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1.
Hippocampus ; 33(1): 37-46, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36519826

RESUMO

Although recent studies support significant differences in intrinsic structure, function, and connectivity along the longitudinal axis of the hippocampus, few studies have investigated the normative development of this dimension. In addition, factors known to influence hippocampal structure, such as sex or puberty, have yet to be characterized when assessing age-related effects on its subregions. This study addresses this gap by investigating the relationship of the anterior (antHC) and posterior (postHC) hippocampus volumes with age, and how these are moderated by sex or puberty, in structural magnetic resonance imaging scans from 183 typically developing participants aged 6-21 years. Based on previous literature, we first anticipated that non-linear models would best represent the relationship between age and the antHC and postHC volumes. We found that age-related effects are region-specific, such that the antHC volume remains stable with increasing age, while the postHC shows a cubic function characterized by overall volume increase with age but a slower rate during adolescence. Second, we hypothesized that models, which include biological sex or pubertal status would best describe these relationships. Contrary to expectation, models comprising either biological sex or pubertal status did not significantly improve model performance. Further longitudinal research is needed to evaluate their effects on the antHC and postHC development.


Assuntos
Hipocampo , Puberdade , Adolescente , Humanos , Hipocampo/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos
2.
Epilepsia ; 64(11): 3061-3072, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37643922

RESUMO

OBJECTIVE: Predicting memory morbidity after temporal lobectomy in patients with temporal lobe epilepsy (TLE) relies on indices of preoperative temporal lobe structural and functional integrity. However, epilepsy is increasingly considered a network disorder, and memory a network phenomenon. We assessed the utility of functional network measures to predict postoperative memory changes. METHODS: Seventy-two adults with TLE (37 left/35 right) underwent preoperative resting-state functional magnetic resonance imaging and pre- and postoperative neuropsychological assessment. We compared functional connectivity throughout the memory network of each patient to a healthy control template (n = 19) to identify differences in global organization. A second metric indicated the degree of integration of the to-be-resected temporal lobe with the rest of the memory network. We included these measures in a linear regression model alongside standard clinical variables as predictors of memory change after surgery. RESULTS: Left TLE patients with more atypical memory networks, and with greater functional integration of the to-be-resected region with the rest of the memory network preoperatively, experienced the greatest decline in verbal memory after surgery. Together, these two measures explained 44% of variance in verbal memory change, outperforming standard clinical and demographic variables. None of the variables examined was associated with visuospatial memory change in patients with right TLE. SIGNIFICANCE: Resting-state connectivity provides valuable information concerning both the integrity of to-be-resected tissue and functional reserve across memory-relevant regions outside of the to-be-resected tissue. Intrinsic functional connectivity has the potential to be useful for clinical decision-making regarding memory outcomes in left TLE, and more work is needed to identify the factors responsible for differences seen in right TLE.


Assuntos
Epilepsia do Lobo Temporal , Imageamento por Ressonância Magnética , Adulto , Humanos , Encéfalo/diagnóstico por imagem , Epilepsia do Lobo Temporal/diagnóstico por imagem , Epilepsia do Lobo Temporal/cirurgia , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/cirurgia , Transtornos da Memória/diagnóstico por imagem , Transtornos da Memória/etiologia
3.
Acta Neurochir (Wien) ; 165(6): 1665-1669, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37079109

RESUMO

Intraoperative direct cortical stimulation (DCS) is the gold standard technique to maximize the extent of resection of tumors located in eloquent areas. To date, there are three cases reported of awake mapping for language centers in deaf patients who could communicate only with sign language. We present the case of DCS in a deaf patient who could communicate vocally, native to American Sign Language and English, that underwent intraoperative awake mapping. DCS showed similar disruption of expressive phonology to both pictorial and gestural stimuli, confirming that sign language follows the same pattern as oral language.


Assuntos
Neoplasias Encefálicas , Glioma , Perda Auditiva , Humanos , Língua de Sinais , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/cirurgia , Vigília/fisiologia , Glioma/diagnóstico por imagem , Glioma/cirurgia , Craniotomia/métodos , Audição
4.
Health Res Policy Syst ; 21(1): 43, 2023 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-37277824

