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1.
Biol Psychiatry Glob Open Sci ; 4(3): 100309, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38690260

RESUMO

Background: Fear overgeneralization is a promising pathogenic mechanism of clinical anxiety. A dominant model posits that hippocampal pattern separation failures drive overgeneralization. Hippocampal network-targeted transcranial magnetic stimulation (HNT-TMS) has been shown to strengthen hippocampal-dependent learning/memory processes. However, no study has examined whether HNT-TMS can alter fear learning/memory. Methods: Continuous theta burst stimulation was delivered to individualized left posterior parietal stimulation sites derived via seed-based connectivity, precision functional mapping, and electric field modeling methods. A vertex control site was also stimulated in a within-participant, randomized controlled design. Continuous theta burst stimulation was delivered prior to 2 visual discrimination tasks (1 fear based, 1 neutral). Multilevel models were used to model and test data. Participants were undergraduates with posttraumatic stress symptoms (final n = 25). Results: Main analyses did not indicate that HNT-TMS strengthened discrimination. However, multilevel interaction analyses revealed that HNT-TMS strengthened fear discrimination in participants with lower fear sensitization (indexed by responses to a control stimulus with no similarity to the conditioned fear cue) across multiple indices (anxiety ratings: ß = 0.10, 95% CI, 0.04 to 0.17, p = .001; risk ratings: ß = 0.07, 95% CI, 0.00 to 0.13, p = .037). Conclusions: Overgeneralization is an associative process that reflects deficient discrimination of the fear cue from similar cues. In contrast, sensitization reflects nonassociative responding unrelated to fear cue similarity. Our results suggest that HNT-TMS may selectively sharpen fear discrimination when associative response patterns, which putatively implicate the hippocampus, are more strongly engaged.


Fear overgeneralization is a promising pathogenic mechanism of clinical anxiety that is thought to be driven by deficient hippocampal discrimination. Using hippocampal network­targeted transcranial magnetic stimulation (HNT-TMS) in healthy participants with symptoms of posttraumatic stress, Webler et al. report that HNT-TMS did not strengthen discrimination overall, but it did strengthen fear discrimination in participants with lower fear sensitization. Sensitization reflects nonassociative fear responding unrelated to fear cue similarity and therefore is not expected to engage the hippocampal discrimination function. These results suggest that HNT-TMS may selectively sharpen fear discrimination when the hippocampal discrimination function is more strongly engaged.

2.
Brain Stimul ; 17(2): 448-459, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38574853

RESUMO

BACKGROUND: RECOVER is a randomized sham-controlled trial of vagus nerve stimulation and the largest such trial conducted with a psychiatric neuromodulation intervention. OBJECTIVE: To describe pre-implantation baseline clinical characteristics and treatment history of patients with unipolar, major depressive disorder (MDD), overall and as a function of exposure to interventional psychiatric treatments (INTs), including electroconvulsive therapy, transcranial magnetic stimulation, and esketamine. METHODS: Medical, psychiatric, and treatment records were reviewed by study investigators and an independent Study Eligibility Committee prior to study qualification. Clinical characteristics and treatment history (using Antidepressant Treatment History [Short] Form) were compared in those qualified (N = 493) versus not qualified (N = 228) for RECOVER, and among the qualified group as a function of exposure to INTs during the current major depressive episode (MDE). RESULTS: Unipolar MDD patients who qualified for RECOVER had marked TRD (median of 11.0 lifetime failed antidepressant treatments), severe disability (median WHODAS score of 50.0), and high rate of baseline suicidality (77% suicidal ideation, 40% previous suicide attempts). Overall, 71% had received at least one INT. Compared to the no INT group, INT recipients were younger and more severely depressed (QIDS-C, QIDS-SR), had greater suicidal ideation, earlier diagnosis of MDD, and failed more antidepressant medication trials. CONCLUSIONS: RECOVER-qualified unipolar patients had marked TRD and marked treatment resistance with most failing one or more prior INTs. Treatment with ≥1 INTs in the current MDE was associated with earlier age of MDD onset, more severe clinical presentation, and greater treatment resistance relative to patients without a history of INT. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT03887715.


