Diffusion magnetic resonance spectroscopy captures microglial reactivity related to gut-derived systemic lipopolysaccharide: A preliminary study.

Neuroinflammation is a key component underlying multiple neurological disorders, yet non-invasive and cost-effective assessment of in vivo neuroinflammatory processes in the central nervous system remains challenging. Diffusion weighted magnetic resonance spectroscopy (dMRS) has shown promise in addressing these challenges by measuring diffusivity properties of different neurometabolites, which can reflect cell-specific morphologies. Prior work has demonstrated dMRS utility in capturing microglial reactivity in the context of lipopolysaccharide (LPS) challenges and serious neurological disorders, detected as changes of microglial metabolite diffusivity properties. However, the extent to which such dMRS metrics are capable of detecting subtler and more nuanced levels of neuroinflammation in populations without overt neuropathology is unknown. Here we examined the relationship between intrinsic, gut-derived levels of systemic LPS and dMRS-based apparent diffusion coefficients (ADC) of choline, creatine, and N-acetylaspartate (NAA) in two brain regions: the thalamus and the corona radiata. Higher plasma LPS concentrations were significantly associated with increased ADC of choline and NAA in the thalamic region, with no such relationships observed in the corona radiata for any of the metabolites examined. As such, dMRS may have the sensitivity to measure microglial reactivity across populations with highly variable levels of neuroinflammation, and holds promising potential for widespread applications in both research and clinical settings.

Electroconvulsive therapy, electric field, neuroplasticity, and clinical outcomes.

Electroconvulsive therapy (ECT) remains the gold-standard treatment for patients with depressive episodes, but the underlying mechanisms for antidepressant response and procedure-induced cognitive side effects have yet to be elucidated. Such mechanisms may be complex and involve certain ECT parameters and brain regions. Regarding parameters, the electrode placement (right unilateral or bitemporal) determines the geometric shape of the electric field (E-field), and amplitude determines the E-field magnitude in select brain regions (e.g., hippocampus). Here, we aim to determine the relationships between hippocampal E-field strength, hippocampal neuroplasticity, and antidepressant and cognitive outcomes. We used hippocampal E-fields and volumes generated from a randomized clinical trial that compared right unilateral electrode placement with different pulse amplitudes (600, 700, and 800 mA). Hippocampal E-field strength was variable but increased with each amplitude arm. We demonstrated a linear relationship between right hippocampal E-field and right hippocampal neuroplasticity. Right hippocampal neuroplasticity mediated right hippocampal E-field and antidepressant outcomes. In contrast, right hippocampal E-field was directly related to cognitive outcomes as measured by phonemic fluency. We used receiver operating characteristic curves to determine that the maximal right hippocampal E-field associated with cognitive safety was 112.5 V/m. Right hippocampal E-field strength was related to the whole-brain ratio of E-field strength per unit of stimulation current, but this whole-brain ratio was unrelated to antidepressant or cognitive outcomes. We discuss the implications of optimal hippocampal E-field dosing to maximize antidepressant outcomes and cognitive safety with individualized amplitudes.

Test-Retest Reliability of a Semi-Structured Interview to Aid in Pediatric Traumatic Brain Injury Diagnosis.

OBJECTIVE: Retrospective self-report is typically used for diagnosing previous pediatric traumatic brain injury (TBI). A new semi-structured interview instrument (New Mexico Assessment of Pediatric TBI; NewMAP TBI) investigated test-retest reliability for TBI characteristics in both the TBI that qualified for study inclusion and for lifetime history of TBI. METHOD: One-hundred and eight-four mTBI (aged 8-18), 156 matched healthy controls (HC), and their parents completed the NewMAP TBI within 11 days (subacute; SA) and 4 months (early chronic; EC) of injury, with a subset returning at 1 year (late chronic; LC). RESULTS: The test-retest reliability of common TBI characteristics [loss of consciousness (LOC), post-traumatic amnesia (PTA), retrograde amnesia, confusion/disorientation] and post-concussion symptoms (PCS) were examined across study visits. Aside from PTA, binary reporting (present/absent) for all TBI characteristics exhibited acceptable (≥0.60) test-retest reliability for both Qualifying and Remote TBIs across all three visits. In contrast, reliability for continuous data (exact duration) was generally unacceptable, with LOC and PCS meeting acceptable criteria at only half of the assessments. Transforming continuous self-report ratings into discrete categories based on injury severity resulted in acceptable reliability. Reliability was not strongly affected by the parent completing the NewMAP TBI. CONCLUSIONS: Categorical reporting of TBI characteristics in children and adolescents can aid clinicians in retrospectively obtaining reliable estimates of TBI severity up to a year post-injury. However, test-retest reliability is strongly impacted by the initial data distribution, selected statistical methods, and potentially by patient difficulty in distinguishing among conceptually similar medical concepts (i.e., PTA vs. confusion).