RESUMO

BACKGROUND: In prior research, we identified and prioritized ten measures to assess research performance that comply with the San Francisco Declaration on Research Assessment, a principle adopted worldwide that discourages metrics-based assessment. Given the shift away from assessment based on Journal Impact Factor, we explored potential barriers to implementing and adopting the prioritized measures. METHODS: We identified administrators and researchers across six research institutes, conducted telephone interviews with consenting participants, and used qualitative description and inductive content analysis to derive themes. RESULTS: We interviewed 18 participants: 6 administrators (research institute business managers and directors) and 12 researchers (7 on appointment committees) who varied by career stage (2 early, 5 mid, 5 late). Participants appreciated that the measures were similar to those currently in use, comprehensive, relevant across disciplines, and generated using a rigorous process. They also said the reporting template was easy to understand and use. In contrast, a few administrators thought the measures were not relevant across disciplines. A few participants said it would be time-consuming and difficult to prepare narratives when reporting the measures, and several thought that it would be difficult to objectively evaluate researchers from a different discipline without considerable effort to read their work. Strategies viewed as necessary to overcome barriers and support implementation of the measures included high-level endorsement of the measures, an official launch accompanied by a multi-pronged communication strategy, training for both researchers and evaluators, administrative support or automated reporting for researchers, guidance for evaluators, and sharing of approaches across research institutes. CONCLUSIONS: While participants identified many strengths of the measures, they also identified a few limitations and offered corresponding strategies to address the barriers that we will apply at our organization. Ongoing work is needed to develop a framework to help evaluators translate the measures into an overall assessment. Given little prior research that identified research assessment measures and strategies to support adoption of those measures, this research may be of interest to other organizations that assess the quality and impact of research.

5.
Health Expect ; 24(3): 978-990, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33769657

RESUMO

BACKGROUND: Waiting for procedures delayed by COVID-19 may cause anxiety and related adverse consequences. OBJECTIVE: To synthesize research on the mental health impact of waiting and patient-centred mitigation strategies that could be applied in the COVID-19 context. METHODS: Using a scoping review approach, we searched 9 databases for studies on waiting lists and mental health and reported study characteristics, impacts and intervention attributes and outcomes. RESULTS: We included 51 studies that focussed on organ transplant (60.8%), surgery (21.6%) or cancer management (13.7%). Most patients and caregivers reported anxiety, depression and poor quality of life, which deteriorated with increasing wait time. The impact of waiting on mental health was greater among women and new immigrants, and those of younger age, lower socio-economic status, or with less-positive coping ability. Six studies evaluated educational strategies to develop coping skills: 2 reduced depression (2 did not), 1 reduced anxiety (2 did not) and 2 improved quality of life (2 did not). In contrast, patients desired acknowledgement of concerns, peer support, and periodic communication about wait-list position, prioritization criteria and anticipated procedure date. CONCLUSIONS: Findings revealed patient-centred strategies to alleviate the mental health impact of waiting for procedures. Ongoing research should explore how to optimize the impact of those strategies for diverse patients and caregivers, particularly in the COVID-19 context. PATIENT OR PUBLIC CONTRIBUTION: Six patients and four caregivers waiting for COVID-19-delayed procedures helped to establish eligibility criteria, plan data extraction and review a draft and final report.


Assuntos
COVID-19/psicologia , Cuidadores/psicologia , Pandemias , Assistência Centrada no Paciente , Listas de Espera , COVID-19/epidemiologia , Feminino , Humanos , Saúde Mental , Qualidade de Vida , SARS-CoV-2
6.
Epilepsy Behav ; 98(Pt A): 153-160, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31374471

RESUMO

About one-third of people with epilepsy experience comorbid depression. The present study examined outcomes of a distance-delivery group intervention program designed to improve emotional well-being. Participants were 55 adults with epilepsy and self-reported depressive symptoms who were randomly assigned to take part in either a mindfulness-based cognitive behavioral therapy (CBT) program (UPLIFT, n = 20), an epilepsy information and self-management program (EpINFO, n = 24) that served as an active control group, or a wait-list control (WLC) group (n = 11). The Quick Inventory of Depressive Symptomatology (QIDS), Neurological Disorders Depression Inventory for Epilepsy (NDDIE), and the psychological health subscale of the World Health Organization Quality of Life (WHOQOL-BREF) scale were used to assess depression and psychological quality of life before and after treatment, and at short-term (six months) and long-term follow-up (one year) upon program completion. From pre- to posttreatment, a main effect of time was found, with participants in both the UPLIFT and EpINFO groups having reported to a similar degree a significant decrease in depressive symptoms and improved psychological health, improvements that were not seen in the WLC group. The time by group interaction effect was not significant. The effects seen at posttreatment in the UPLIFT and EpINFO groups remained at six months and one year after treatment. These data suggest that distance-delivery group intervention programs are effective at improving depression and psychological quality of life, with the EpINFO program offering benefits similar to the UPLIFT program.