Assuntos
Transtorno Depressivo Maior , Transtorno Depressivo Resistente a Tratamento , Estimulação Magnética Transcraniana , Humanos , Masculino , Feminino , Transtorno Depressivo Maior/terapia , Pessoa de Meia-Idade , Adulto , Transtorno Depressivo Resistente a Tratamento/terapia , Eletroconvulsoterapia , Estimulação do Nervo Vago , Antidepressivos/uso terapêutico , Ketamina , Resultado do Tratamento
3.
J Affect Disord ; 354: 589-600, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38484878

RESUMO

BACKGROUND: Transcranial magnetic stimulation (TMS) is an intervention for treatment-resistant depression (TRD) that modulates neural activity. Deep TMS (dTMS) can target not only cortical but also deeper limbic structures implicated in depression. Although TMS has demonstrated safety in adolescents, dTMS has yet to be applied to adolescent TRD. OBJECTIVE/HYPOTHESIS: This pilot study evaluated the safety, tolerability, and clinical effects of dTMS in adolescents with TRD. We hypothesized dTMS would be safe, tolerable, and efficacious for adolescent TRD. METHODS: 15 adolescents with TRD (Age, years: M = 16.4, SD = 1.42) completed a six-week daily dTMS protocol targeting the left dorsolateral prefrontal cortex (BrainsWay H1 coil, 30 sessions, 10 Hz, 3.6 s train duration, 20s inter-train interval, 55 trains; 1980 total pulses per session, 80 % to 120 % of motor threshold). Participants completed clinical, safety, and neurocognitive assessments before and after treatment. The primary outcome was depression symptom severity measured by the Children's Depression Rating Scale-Revised (CDRS-R). RESULTS: 14 out of 15 participants completed the dTMS treatments. One participant experienced a convulsive syncope; the other participants only experienced mild side effects (e.g., headaches). There were no serious adverse events and minimal to no change in cognitive performance. Depression symptom severity significantly improved pre- to post-treatment and decreased to a clinically significant degree after 10 treatment sessions. Six participants met criteria for treatment response. LIMITATIONS: Main limitations include a small sample size and open-label design. CONCLUSIONS: These findings provide preliminary evidence that dTMS may be tolerable and associated with clinical improvement in adolescent TRD.


Assuntos
Transtorno Depressivo Resistente a Tratamento , Estimulação Magnética Transcraniana , Criança , Humanos , Adolescente , Estimulação Magnética Transcraniana/efeitos adversos , Estimulação Magnética Transcraniana/métodos , Depressão , Projetos Piloto , Resultado do Tratamento , Transtorno Depressivo Resistente a Tratamento/tratamento farmacológico , Córtex Pré-Frontal
4.
Neurosci Biobehav Rev ; 144: 105005, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36549377

RESUMO

Laboratory threat extinction paradigms and exposure-based therapy both involve repeated, safe confrontation with stimuli previously experienced as threatening. This fundamental procedural overlap supports laboratory threat extinction as a compelling analogue of exposure-based therapy. Threat extinction impairments have been detected in clinical anxiety and may contribute to exposure-based therapy non-response and relapse. However, efforts to improve exposure outcomes using techniques that boost extinction - primarily rodent extinction - have largely failed to date, potentially due to fundamental differences between rodent and human neurobiology. In this review, we articulate a comprehensive pre-clinical human research agenda designed to overcome these failures. We describe how connectivity guided depolarizing brain stimulation methods (i.e., TMS and DBS) can be applied concurrently with threat extinction and dual threat reconsolidation-extinction paradigms to causally map human extinction relevant circuits and inform the optimal integration of these methods with exposure-based therapy. We highlight candidate targets including the amygdala, hippocampus, ventromedial prefrontal cortex, dorsal anterior cingulate cortex, and mesolimbic structures, and propose hypotheses about how stimulation delivered at specific learning phases could strengthen threat extinction.


