute migraine treatment published in extenso or presented at congresses are reviewed. The paper analyzes neuroimaging and neurophysiological studies on mechanisms of action of eTNS. As many of these studies point toward the anterior cingulate cortex (ACC) as a likely eTNS target, the paper scrutinizes the available literature on the ACC implication in migraine pathophysiology. Expert commentary: eTNS is a viable alternative to standard pharmacological antimigraine strategies both for prevention and abortive therapy. eTNS could chiefly exert its action by modulating the perigenual ACC, which might also be of interest for treating other disorders like fibromyalgia or depression. It remains to be determined if this might be a common mechanism to other peripheral noninvasive neurostimulation methods.

Neuroprotective Effects of Trigeminal Nerve Stimulation in Severe Traumatic Brain Injury

Following traumatic brain injury (TBI), ischemia and hypoxia play a major role in further worsening of the damage, a process referred to as 'secondary injury'. Protecting neurons from causative factors of secondary injury has been the guiding principle of modern TBI management. Stimulation of trigeminal nerve induces pressor response and improves cerebral blood flow (CBF) by activating the rostral ventrolateral medulla. Moreover, it causes cerebrovasodilation through the trigemino-cerebrovascular system and trigemino-parasympathetic reflex. These effects are capable of increasing cerebral perfusion, making trigeminal nerve stimulation (TNS) a promising strategy for TBI management. Here, we investigated the use of electrical TNS for improving CBF and brain oxygen tension (PbrO2), with the goal of decreasing secondary injury. Severe TBI was produced using controlled cortical impact (CCI) in a rat model, and TNS treatment was delivered for the first hour after CCI. In comparison to TBI group, TBI animals with TNS treatment demonstrated significantly increased systemic blood pressure, CBF and PbrO2 at the hyperacute phase of TBI. Furthermore, rats in TNS-treatment group showed significantly reduced brain edema, blood-brain barrier disruption, lesion volume, and brain cortical levels of TNF-α and IL-6. These data provide strong early evidence that TNS could be an effective neuroprotective strategy.

Low-Intensity Transcranial Current Stimulation in Psychiatry

Neurostimulation is rapidly emerging as an important treatment modality for psychiatric disorders. One of the fastest-growing and least-regulated approaches to noninvasive therapeutic stimulation involves the application of weak electrical currents. Widespread enthusiasm for low-intensity transcranial electrical current stimulation (tCS) is reflected by the recent surge in direct-to-consumer device marketing, do-it-yourself enthusiasm, and an escalating number of clinical trials. In the wake of this rapid growth, clinicians may lack sufficient information about tCS to inform their clinical practices. Interpretation of tCS clinical trial data is aided by familiarity with basic neurophysiological principles, potential mechanisms of action of tCS, and the complicated regulatory history governing tCS devices. A growing literature includes randomized controlled trials of tCS for major depression, schizophrenia, cognitive disorders, and substance use disorders. The relative ease of use and abundant access to tCS may represent a broad-reaching and important advance for future mental health care. Evidence supports application of one type of tCS, transcranial direct current stimulation (tDCS), for major depression. However, tDCS devices do not have regulatory approval for treating medical disorders, evidence is largely inconclusive for other therapeutic areas, and their use is associated with some physical and psychiatric risks. One unexpected finding to arise from this review is that the use of cranial electrotherapy stimulation devices-the only category of tCS devices cleared for use in psychiatric disorders-is supported by low-quality evidence.

Morbid Anxiety: Identification and Treatment

Due to their prevalence, chronicity, and poorly understood pathophysiology, anxiety disorders remain an important public health problem. Despite clear diagnostic guidelines and the availability of excellent evidence-based treatments, most anxiety patients remain underrecognized and inadequately treated. This clinical synthesis highlights changes to anxiety disorder diagnosis that became effective with DSM-5. The article also provides some clinical perspective on clarifying differential diagnostic problems and building an alliance with the anxious patient. The quality and strength of the evidence base for current anxiolytic medications options (selective serotonin reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors, benzodiazepines, and other agents), antianxiety psychotherapies (cognitive-behavioral therapy and brief dynamic therapies), and combination treatments are discussed. A brief update on newer treatment strategies, such as cognitive enhancement, complementary therapies, and neuromodulation, is included. Future directions for anxiety nosology and treatment are summarized, including the National Institute of Mental Health Research Domain Criteria initiative and the promising role of personalized medicine.

Low dose X-irradiation mitigates diazepam induced depression in rat brain

Depression is considered as one of the most prevalent health ailments. Various anti-depressant drugs have been used to provide succour to this ailment, but with little success and rather have resulted in many side effects. On the other hand, low dose of ionizing radiations are reported to exhibit many beneficial effects on human body by stimulating various biological processes. The present study was conducted to investigate the beneficial effects of low doses of X-rays, if any, during diazepam induced depression in rats. Female Sprague Dawley rats were segregated into four different groups viz: Normal control, Diazepam treated, X-irradiated and Diazepam + X-irradiated. Depression model was created in rats by subjecting them to diazepam treatment at a dosage of 2 mg/kg b.wt./day for 3 weeks. The skulls of animals belonging to X-irradiated and Diazepam + X-irradiated rats were X-irradiated with a single fraction of 0.5 Gy, given twice a day for 3 days, thereby delivered dose of 3 Gy. Diazepam treated animals showed significant alterations in the neurobehavior and neuro-histoarchitecture, which were improved after X-irradiation. Further, diazepam exposure significantly decreased the levels of neurotransmitters and acetylcholinesterase activity, but increased the monoamine oxidase activity in brain. Interestingly, X-rays exposure to diazepam treated rats increased the levels of neurotransmitters, acetylcholinesterase activity and decreased the monoamine oxidase activity. Further, depressed rats also showed increased oxidative stress with altered antioxidant parameters, which were normalized on X-rays exposure. The present study, suggests that low dose of ionizing radiations, shall prove to be an effective intervention and a novel therapy in controlling depression and possibly other brain related disorders.