Comparative Efficacy of Therapies for Treatment of Depression for Patients Undergoing Maintenance Hemodialysis: A Randomized Clinical Trial.

Background: Although depression is common among patients receiving maintenance hemodialysis, data on their acceptance of treatment and on the comparative efficacy of various therapies are limited. Objective: To determine the effect of an engagement interview on treatment acceptance (phase 1) and to compare the efficacy of cognitive behavioral therapy (CBT) versus sertraline (phase 2) for treating depression in patients receiving hemodialysis. Design: Multicenter, parallel-group, open-label, randomized controlled trial. (ClinicalTrials.gov: NCT02358343). Setting: 41 dialysis facilities in 3 U.S. metropolitan areas. Participants: Patients who had been receiving hemodialysis for at least 3 months and had a Beck Depression Inventory-II score of 15 or greater; 184 patients participated in phase 1, and 120 subsequently participated in phase 2. Intervention: Engagement interview versus control visit (phase 1) and 12 weeks of CBT delivered in the dialysis facility versus sertraline treatment (phase 2). Measurements: The primary outcome for phase 1 was the proportion of participants who started depression treatment within 28 days. For phase 2, the primary outcome was depressive symptoms measured by the Quick Inventory of Depressive Symptoms-Clinician-Rated (QIDS-C) at 12 weeks. Results: The proportion of participants who initiated treatment after the engagement or control visit did not differ (66% vs. 64%, respectively; P = 0.77; estimated risk difference, 2.1 [95% CI, -12.1 to 16.4]). Compared with CBT, sertraline treatment resulted in lower QIDS-C depression scores at 12 weeks (effect estimate, -1.84 [CI, -3.54 to -0.13]; P = 0.035). Adverse events were more frequent in the sertraline than the CBT group. Limitation: No randomized comparison was made with no treatment, and persistence of treatment effect was not assessed. Conclusion: An engagement interview with patients receiving maintenance hemodialysis had no effect on their acceptance of treatment for depression. After 12 weeks of treatment, depression scores were modestly better with sertraline treatment than with CBT. Primary Funding Source: Patient-Centered Outcomes Research Institute, Dialysis Clinic, Kidney Research Institute, and National Institute of Diabetes and Digestive and Kidney Diseases.

Proactive inhibition deficits with normal perfusion after pediatric mild traumatic brain injury.

Although much attention has been generated in popular media regarding the deleterious effects of pediatric mild traumatic brain injury (pmTBI), a paucity of empirical evidence exists regarding the natural course of biological recovery. Fifty pmTBI patients (12-18 years old) were consecutively recruited from Emergency Departments and seen approximately 1 week and 4 months post-injury in this prospective cohort study. Data from 53 sex- and age-matched healthy controls (HC) were also collected. Functional magnetic resonance imaging was obtained during proactive response inhibition and at rest, in conjunction with independent measures of resting cerebral blood flow. High temporal resolution imaging enabled separate modeling of neural responses for preparation and execution of proactive response inhibition. A priori predictions of failed inhibitory responses (i.e., hyperactivation) were observed in motor circuitry (pmTBI>HC) and sensory areas sub-acutely and at 4 months post-injury. Paradoxically, pmTBI demonstrated hypoactivation (HC>pmTBI) during target processing, along with decreased activation within prefrontal cognitive control areas. Functional connectivity within motor circuitry at rest suggested that deficits were limited to engagement during the inhibitory task, whereas normal resting cerebral perfusion ruled out deficits in basal perfusion. In conclusion, current results suggest blood oxygen-level dependent deficits during inhibitory control may exceed commonly held beliefs about physiological recovery following pmTBI, potentially lasting up to 4 months post-injury.

Transcranial Direct Current Stimulation to the Right Temporoparietal Junction for Social Functioning in Autism Spectrum Disorder: A Case Report.