Assuntos
Extinção Psicológica , Imageamento por Ressonância Magnética , Humanos , Extinção Psicológica/fisiologia , Encéfalo , Córtex Pré-Frontal/fisiologia , Tonsila do Cerebelo , Mapeamento Encefálico
5.
Cells ; 11(21)2022 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-36359809

RESUMO

Adult hippocampal neurogenesis is prone to modulation by several intrinsic and extrinsic factors. The anterior nucleus (AN) of the thalamus has extensive connections with the hippocampus, and stimulation of this region may play a role in altering neurogenesis. We have previously shown that electrical stimulation of the AN can substantially boost hippocampal neurogenesis in adult rats. Here, we performed selective unilateral chemical excitation of the cell bodies of the AN as it offers a more specific and sustained stimulation when compared to electrical stimulation. Our aim is to investigate the long-term effects of KA stimulation of the AN on baseline hippocampal proliferation of neural stem cells and neurogenesis. Continuous micro-perfusion of very low doses of kainic acid (KA) was administered into the right AN for seven days. Afterwards, adult male rats received 5'-bromo-2'-deoxyuridine (BrdU) injections (200 mg/kg, i.p) and were euthanized at either one week or four weeks post micro-perfusion. Open field and Y-maze tests were performed before euthanasia. The KA stimulation of the AN evoked sustained hippocampal neurogenesis that was associated with improved spatial memory in the Y-maze test. Administering dexamethasone prior to and simultaneously with the KA stimulation decreased both the hippocampal neurogenesis and the improved spatial recognition memory previously seen in the Y-maze test. These results suggest that hippocampal neurogenesis may be a downstream effect of stimulation in general, and of excitation of the cell bodies of the AN in particular, and that stimulation of that area improves spatial memory in rats.


Assuntos
Ácido Caínico , Neurogênese , Masculino , Ratos , Animais , Ácido Caínico/farmacologia , Hipocampo , Neurônios , Memória Espacial , Bromodesoxiuridina/farmacologia
6.
Brain Stimul ; 15(3): 823-832, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35644517

RESUMO

BACKGROUND: Findings from correlative neuroimaging studies link increased frontoparietal network (FPN) activation and default mode network (DMN) deactivation to enhanced high cognitive demand processing. To causally investigate FPN-DMN contributions to high cognitive demand processing, the current interleaved TMS-fMRI study simultaneously manipulated and indexed neural activity while tracking cognitive performance during high and low cognitive load conditions. METHODS: Twenty participants completed an n-back task consisting of four conditions (0-back, 0-backTMS, 2-back, 2-backTMS) while undergoing interleaved TMS-fMRI. During TMS concurrent with n-back blocks, TMS single pulses were delivered to the left DLPFC at 100% motor-threshold every 2.4s. RESULTS: TMS delivered during high cognitive load strengthened cognitive processing. FPN node activations and DMN node deactivations were increased in the high versus low cognitive load TMS condition. Contrary to our hypothesis, TMS did not increase high load related activation in FPN nodes. However, as hypothesized, increased DMN node deactivations emerged as a function of TMS during high load (right angular gyrus) and from interactions between cognitive load and TMS (right middle temporal gyrus). Load and TMS combined to dampen activation within the DMN at trend level (p = .058). Deactivation in a dorsomedial DMN node was associated with TMS driven improvements in high load cognitive processing. CONCLUSIONS: Exogenous perturbation of the DLPFC via single pulse TMS amplified DMN node deactivations and enhanced high cognitive demand processing. Neurobehavioral findings linking these effects hint at a promising, albeit preliminary, cognitive control substrate requiring replication in higher-powered studies that use control stimulation.


Assuntos
Imageamento por Ressonância Magnética , Memória de Curto Prazo , Encéfalo/fisiologia , Mapeamento Encefálico , Córtex Pré-Frontal Dorsolateral , Humanos , Imageamento por Ressonância Magnética/métodos , Memória de Curto Prazo/fisiologia
7.
Braz. J. Psychiatry (São Paulo, 1999, Impr.) ; 44(3): 317-330, May-June 2022. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1374608

