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1.
J Affect Disord ; 355: 175-183, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38548207

RESUMEN

BACKGROUND: Non-invasive neuromodulation is a promising intervention for obsessive-compulsive disorder (OCD), although its neurobiological mechanisms of action are still poorly understood. Recent evidence suggests that abnormalities in the connectivity of the default mode network (DMN) and the supplementary motor area (SMA) with other brain regions and networks are involved in OCD pathophysiology. We examined if transcranial direct current stimulation (tDCS) alters these connectivity patterns and if they correlate with symptom improvement in treatment-resistant OCD. METHODS: In 23 patients from a larger clinical trial (comparing active tDCS to sham) who underwent pre- and post-treatment MRI scans, we assessed resting-state functional MRI (rs-fMRI) data. The treatment involved 30-minute daily tDCS sessions for four weeks (weekdays only), with the cathode over the SMA and the anode over the left deltoid. We conducted whole-brain connectivity analysis comparing active tDCS-treated to sham-treated patients. RESULTS: We found that active tDCS, but not sham, led to connectivity increasing between the DMN and the bilateral pre/postcentral gyri (p = 0.004, FDR corrected) and temporal-auditory areas plus the SMA (p = 0.028, FDR corrected). Also, symptom improvement was directly associated with connectivity increasing between the left lateral sensorimotor network and the left precuneus (r = 0.589, p = 0.034). LIMITATIONS: Limited sample size (23 participants with resting-state neuroimaging), inability to analyze specific OCD symptom dimensions (e.g., harm, sexual/religious, symmetry/checking, cleaning/contamination). CONCLUSIONS: These data offer novel information concerning functional connectivity changes associated with non-invasive neuromodulation interventions in OCD and can guide new brain stimulation interventions in the framework of personalized interventions.


Asunto(s)
Trastorno Obsesivo Compulsivo , Estimulación Transcraneal de Corriente Directa , Humanos , Estimulación Transcraneal de Corriente Directa/métodos , Red en Modo Predeterminado , Resultado del Tratamiento , Encéfalo/diagnóstico por imagen , Trastorno Obsesivo Compulsivo/diagnóstico por imagen , Trastorno Obsesivo Compulsivo/terapia , Imagen por Resonancia Magnética
2.
Braz J Med Biol Res ; 56: e12945, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37878887

RESUMEN

Non-invasive brain stimulation (NIBS) probing the dorsolateral prefrontal cortex (DLPFC) has been shown to have little effect on working memory. The variability of NIBS responses might be explained by inter-subject brain anatomical variability. We investigated whether baseline cortical brain thickness of regions of interest was associated with working memory performance after NIBS by performing a secondary analysis of previously published research. Structural magnetic resonance imaging data were analyzed from healthy subjects who received transcranial direct current stimulation (tDCS), intermittent theta-burst stimulation (iTBS), and placebo. Twenty-two participants were randomly assigned to receive all the interventions in a random order. The working memory task was conducted after the end of each NIBS session. Regions of interest were the bilateral DLPFC, medial prefrontal cortex, and posterior cingulate cortex. Overall, 66 NIBS sessions were performed. Findings revealed a negative significant association between cortical thickness of the bilateral dorsolateral prefrontal cortex and reaction time for both tDCS (left: P=0.045, right: P=0.037) and iTBS (left: P=0.007, right: P=0.007) compared to placebo. A significant positive association was found for iTBS and posterior cingulate cortex (P=0.03). No association was found for accuracy. Our findings provide the first evidence that individual cortical thickness of healthy subjects might be associated with working memory performance following different NIBS interventions. Therefore, cortical thickness could explain - to some extent - the heterogeneous effects of NIBS probing the DLPFC.


