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Brain and Behavior Dec 2023Posttraumatic stress disorder (PTSD) is a complex and heterogeneous mental health condition that can develop after exposure to a traumatic event. Clinical trials have... (Review)
Review
BACKGROUND
Posttraumatic stress disorder (PTSD) is a complex and heterogeneous mental health condition that can develop after exposure to a traumatic event. Clinical trials have used alternative pharmacological agents to treat PTSD, but their associated neural correlates remain unclear. The present systematic review aims to summarize the changes in brain function associated with the use of these alternative pharmacological agents in PTSD.
METHODS
Clinical trials using functional magnetic resonance imaging, either at rest or during the performance of tasks, were included if they compared the effects of alternative pharmacological agents between PTSD patients and either trauma-exposed controls or never-exposed healthy controls.
RESULTS
Sixteen studies were included, of which 11 used intranasal oxytocin, 2 used hydrocortisone, and 3 used delta-9-tetrahydrocannabinol (THC). Oxytocin administration was associated with the normalization of functional connectivity between the ventromedial prefrontal cortex and amygdala as well as enhanced the function of brain regions specifically involved in emotion processing (e.g., amygdala), working memory (e.g., dorsolateral prefrontal cortex), and reward (e.g., putamen). Hydrocortisone did not influence brain function at rest or during the performance of an autobiographical memory task, whereas THC was associated with the reduction of the amygdala and increased medial prefrontal cortex activation.
CONCLUSIONS
This systematic review identified preliminary evidence for normalizing brain function after the use of alternative pharmacological agents. Importantly, sex-specific differences were noted, in particular when using oxytocin, that will require further investigation.
Topics: Female; Humans; Male; Brain; Emotions; Hydrocortisone; Magnetic Resonance Imaging; Oxytocin; Stress Disorders, Post-Traumatic; Clinical Trials as Topic
PubMed: 37864378
DOI: 10.1002/brb3.3292 -
Schizophrenia Research Nov 2023Transcranial magnetic stimulation (TMS) can offer therapeutic benefits and provide value in neurophysiological research. One of the newer TMS paradigms is theta burst... (Review)
Review
Transcranial magnetic stimulation (TMS) can offer therapeutic benefits and provide value in neurophysiological research. One of the newer TMS paradigms is theta burst stimulation (TBS) which can be delivered in two patterns: continuous (cTBS - inducing LTD-like effects) and intermittent (iTBS - inducing LTP-like effects). This review paper aims to explore studies that have utilized TBS protocols over different areas of the cortex to study the neurophysiological functions and treatment of patients with schizophrenia. PubMed was searched using the following keywords "schizophrenia", "schizoaffective", or "psychosis", and "theta burst stimulation". Out of the 90 articles which were found, thirty met review inclusion criteria. The inclusion criteria included studying the reported effect (clinical, physiological, or both) of at least one session of TBS on human subjects, and abstracts (at minimum) must have been in English. The main target areas included prefrontal cortex (12 studies - 10 dorsolateral prefrontal cortex (DLPFC), 2 dorsomedial prefrontal cortex (DMPFC)) vermal cerebellum (5), and temporo-parietal cortex (8). Other target areas included inferior parietal lobe (2), and motor cortex (3). TBS neurophysiological effect was explored in 5 studies using functional magnetic resonance image (fMRI), magnetic resonance spectroscopy (MRS), electroencephalography (EEG), electromyography (EMG) and positron emission topography (PET) scan. Overall, TBS can offer great therapeutic potential as it is well-tolerated, feasible, and has few, if any, adverse effects. TBS may be targeted to treat specific symptomatology, as an augmenting intervention to pharmacotherapy, or even improving patient's insight into their diagnosis.
Topics: Humans; Transcranial Magnetic Stimulation; Schizophrenia; Electroencephalography; Prefrontal Cortex; Parietal Lobe; Theta Rhythm
PubMed: 37844414
DOI: 10.1016/j.schres.2023.10.005 -
Physiotherapy Research International :... Jan 2024Fatigue following neurological conditions negatively impacts daily activities, reducing overall quality of life. Transcranial direct current stimulation (tDCS) for...
BACKGROUND AND PURPOSE
Fatigue following neurological conditions negatively impacts daily activities, reducing overall quality of life. Transcranial direct current stimulation (tDCS) for fatigue management is still underexplored. This scoping review explores its use in managing fatigue among various neurological conditions.
METHODS
A thorough literature search was carried out using PubMed, Scopus, CINAHL, Web of Science, Embase, ProQuest, and the Cochrane Library. Google Scholar and clinicaltrials.gov were manually searched for gray literature and ongoing trials, respectively. Regardless of the study design, all studies utilizing tDCS for the management of fatigue in various neurological conditions were considered. Two reviewers independently screened all the studies, following which the data were retrieved.