RESUMO

While most patients with depression respond to pharmacotherapy and psychotherapy, about one-third will present treatment resistance to these interventions. For patients with treatment-resistant depression (TRD), invasive neurostimulation therapies such as vagus nerve stimulation, deep brain stimulation, and epidural cortical stimulation may be considered. We performed a narrative review of the published literature to identify papers discussing clinical studies with invasive neurostimulation therapies for TRD. After a database search and title and abstract screening, relevant English-language articles were analyzed. Vagus nerve stimulation, approved by the U.S. Food and Drug Administration as a TRD treatment, may take several months to show therapeutic benefits, and the average response rate varies from 15.2-83%. Deep brain stimulation studies have shown encouraging results, including rapid response rates (> 30%), despite conflicting findings from randomized controlled trials. Several brain regions, such as the subcallosal-cingulate gyrus, nucleus accumbens, ventral capsule/ventral striatum, anterior limb of the internal capsule, medial-forebrain bundle, lateral habenula, inferior-thalamic peduncle, and the bed-nucleus of the stria terminalis have been identified as key targets for TRD management. Epidural cortical stimulation, an invasive intervention with few reported cases, showed positive results (40-60% response), although more extensive trials are needed to confirm its potential in patients with TRD.

8.
Braz J Psychiatry ; 44(3): 317-330, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34468549

RESUMO

While most patients with depression respond to pharmacotherapy and psychotherapy, about one-third will present treatment resistance to these interventions. For patients with treatment-resistant depression (TRD), invasive neurostimulation therapies such as vagus nerve stimulation, deep brain stimulation, and epidural cortical stimulation may be considered. We performed a narrative review of the published literature to identify papers discussing clinical studies with invasive neurostimulation therapies for TRD. After a database search and title and abstract screening, relevant English-language articles were analyzed. Vagus nerve stimulation, approved by the U.S. Food and Drug Administration as a TRD treatment, may take several months to show therapeutic benefits, and the average response rate varies from 15.2-83%. Deep brain stimulation studies have shown encouraging results, including rapid response rates (> 30%), despite conflicting findings from randomized controlled trials. Several brain regions, such as the subcallosal-cingulate gyrus, nucleus accumbens, ventral capsule/ventral striatum, anterior limb of the internal capsule, medial-forebrain bundle, lateral habenula, inferior-thalamic peduncle, and the bed-nucleus of the stria terminalis have been identified as key targets for TRD management. Epidural cortical stimulation, an invasive intervention with few reported cases, showed positive results (40-60% response), although more extensive trials are needed to confirm its potential in patients with TRD.


Assuntos
Estimulação Encefálica Profunda , Transtorno Depressivo Resistente a Tratamento , Encéfalo , Estimulação Encefálica Profunda/métodos , Depressão , Transtorno Depressivo Resistente a Tratamento/terapia , Humanos , Psicoterapia
9.
Asian J Psychiatr ; 59: 102635, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33845301

RESUMO

BACKGROUND: Suicide is a leading preventable cause of mortality worldwide. Suicide rates in Lebanon are unknown, as reported numbers are extrapolated and modeled over neighboring countries with poor quality of vital registration data. METHODS: Numbers of death by suicide were obtained from the Internal Security Forces records from January 2008 through December 2018. Records from 2011 through 2018 specified the gender of the individual, the means of the suicide, the date and place of suicide. As of March 2014, nationality of the individual was recorded. RESULTS: The total recorded number of completed suicides over 11 years is 1366 with an annual rate ranging between 1.87 and 2.4 per 100,000 capita. The male to female ratio was 2:1. Death by firearms (41.4 %) was the most common means used, followed by hanging (26.5 %), jumping from a height (13.6 %), and poisoning (13.5 %). Males were more likely to use firearms while females were more likely to use hanging or jumping from a height (p < 0.001), the latter being a common finding in non-Lebanese nationals (Ethiopian). Suicides were most common in Mount Lebanon and least common in Nabatieh governates, while their distribution across seasons was similar. CONCLUSION: In Lebanon, like most of the Middle Eastern countries, suicide is a social and religious taboo. Our study shows a sizable prevalence of suicide rates, particularly after national efforts to improve awareness and reporting. Suicide means and vulnerable populations should be at the heart of targeted prevention strategies.