Asunto(s)
Memoria a Corto Plazo , Estimulación Transcraneal de Corriente Directa , Humanos , Memoria a Corto Plazo/fisiología , Estimulación Transcraneal de Corriente Directa/métodos , Estimulación Magnética Transcraneal/métodos , Corteza Prefrontal/diagnóstico por imagen , Encéfalo
3.
Braz. j. med. biol. res ; 56: e12945, 2023. tab, graf
Artículo en Inglés | LILACS-Express | LILACS | ID: biblio-1520469

RESUMEN

Non-invasive brain stimulation (NIBS) probing the dorsolateral prefrontal cortex (DLPFC) has been shown to have little effect on working memory. The variability of NIBS responses might be explained by inter-subject brain anatomical variability. We investigated whether baseline cortical brain thickness of regions of interest was associated with working memory performance after NIBS by performing a secondary analysis of previously published research. Structural magnetic resonance imaging data were analyzed from healthy subjects who received transcranial direct current stimulation (tDCS), intermittent theta-burst stimulation (iTBS), and placebo. Twenty-two participants were randomly assigned to receive all the interventions in a random order. The working memory task was conducted after the end of each NIBS session. Regions of interest were the bilateral DLPFC, medial prefrontal cortex, and posterior cingulate cortex. Overall, 66 NIBS sessions were performed. Findings revealed a negative significant association between cortical thickness of the bilateral dorsolateral prefrontal cortex and reaction time for both tDCS (left: P=0.045, right: P=0.037) and iTBS (left: P=0.007, right: P=0.007) compared to placebo. A significant positive association was found for iTBS and posterior cingulate cortex (P=0.03). No association was found for accuracy. Our findings provide the first evidence that individual cortical thickness of healthy subjects might be associated with working memory performance following different NIBS interventions. Therefore, cortical thickness could explain - to some extent - the heterogeneous effects of NIBS probing the DLPFC.

4.
Eur Rev Med Pharmacol Sci ; 25(3): 1536-1547, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33629323

RESUMEN

OBJECTIVE: Alzheimer's disease (AD) is a leading cause of years lived with disability in older age, and several cerebrospinal fluid (CSF) markers have been proposed in individual meta-analyses to be associated with AD but field-wide evaluation and scrutiny of the literature is not available. MATERIALS AND METHODS: We performed an umbrella review for the reported associations between CSF biomarkers and AD. Data from available meta-analyses were reanalyzed using both random and fixed effects models. We also estimated between-study heterogeneity, small-study effects, excess significance, and prediction interval. RESULTS: A total of 38 meta-analyses on CSF markers from 11 eligible articles were identified and reanalyzed. In 14 (36%) of the meta-analyses, the summary estimate and the results of the largest study showed non-concordant results in terms of statistical significance. Large heterogeneity (I2≥75%) was observed in 73% and small-study effects under Egger's test were shown in 28% of CSF biomarkers. CONCLUSIONS: Our results suggest that there is an excess of statistically significant results and significant biases in the literature of CSF biomarkers for AD. Therefore, the results of CSF biomarkers should be interpreted with caution.


Asunto(s)
Enfermedad de Alzheimer/diagnóstico , Biomarcadores/líquido cefalorraquídeo , Humanos
5.
Eur J Neurol ; 28(1): 71-80, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-32920963

RESUMEN

BACKGROUND AND PURPOSE: Most evidence for the association between ideal vascular health (IVH) and cognitive performance comes from high income countries. The aim was to investigate this association in the Brazilian Longitudinal Study of Adult Health. METHODS: Cognition was assessed using the word list, verbal fluency and trail making tests. The IVH score included ideal metrics for body mass index, smoking, physical activity, diet, blood pressure, fasting glucose and total cholesterol. Poor, intermediate and optimal health were characterized in those presenting 0-2, 3-4, 5-7 ideal metrics, respectively. To determine the association between IVH score and cognitive performance, linear regression models adjusted for age, sex, education, race, alcohol use, depression and thyroid function were used. RESULTS: In 12 271 participants, the mean age was 51.3 ± 8.9 years, 54% were women, 57% White and 53% had poor vascular health. Participants with intermediate (ß = 0.064, 95% confidence interval 0.033; 0.096) and optimal health (ß = 0.108, 95% confidence interval 0.052; 0.164) had better global cognitive Z-scores. In addition, interactions of IVH score with age, education and race were found, suggesting a better cognitive performance with higher IVH in older adults, Black/Brown participants and those with lower levels of education. CONCLUSION: Ideal vascular health was associated with better cognitive performance. Older, Black/Brown and low-educated participants had better cognition in the presence of higher IVH scores.