RESULTS
Studies employing tDCS for fatigue management across neurological conditions is as follows: Multiple sclerosis (MS) (n = 28, 66%), stroke (n = 5, 12%), Parkinson's disease (PD) (n = 4, 10%), post-polio syndrome (PPS) (n = 2, 5%), traumatic brain injury (TBI) (n = 2, 5%), and amyotrophic lateral sclerosis (n = 1, 2%). All the studies used anodal stimulation, with the common stimulation site being the left dorsolateral prefrontal cortex for MS, stroke, and PD. A stimulation intensity of 1.0-4.0 mA with a duration ranging from 15 to 30 min in 1 to 24 sessions were commonly reported. The Fatigue Severity Scale (n = 21) and Modified Fatigue Impact Scale (n = 17) were frequently implemented outcome measures. Regardless of the study design, 36/42 (85.7%) studies reported an improvement in fatigue scores in the tDCS group. The common adverse events noted were tingling (n = 8, 35%), headache (n = 6, 26%), and itching (n = 6, 26%).
DISCUSSION
Application of tDCS for fatigue was explored in individuals with stroke, PD, PPS, and TBI after MS. Even though a wide range of treatment parameters and outcome measures were adopted to assess and target fatigue, tDCS proves to have a promising role in alleviating this symptom.
Topics: Humans; Brain Injuries, Traumatic; Fatigue; Multiple Sclerosis; Parkinson Disease; Quality of Life; Stroke; Transcranial Direct Current Stimulation
PubMed: 37838979
DOI: 10.1002/pri.2054 -
Journal of Clinical Medicine Sep 2023Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation technique also used as a non-pharmacological intervention against cognitive... (Review)
Review
Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation technique also used as a non-pharmacological intervention against cognitive impairment. The purpose of the present review was to summarize what is currently known about the effectiveness of rTMS intervention on different cognitive domains in patients with mild cognitive impairment (MCI) and to address potential neuromodulation approaches in combination with electroencephalography (EEG) and neuroimaging, especially functional magnetic resonance imaging (fMRI). In this systematic review, we consulted three main databases (PubMed, Science Direct, and Scopus), and Google Scholar was selected for the gray literature search. The PRISMA flowchart drove the studies' inclusion. The selection process ensured that only high-quality studies were included; after removing duplicate papers, explicit ratings were given based on the quality classification as high (A), moderate (B), or low (C), considering factors such as risks of bias, inaccuracies, inconsistencies, lack of direction, and publication bias. Seven full-text articles fulfilled the stated inclusion, reporting five double-blind, randomized, sham-controlled studies, a case study, and a randomized crossover trial. The results of the reviewed studies suggested that rTMS in MCI patients is safe and effective for enhancing cognitive functions, thus making it a potential therapeutic approach for MCI patients. Changes in functional connectivity within the default mode network (DMN) after targeted rTMS could represent a valuable indicator of treatment response. Finally, high-frequency rTMS over the dorsolateral prefrontal cortex (DLPFC) has been shown to significantly enhance cognitive functions, such as executive performance, together with the increase of functional connectivity within frontoparietal networks. The main limitations were the number of included studies and the exclusion of studies using intermittent theta-burst stimulation, used in studies on Alzheimer's disease. Therefore, neuroimaging techniques in combination with rTMS have been shown to be useful for future network-based, fMRI-guided therapeutic approaches.
PubMed: 37834834
DOI: 10.3390/jcm12196190 -
Psychiatry Research Nov 2023While pharmacological strategies appear to be ineffective in treating long-term addiction, repetitive transcranial magnetic stimulation (rTMS) is emerging as a promising... (Review)
Review
OBJECTIVE
While pharmacological strategies appear to be ineffective in treating long-term addiction, repetitive transcranial magnetic stimulation (rTMS) is emerging as a promising new tool for the attenuation of craving among multiple substance dependent populations.
METHOD
A systematic review of randomized controlled trials (RCTs) was conducted on the efficacy and tolerability of rTMS in treating cocaine use disorder (CUD). Relevant papers published in English through November 30 2022 were identified, searching the electronic databases MEDLINE, Embase, PsycINFO and the Cochrane Library.
RESULTS
Eight studies matched inclusion criteria. The best findings were reported by the RCTs conducted at high-frequency (≥5 Hz) multiple sessions of rTMS delivered over the left dorsolateral prefrontal cortex (DLPFC): a significant decrease in self-reported cue-induced cocaine craving and lower cocaine craving scores and a considerable amelioration in the tendency to act rashly under extreme negative emotions (impulsivity) were found in the active group compared to controls.
CONCLUSION
Although still scant and heterogeneous, the strongest evidence so far on the use of rTMS on individuals with CUD support the high frequency stimulation over the left DLPFC as a well tolerated treatment of cocaine craving and impulsivity.
