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1.
Brain Cogn ; 173: 106105, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37963422

RESUMO

OBJECTIVE: To compare effects of transcranial direct current stimulation (tDCS) and transcranial random noise stimulation with a direct-current offset (tRNS + DC-offset) on working memory (WM) performance and task-related electroencephalography (EEG) in individuals with Major Depressive Disorder (MDD). METHODS: Using a sham-controlled, parallel-groups design, 49 participants with MDD received either anodal tDCS (N = 16), high-frequency tRNS + DC-offset (N = 16), or sham stimulation (N = 17) to the left dorsolateral prefrontal cortex (DLPFC) for 20-minutes. The Sternberg WM task was completed with concurrent EEG recording before and at 5- and 25-minutes post-stimulation. Event-related synchronisation/desynchronisation (ERS/ERD) was calculated for theta, upper alpha, and gamma oscillations during WM encoding and maintenance. RESULTS: tDCS significantly increased parieto-occipital upper alpha ERS/ERD during WM maintenance, observed on EEG recorded 5- and 25-minutes post-stimulation. tRNS + DC-offset did not significantly alter WM-related oscillatory activity when compared to sham stimulation. Neither tDCS nor tRNS + DC-offset improved WM performance to a significantly greater degree than sham stimulation. CONCLUSIONS: Although tDCS induced persistent effects on WM-related oscillatory activity, neither tDCS nor tRNS + DC-offset enhanced WM performance in MDD. SIGNIFICANCE: This reflects the first sham-controlled comparison of tDCS and tRNS + DC-offset in MDD. These findings directly contrast with evidence of tRNS-induced enhancements in WM in healthy individuals.


Assuntos
Transtorno Depressivo Maior , Estimulação Transcraniana por Corrente Contínua , Humanos , Transtorno Depressivo Maior/terapia , Eletroencefalografia , Memória de Curto Prazo/fisiologia , Córtex Pré-Frontal/fisiologia
2.
Psychiatr Q ; 92(4): 1565-1579, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34097245

RESUMO

People with Bipolar Disorder (BD) consistently report a desire for employment; however, this is not reflected in employment figures. Individuals' perceptions of barriers to employment, along with endorsement of facilitators to employment remain under-investigated. We aimed to address this limitation by: (i) first examining differences in employed versus unemployed individuals (demographic, clinical, functioning); then (ii) identifying barriers and/or facilitators to employment, perception of same, and subsequent impact on employment. We assessed demographics, functioning, and illness-related characteristics in 35 participants with BD (19 employed, 16 unemployed). Participants were asked to indicate perception of common barriers and facilitators to employment. Groups did not differ regarding demographic or clinical variables. High levels of absenteeism, termination of last role and commonly perceived barriers were attributed to mental ill-health. 93.3% of unemployed participants reportedly desired employment, and more perceived barriers were observed in the unemployed group. Identified facilitators included increased support and flexible work strategies. A comprehensive understanding of perceptions of limiting and helpful factors related to employment for people with BD was obtained. These findings have implications for service provision, encouraging targeted discussion, and tailored treatment approaches to individual's unique perceptions of factors related to employment.


Assuntos
Transtorno Bipolar , Emprego , Humanos , Desemprego
3.
Mol Psychiatry ; 20(6): 695-702, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24732671

RESUMO

Many women with schizophrenia remain symptomatic despite optimal use of current therapies. While previous studies suggest that adjunctive oestrogen therapy might be effective, large-scale clinical trials are required before clinical applications are possible. This study is the first large-scale randomized-controlled trial in women with treatment-resistant schizophrenia. This Definitive Oestrogen Patch Trial was an 8-week, three-arm, double-blind, randomized-controlled trial conducted between 2006 and 2011. The 183 female participants were aged between 18 and 45 (mean = 35 years), with schizophrenia or schizoaffective disorder and ongoing symptoms of psychosis (Positive and Negative Syndrome Scale, PANSS score>60) despite a stable dose of antipsychotic medication for at least 4 weeks. Mean duration of illness was more than 10 years. Participants received transdermal estradiol 200 µg, transdermal estradiol 100 µg or an identical placebo patch. For the 180 women who completed the study, the a priori outcome measure was the change in PANSS score measured at baseline and days 7, 14, 28 and 56. Cognition was assessed at baseline and day 56 using the Repeatable Battery of Neuropsychological Status. Data were analysed using latent growth curve modelling. Both estradiol groups had greater decreases in PANSS positive, general and total symptoms compared with the placebo group (P<0.01), with a greater effect seen for 200 µg than 100 µg estradiol. The largest effect size was for the positive subscale of PANSS in the estradiol 200 µg treatment group (effect size 0.44, P<0.01). This study shows estradiol is an effective and clinically significant adjunctive therapy for women with treatment-resistant schizophrenia, particularly for positive symptoms.