Asunto(s)
Negro o Afroamericano , Cognición , Adulto , Anciano , Estudios Transversales , Escolaridad , Femenino , Humanos , Estudios Longitudinales , Persona de Mediana Edad , Factores de Riesgo , Población Blanca
6.
Braz J Med Biol Res ; 53(12): e10347, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33146284

RESUMEN

Recent evidence suggests that glaucoma and Alzheimer's disease are neurodegenerative diseases sharing common pathophysiological and etiological features, although findings are inconclusive. We sought to investigate whether self-reported glaucoma patients without dementia present poorer cognitive performance, an issue that has been less investigated. We employed cross-sectional data from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) and included participants ≥50 years of age without a known diagnosis of dementia and a self-reported glaucoma diagnosis. We excluded those with previous stroke, other eye conditions, and using drugs that could impair cognition. We evaluated cognition using delayed word recall, phonemic verbal fluency, and trail making (version B) tests. We used multinomial linear regression models to investigate associations between self-reported glaucoma with cognition, adjusted by several sociodemographic and clinical variables. Out of 4,331 participants, 139 reported glaucoma. Fully-adjusted models showed that self-reported glaucoma patients presented poorer performance in the verbal fluency test (ß=-0.39, 95%CI=-0.64 to -0.14, P=0.002), but not in the other cognitive assessments. Thus, our results support the hypothesis that self-reported glaucoma is associated with poor cognitive performance; however, longitudinal data are necessary to corroborate our findings.


Asunto(s)
Cognición , Glaucoma , Anciano , Brasil , Estudios Transversales , Femenino , Humanos , Estudios Longitudinales , Persona de Mediana Edad , Pruebas Neuropsicológicas , Autoinforme
7.
Acta Psychiatr Scand ; 141(3): 254-264, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31797353

RESUMEN

OBJECTIVE: To identify factors associated with a history of suicide attempt in medical students. METHODS: A Web-based survey was sent out to a sample of medical students. A multi-predictor Poisson regression was performed to identify factors associated with a history of suicide attempt. In addition, an elastic net regularization was used to build a risk calculator to identify students at risk for attempted suicide. RESULTS: A total of 4,840 participants were included in the study. Prevalence of suicide attempts in the sample was 8.94%. Risk factors associated with past suicide attempt in the multi-predictor Poisson regression were as follows: female gender (P < 0.001); homosexuality (P < 0.001); low income (P = 0.026); bullying by university peers (P = 0.006); childhood (P = 0.001) or adult (P = 0.001) trauma; family history of suicide (P = 0.005); suicidal ideation within the last month (P < 0.001); daily tobacco use (P = 0.037); and being at severe risk for alcohol abuse (P = 0.023). Our elastic net model performed well with an AUC of 0.83. CONCLUSIONS: This study identifies a number of key factors associated with a history of suicide attempts among medical students. Future longitudinal studies should assess the causal relationship between these factors and suicide attempts. Additionally, these results demonstrate that current available data on suicide attempts among medical students can be used to develop an accurate risk algorithm.


Asunto(s)
Estudiantes de Medicina/psicología , Ideación Suicida , Intento de Suicidio/estadística & datos numéricos , Adolescente , Adulto , Brasil/epidemiología , Acoso Escolar/estadística & datos numéricos , Femenino , Humanos , Masculino , Prevalencia , Factores de Riesgo , Factores Sexuales , Encuestas y Cuestionarios , Adulto Joven
8.
Braz. j. med. biol. res ; 53(12): e10347, 2020. tab, graf
Artículo en Inglés | LILACS, Coleciona SUS | ID: biblio-1132512

RESUMEN

Recent evidence suggests that glaucoma and Alzheimer's disease are neurodegenerative diseases sharing common pathophysiological and etiological features, although findings are inconclusive. We sought to investigate whether self-reported glaucoma patients without dementia present poorer cognitive performance, an issue that has been less investigated. We employed cross-sectional data from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) and included participants ≥50 years of age without a known diagnosis of dementia and a self-reported glaucoma diagnosis. We excluded those with previous stroke, other eye conditions, and using drugs that could impair cognition. We evaluated cognition using delayed word recall, phonemic verbal fluency, and trail making (version B) tests. We used multinomial linear regression models to investigate associations between self-reported glaucoma with cognition, adjusted by several sociodemographic and clinical variables. Out of 4,331 participants, 139 reported glaucoma. Fully-adjusted models showed that self-reported glaucoma patients presented poorer performance in the verbal fluency test (β=-0.39, 95%CI=-0.64 to -0.14, P=0.002), but not in the other cognitive assessments. Thus, our results support the hypothesis that self-reported glaucoma is associated with poor cognitive performance; however, longitudinal data are necessary to corroborate our findings.