Assuntos
Terapia Cognitivo-Comportamental , Transtorno Depressivo/terapia , Epilepsia/terapia , Avaliação de Processos e Resultados em Cuidados de Saúde , Autogestão , Telemedicina , Adulto , Comorbidade , Epilepsia/epidemiologia , Feminino , Humanos , Masculino , Psicoterapia de Grupo
7.
Hippocampus ; 28(10): 745-764, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29989271

RESUMO

The dynamic process of memory consolidation involves a reorganization of brain regions that support a memory trace over time, but exactly how the network reorganizes as the memory changes remains unclear. We present novel converging evidence from studies of animals (rats) and humans for the time-dependent reorganization and transformation of different types of memory as measured both by behavior and brain activation. We find that context-specific memories in rats, and naturalistic episodic memories in humans, lose precision over time and activity in the hippocampus decreases. If, however, the retrieved memories retain contextual or perceptual detail, the hippocampus is engaged similarly at recent and remote timepoints. As the interval between the timepoint increases, the medial prefrontal cortex is engaged increasingly during memory retrieval, regardless of the context or the amount of retrieved detail. Moreover, these hippocampal-frontal shifts are accompanied by corresponding changes in a network of cortical structures mediating perceptually-detailed as well as less precise, schematic memories. These findings provide cross-species evidence for the crucial interplay between hippocampus and neocortex that reflects changes in memory representation over time and underlies systems consolidation.


Assuntos
Encéfalo/fisiologia , Hipocampo/citologia , Consolidação da Memória/fisiologia , Memória Episódica , Neurônios/fisiologia , Adulto , Análise de Variância , Animais , Aprendizagem da Esquiva/fisiologia , Encéfalo/diagnóstico por imagem , Medo/psicologia , Feminino , Lateralidade Funcional , Hipocampo/diagnóstico por imagem , Hipocampo/fisiologia , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Oxigênio/sangue , Proteínas Proto-Oncogênicas c-fos/metabolismo , Distribuição Aleatória , Ratos , Ratos Long-Evans , Fatores de Tempo , Adulto Jovem
8.
Intern Med J ; 48(7): 795-802, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29521453

RESUMO

BACKGROUND: Few studies have investigated sleep in patients after intensive care despite the possibility that inadequate sleep might further complicate an acute illness impeding recovery. AIMS: To assess the quality and quantity of a patient's sleep on the ward by polysomnography (PSG) within a week of intensive care unit (ICU) discharge and to explore the prevalence of key in-ICU risk factors for persistent sleep fragmentation. METHODS: We enrolled 20 patients after they have been mechanically ventilated for at least 3 days and survived to ICU discharge. We included all patients over the age of 16 years and excluded patients with advanced cognitive impairment or who were unable to follow simple commands before their acute illness, primary admission diagnosis of neurological injury, uncontrolled psychiatric illness or not fluent in English. RESULTS: Twenty patients underwent an overnight PSG recording on day 7 after ICU discharge (SD, 1 day). ICU survivors provided 292.8 h of PSG recording time with median recording times of 16.8 h (Interquartile range (IQR), 15.0-17.2 h). The median total sleep time per patient was 5.3 h (IQR, 2.6-6.3 h). In a multivariable regression model, postoperative admission diagnosis (P = 0.04) and patient report of poor ICU sleep (P = 0.001) were associated with less slow-wave (restorative) sleep on the wards after ICU discharge. CONCLUSIONS: Patients reported poor sleep while in the ICU, and a postoperative admission diagnosis may identify a high-risk subgroup of patients who may derive greater benefit from interventions to improve sleep hygiene.


Assuntos
Unidades de Terapia Intensiva , Alta do Paciente , Polissonografia , Fases do Sono , Sono , Adulto , Idoso , Feminino , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Higiene do Sono , Sobreviventes , Fatores de Tempo
9.
Epilepsia ; 58(9): 1502-1517, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28681381