OBJECTIVES: While there is evidence of improved social functioning after applying transcranial direct current stimulation (tDCS) at the right temporoparietal junction (rTPJ) in individuals who are healthy, no current studies have investigated the use of tDCS at the rTPJ to improve social functioning in individuals with autism spectrum disorder (ASD). This case investigates the use of tDCS applied to the rTPJ to target social functioning in a high-functioning adult with ASD. METHODS: The authors present a case of an 18-year old patient with ASD treated successfully with tDCS; 1.5 mA of tDCS was applied once a day for 30 minutes for 8 consecutive days with the anode electrode over rTPJ (CP6 in the 10/10 electroencephalogram system) and the cathode electrode placed on the ipsilateral deltoid. Behavioral outcome was assessed using the Autism Treatment Evaluation Checklist prior to tDCS, after the final tDCS session, and at 2 months after tDCS. An additional, informal follow-up was also made 1 year after tDCS. RESULTS: Autism Treatment Evaluation Checklist showed substantial improvement in social functioning from baseline to post-tDCS, which was maintained at 2 months. The patient also reported lessened feelings of anger and frustration over social disappointments. Informal follow-up 1 year after stimulation indicates that the patient continues to maintain many improvements. CONCLUSIONS: Anodal tDCS to the rTPJ may represent an effective treatment for improving social functioning in ASD, with a larger clinical trial needed to validate this effect.

Psychotherapeutic Agents in End-Stage Renal Disease.

Patients with end-stage renal disease (ESRD) are often affected by many comorbid conditions, including mental health disorders. Psychiatric illness among patients with ESRD has been associated with increased risks for nonadherence, hospitalizations, suicide, and all-cause mortality. We reviewed the pharmacokinetic data available with psychotherapeutic agents, focusing on physiologic data rather than specific dosing recommendations. Unfortunately data regarding the pharmacokinetics, efficacy, and safety of psychotherapeutic agents in ESRD remain rather limited. Of the agents available, it appears that the most data in this patient group were found with selective serotonin reuptake inhibitors and benzodiazepines. Given the small number of patients enrolled in many of the studies and the wide inter-individual variability, it was difficult to interpret the significance of results in many instances. A number of agents, such as tricyclic antidepressants, were associated with adverse effects that would be imperative to avoid in patients with ESRD. Psychotherapeutic medications should be started at low doses and titrated carefully, while monitoring the efficacy and safety of each agent.

A review of longitudinal electroconvulsive therapy: neuroimaging investigations.

Electroconvulsive therapy (ECT) is the most effective treatment for a depressive episode but the mechanism of action and neural correlates of response are poorly understood. Different theories have suggested that anticonvulsant properties or neurotrophic effects are related to the unique mechanism of action of ECT. This review assessed longitudinal imaging investigations (both structural and functional) associated with ECT response published from 2002 to August 2013. We identified 26 investigations that used a variety of different imaging modalities and data analysis methods. Despite these methodological differences, we summarized the major findings of each investigation and identified common patterns that exist across multiple investigations. The ECT response is associated with decreased frontal perfusion, metabolism, and functional connectivity and increased volume and neuronal chemical metabolites. The general collective of longitudinal neuroimaging investigations support both the anticonvulsant and the neurotrophic effects of ECT. We propose a conceptual framework that integrates these seemingly contradictory hypotheses.

Catatonia after cerebral hypoxia: do the usual treatments apply?

BACKGROUND: Neurologic deterioration occurring days to weeks after a cerebral hypoxic event accompanied by diffuse white matter demyelination is called delayed posthypoxic leukoencephalopathy (DPHL). Manifestations of DPHL are diverse and include dementia, gait disturbance, incontinence, pyramidal tract signs, parkinsonism, chorea, mood and thought disorders, akinetic mutism, and rarely catatonia. METHODS: We report a case of malignant catatonia in a patient diagnosed with DPHL that was refractory to electroconvulsive therapy (ECT) and review the literature on catatonia in DPHL. RESULTS: The patient was a 56-year-old woman with schizoaffective disorder who was admitted with catatonia 2 weeks after hospitalization for drug overdose and respiratory failure. Her catatonic symptoms did not respond to treatment of lorazepam, amantadine, methylphenidate, or 10 sessions of bilateral ECT at maximum energy. Repeat magnetic resonance imaging revealed extensive periventricular white matter lesions not present on admission scans, and she was diagnosed with DPHL. DISCUSSION: No treatment for DPHL has been proven to be widely effective. Hyperbaric oxygen treatments may reduce the rate of development, and symptom improvement has been reported with stimulants and other psychotropic agents. Review of literature reveals rare success with GABAergic agents for catatonia after cerebral hypoxia and no cases successfully treated with ECT. There are 7 case reports of neurologic decompensation during ECT treatment after a cerebral hypoxic event. CONCLUSION: Caution is advised when considering ECT for catatonia when delayed sequelae of cerebral hypoxia are on the differential diagnosis, as there is a dearth of evidence to support this treatment approach.