Asunto(s)
Humanos , Femenino , Persona de Mediana Edad , Anciano , Glaucoma , Cognición , Brasil , Estudios Transversales , Estudios Longitudinales , Autoinforme , Pruebas Neuropsicológicas
9.
Acta Psychiatr Scand ; 140(6): 552-562, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31587258

RESUMEN

OBJECTIVE: We investigated whether ideal cardiovascular health (ICH), a metric proposed by the American Heart Association, predicts depression development. METHODS: Cohort analysis from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). Adults with no current depression and other common mental disorders, cardiovascular diseases, and antidepressant drug use at baseline had their ICH (composite score of smoking, dietary habits, body mass index, blood pressure, fasting glucose, cholesterol, and physical activity) assessed and classified into poor, intermediate, and optimal. Depression was assessed using the Clinical Interview Schedule-Revised (CIS-R). Poisson regression models, adjusted for sociodemographic factors and alcohol consumption, were employed. Stratified analyses were performed for age and sex. RESULTS: We included 9214 participants (mean age 52 ± 9 years, 48.6% women). Overall depression incidence at 3.8-year follow-up was 1.5%. Intermediate and poor ICH significantly increased the risk rate (RR) of developing depression (2.48 [95%CI 1.06-5.78] and 3 [1.28-7.03], respectively) at a 3.8-year follow-up. Higher ICH scores decreased the rate of depression development (RR = 0.84 [0.73-0.96] per metric). Stratified analyses were significant for women and adults < 55 years old. CONCLUSIONS: Poor cardiovascular health tripled depression risk at follow-up in otherwise healthy adults. Ameliorating cardiovascular health might decrease depression risk development.


Asunto(s)
Enfermedades Cardiovasculares/epidemiología , Trastorno Depresivo Mayor/epidemiología , Indicadores de Salud , Adulto , Anciano , Brasil/epidemiología , Femenino , Humanos , Incidencia , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Riesgo
10.
Braz J Med Biol Res ; 51(11): e7704, 2018 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-30156596

RESUMEN

The association between subclinical thyroid dysfunctions and autonomic modulation changes has been described by many studies with conflicting results. We aimed to analyze the association between subclinical hyperthyroidism (SCHyper), subclinical hypothyroidism (SCHypo), and heart rate variability (HRV) using the baseline from ELSA-Brasil. SCHyper and SCHypo were classified by use of medication to treat thyroid disorders, thyrotropin levels respectively above and under the reference range, and normal free thyroxine levels. For HRV, the participants underwent 10 min in supine position and the R-R intervals of the final 5 min were selected for analysis. We first used linear regression models to report crude data and then, multivariate adjustment for sociodemographic (age, sex, and race) and cardiovascular risk factors (hypertension, dyslipidemia, diabetes, smoking, body mass index, use of alcohol, and leisure physical activity) using the euthyroid group as reference. From 9270 subjects (median age, 50; interquartile range: 44-56), 8623 (93.0%) were classified as euthyroid, 136 (1.5%) as SCHyper, and 511 (5.5%) as SCHypo. Compared to euthyroid subjects, SCHyper participants presented significantly higher heart rate (68.8 vs 66.5 for euthyroidism, P=0.007) and shorter R-R intervals (871.4 vs 901.6, P=0.007). Although SCHyper was associated with lower standard deviation of NN interval (SDNN) (ß: -0.070; 95% confidence interval (95%CI): -0.014 to -0.009) and low-frequency (LF) (ß: -0.242, 95%CI: -0.426 to -0.058) compared to the euthyroid group, these differences lost significance after multivariate adjustment for confounders. No significant differences were found for HRV in SCHypo. No association was found between HRV and SCHyper or SCHypo compared to euthyroid subjects in this sample of apparently healthy subjects.