Assuntos
Estradiol/uso terapêutico , Estrogênios/uso terapêutico , Esquizofrenia/tratamento farmacológico , Adolescente , Adulto , Transtornos Cognitivos/tratamento farmacológico , Transtornos Cognitivos/etiologia , Relação Dose-Resposta a Droga , Método Duplo-Cego , Estradiol/sangue , Estrogênios/sangue , Feminino , Humanos , Pessoa de Meia-Idade , Testes Neuropsicológicos , Gravidez , Escalas de Graduação Psiquiátrica , Estudos Retrospectivos , Esquizofrenia/complicações , Adesivo Transdérmico , Resultado do Tratamento , Adulto Jovem
5.
Psychol Med ; 45(16): 3411-32, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26349810

RESUMO

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


Assuntos
Antidepressivos/uso terapêutico , Depressão/terapia , Transtorno Depressivo Resistente a Tratamento/terapia , Córtex Pré-Frontal/fisiopatologia , Estimulação Magnética Transcraniana , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto
6.
Acta Psychiatr Scand ; 132(4): 231-40, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25865238

RESUMO

OBJECTIVE: We review the published cases of clozapine-induced myocarditis and describe reasons for the higher incidence in Australia (>1%) than elsewhere (<0.1%). METHOD: Medline was searched to September 2014 using 'clozapine' as the sole term. RESULTS: A total of around 250 cases of clozapine-induced myocarditis have been published. Fever among patients commencing clozapine has been reported internationally, and very few of these cases were investigated for myocarditis. The time to onset of fever is consistent with its being part of a prodrome of undiagnosed myocarditis, and the risk factors are similar to those for myocarditis. In more severe cases, clozapine is discontinued, avoiding fatalities which may occur with myocarditis. Furthermore, cases of sudden death and respiratory illness may well have been undiagnosed myocarditis. The diagnosis of myocarditis is confounded by the non-specific nature of the signs and symptoms, and it depends on appropriate investigations being conducted at the time of myocardial involvement or, for fatal cases, the affected area of the myocardium being sampled for histology. CONCLUSION: It is likely that the incidence of myocarditis is around 3%. Implementation of monitoring procedures will increase case ascertainment and result in more patients benefiting from this valuable medication.


Assuntos
Antipsicóticos/efeitos adversos , Clozapina/efeitos adversos , Miocardite/induzido quimicamente , Adolescente , Adulto , Idoso , Antipsicóticos/administração & dosagem , Austrália/epidemiologia , Clozapina/administração & dosagem , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Miocardite/diagnóstico , Fatores de Risco , Adulto Jovem
7.
Compr Psychiatry ; 55(7): 1540-5, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24962450

RESUMO

PURPOSE: The aim of this study was to evaluate the health-related quality of life (HRQoL) in bipolar type I (BD I) and schizoaffective (SQA) patients during a 2-year period in a naturalistic study. METHODS: This study was based on the data generated by the Bipolar Comprehensive Outcome Study, a prospective, non-interventional, observational study of participants with BD I and SQA disorder. Mixed-Model Repeated Measures Analysis was used to analyze changes in the SF-36 and EQ-5D. RESULTS: Participants exhibited low health status at baseline with SF-36 mean scores of 46.7±10.5 and 36.9±12.9 (best imaginable health=100, normal population≈50) for physical and mental components, respectively. No significant differences were found between the ratings of the BD I and SQA patients on HRQoL. The SF-36 SMC improved significantly over 24 months although SPC scores remained consistent across the study. On the whole, the lowest SMC score was observed among the depressed patients (38.20), followed by the patients with a mixed state (39.01) and the manic patients (39.83). LIMITATIONS: The observational design may have limited the causal relationships and the generalizability within the current findings. CONCLUSIONS: HRQoL was significantly impaired in all stages of BD and SQA when compared to the general population. The impairment of HRQoL was most pronounced in the depressed state, followed by the mixed state and then the manic state. The euthymic patients showed the least impairment. In addition, patients showed a global improvement in their mental health satisfaction over the 2 years follow up period.