Catatonia after deep brain stimulation successfully treated with lorazepam and right unilateral electroconvulsive therapy: a case report.

OBJECTIVES: The presence of a deep brain stimulator (DBS) in a patient who develops neuropsychiatric symptoms poses unique diagnostic challenges and questions for the treating psychiatrist. Catatonia has been described only once, during DBS implantation, but has not been reported in a successfully implanted DBS patient. METHODS: We present a case of a patient with bipolar disorder and renal transplant who developed catatonia after DBS for essential tremor. RESULTS: The patient was successfully treated for catatonia with lorazepam and electroconvulsive therapy after careful diagnostic workup. Electroconvulsive therapy has been successfully used with DBS in a handful of cases, and certain precautions may help reduce potential risk. CONCLUSIONS: Catatonia is a rare occurrence after DBS but when present may be safely treated with standard therapies such as lorazepam and electroconvulsive therapy.

Differential diagnosis of psychiatric symptoms after deep brain stimulation for movement disorders.

OBJECTIVES: The presence of a deep brain stimulator (DBS) in a patient with a movement disorder who develops psychiatric symptoms poses unique diagnostic and therapeutic challenges for the treating clinician. Few sources discuss approaches to diagnosing and treating these symptoms. MATERIALS AND METHODS: The authors review the literature on psychiatric complications in DBS for movement disorders and propose a heuristic for categorizing symptoms according to their temporal relationship with the DBS implantation process. RESULTS: Psychiatric symptoms after DBS can be categorized as preimplantation, intra-operative/perioperative, stimulation related, device malfunction, medication related, and chronic stimulation related/long term. Once determined, the specific etiology of a symptom guides the practitioner in treatment. CONCLUSIONS: A structured approach to psychiatric symptoms in DBS patients allows practitioners to effectively diagnose and treat them when they arise.

Neural response to monetary incentives in acquired adolescent depression after mild traumatic brain injury: Stage 2 Registered Report.

Depression is a common consequence of traumatic brain injury. Separately, spontaneous depression-arising without brain injury-has been linked to abnormal responses in motivational neural circuitry to the anticipation or receipt of rewards. It is unknown if post-injury and spontaneously occurring depression share similar phenotypic profiles. This issue is compounded by the fact that nearly all examinations of these psychiatric sequelae are post hoc: there are rarely any prospective assessments of mood and neural functioning before and after a brain injury. In this Stage 2 Registered Report, we used the Adolescent Brain Cognitive Development Consortium dataset to examine if a disruption in functional neural responses to rewards is present in patients with depression after a mild traumatic brain injury. Notably, this study provides an unparalleled opportunity to examine the trajectory of neuropsychiatric symptoms longitudinally within-subjects. This allowed us to isolate mild traumatic brain injury-specific variance independent from pre-existing functioning. Here, we focus on a case-control comparison between 43 youth who experienced a mild traumatic brain injury between MRI visits, and 43 well-matched controls. Contrary to pre-registered predictions (https://osf.io/h5uba/), there was no statistically credible increase in depression in mild traumatic brain injury cases relative to controls. Mild traumatic brain injury was associated with subtle changes in motivational neural circuit recruitment during the anticipation of incentives on the Monetary Incentive Delay paradigm. Specifically, changes in neural recruitment appeared to reflect a failure to deactivate 'task-negative' brain regions (ventromedial prefrontal cortex), alongside blunted recruitment of 'task-positive' regions (anterior cingulate, anterior insula and caudate), during the anticipation of reward and loss in adolescents following mild brain injuries. Critically, these changes in brain activity were not correlated with depressive symptoms at either visit or depression change scores before and after the brain injury. Increased time since injury was associated with a recovery of cognitive functioning-driven primarily by processing speed differences-but depression did not scale with time since injury. These cognitive changes were also uncorrelated with neural changes after mild traumatic brain injury. This report provides evidence that acquired depression may not be observed as commonly after a mild traumatic brain injury in late childhood and early adolescence, relative to findings in adult cases. Several reasons for these differing findings are considered, including sampling enrichment in retrospective cohort studies, under-reporting of depressive symptoms in parent-report data, and neuroprotective factors in childhood and adolescence.