Asunto(s)
Frecuencia Cardíaca/fisiología , Enfermedades de la Tiroides/fisiopatología , Adulto , Anciano , Sistema Nervioso Autónomo/fisiología , Femenino , Humanos , Hipertiroidismo/complicaciones , Hipotiroidismo/complicaciones , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Factores de Riesgo , Tirotropina/sangre
11.
Braz. j. med. biol. res ; 51(11): e7704, 2018. tab, graf
Artículo en Inglés | LILACS | ID: biblio-951722

RESUMEN

The association between subclinical thyroid dysfunctions and autonomic modulation changes has been described by many studies with conflicting results. We aimed to analyze the association between subclinical hyperthyroidism (SCHyper), subclinical hypothyroidism (SCHypo), and heart rate variability (HRV) using the baseline from ELSA-Brasil. SCHyper and SCHypo were classified by use of medication to treat thyroid disorders, thyrotropin levels respectively above and under the reference range, and normal free thyroxine levels. For HRV, the participants underwent 10 min in supine position and the R-R intervals of the final 5 min were selected for analysis. We first used linear regression models to report crude data and then, multivariate adjustment for sociodemographic (age, sex, and race) and cardiovascular risk factors (hypertension, dyslipidemia, diabetes, smoking, body mass index, use of alcohol, and leisure physical activity) using the euthyroid group as reference. From 9270 subjects (median age, 50; interquartile range: 44-56), 8623 (93.0%) were classified as euthyroid, 136 (1.5%) as SCHyper, and 511 (5.5%) as SCHypo. Compared to euthyroid subjects, SCHyper participants presented significantly higher heart rate (68.8 vs 66.5 for euthyroidism, P=0.007) and shorter R-R intervals (871.4 vs 901.6, P=0.007). Although SCHyper was associated with lower standard deviation of NN interval (SDNN) (β: -0.070; 95% confidence interval (95%CI): -0.014 to -0.009) and low-frequency (LF) (β: -0.242, 95%CI: -0.426 to -0.058) compared to the euthyroid group, these differences lost significance after multivariate adjustment for confounders. No significant differences were found for HRV in SCHypo. No association was found between HRV and SCHyper or SCHypo compared to euthyroid subjects in this sample of apparently healthy subjects.


Asunto(s)
Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Anciano , Enfermedades de la Tiroides/fisiopatología , Frecuencia Cardíaca/fisiología , Sistema Nervioso Autónomo/fisiología , Tirotropina/sangre , Factores de Riesgo , Estudios Longitudinales , Hipertiroidismo/complicaciones , Hipotiroidismo/complicaciones
12.
Clin Neurophysiol ; 128(9): 1774-1809, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28709880

RESUMEN

Low intensity transcranial electrical stimulation (TES) in humans, encompassing transcranial direct current (tDCS), transcutaneous spinal Direct Current Stimulation (tsDCS), transcranial alternating current (tACS), and transcranial random noise (tRNS) stimulation or their combinations, appears to be safe. No serious adverse events (SAEs) have been reported so far in over 18,000 sessions administered to healthy subjects, neurological and psychiatric patients, as summarized here. Moderate adverse events (AEs), as defined by the necessity to intervene, are rare, and include skin burns with tDCS due to suboptimal electrode-skin contact. Very rarely mania or hypomania was induced in patients with depression (11 documented cases), yet a causal relationship is difficult to prove because of the low incidence rate and limited numbers of subjects in controlled trials. Mild AEs (MAEs) include headache and fatigue following stimulation as well as prickling and burning sensations occurring during tDCS at peak-to-baseline intensities of 1-2mA and during tACS at higher peak-to-peak intensities above 2mA. The prevalence of published AEs is different in studies specifically assessing AEs vs. those not assessing them, being higher in the former. AEs are frequently reported by individuals receiving placebo stimulation. The profile of AEs in terms of frequency, magnitude and type is comparable in healthy and clinical populations, and this is also the case for more vulnerable populations, such as children, elderly persons, or pregnant women. Combined interventions (e.g., co-application of drugs, electrophysiological measurements, neuroimaging) were not associated with further safety issues. Safety is established for low-intensity 'conventional' TES defined as <4mA, up to 60min duration per day. Animal studies and modeling evidence indicate that brain injury could occur at predicted current densities in the brain of 6.3-13A/m2 that are over an order of magnitude above those produced by tDCS in humans. Using AC stimulation fewer AEs were reported compared to DC. In specific paradigms with amplitudes of up to 10mA, frequencies in the kHz range appear to be safe. In this paper we provide structured interviews and recommend their use in future controlled studies, in particular when trying to extend the parameters applied. We also discuss recent regulatory issues, reporting practices and ethical issues. These recommendations achieved consensus in a meeting, which took place in Göttingen, Germany, on September 6-7, 2016 and were refined thereafter by email correspondence.