Assuntos
Transtorno Bipolar/psicologia , Transtornos Psicóticos/psicologia , Qualidade de Vida/psicologia , Adulto , Transtorno Bipolar/diagnóstico , Avaliação da Deficiência , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Transtornos Psicóticos/diagnóstico , Inquéritos e Questionários
8.
Artigo em Inglês | MEDLINE | ID: mdl-37406796

RESUMO

OBJECTIVES: Repetitive transcranial magnetic stimulation (rTMS) is a level 1a evidence-based treatment for major depression, but high cost of care and limited effectiveness in naturalistic cohorts have been lingering criticisms. This naturalistic, retrospective cohort analysis compares the effect of once and twice daily treatment protocols of rTMS using quality assurance data collected at an Australian private psychiatric hospital. METHODS: A total of 210 inpatients self-selected into two groups receiving up to 30 sessions of either daily (n = 101) or twice daily (n = 109) 10 Hz rTMS to the left dorsolateral prefrontal cortex (DLPFC). The a priori primary outcome measure was remission rate as measured by pre and post treatment HAMD-17 scores. Length of hospital stay was a secondary post hoc outcome adopted due to the importance to cost of acute psychiatric care. RESULTS: Remission rates were similar across groups, with 44.9% and 45.4% for twice daily and daily rTMS groups respectively, although these may be confounded by patient expectations, other treatments and medication changes given the naturalistic setting. The length of hospital stay was 10.11 days and 18.44 days for twice daily and daily rTMS respectively - the twice daily rTMS length of hospital stay was 45.1% shorter 95% CI [38.7% - 51.56%]. Dropout rates were high; Twenty-seven (24.77%) twice daily participants dropped out before 20 sessions were completed, and 35 (34.65%) of daily participants. CONCLUSIONS: Twice daily 10 Hz left sided rTMS remission outcomes were similar to traditional once daily rTMS but required a shorter length of hospital stay. This finding has substantial cost of care implications. If these findings are independently replicated, twice daily rTMS may become the standard of care for inpatient rTMS.


Assuntos
Transtorno Depressivo Maior , Humanos , Transtorno Depressivo Maior/psicologia , Depressão/terapia , Tempo de Internação , Estimulação Magnética Transcraniana/métodos , Estudos Retrospectivos , Resultado do Tratamento , Austrália , Córtex Pré-Frontal/fisiologia
9.
Clin Neurophysiol ; 149: 178-201, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36822997

RESUMO

OBJECTIVE: Electroencephalographic (EEG) data are often contaminated with non-neural artifacts which can confound experimental results. Current artifact cleaning approaches often require costly manual input. Our aim was to provide a fully automated EEG cleaning pipeline that addresses all artifact types and improves measurement of EEG outcomes METHODS: We developed RELAX (the Reduction of Electroencephalographic Artifacts). RELAX cleans continuous data using Multi-channel Wiener filtering [MWF] and/or wavelet enhanced independent component analysis [wICA] applied to artifacts identified by ICLabel [wICA_ICLabel]). Several versions of RELAX were compared using three datasets (N = 213, 60 and 23 respectively) against six commonly used pipelines across a range of artifact cleaning metrics, including measures of remaining blink and muscle activity, and the variance explained by experimental manipulations after cleaning. RESULTS: RELAX with MWF and wICA_ICLabel showed amongst the best performance at cleaning blink and muscle artifacts while preserving neural signal. RELAX with wICA_ICLabel only may perform better at differentiating alpha oscillations between working memory conditions. CONCLUSIONS: RELAX provides automated, objective and high-performing EEG cleaning, is easy to use, and freely available on GitHub. SIGNIFICANCE: We recommend RELAX for data cleaning across EEG studies to reduce artifact confounds, improve outcome measurement and improve inter-study consistency.