Cognition and post-concussive symptom status after pediatric mild traumatic brain injury.

Cognitive impairment and post-concussive symptoms (PCS) represent hallmark sequelae of pediatric mild traumatic brain injury (pmTBI). Few studies have directly compared cognition as a function of PCS status longitudinally. Cognitive outcomes were therefore compared for asymptomatic pmTBI, symptomatic pmTBI, and healthy controls (HC) during sub-acute (SA; 1-11 days) and early chronic (EC; approximately 4 months) post-injury phases. We predicted worse cognitive performance for both pmTBI groups relative to HC at the SA visit. At the EC visit, we predicted continued impairment from the symptomatic group, but no difference between asymptomatic pmTBI and HCs. A battery of clinical (semi-structured interviews and self-report questionnaires) and neuropsychological measures were administered to 203 pmTBI and 139 HC participants, with greater than 80% retention at the EC visit. A standardized change method classified pmTBI into binary categories of asymptomatic or symptomatic based on PCS scores. Symptomatic pmTBI performed significantly worse than HCs on processing speed, attention, and verbal memory at SA visit, whereas lower performance was only present for verbal memory for asymptomatic pmTBI. Lower performance in verbal memory persisted for both pmTBI groups at the EC visit. Surprisingly, a minority (16%) of pmTBI switched from asymptomatic to symptomatic status at the EC visit. Current findings suggest that PCS and cognition are more closely coupled during the first week of injury but become decoupled several months post-injury. Evidence of lower performance in verbal memory for both asymptomatic and symptomatic pmTBI suggests that cognitive recovery may be a process separate from the resolution of subjective symptomology.

Amplitude-determined seizure-threshold, electric field modeling, and electroconvulsive therapy antidepressant and cognitive outcomes.

Electroconvulsive therapy (ECT) pulse amplitude, which dictates the induced electric field (E-field) magnitude in the brain, is presently fixed at 800 or 900 milliamperes (mA) without clinical or scientific rationale. We have previously demonstrated that increased E-field strength improves ECT's antidepressant effect but worsens cognitive outcomes. Amplitude-determined seizure titration may reduce the E-field variability relative to fixed amplitude ECT. In this investigation, we assessed the relationships among amplitude-determined seizure-threshold (STa), E-field magnitude, and clinical outcomes in older adults (age range 50 to 80 years) with depression. Subjects received brain imaging, depression assessment, and neuropsychological assessment pre-, mid-, and post-ECT. STa was determined during the first treatment with a Soterix Medical 4×1 High Definition ECT Multi-channel Stimulation Interface (Investigation Device Exemption: G200123). Subsequent treatments were completed with right unilateral electrode placement (RUL) and 800 mA. We calculated Ebrain defined as the 90th percentile of E-field magnitude in the whole brain for RUL electrode placement. Twenty-nine subjects were included in the final analyses. Ebrain per unit electrode current, Ebrain/I, was associated with STa. STa was associated with antidepressant outcomes at the mid-ECT assessment and bitemporal electrode placement switch. Ebrain/I was associated with changes in category fluency with a large effect size. The relationship between STa and Ebrain/I extends work from preclinical models and provides a validation step for ECT E-field modeling. ECT with individualized amplitude based on E-field modeling or STa has the potential to enhance neuroscience-based ECT parameter selection and improve clinical outcomes.

Sex- and Age-Related Differences in Post-Concussive Symptom Reporting Among Children and Their Parents.

Pediatric mild traumatic brain injury (pmTBI) has received increased public attention over the past decade, especially for children who experience persistent post-concussive symptoms (PCS). Common methods for obtaining pediatric PCS rely on both self- and parental report, exhibit moderate test-retest reliability, and variable child-parent agreement, and may yield high false positives. The current study investigated the impact of age and biological sex on PCS reporting (Post-Concussion Symptom Inventory) in patients with pmTBI (n = 286) at retrospective, 1 week, 4 months, and 1 year post-injury time points, as well as reported symptoms in healthy controls (HC; n = 218) at equivalent assessment times. HC and their parents reported higher PCS for their retrospective rating relative to the other three other study visits. Child-parent agreement was highest for female adolescents, but only approached acceptable ranges (≥ 0.75) immediately post-injury. Poor-to-fair child/parental agreement was observed for most other study visits for pmTBI and at all visits for HC. Parents rated female adolescents as being more symptomatic than their male counterparts in spite of small (pmTBI) or no (HC) sex-related differences in self-reported ratings, suggestive of a potential cultural bias in parental ratings. Test-retest reliability for self-report was typically below acceptable ranges for both pmTBI and HC groups, with reliability decreasing for HC and increasing for pmTBI as a function of time between visits. Parental test-retest reliability was higher for females. Although continued research is needed, current results support the use of child self-report over parental ratings for estimating PCS burden. Results also highlight the perils of relying on symptom self-report for diagnostic and prognostic purposes.