Asunto(s)
Encéfalo/fisiología , Guías de Práctica Clínica como Asunto/normas , Estimulación Transcraneal de Corriente Directa/ética , Estimulación Transcraneal de Corriente Directa/normas , Animales , Quemaduras por Electricidad/etiología , Quemaduras por Electricidad/prevención & control , Humanos , Estimulación Transcraneal de Corriente Directa/efectos adversos
13.
Psychol Med ; 46(11): 2287-97, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27193198

RESUMEN

BACKGROUND: To date no comprehensive evaluation has appraised the likelihood of bias or the strength of the evidence of peripheral biomarkers for bipolar disorder (BD). Here we performed an umbrella review of meta-analyses of peripheral non-genetic biomarkers for BD. METHOD: The Pubmed/Medline, EMBASE and PsycInfo electronic databases were searched up to May 2015. Two independent authors conducted searches, examined references for eligibility, and extracted data. Meta-analyses in any language examining peripheral non-genetic biomarkers in participants with BD (across different mood states) compared to unaffected controls were included. RESULTS: Six references, which examined 13 biomarkers across 20 meta-analyses (5474 BD cases and 4823 healthy controls) met inclusion criteria. Evidence for excess of significance bias (i.e. bias favoring publication of 'positive' nominally significant results) was observed in 11 meta-analyses. Heterogeneity was high for (I 2 ⩾ 50%) 16 meta-analyses. Only two biomarkers met criteria for suggestive evidence namely the soluble IL-2 receptor and morning cortisol. The median power of included studies, using the effect size of the largest dataset as the plausible true effect size of each meta-analysis, was 15.3%. CONCLUSIONS: Our findings suggest that there is an excess of statistically significant results in the literature of peripheral biomarkers for BD. Selective publication of 'positive' results and selective reporting of outcomes are possible mechanisms.


Asunto(s)
Biomarcadores , Trastorno Bipolar/diagnóstico , Sesgo de Publicación/estadística & datos numéricos , Humanos
14.
Acta Psychiatr Scand ; 134(2): 172-82, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27028276

RESUMEN

OBJECTIVE: Major depressive disorder (MDD) is a clinically heterogeneous condition. However, the role of cortical glutamate and gamma-aminobutyric acid (GABA) receptor-mediated activity, implicated in MDD pathophysiology, has not been explored in different MDD subtypes. Our aim was to assess the atypical and melancholic depression subtypes regarding potential differences in GABA and glutamate receptor-mediated activity through established transcranial magnetic stimulation (TMS) neurophysiological measures from the motor cortex. METHOD: We evaluated 81 subjects free of antidepressant medication, including 21 healthy controls and 20 patients with atypical, 20 with melancholic, and 20 with undifferentiated MDD. Single and paired-pulse TMS paradigms were used to evaluate intracortical facilitation (ICF), cortical silent period (CSP), and short intracortical inhibition (SICI), which index glutamate, GABAB receptor-, and GABAA receptor-mediated activity respectively. RESULTS: Patients with MDD demonstrated significantly decreased mean CSP values than healthy controls (Cohen's d = 0.22-0.3, P < 0.01 for all comparisons). Atypical depression presented a distinct cortical excitability pattern of decreased cortical inhibition and increased cortical facilitation, that is, an increased mean ICF and SICI ratios than other depression subtypes (d = 0.22-0.33, P < 0.01 for all comparisons). CONCLUSION: Different MDD subtypes may demonstrate different neurophysiology in relation to GABAA and glutamatergic activity. TMS as an investigational tool might be useful to distinguish between different MDD subtypes.