Assuntos
Algoritmos , Processamento de Sinais Assistido por Computador , Humanos , Piscadela , Análise de Ondaletas , Eletroencefalografia/métodos , Artefatos
10.
Clin Neurophysiol ; 149: 202-222, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36822996

RESUMO

OBJECTIVE: Electroencephalography (EEG) is often used to examine neural activity time-locked to stimuli presentation, referred to as Event-Related Potentials (ERP). However, EEG is influenced by non-neural artifacts, which can confound ERP comparisons. Artifact cleaning reduces artifacts, but often requires time-consuming manual decisions. Most automated methods filter frequencies <1 Hz out of the data, so are not recommended for ERPs (which contain frequencies <1 Hz). Our aim was to test the RELAX (Reduction of Electroencephalographic Artifacts) pre-processing pipeline for use on ERP data. METHODS: The cleaning performance of multiple versions of RELAX were compared to four commonly used EEG cleaning pipelines across both artifact cleaning metrics and the amount of variance in ERPs explained by different conditions in a Go-Nogo task. Results RELAX with Multi-channel Wiener Filtering (MWF) and wavelet-enhanced independent component analysis applied to artifacts identified with ICLabel (wICA_ICLabel) cleaned data most effectively and produced amongst the most dependable ERP estimates. RELAX with wICA_ICLabel only or MWF_only may detect effects better for some ERPs. CONCLUSIONS: RELAX shows high artifact cleaning performance even when data is high-pass filtered at 0.25 Hz (applicable to ERP analyses). SIGNIFICANCE: RELAX is easy to implement via EEGLAB in MATLAB and freely available on GitHub. Given its performance and objectivity we recommend RELAX to improve artifact cleaning and consistency across ERP research.


Assuntos
Eletroencefalografia , Processamento de Sinais Assistido por Computador , Humanos , Eletroencefalografia/métodos , Potenciais Evocados/fisiologia , Algoritmos , Análise de Ondaletas , Artefatos
11.
Psychol Med ; 42(5): 981-8, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-21910937

RESUMO

BACKGROUND: Repetitive transcranial magnetic stimulation (rTMS) has been shown to be an effective treatment for depression. However, there has been little research to determine optimal parameters for treatment. METHOD: This study compared two rTMS treatment regimes for the treatment of major depression. Seventy-seven participants were randomized to either spaced or daily treatment. Spaced rTMS was given 3 days/week for 6 weeks (18 treatments in total) and daily rTMS was given 5 days/week for 4 weeks (20 treatments in total). All participants were assessed at baseline and after 4 weeks of treatment. Participants in the spaced treatment group were also assessed after 6 weeks of treatment. All participants were treated at 110% of the resting motor threshold with high-frequency rTMS (10 Hz) to the left dorsolateral prefrontal cortex (DLPFC) followed by low-frequency rTMS to the right DLPFC. RESULTS: Participants in the daily treatment group showed more improvement by week 4 than those in the spaced treatment group; however, both groups had similar improvement by treatment completion. There was significant improvement in both groups in ratings of depression and anxiety, with no significant differences between groups. CONCLUSIONS: Our study indicates that the efficacy of rTMS is related to the number of treatments given and that spacing the treatments neither improves nor reduces efficacy.


Assuntos
Transtorno Depressivo Maior/terapia , Estimulação Magnética Transcraniana/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Transtorno Depressivo Maior/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
12.
Psychol Med ; 41(6): 1187-96, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20925972