Topics: Humans; Cocaine-Related Disorders; Transcranial Magnetic Stimulation; Prefrontal Cortex; Randomized Controlled Trials as Topic; Cocaine; Substance-Related Disorders; Craving; Treatment Outcome
PubMed: 37783092
DOI: 10.1016/j.psychres.2023.115491 -
Social Cognitive and Affective... Oct 2023In recent decades, a substantial volume of work has examined the neural mechanisms of cognitive reappraisal. Distancing and reinterpretation are two frequently used... (Meta-Analysis)
Meta-Analysis
In recent decades, a substantial volume of work has examined the neural mechanisms of cognitive reappraisal. Distancing and reinterpretation are two frequently used tactics through which reappraisal can be implemented. Theoretical frameworks and prior evidence have suggested that the specific tactic through which one employs reappraisal entails differential neural and psychological mechanisms. Thus, we were motivated to assess the neural mechanisms of this distinction by examining the overlap and differentiation exhibited by the neural correlates of distancing (specifically via objective appraisal) and reinterpretation. We analyzed 32 published functional magnetic resonance imaging (fMRI) studies in healthy adults using multilevel kernel density analysis. Results showed that distancing relative to reinterpretation uniquely recruited right bilateral dorsolateral PFC (DLPFC) and left posterior parietal cortex, previously associated with mentalizing, selective attention and working memory. Reinterpretation relative to distancing uniquely recruited left bilateral ventrolateral PFC (VLPFC), previously associated with response selection and inhibition. Further, distancing relative to reinterpretation was associated with greater prevalence of bilateral amygdala attenuation during reappraisal. Finally, a behavioral meta-analysis showed efficacy for both reappraisal tactics. These results are consistent with prior theoretical models for the functional neural architecture of reappraisal via distancing and reinterpretation and suggest potential future applications in region-of-interest specification and neural network analysis in studies focusing on specific reappraisal tactics.
Topics: Adult; Humans; Emotions; Magnetic Resonance Imaging; Parietal Lobe; Amygdala; Attention; Brain Mapping; Cognition
PubMed: 37757486
DOI: 10.1093/scan/nsad050 -
Schizophrenia (Heidelberg, Germany) Sep 2023This systematic review aimed to review neuroimaging studies comparing clozapine-resistant schizophrenia patients with clozapine-responding patients, and with first-line... (Review)
Review
This systematic review aimed to review neuroimaging studies comparing clozapine-resistant schizophrenia patients with clozapine-responding patients, and with first-line antipsychotic responding (FLR) patients. A total of 19 studies including 6 longitudinal studies were identified. Imaging techniques comprised computerized tomography (CT, n = 3), structural magnetic resonance imaging (MRI, n = 7), magnetic resonance spectroscopy (MRS, n = 5), functional MRI (n = 1), single-photon emission computerized tomography (SPECT, n = 3) and diffusion tensor imaging (DTI, n = 1). The most consistent finding was hypo-frontality in the clozapine-resistant group compared with the clozapine-responding group with possible differences in frontal-striatal-basal ganglia circuitry as well as the GABA level between the two treatment-resistant groups. Additional statistically significant findings were reported when comparing clozapine-resistant patients with the FLR group, including lower cortical thickness and brain volume of multiple brain regions as well as lower Glx/Cr level in the dorsolateral prefrontal cortex. Both treatment-resistant groups were found to have extensive differences in neurobiological features in comparison with the FLR group. Overall results suggested treatment-resistant schizophrenia is likely to be a neurobiological distinct type of the illness. Clozapine-resistant and clozapine-responding schizophrenia are likely to have both shared and distinct neurobiological features. However, conclusions from existing studies are limited, and future multi-center collaborative studies are required with a consensus clinical definition of patient samples, multimodal imaging tools, and longitudinal study designs.
PubMed: 37752161
DOI: 10.1038/s41537-023-00392-7 -
Biological Psychiatry Mar 2024Noninvasive brain stimulation (NIBS) treatments have gained considerable attention as potential therapeutic intervention for psychiatric disorders. The identification of... (Review)
Review
Noninvasive brain stimulation (NIBS) treatments have gained considerable attention as potential therapeutic intervention for psychiatric disorders. The identification of reliable biomarkers for predicting clinical response to NIBS has been a major focus of research in recent years. Neuroimaging techniques, such as electroencephalography (EEG) and functional magnetic resonance imaging (MRI), have been used to identify potential biomarkers that could predict response to NIBS. However, identifying clinically actionable brain biomarkers requires robustness. In this systematic review, we aimed to summarize the current state of brain biomarker research for NIBS in depression, focusing only on well-powered studies (N ≥ 88) and/or studies that aimed at independently replicating previous findings, either successfully or unsuccessfully. A total of 220 studies were initially identified, of which 18 MRI studies and 18 EEG studies met the inclusion criteria. All focused on repetitive transcranial magnetic stimulation treatment in depression. After reviewing the included studies, we found the following MRI and EEG biomarkers to be most robust: 1) functional MRI-based functional connectivity between the dorsolateral prefrontal cortex and subgenual anterior cingulate cortex, 2) functional MRI-based network connectivity, 3) task-induced EEG frontal-midline theta, and 4) EEG individual alpha frequency. Future prospective studies should further investigate the clinical actionability of these specific EEG and MRI biomarkers to bring biomarkers closer to clinical reality.