RESUMO

The transition from a pediatric to adult health care system is challenging for many youths with epilepsy and their families. Recently, the Ministry of Health and Long-Term Care of the Province of Ontario, Canada, created a transition working group (TWG) to develop recommendations for the transition process for patients with epilepsy in the Province of Ontario. Herein we present an executive summary of this work. The TWG was composed of a multidisciplinary group of pediatric and adult epileptologists, psychiatrists, and family doctors from academia and from the community; neurologists from the community; nurses and social workers from pediatric and adult epilepsy programs; adolescent medicine physician specialists; a team of physicians, nurses, and social workers dedicated to patients with complex care needs; a lawyer; an occupational therapist; representatives from community epilepsy agencies; patients with epilepsy; parents of patients with epilepsy and severe intellectual disability; and project managers. Three main areas were addressed: (1) Diagnosis and Management of Seizures; 2) Mental Health and Psychosocial Needs; and 3) Financial, Community, and Legal Supports. Although there are no systematic studies on the outcomes of transition programs, the impressions of the TWG are as follows. Teenagers at risk of poor transition should be identified early. The care coordination between pediatric and adult neurologists and other specialists should begin before the actual transfer. The transition period is the ideal time to rethink the diagnosis and repeat diagnostic testing where indicated (particularly genetic testing, which now can uncover more etiologies than when patients were initially evaluated many years ago). Some screening tests should be repeated after the move to the adult system. The seven steps proposed herein may facilitate transition, thereby promoting uninterrupted and adequate care for youth with epilepsy leaving the pediatric system.


Assuntos
Epilepsia/terapia , Transição para Assistência do Adulto/normas , Adolescente , Epilepsia/diagnóstico , Necessidades e Demandas de Serviços de Saúde , Humanos , Adulto Jovem
10.
Bipolar Disord ; 19(3): 198-213, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28599348

RESUMO

OBJECTIVES: The objectives of the study were to determine if adjunctive minocycline mitigates depressive symptom severity and improves cognitive function in individuals with bipolar I/II disorder (BD). The study also aimed to determine if changes in depressive and/or cognitive symptoms over the course of treatment were associated with changes in circulating inflammatory cytokine levels. METHODS: A total of 29 (intention-to-treat: n=27) adults meeting DSM-IV-TR criteria for a major depressive episode as part of bipolar I or II disorder (i.e. Hamilton Depression Rating Scale 17-item [HAMD-17] ≥20) were enrolled in an 8-week, open-label study with adjunctive minocycline (100 mg bid). The primary outcome measure was the Montgomery-Åsberg Depression Rating Scale (MADRS). The HAMD-17, Clinical Global Impression-Severity (CGI-S), cognitive test composite scores and plasma cytokines were secondary outcome measures. Plasma cytokines were measured with the 30 V-Plex Immunoassay from Meso Scale Discovery. RESULTS: Adjunctive minocycline was associated with a reduction in depressive symptom severity from baseline to week 8 on the MADRS (P<.001, d=0.835), HAMD-17 (P<.001, d=0.949) and CGI-S (P<.001, d=1.09). Improvement in psychomotor speed, but not verbal memory or executive function, was observed only amongst individuals exhibiting a reduction in depression severity (P=.007, d=0.826). Levels of interleukin (IL)-12/23p40 (P=.002) were increased, while levels of IL-12p70 (P=.001) and C-C motif chemokine ligand 26 (CCL26) (P<.001) were reduced from baseline to week 8. A reduction in CCL26 levels was associated with a less favourable treatment response (P<.001). CONCLUSIONS: Results from the pilot study suggest that adjunctive minocycline may exert antidepressant effects in individuals with bipolar depression, possibly by targeting inflammatory cytokines.


Assuntos
Transtorno Bipolar , Quimiocina CCL26/análise , Interleucina-12/análise , Minociclina/administração & dosagem , Adulto , Antibacterianos/administração & dosagem , Antidepressivos/administração & dosagem , Transtorno Bipolar/diagnóstico , Transtorno Bipolar/tratamento farmacológico , Transtorno Bipolar/imunologia , Transtorno Bipolar/psicologia , Cognição/efeitos dos fármacos , Manual Diagnóstico e Estatístico de Transtornos Mentais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Escalas de Graduação Psiquiátrica , Resultado do Tratamento
11.
Can J Neurol Sci ; 44(5): 483-497, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28468691

RESUMO

BACKGROUND: In this case series, functional magnetic resonance imaging was used to examine brain networks that mediate different aspects of language function in 4 young adults (17-22 years) with a history of left middle cerebral artery (MCA) stroke in childhood (40 years of age). Although it is widely believed that altered lateralization patterns are more likely to occur following early brain injuries compared with later brain injuries, the presumed plasticity of the young brain has been challenged in recent years, particularly in the domain of language. METHODS: We explored this issue by contrasting the brain activation patterns of individuals with childhood left MCA stroke and adult left MCA stroke while performing two language tasks: verb generation and picture-word matching. Importantly, both groups showed significant recovery of language function, based on standard clinical indicators. RESULTS: Controls showed left lateralized activation for both tasks, although much more pronounced for verb generation. Adult stroke patients also showed left lateralization for both tasks, though somewhat weaker than controls. Childhood stroke patients exhibited significantly weaker lateralization than the adult group for verb generation, but there was no significant group difference for picture-word matching. CONCLUSIONS: These preliminary findings suggest that successful reorganization of language function is more likely to involve bilateral recruitment following left MCA stroke in childhood than in adulthood. Of importance, although childhood stroke patients had primarily subcortical lesions, there were substantial alterations in cortical activation patterns.