RESUMO

BACKGROUND: Although several studies have reported that repetitive transcranial magnetic stimulation (rTMS) treatment has demonstrable efficacy in patients with depression, the parameters needed to optimize therapeutic efficacy remain unclear. To this end we determined the efficacy of low-frequency right rTMS to the dorsolateral prefrontal cortex (DLPFC) compared to two forms of bilateral rTMS to the DLPFC: (1) sequential low-frequency right-sided followed by high-frequency left-sided rTMS and (2) sequential low-frequency rTMS to both hemispheres. METHOD: A total of 219 patients with treatment-resistant depression (TRD) were randomized to a 4-week course of rTMS applied with one of the three treatment conditions. Outcomes were assessed with standard rating scales. RESULTS: Overall, slightly more than 50% of the patients achieved clinical response criteria. There was no substantial difference in response between the unilateral and bilateral treatment groups. Successful response to rTMS was predicted by a greater degree of baseline depression severity. CONCLUSIONS: There is no substantial difference in efficacy between unilateral right-sided rTMS and the two forms of bilateral rTMS assessed in the study. Furthermore, our results call into question the specificity between frequency and laterality and rTMS response.


Assuntos
Transtorno Depressivo Maior/fisiopatologia , Transtorno Depressivo Maior/terapia , Transtorno Depressivo Resistente a Tratamento/fisiopatologia , Transtorno Depressivo Resistente a Tratamento/terapia , Dominância Cerebral/fisiologia , Córtex Pré-Frontal/fisiopatologia , Estimulação Magnética Transcraniana/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Transtorno Depressivo Maior/psicologia , Transtorno Depressivo Resistente a Tratamento/psicologia , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inventário de Personalidade/estatística & dados numéricos , Psicometria , Resultado do Tratamento , Adulto Jovem
13.
Brain Stimul ; 13(5): 1370-1380, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32659482

RESUMO

BACKGROUND: Transcranial direct current stimulation (tDCS) has been shown to improve working memory (WM) performance in healthy individuals, however effects tend to be modest and variable. Transcranial random noise stimulation (tRNS) can be delivered with a direct-current offset (DC-offset) to induce equal or even greater effects on cortical excitability than tDCS. To-date, no research has directly compared the effects of these techniques on WM performance or underlying neurophysiological activity. OBJECTIVE: To compare the effects of anodal tDCS, tRNS + DC-offset, or sham stimulation over the left dorsolateral prefrontal cortex (DLPFC) on WM performance and task-related EEG oscillatory activity in healthy adults. METHODS: Using a between-subjects design, 49 participants were allocated to receive either anodal tDCS (N = 16), high-frequency tRNS + DC-offset (N = 16), or sham stimulation (N = 17) to the left DLPFC. Changes in WM performance were assessed using the Sternberg WM task completed before and 5- and 25-min post-stimulation. Event-related synchronisation/desynchronisation (ERS/ERD) of oscillatory activity was analysed from EEG recorded during WM encoding and maintenance. RESULTS: tRNS induced more pronounced and consistent enhancements in WM accuracy when compared to both tDCS and sham stimulation. Improvements in WM performance following tRNS were accompanied by increased theta ERS and diminished gamma ERD during WM encoding, which were significantly greater than those observed following anodal tDCS or sham stimulation. CONCLUSIONS: These findings demonstrate the potential of tRNS + DC-offset to modulate cognitive and electrophysiological measures of WM and raise the possibility that tRNS + DC-offset may be more effective and reliable than tDCS for enhancing WM performance in healthy individuals.


Assuntos
Cognição/fisiologia , Memória de Curto Prazo/fisiologia , Desempenho Psicomotor/fisiologia , Estimulação Transcraniana por Corrente Contínua/métodos , Adolescente , Adulto , Excitabilidade Cortical/fisiologia , Fenômenos Eletrofisiológicos/fisiologia , Feminino , Voluntários Saudáveis , Humanos , Masculino , Córtex Pré-Frontal/fisiologia , Adulto Jovem
14.
Acta Psychiatr Scand ; 120(4): 265-73, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19486330

RESUMO

OBJECTIVE: To identify possible differences in the mean midsagittal corpus callosum (CC) total and subdivision areas in treatment-resistant schizophrenia and depression (TRS and TRD) patients. METHOD: Areas of the total CC and its five equidistant subregions (from CC1 to CC5) obtained by parallel grid partitioning schemes were manually segmented from brain MRI of 42 TRS, 45 TRD patients and 30 healthy controls. The intracranial volume (ICV) normalized areas were calculated and compared between groups. RESULTS: When compared with controls, patients with TRS had reduced ICV and a larger CC5, and TRD patients had a smaller CC4 while no significant difference in CC total area in patients with TRS or TRD was found. Multiple individual segments and total CC areas were significantly larger in TRS than TRD patients after normalization. CONCLUSION: Patients with TRS and TRD have different CC morphological characteristics, and therefore there may be aberrant interhemispheric connectivity in schizophrenia and major depressive disorder patients.