Asunto(s)
Trastorno Depresivo Mayor/terapia , Corteza Motora/fisiopatología , Estimulación Magnética Transcraneal/métodos , Adulto , Trastorno Depresivo Mayor/metabolismo , Trastorno Depresivo Mayor/fisiopatología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Corteza Motora/metabolismo , Receptores de GABA/metabolismo , Receptores de Glutamato/metabolismo , Adulto Joven
15.
Curr Mol Med ; 16(2): 187-205, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26812916

RESUMEN

Several biological systems are implicated in the neuroprogression of bipolar disorder including but not limited to cytokine levels, oxidative stress markers, monoamine levels, tryptophan catabolite and glutamate-mediated excitotoxicity, microglial activation as well as structural and functional changes. The high rate of smoking behaviour in individuals with bipolar disorder provides the impetus for exploring shared and discrete pathogenetic mechanisms. In addition to contributing to increased mortality, smoking activates several neurobiological effector systems implicated in the progression of bipolar disorder. Here, a narrative review provides evidence and putative mechanisms of comorbid effects of BD, cigarette use, and nicotine dependence, and discusses the clinical implications of these interactions.


Asunto(s)
Trastorno Bipolar/etiología , Fumar/efectos adversos , Biomarcadores/metabolismo , Trastorno Bipolar/genética , Epigénesis Genética , Humanos , Estrés Oxidativo , Resultado del Tratamiento
16.
Clin Neurophysiol ; 127(2): 1031-1048, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26652115

RESUMEN

Transcranial electrical stimulation (tES), including transcranial direct and alternating current stimulation (tDCS, tACS) are non-invasive brain stimulation techniques increasingly used for modulation of central nervous system excitability in humans. Here we address methodological issues required for tES application. This review covers technical aspects of tES, as well as applications like exploration of brain physiology, modelling approaches, tES in cognitive neurosciences, and interventional approaches. It aims to help the reader to appropriately design and conduct studies involving these brain stimulation techniques, understand limitations and avoid shortcomings, which might hamper the scientific rigor and potential applications in the clinical domain.


Asunto(s)
Encéfalo/fisiología , Estimulación Transcraneal de Corriente Directa/métodos , Cognición/fisiología , Humanos , Estimulación Transcraneal de Corriente Directa/instrumentación
17.
Braz J Med Biol Res ; 48(8): 711-4, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26200230

RESUMEN

Brain-derived neurotrophic factor (BDNF) is associated with neuroplasticity and synaptic strength, and is decreased in conditions associated with chronic stress. Nevertheless, BDNF has not yet been investigated in psoriasis, a chronic inflammatory systemic disease that is exacerbated by stress. Therefore, our aim was to determine BDNF plasma levels in psoriasis patients and healthy controls. Adult patients (n=94) presenting with psoriasis for at least 1 year were enrolled, and age- and gender-matched with healthy controls (n=307) from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). Participants had neither a previous history of coronary artery disease nor current episode of major depression. BDNF plasma levels were determined using the Promega ELISA kit. A general linear model was used to compare BDNF levels in psoriasis patients and controls, with age, gender, systolic blood pressure, serum fasting glucose, blood lipid levels, triglycerides, smoking status, and body mass index examined. After adjusting for clinical and demographic variables, significantly decreased BNDF plasma levels were observed in psoriasis patients (P=0.01) (estimated marginal means of 3922 pg/mL; 95%CI=2660-5135) compared with controls (5788 pg/mL; 95%CI=5185-6442). Similar BDNF levels were found in both mild and severe cases of psoriasis. Our finding, that BDNF is decreased in psoriasis, supports the concept of a brain-skin connection in psoriasis. Further studies should determine if BDNF is increased after specific psoriasis treatments, and associated with different disease stages.


Asunto(s)
Factor Neurotrófico Derivado del Encéfalo/sangre , Psoriasis/sangre , Adulto , Biomarcadores/sangre , Estudios de Casos y Controles , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad
18.
Clin Res Regul Aff ; 32(1): 22-35, 2015 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-25983531

RESUMEN

The field of transcranial electrical stimulation (tES) has experienced significant growth in the past 15 years. One of the tES techniques leading this increased interest is transcranial direct current stimulation (tDCS). Significant research efforts have been devoted to determining the clinical potential of tDCS in humans. Despite the promising results obtained with tDCS in basic and clinical neuroscience, further progress has been impeded by a lack of clarity on international regulatory pathways. We therefore convened a group of research and clinician experts on tDCS to review the research and clinical use of tDCS. In this report, we review the regulatory status of tDCS, and we summarize the results according to research, off-label and compassionate use of tDCS in the following countries: Australia, Brazil, France, Germany, India, Iran, Italy, Portugal, South Korea, Taiwan and United States. Research use, off label treatment and compassionate use of tDCS are employed in most of the countries reviewed in this study. It is critical that a global or local effort is organized to pursue definite evidence to either approve and regulate or restrict the use of tDCS in clinical practice on the basis of adequate randomized controlled treatment trials.