Assuntos
Suicídio , Etnicidade , Feminino , Humanos , Líbano/epidemiologia , Masculino , Prevalência
10.
Behav Brain Res ; 402: 113114, 2021 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-33417991

RESUMO

Deep brain stimulation (DBS) has shown positive clinical results in neurodegenerative diseases. Previous work from our group showed that a single session of DBS to the anteromedial thalamic nucleus (AMN) in awake rats, increased proliferation of stem/progenitor cells in the dentate gyrus (DG) of the hippocampus. We thought to examine the effect of single versus multiple sessions of DBS to the AMN in modulating adult hippocampal neurogenesis. Rats received unilateral single session, multiple sessions or no electrical stimulation (sham) in the right AMN. Rats received 5'-bromo-2'-deoxyuridine (BrdU) injections and were followed over a period of 1 week or 4 weeks. Single session of electrical stimulation induced a 1.9-fold increase in the number of proliferating BrdU positive cells after one week from stimulation and a 1.8-fold increase at four weeks post stimulation, both in the ipsilateral DG. As for multiple sessions of stimulation, they induced a 3- fold increase that extended to the contralateral DG after 4 weeks from stimulation. Spatial reference memory was tested in the Y-maze test by examining novel arm exploration. Both single and multiple sessions of stimulation prompted an increase in novel arm exploration at week 4, while only the multiple sessions of stimulation had this effect starting from week 1. This study demonstrates that sustained activation of the AMN boosts neurogenesis and improves spatial reference memory.


Assuntos
Núcleos Anteriores do Tálamo/fisiologia , Estimulação Encefálica Profunda , Hipocampo/fisiologia , Células-Tronco Neurais/fisiologia , Neurogênese/fisiologia , Memória Espacial/fisiologia , Animais , Giro Denteado/fisiologia , Masculino , Ratos , Ratos Sprague-Dawley
11.
Brain Sci ; 12(1)2021 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-35053769

RESUMO

Central pain disorders, such as central post-stroke pain, remain clinically challenging to treat, despite many decades of pharmacological advances and the evolution of neuromodulation. For treatment refractory cases, previous studies have highlighted some benefits of cortical stimulation. Recent advances in new targets for pain and the optimization of neuromodulation encouraged our group to develop a dual cortical target approach paired with Bayesian optimization to provide a personalized treatment. Here, we present a case report of a woman who developed left-sided facial pain after multiple thalamic strokes. All previous pharmacologic and interventional treatments failed to mitigate the pain, leaving her incapacitated due to pain and medication side effects. She subsequently underwent a single burr hole for placement of motor cortex (M1) and dorsolateral prefrontal cortex (dlPFC) paddles for stimulation with externalization. By using Bayesian optimization to find optimal stimulation parameters and stimulation sites, we were able to reduce pain from an 8.5/10 to a 0/10 during a 5-day inpatient stay, with pain staying at or below a 2/10 one-month post-procedure. We found optimal treatment to be simultaneous stimulation of M1 and dlPFC without any evidence of seizure induction. In addition, we found no worsening in cognitive performance during a working memory task with dlPFC stimulation. This personalized approach using Bayesian optimization may provide a new foundation for treating central pain and other functional disorders through systematic evaluation of stimulation parameters.

12.
Brain Stimul ; 13(5): 1467-1475, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32585355

RESUMO

BACKGROUND: Prefrontal abnormalities in schizophrenia have consistently emerged from resting state and cognitive neuroimaging studies. However, these correlative findings require causal verification via combined imaging/stimulation approaches. To date, no interleaved transcranial magnetic stimulation and functional magnetic resonance imaging study (TMS fMRI) has probed putative prefrontal cortex abnormalities in schizophrenia. OBJECTIVE: /Hypothesis: We hypothesized that subjects with schizophrenia would show significant hyperexcitability at the site of stimulation (BA9) and decreased interhemispheric functional connectivity. METHODS: We enrolled 19 unmedicated subjects with schizophrenia and 22 controls. All subjects underwent brain imaging using a 3T MRI scanner with a SENSE coil. They also underwent a single TMS fMRI session involving motor threshold (rMT) determination, structural imaging, and a parametric TMS fMRI protocol with 10 Hz triplet pulses at 0, 80, 100 and 120% rMT. Scanning involved a surface MR coil optimized for bilateral prefrontal cortex image acquisition. RESULTS: Of the original 41 enrolled subjects, 8 subjects with schizophrenia and 11 controls met full criteria for final data analyses. At equal TMS intensity, subjects with schizophrenia showed hyperexcitability in left BA9 (p = 0.0157; max z-score = 4.7) and neighboring BA46 (p = 0.019; max z-score = 4.47). Controls showed more contralateral functional connectivity between left BA9 and right BA9 through increased activation in right BA9 (p = 0.02; max z-score = 3.4). GM density in subjects with schizophrenia positively correlated with normalized prefrontal to motor cortex ratio of the corresponding distance from skull to cortex ratio (S-BA9/S-MC) (r = 0.83, p = 0.004). CONCLUSIONS: Subjects with schizophrenia showed hyperexcitability in left BA9 and impaired interhemispheric functional connectivity compared to controls. Interleaved TMS fMRI is a promising tool to investigate prefrontal dysfunction in schizophrenia.