Assuntos
Agenesia do Corpo Caloso , Corpo Caloso/fisiopatologia , Transtorno Depressivo Maior/tratamento farmacológico , Transtorno Depressivo Maior/fisiopatologia , Resistência a Medicamentos , Esquizofrenia/tratamento farmacológico , Esquizofrenia/fisiopatologia , Adolescente , Adulto , Antipsicóticos/classificação , Antipsicóticos/uso terapêutico , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Adulto Jovem
15.
Neuropsychologia ; 125: 51-61, 2019 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-30625292

RESUMO

Transcranial direct current stimulation (tDCS) has been investigated as a way to improve motor and cognitive functioning, with largely variable results. Currently, relatively little is known about the neurobiological effects, and possible drivers of variability, in either healthy or clinical populations. Therefore, this study aimed to characterise the neurobiological effects to tDCS in younger adults, older adults and adults with mild cognitive impairment (MCI), and their relationship to cognitive performance. 20 healthy younger adults, 20 healthy older adults and 9 individuals with MCI participated in the study. All completed neuropsychological tasks and TMS-EEG, prior to and following delivery of 20 min of anodal tDCS to the left dorsolateral prefrontal cortex (DLPFC). EEG was also recorded during the 2-Back working memory task. Following tDCS, younger adults demonstrated alterations in early TMS-Evoked Potentials (TEPs), namely P30 and P60. Both younger and older adults exhibited a larger task-related N250 amplitude after stimulation, with contrasting relationships to cognitive performance. The MCI group showed no change in TEPs or ERPs over time. Comparisons between the groups revealed differences in the change in amplitude of early TEP (P60) and ERP (N100) peaks between younger and older adults. Our findings indicate that tDCS was able to modulate cortical activity in younger and older healthy adults, but in varying ways. These findings suggest that varied response to tDCS may be related to factors such as age and the presence/absence of cognitive impairment, and these factors should be considered when assessing the effectiveness of tDCS in healthy and pathological aging.


Assuntos
Disfunção Cognitiva/fisiopatologia , Memória de Curto Prazo/fisiologia , Córtex Pré-Frontal/fisiopatologia , Estimulação Transcraniana por Corrente Contínua , Adulto , Fatores Etários , Idoso , Eletroencefalografia , Potenciais Evocados , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Adulto Jovem
16.
Biol Psychol ; 148: 107766, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31509766

RESUMO

PURPOSE: To investigate neural oscillatory activity supporting working memory (WM) processing in depressed individuals and healthy controls. METHODS: Forty-six participants with Major Depressive Disorder (MDD) and 41 healthy controls balanced on age, gender, and WM ability completed a Sternberg verbal WM task with concurrent electroencephalography recording. Oscillatory activity was calculated for upper alpha, theta, and gamma frequency bands during WM encoding and maintenance. RESULTS: WM performance did not differ between groups. When compared to healthy controls, depressed individuals displayed reduced frontal-midline theta power and increased occipital upper alpha power during WM encoding, and reductions in frontal-midline theta power and occipital gamma and upper alpha power during WM maintenance. Higher depression severity was associated with greater reductions upper alpha and gamma power during WM maintenance. CONCLUSIONS: Depressed individuals displayed prominent alterations in oscillatory activity during WM encoding and maintenance, indicating that the neural processes which support WM processing are altered in MDD even when no cognitive impairments are observed.