19.
Braz. j. med. biol. res ; 47(12): 1102-1106, 12/2014. tab
Artículo en Inglés | LILACS | ID: lil-727665

RESUMEN

Psoriasis is a chronic inflammatory disease that significantly impacts life quality, being associated with stress and mental disorders. We investigated whether the activity of the hypothalamic-pituitary-adrenal (HPA) axis was associated with psoriasis severity, daily life stress and anxiety, and depressive symptoms. In this ancillary study, which was part of the CALIPSO (coronary artery calcium in psoriasis) study, saliva was collected from 102 patients with psoriasis immediately upon awakening, 30, and 60 min after awakening, at 2:00 pm and at bedtime (five time points) to determine salivary cortisol levels. We used Pearson's correlation coefficient to evaluate the association of clinical and psychopathological variables with HPA activity. We found a direct correlation between bedtime cortisol and psoriasis severity evaluated by the psoriasis area severity index (PASI; r=0.39, P<0.001). No correlations between other clinical and psychopathological variables or with other cortisol assessments were observed. The findings indicated that HPA dysfunction may be present in psoriasis, as bedtime cortisol was correlated with psoriasis severity. Our study is limited by the lack of a control group; therefore, we were not able to explore whether these cortisol values were different compared with a concurrent, healthy sample.


Asunto(s)
Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Hidrocortisona , Sistema Hipotálamo-Hipofisario/fisiopatología , Sistema Hipófiso-Suprarrenal/patología , Sistema Hipófiso-Suprarrenal/fisiopatología , Psoriasis/fisiopatología , Actividades Cotidianas/psicología , Ansiedad/psicología , Ensayos Clínicos como Asunto , Depresión/psicología , Sistema Hipotálamo-Hipofisario/metabolismo , Sistemas de Información , Psoriasis/metabolismo , Psoriasis/psicología , Calidad de Vida/psicología , Índice de Severidad de la Enfermedad , Factores Socioeconómicos , Saliva/química , Estrés Psicológico/psicología
20.
Braz J Med Biol Res ; 47(12): 1102-6, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25387679

RESUMEN

Psoriasis is a chronic inflammatory disease that significantly impacts life quality, being associated with stress and mental disorders. We investigated whether the activity of the hypothalamic-pituitary-adrenal (HPA) axis was associated with psoriasis severity, daily life stress and anxiety, and depressive symptoms. In this ancillary study, which was part of the CALIPSO (coronary artery calcium in psoriasis) study, saliva was collected from 102 patients with psoriasis immediately upon awakening, 30, and 60 min after awakening, at 2:00 pm and at bedtime (five time points) to determine salivary cortisol levels. We used Pearson's correlation coefficient to evaluate the association of clinical and psychopathological variables with HPA activity. We found a direct correlation between bedtime cortisol and psoriasis severity evaluated by the psoriasis area severity index (PASI; r=0.39, P<0.001). No correlations between other clinical and psychopathological variables or with other cortisol assessments were observed. The findings indicated that HPA dysfunction may be present in psoriasis, as bedtime cortisol was correlated with psoriasis severity. Our study is limited by the lack of a control group; therefore, we were not able to explore whether these cortisol values were different compared with a concurrent, healthy sample.


Asunto(s)
Hidrocortisona/metabolismo , Sistema Hipotálamo-Hipofisario/fisiopatología , Sistema Hipófiso-Suprarrenal/patología , Sistema Hipófiso-Suprarrenal/fisiopatología , Psoriasis/fisiopatología , Actividades Cotidianas/psicología , Anciano , Ansiedad/psicología , Ensayos Clínicos como Asunto , Depresión/psicología , Femenino , Humanos , Sistema Hipotálamo-Hipofisario/metabolismo , Sistemas de Información , Masculino , Persona de Mediana Edad , Psoriasis/metabolismo , Psoriasis/psicología , Calidad de Vida/psicología , Saliva/química , Índice de Severidad de la Enfermedad , Factores Socioeconómicos , Estrés Psicológico/psicología
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