Assuntos
Excitabilidade Cortical , Imageamento por Ressonância Magnética/métodos , Rede Nervosa/diagnóstico por imagem , Córtex Pré-Frontal/diagnóstico por imagem , Esquizofrenia/diagnóstico por imagem , Estimulação Magnética Transcraniana/métodos , Adulto , Mapeamento Encefálico/métodos , Excitabilidade Cortical/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Córtex Motor/diagnóstico por imagem , Córtex Motor/fisiologia , Rede Nervosa/fisiologia , Córtex Pré-Frontal/fisiologia , Esquizofrenia/fisiopatologia
13.
Aggress Behav ; 45(6): 652-661, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31418875

RESUMO

Our study's objective is to determine whether substance use disorders' association with aggression differs according to the type of substance and/or the form of aggression, within the same population. We used data from the National Survey on Drug Use and Health across 2008-2014, with a pooled sample of 270,227 adult respondents. We used regression models to estimate the odds ratios for those having alcohol and/or drug use disorder(s) perpetrating (a) each form of aggression compared with no aggression and (b) other-directed compared with self-directed aggression. Alcohol use disorder alone and drug use disorder(s) alone were both associated with significantly increased odds of committing self-directed, other-directed, and combined aggression. Individuals with drug use disorder(s) alone were more likely to commit other-directed than self-directed aggression (adjusted odds ratio = 1.46, 95% CI = 1.04-2.05). Individuals with alcohol use disorder alone were not likely to commit one over the other (adjusted odds ratio = 1.20, 95% CI = 0.90-1.61). In conclusion, the integrated model of aggression based on the stress-diathesis model is a relevant framework to study risk factors for aggression. Further research is needed to identify longitudinal predictors of directionality of aggression.


Assuntos
Agressão/psicologia , Transtornos Relacionados ao Uso de Substâncias/psicologia , Violência/psicologia , Adulto , Alcoolismo/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Tentativa de Suicídio/psicologia
14.
Brain Topogr ; 32(1): 28-65, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30076488

RESUMO

Model-based network discovery measures, such as the brain effective connectivity, require fitting of generative process models to measurements obtained from key areas across the network. For distributed dynamic phenomena, such as generalized seizures and slow-wave sleep, studying effective connectivity from real-time recordings is significantly complicated since (i) outputs from only a subnetwork can be practically measured, and (ii) exogenous subnetwork inputs are unobservable. Model fitting, therefore, constitutes a challenging blind module identification or model inversion problem for finding both the parameters and the many unknown inputs of the subnetwork. We herein propose a novel estimation framework for identifying nonlinear dynamic subnetworks in the case of slowly-varying, otherwise unknown local inputs. Starting with approximate predictions obtained using Cubature Kalman filtering, residuals of local output predictions are utilized to improve upon local input estimates. The algorithm performance is tested on both simulated and clinical EEG of induced seizures under electroconvulsive therapy (ECT). For the simulated network, the algorithm significantly boosted the estimation accuracy for inputs and connections from noisy EEG. For the clinical data, the algorithm predicted increased subnetwork inputs during the pre-stimulus anesthesia condition. Importantly, it predicted an increased frontocentral connectivity during the generalized seizure that is commensurate with electrode placement and that corroborates the clinical hypothesis of increased frontal focality of therapeutic ECT seizures. The proposed framework can be extended to account for several input configurations and can in principle be applied to study effective connectivity within brain subnetworks defined at the microscale (cortical lamina interaction) or at the macroscale (sensory integration).