Assuntos
Processamento de Imagem Assistida por Computador , Infarto da Artéria Cerebral Média/terapia , Idioma , Imageamento por Ressonância Magnética , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/fisiopatologia , Adolescente , Adulto , Encéfalo/patologia , Encéfalo/fisiopatologia , Mapeamento Encefálico/métodos , Feminino , Lateralidade Funcional/fisiologia , Humanos , Processamento de Imagem Assistida por Computador/métodos , Infarto da Artéria Cerebral Média/patologia , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Acidente Vascular Cerebral/terapia , Adulto Jovem
13.
Cereb Cortex ; 25(5): 1297-305, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-24275829

RESUMO

Autobiographical memory (AM) provides the opportunity to study interactions among brain areas that support the search for a specific episodic memory (construction), and the later experience of mentally reliving it (elaboration). While the hippocampus supports both construction and elaboration, it is unclear how hippocampal-neocortical connectivity differs between these stages, and how this connectivity involves the anterior and posterior segments of the hippocampus, as these have been considered to support the retrieval of general concepts and recollection processes, respectively. We acquired fMRI data in 18 healthy participants during an AM retrieval task in which participants were asked to access a specific AM (construction) and then to recollect it by recovering as many episodic details as possible (elaboration). Using multivariate analytic techniques, we examined changes in functional and effective connectivity of hippocampal-neocortical interactions during these phases of AM retrieval. We found that the left anterior hippocampus interacted with frontal areas during construction and bilateral posterior hippocampi with visual perceptual areas during elaboration, indicating key roles for both hippocampi in coordinating transient neocortical networks at both AM stages. Our findings demonstrate the importance of direct interrogation of hippocampal-neocortical interactions to better illuminate the neural dynamics underlying complex cognitive tasks such as AM retrieval.


Assuntos
Hipocampo/fisiologia , Imageamento por Ressonância Magnética , Memória Episódica , Neocórtex/fisiologia , Rede Nervosa/fisiologia , Adulto , Mapeamento Encefálico/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
14.
BMC Psychiatry ; 16: 105, 2016 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-27084692

RESUMO

BACKGROUND: Major Depressive Disorder (MDD) is among the most prevalent and disabling medical conditions worldwide. Identification of clinical and biological markers ("biomarkers") of treatment response could personalize clinical decisions and lead to better outcomes. This paper describes the aims, design, and methods of a discovery study of biomarkers in antidepressant treatment response, conducted by the Canadian Biomarker Integration Network in Depression (CAN-BIND). The CAN-BIND research program investigates and identifies biomarkers that help to predict outcomes in patients with MDD treated with antidepressant medication. The primary objective of this initial study (known as CAN-BIND-1) is to identify individual and integrated neuroimaging, electrophysiological, molecular, and clinical predictors of response to sequential antidepressant monotherapy and adjunctive therapy in MDD. METHODS: CAN-BIND-1 is a multisite initiative involving 6 academic health centres working collaboratively with other universities and research centres. In the 16-week protocol, patients with MDD are treated with a first-line antidepressant (escitalopram 10-20 mg/d) that, if clinically warranted after eight weeks, is augmented with an evidence-based, add-on medication (aripiprazole 2-10 mg/d). Comprehensive datasets are obtained using clinical rating scales; behavioural, dimensional, and functioning/quality of life measures; neurocognitive testing; genomic, genetic, and proteomic profiling from blood samples; combined structural and functional magnetic resonance imaging; and electroencephalography. De-identified data from all sites are aggregated within a secure neuroinformatics platform for data integration, management, storage, and analyses. Statistical analyses will include multivariate and machine-learning techniques to identify predictors, moderators, and mediators of treatment response. DISCUSSION: From June 2013 to February 2015, a cohort of 134 participants (85 outpatients with MDD and 49 healthy participants) has been evaluated at baseline. The clinical characteristics of this cohort are similar to other studies of MDD. Recruitment at all sites is ongoing to a target sample of 290 participants. CAN-BIND will identify biomarkers of treatment response in MDD through extensive clinical, molecular, and imaging assessments, in order to improve treatment practice and clinical outcomes. It will also create an innovative, robust platform and database for future research. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT01655706 . Registered July 27, 2012.