Assuntos
Ondas Encefálicas/fisiologia , Transtorno Depressivo Maior/fisiopatologia , Memória de Curto Prazo/fisiologia , Adulto , Estudos de Casos e Controles , Eletroencefalografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
17.
J Affect Disord ; 242: 68-79, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30172227

RESUMO

BACKGROUND: Non-response to repetitive transcranial magnetic stimulation (rTMS) treatment for depression is costly for both patients and clinics. Simple and cheap methods to predict response would reduce this burden. Resting EEG measures differentiate responders from non-responders, so may have utility for response prediction. METHODS: Fifty patients with treatment resistant depression and 21 controls had resting electroencephalography (EEG) recorded at baseline (BL). Patients underwent 5-8 weeks of rTMS treatment, with EEG recordings repeated at week 1 (W1). Forty-two participants had valid BL and W1 EEG data, and 12 were responders. Responders and non-responders were compared at BL and W1 in measures of theta (4-8 Hz) and alpha (8-13 Hz) power and connectivity, frontal theta cordance and alpha peak frequency. Control group comparisons were made for measures that differed between responders and non-responders. A machine learning algorithm assessed the potential to differentiate responders from non-responders using EEG measures in combination with change in depression scores from BL to W1. RESULTS: Responders showed elevated theta connectivity across BL and W1. No other EEG measures differed between groups. Responders could be distinguished from non-responders with a mean sensitivity of 0.84 (p = 0.001) and specificity of 0.89 (p = 0.002) using cross-validated machine learning classification on the combination of all EEG and mood measures. LIMITATIONS: The low response rate limited our sample size to only 12 responders. CONCLUSION: Resting theta connectivity at BL and W1 differ between responders and non-responders, and show potential for predicting response to rTMS treatment for depression.


Assuntos
Transtorno Depressivo Maior/terapia , Transtorno Depressivo Resistente a Tratamento/diagnóstico , Estimulação Magnética Transcraniana/métodos , Adulto , Idoso , Algoritmos , Transtorno Depressivo Maior/fisiopatologia , Eletroencefalografia/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Adulto Jovem
18.
Brain Stimul ; 11(1): 190-203, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29128490

RESUMO

BACKGROUND: Repetitive transcranial magnetic stimulation (rTMS) is an effective treatment for depression, but only some individuals respond. Predicting response could reduce patient and clinical burden. Neural activity related to working memory (WM) has been related to mood improvements, so may represent a biomarker for response prediction. PRIMARY HYPOTHESES: We expected higher theta and alpha activity in responders compared to non-responders to rTMS. METHODS: Fifty patients with treatment resistant depression and twenty controls performed a WM task while electroencephalography (EEG) was recorded. Patients underwent 5-8 weeks of rTMS treatment, repeating the EEG at week 1 (W1). Of the 39 participants with valid WM-related EEG data from baseline and W1, 10 were responders. Comparisons between responders and non-responders were made at baseline and W1 for measures of theta (4-8 Hz), upper alpha (10-12.5 Hz), and gamma (30-45 Hz) power, connectivity, and theta-gamma coupling. The control group's measures were compared to the depression group's baseline measures separately. RESULTS: Responders showed higher levels of WM-related fronto-midline theta power and theta connectivity compared to non-responders at baseline and W1. Responder's fronto-midline theta power and connectivity was similar to controls. Responders also showed an increase in gamma connectivity from baseline to W1, with a concurrent improvement in mood and WM reaction times. An unbiased combination of all measures provided mean sensitivity of 0.90 at predicting responders and specificity of 0.92 in a predictive machine learning algorithm. CONCLUSION: Baseline and W1 fronto-midline theta power and theta connectivity show good potential for predicting response to rTMS treatment for depression.


Assuntos
Depressão/fisiopatologia , Depressão/terapia , Ritmo Teta/fisiologia , Estimulação Magnética Transcraniana , Adolescente , Adulto , Afeto , Idoso , Estudos de Casos e Controles , Depressão/psicologia , Transtorno Depressivo/fisiopatologia , Transtorno Depressivo/psicologia , Transtorno Depressivo/terapia , Eletroencefalografia , Feminino , Humanos , Masculino , Memória de Curto Prazo , Pessoa de Meia-Idade , Tempo de Reação , Resultado do Tratamento , Adulto Jovem
19.
Eur J Pain ; 22(7): 1255-1267, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29542208