Assuntos
Encéfalo/fisiopatologia , Modelos Neurológicos , Rede Nervosa/fisiopatologia , Algoritmos , Eletroencefalografia , Humanos , Dinâmica não Linear , Convulsões/fisiopatologia
15.
Front Cell Neurosci ; 12: 135, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29867368

RESUMO

The identification of distinct and more efficacious antidepressant treatments is highly needed. Nitrous oxide (N2O) is an N-methyl-D-aspartic acid (NMDA) antagonist that has been reported to exhibit antidepressant effects in treatment-resistant depression (TRD) patients. Yet, no studies have investigated the effects of sub-anesthetic dosages of N2O on hippocampal cell proliferation and neurogenesis in adult brain rats. In our study, adult male Sprague-Dawley rats were exposed to single or multiple exposures to mixtures of 70% N2O and 30% oxygen (O2). Sham groups were exposed to 30% O2 and the control groups to atmospheric air. Hippocampal cell proliferation was assessed by bromodeoxyuridine (BrdU) incorporation, and BrdU-positive cells were counted in the dentate gyrus (DG) using confocal microscopy. Results showed that while the rates of hippocampal cell proliferation were comparable between the N2O and sham groups at day 1, levels increased by 1.4 folds at day 7 after one session exposure to N2O. Multiple N2O exposures significantly increased the rate of hippocampal cell proliferation to two folds. Therefore, sub-anesthetic doses of N2O, similar to ketamine, increase hippocampal cell proliferation, suggesting that there will ultimately be an increase in neurogenesis. Future studies should investigate added N2O exposures and their antidepressant behavioral correlates.

16.
Schizophr Res Cogn ; 12: 56-65, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29928598

RESUMO

BACKGROUND: Schizophrenia is often associated with poor clinical insight (unawareness of mental illness and its symptoms) and deficits in empathy, which are important for social functioning. Cognitive empathy has been linked to clinical insight while affective empathy and its role in insight and pathology have received mixed evidence. METHODS: Instruments assessing symptomatology (Positive and Negative Syndrome Scale; PANSS), clinical insight (Scales to assess awareness of mental disorders; SUMD), and cognitive and affective empathy were administered to 22 participants with first episode and chronic schizophrenia and 21 healthy controls. Self-report, parent-report, and performance based measures were used to assess cognitive and affective empathy (The interpersonal reactivity index; IRI/Reading the Mind in the Eyes Test/Faux Pas) to reduce bias and parse shared variance. RESULTS: Age of onset, gender, and symptomatology emerged as significant predictors of poor clinical insight. Additionally, the fantasy subscale of the IRI as reported by parents emerged as a positive predictor while the personal distress (parent report) subscale emerged as a negative predictor of awareness into mental illness. There were significant differences on performance-based measures of empathy between the control and schizophrenia groups. CONCLUSION: Findings suggest that affective empathy is relatively intact across phases of illness whereas cognitive empathy abilities are compromised and could be targets for psychotherapy intervention.

18.
Brain Stimul ; 9(6): 897-904, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27443912

RESUMO

BACKGROUND: Epidural prefrontal cortical stimulation (EpCS) represents a novel therapeutic approach with many unique benefits that can be used for treatment-resistant depression (TRD). OBJECTIVE: To examine the long-term safety and efficacy of EpCS of the frontopolar cortex (FPC) and dorsolateral prefrontal cortex (DLPFC) for treatment of TRD. METHODS: Adults (N = 5) who were 21-80 years old with severe TRD [failure to respond to adequate courses of at least 4 antidepressant medications, psychotherapy and ≥20 on the Hamilton Rating Scale for Depression (HRSD24)] were recruited. Participants were implanted with bilateral EpCS over the FPC and DLPFC and received constant, chronic stimulation throughout the five years with Medtronic IPGs. They were followed for 5 years (2/1/2008-10/14/2013). Efficacy of EpCS was assessed with the HRSD24 in an open-label design as the primary outcome measure at five years. RESULTS: All 5 patients continued to tolerate the therapy. The mean improvements from pre-implant baseline on the HRSD24 were [7 months] 54.9% (±37.7), [1 year] 41.2% (±36.6), [2 years] 53.8% (±21.7), and [5 years] 45% (±47). Three of 5 (60%) subjects continued to be in remission at 5 years. There were 5 serious adverse events: 1 electrode 'paddle' infection and 4 device malfunctions, all resulting in suicidal ideation and/or hospitalization. CONCLUSION: These results suggest that chronic bilateral EpCS over the FPC and DLPFC is a promising and potentially durable new technology for treating TRD, both acutely and over 5 years.