Topics: Humans; Prefrontal Cortex; Depression; Prospective Studies; Brain; Transcranial Magnetic Stimulation; Magnetic Resonance Imaging; Electroencephalography
PubMed: 37734515
DOI: 10.1016/j.biopsych.2023.09.009 -
Progress in Neuro-psychopharmacology &... Jan 2024Traumatic brain injury (TBI) is a major cause of long-term disability with conventional treatments frequently falling short to restore a good quality-of-life.... (Meta-Analysis)
Meta-Analysis Review
INTRODUCTION
Traumatic brain injury (TBI) is a major cause of long-term disability with conventional treatments frequently falling short to restore a good quality-of-life. Non-invasive brain stimulation (NIBS) techniques have shown potential as therapeutic options for neuropsychiatric conditions, including TBI sequelae. This study aims at providing a systematic review and meta-analysis on the effectiveness of repetitive transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) on post-TBI symptoms.
METHODS
Fifteen randomized controlled trials (RCTs) on adult TBI patients that examined the effects of multiple treatment sessions of NIBS techniques were selected from five databases. Symptoms were clustered into four categories: depression, anxiety, headache and cognitive dysfunctions. Meta-analysis was performed using correlated and hierarchical effects models.
RESULTS
There were only few and heterogeneous studies with generally small sample sizes. Most studies targeted the dorsolateral prefrontal cortex (dlPFC). Overall, the effects of NIBS were small. However, there was a significant effect for overall symptoms (0.404, p = 0.031). Moreover, subgroup analyses revealed significant overall effects for anxiety (0.195, p = 0.020) and headache (0.354, p = 0.040).
CONCLUSIONS
To date, there is limited evidence supporting the effectiveness of NIBS concerning treatment for TBI sequelae. The observed effect sizes were modest, suggesting subtle improvements rather than drastic changes. While NIBS techniques remain promising for treating neuropsychiatric conditions, larger RCT studies with longer follow-ups, optimized stimulation parameters and standardized methodology are required to establish their efficacy in addressing TBI sequelae.
Topics: Humans; Transcranial Magnetic Stimulation; Transcranial Direct Current Stimulation; Brain Injuries, Traumatic; Randomized Controlled Trials as Topic; Treatment Outcome; Chronic Disease
PubMed: 37709126
DOI: 10.1016/j.pnpbp.2023.110863 -
Frontiers in Psychiatry 2023Intermittent theta-burst stimulation (iTBS), which is a form of repetitive transcranial magnetic stimulation (rTMS), can produce 600 pulses to the left dorsolateral...
Efficacy and safety of intermittent theta burst stimulation versus high-frequency repetitive transcranial magnetic stimulation for patients with treatment-resistant depression: a systematic review.
OBJECTIVE
Intermittent theta-burst stimulation (iTBS), which is a form of repetitive transcranial magnetic stimulation (rTMS), can produce 600 pulses to the left dorsolateral prefrontal cortex (DLPFC) in a stimulation time of just over 3 min. The objective of this systematic review was to compare the safety and efficacy of iTBS and high-frequency (≥ 5 Hz) rTMS (HF-rTMS) for patients with treatment-resistant depression (TRD).
METHODS
Randomized controlled trials (RCTs) comparing the efficacy and safety of iTBS and HF-rTMS were identified by searching English and Chinese databases. The primary outcomes were study-defined response and remission.
RESULTS
Two RCTs ( = 474) investigating the efficacy and safety of adjunctive iTBS ( = 239) versus HF-rTMS ( = 235) for adult patients with TRD met the inclusion criteria. Among the two included studies (Jadad score = 5), all were classified as high quality. No group differences were found regarding the overall rates of response (iTBS group: 48.0% versus HF-rTMS group: 45.5%) and remission (iTBS group: 30.0% versus HF-rTMS group: 25.2%; all > 0.05). The rates of discontinuation and adverse events such as headache were similar between the two groups (all > 0.05).
CONCLUSION
The antidepressant effects and safety of iTBS and HF-rTMS appeared to be similar for patients with TRD, although additional RCTs with rigorous methodology are needed.
PubMed: 37583841
DOI: 10.3389/fpsyt.2023.1244289