RESUMO

BACKGROUND: Fibromyalgia is a complex chronic disorder with few effective treatments currently available. One promising treatment option is repetitive transcranial magnetic stimulation (rTMS), a non-invasive brain stimulation technique that has shown promise in disorders effecting the central nervous system. METHODS: We assessed the efficacy of a course of high-frequency (10 Hz) left-hemisphere dorsolateral prefrontal cortex (DLPFC) rTMS in 26 patients (14 active; 12 sham) with a diagnosis of fibromyalgia. Participants underwent a double-blind stimulation protocol of daily (Monday-Friday) rTMS sessions over four consecutive weeks (total of 20 sessions; 75 × 4-s 10 Hz trains at 120% resting motor threshold). Assessments were conducted at baseline, 4 weeks and at 1-month follow-up. RESULTS: Using mixed-model analysis we did not identify a group difference for our primary outcome measures. However, we found that patients in the active group compared to sham treatment group had significantly greater improvement in the Physical Fatigue (p = 0.045) and General Fatigue (p = 0.023) scales of the Multidimensional Fatigue Inventory-20 at the 1 month follow-up. In a responder analysis, we also found the active group was significantly more likely (2.84 times) to achieve a minimum 30% improvement in pain intensity ratings. (p = 0.024). CONCLUSIONS: High-frequency rTMS applied daily for 4 weeks to the left DLPFC induces significant relief from fatigue and a greater chance of clinically meaningful improvement in pain intensity in patients with fibromyalgia. These results suggest DLPFC rTMS may be a relevant therapy for fibromyalgia. SIGNIFICANCE: This study provides evidence that 4-weeks of daily rTMS to the left DLPFC is able to improve fatigue in fibromyalgia. This novel finding provides impetus for the further investigation of the utility of TMS approaches for the relief of fatigue, an otherwise difficult-to-treat symptom, in fibromyalgia and related disorders.


Assuntos
Fadiga/terapia , Fibromialgia/terapia , Córtex Pré-Frontal , Estimulação Magnética Transcraniana/métodos , Adulto , Doença Crônica , Método Duplo-Cego , Fadiga/complicações , Fadiga/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Medição da Dor , Resultado do Tratamento
20.
Brain Res ; 1106(1): 134-141, 2006 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-16822490

RESUMO

Patients with Parkinson's disease (PD) manifest difficulty in initiation and execution of movements, particularly when movements are sequential, simultaneous or repetitive. Eye movements are particularly effective in evaluating motor impairments. We utilized a series of saccadic eye movement paradigms to explore the ability of 13 patients with mild-moderate PD and 13 age-matched healthy controls to self-pace saccades between two continuously illuminated targets, before and after an externally cued tracking period, and respond to unexpected changes in task demand. The latter was explored by measuring saccadic responses to unexpected "oddball" targets that appeared during a well-learned reciprocating sequence of saccades, in either the opposite direction to that expected or at twice the anticipated extent. Results indicated that all participants demonstrated a marked increase in saccade amplitudes from the externally cued saccade tracking to the self-paced saccades. Unexpectedly, this difference was magnified in PD patients. Self-paced saccades before externally cueing were also more frequent than requested in the PD group, but timing improved following external cueing. The second key finding was that while patients were able to respond to unexpected changes in target amplitude, performance was more variable (in terms of latency and accuracy) when responding to unexpected changes in target direction. Hence, beneficial effects of external cueing on the timing of self-paced saccades may be mediated through cortical regions, placing less emphasis on striatal regions known to be compromised in PD. Additionally, responding to changes in saccade direction (but not amplitude) may rely on basal ganglia circuitry.


Assuntos
Fixação Ocular/fisiologia , Transtornos da Motilidade Ocular/etiologia , Transtornos da Motilidade Ocular/fisiopatologia , Doença de Parkinson/complicações , Doença de Parkinson/fisiopatologia , Movimentos Sacádicos/fisiologia , Adulto , Idoso , Gânglios da Base/fisiopatologia , Sinais (Psicologia) , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Vias Neurais/fisiopatologia , Transtornos da Motilidade Ocular/diagnóstico , Orientação/fisiologia , Estimulação Luminosa , Desempenho Psicomotor/fisiologia , Tempo de Reação/fisiologia
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