Assuntos
Transtorno Depressivo Resistente a Tratamento/terapia , Dura-Máter , Terapia por Estimulação Elétrica/métodos , Córtex Pré-Frontal , Adulto , Idoso , Idoso de 80 Anos ou mais , Espaço Epidural , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Adulto Jovem
19.
J ECT ; 32(3): 197-203, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27379790

RESUMO

OBJECTIVE: Electroconvulsive therapy (ECT) is the most rapid and effective antidepressant treatment but with concerns about cognitive adverse effects. A new form of ECT, focal electrically administered seizure therapy (FEAST), was designed to increase the focality of stimulation and better match stimulus parameters with neurophysiology. We recently reported on the safety and feasibility of FEAST in a cohort (n = 17) of depressed patients. We now report on the safety, feasibility, preliminary efficacy, and cognitive effects of FEAST in a new cohort. METHODS: Open-label FEAST was administered to 20 depressed adults (6 men; 3 with bipolar disorder; age 49.1 ± 10.6 years). Clinical and cognitive assessments were obtained at baseline and end of course. Time to orientation recovery was assessed at each treatment. Nonresponders switched to conventional ECT. RESULTS: Participants tolerated the treatment well with no dropouts. Five patients (25%) transitioned from FEAST to conventional ECT due to inadequate response. After FEAST (mean, 9.3 ± 3.5 sessions; range, 4-14), there was a 58.1% ± 36.0% improvement in Hamilton Rating Scale for Depression scores compared with that in the baseline (P < 0.0001); 13 (65%) of 20 patients met response criteria, and 11 (55%) of 20 met remission criteria. Patients achieved reorientation (4 of 5 items) in 4.4 ± 3.0 minutes (median, 4.5 minutes), timed from eyes opening. There was no deterioration in neuropsychological measures. CONCLUSIONS: These findings provide further support for the safety and efficacy of FEAST. The remission and response rates were in the range found using conventional ECT, and the time to reorientation may be quicker. However, without a randomized comparison group, conclusions are tentative.


Assuntos
Transtorno Depressivo/terapia , Eletroconvulsoterapia/métodos , Convulsões , Adulto , Idoso , Anestesia , Transtorno Bipolar/psicologia , Transtorno Bipolar/terapia , Transtornos Cognitivos/etiologia , Transtorno Depressivo/psicologia , Eletroconvulsoterapia/efeitos adversos , Eletrodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica , Resultado do Tratamento
20.
Psychiatry Res ; 239: 245-52, 2016 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-27031595

RESUMO

The Patient Health Questionnaire - 9 (PHQ-9) and Generalized Anxiety Disorder - 7 (GAD-7) are short screening measures used in medical and community settings to assess depression and anxiety severity. The aim of this study is to translate the screening tools into Arabic and evaluate their psychometric properties in an Arabic-speaking Lebanese psychiatric outpatient sample. The patients completed the questionnaires, among others, prior to being evaluated by a clinical psychiatrist or psychologist. The scales' internal consistency and factor structure were measured and convergent and discriminant validity were established by comparing the scores with clinical diagnoses and the Psychiatric Diagnostic Screening Questionnaire - MDD subset (PDSQ - MDD). Results showed that the PHQ-9 and GAD-7 are reliable screening tools for depression and anxiety and their factor structures replicated those reported in the literature. Sensitivity and specificity analyses showed that the PHQ-9 is sensitive but not specific at capturing depressive symptoms when compared to clinician diagnoses whereas the GAD-7 was neither sensitive nor specific at capturing anxiety symptoms. The implications of these findings are discussed in reference to the scales themselves and the cultural specificity of the Lebanese population.


Assuntos
Transtornos de Ansiedade/diagnóstico , Transtorno Depressivo Maior/diagnóstico , Escalas de Graduação Psiquiátrica/normas , Psicometria/métodos , Adulto , Feminino , Humanos , Líbano , Masculino , Pessoa de Meia-Idade , Pacientes Ambulatoriais , Psicometria/instrumentação , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Inquéritos e Questionários/normas
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