Standardizing Attention Process Training-III for a Multisite Clinical Trial of Neuromodulation.

INTRODUCTION: The Control Network Neuromodulation to Enhance Cognitive Training in Complex Traumatic Brain Injury (CONNECT-TBI) study is an ongoing randomized, double-blinded, sham-controlled multisite clinical trial to determine the enhancing effects of noninvasive neuromodulation when paired with cognitive training in military participants (Veterans and active duty) with mild TBI. Attention Process Training-III (APT-III) was selected for its strong evidence base, manualized procedures, and computerized program. However, many aspects of APT-III that make it ideal for personalization make it less ideal for reliable implementation across participants, clinicians/technicians, and sites. The purpose of this feature article is to highlight APT-III procedures that require additional standardization for reliable administration across participants and sites. MATERIALS AND METHODS: Ten studies using APT-III were reviewed for methodology of APT-III administration. The manual was also scrutinized; aspects of administration that involved clinical decision-making, subjectivity, flexibility, and/or that were identified by the APT-III developers as areas in need of "empirical evaluation" were flagged by clinicians. Literature and manual review findings were presented to the team for discussion and solution-finding. The authors created and refined a standardized process that would allow participants to move through APT-III training, including task movement algorithms and new materials drafts. Refining of algorithms and drafts continued until there was a consensus from team members. RESULTS: Many gray areas were identified, but we will limit our reporting to focus on (1) dosage, (2) adaptation, (3) metacognitive strategy instruction, and (4) goal attainment scaling. We present APT-III manual details, literature review findings, and CONNECT-TBI decisions and materials for each of these areas of focus. CONCLUSIONS: We have highlighted some of the major gray areas of APT-III administration so that fellow researchers can understand the need to take similar steps in clinical trials using APT-III. We provide examples of our standardization process and resultant rules and materials. Our algorithm, based on prior studies using the APT-III and our own iterative adjustments, allows for adjustment of the difficulty and speed of the training tasks (but within certain parameters) in order to achieve the best balance between individualization and consistency across participants and sites. We provide an example of a workflow and reporting process for future studies.

Effects of anodal tDCS on electroencephalography correlates of cognitive control in mild-to-moderate traumatic brain injury.

BACKGROUND: Transcranial direct current stimulation (tDCS) may provide a potential therapy for cognitive deficits caused by traumatic brain injury (TBI), yet its efficacy and mechanisms of action are still uncertain. OBJECTIVE: We hypothesized that anodal tDCS over the left dorsolateral prefrontal cortex (DLPFC) would boost the influence of a cognitive training regimen in a mild-to-moderate TBI (mmTBI) sample. Cognitive enhancement was measured by examining event-related potentials (ERPs) during cognitive control tasks from pre- to post-treatment. METHODS: Thirty-four participants with mmTBI underwent ten sessions of cognitive training with active (n = 17) or sham (n = 17) anodal tDCS to the left DLPFC. ERPs were assessed during performance of an auditory oddball (3AOB), N-back, and dot pattern expectancy (DPX) task before and after treatment. RESULTS: P3b amplitudes significantly decreased from baseline to post-treatment testing, regardless of tDCS condition, in the N-back task. The active tDCS group demonstrated a significantly increased P3a amplitude in the DPX task. No statistically significant stimulation effects were seen during the 3AOB and N-back tasks. CONCLUSION: Active anodal tDCS paired with cognitive training led to increases in P3a amplitudes in the DPX, inferring increased cognitive control. P3b decreased in the N-back task demonstrating the effects of cognitive training. These dissociated P3 findings suggest separate mechanisms invoked by different neuroplasticity-inducing paradigms (stimulation versus training) in brain networks that support executive functioning.