Assuntos
Antidepressivos/uso terapêutico , Transtorno Depressivo Maior/sangue , Transtorno Depressivo Maior/tratamento farmacológico , Adulto , Biomarcadores/sangue , Canadá , Citalopram/uso terapêutico , Eletroencefalografia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Proteômica , Qualidade de Vida , Resultado do Tratamento
15.
J Neurosci ; 33(23): 9855-65, 2013 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-23739982

RESUMO

Computational modeling suggests that variability in brain signals provides important information regarding the system's capacity to adopt different network configurations that may promote optimal responding to stimuli. Although there is limited empirical work on this construct, a recent study indicates that age-related decreases in variability across the adult lifespan correlate with less efficient and less accurate performance. Here, we extend this construct to the assessment of cerebral integrity by comparing fMRI BOLD variability and fMRI BOLD amplitude in their ability to account for differences in functional capacity in patients with focal unilateral medial temporal dysfunction. We were specifically interested in whether either of these BOLD measures could identify a link between the affected medial temporal region and memory performance (as measured by a clinical test of verbal memory retention). Using partial least-squares analyses, we found that variability in a set of regions including the left hippocampus predicted verbal retention and, furthermore, this relationship was similar across a range of cognitive tasks measured during scanning (i.e., the same pattern was seen in fixation, autobiographical recall, and word generation). In contrast, signal amplitude in the hippocampus did not predict memory performance, even for a task that reliably activates the medial temporal lobes (i.e., autobiographical recall). These findings provide a powerful validation of the concept that variability in brain signals reflects functional integrity. Furthermore, this measure can be characterized as a robust biomarker in this clinical setting because it reveals the same pattern regardless of cognitive challenge or task engagement during scanning.


Assuntos
Encéfalo/fisiologia , Epilepsia do Lobo Temporal/diagnóstico , Epilepsia do Lobo Temporal/fisiopatologia , Individualidade , Memória/fisiologia , Desempenho Psicomotor/fisiologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estimulação Luminosa/métodos , Valor Preditivo dos Testes , Transdução de Sinais/fisiologia , Adulto Jovem
16.
Hippocampus ; 24(5): 560-76, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24449286

RESUMO

Perceptual richness, a defining feature of episodic memory, emerges from the reliving of multimodal sensory experiences. Although the importance of the medial temporal lobe (MTL) to episodic memory retrieval is well documented, the features that determine its engagement are not well characterized. The current study assessed the relationship between MTL function and episodic memory's perceptual richness. We designed a laboratory memory task meant to capture the complexity of memory for life episodes, while manipulating memory's perceptual content. Participants encoded laboratory episodes with rich (film clips) and impoverished (written narratives) perceptual content that were matched for other characteristics such as personal significance, emotionality and story content. At retrieval, participants were probed to describe the stories' perceptual features and storyline. Participants also recalled autobiographical memories (AMs) in a comparison condition. We compared the performance of patients with unilateral medial temporal lobe epilepsy (mTLE) and healthy controls to assess how damage to the MTL affects retrieval in these conditions. We observed an overall decrease in detail count in the mTLE group, along with a disproportionate deficit in perceptual details that was most acute in the AM and the perceptually enriched film clip conditions. Our results suggest that the impaired sense of reliving the past that accompanies MTL insult is mediated by a paucity of perceptual episodic memory details. We also introduce a new protocol that successfully mimics naturalistic memories while benefiting from the experimental control provided by using laboratory stimuli.


Assuntos
Epilepsia do Lobo Temporal/complicações , Epilepsia do Lobo Temporal/patologia , Transtornos da Memória/etiologia , Memória Episódica , Percepção/fisiologia , Lobo Temporal/fisiopatologia , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Linguística , Masculino , Rememoração Mental , Pessoa de Meia-Idade , Testes Neuropsicológicos , Vocabulário
17.
Epilepsy Behav ; 32: 114-20, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24534479

RESUMO

fMRI language mapping has become increasingly utilized for determining language dominance before surgical intervention for temporal lobe epilepsy (TLE). This study aimed to examine the differences between two classes of fMRI word generation tasks used in our clinic: tasks using a single word cue, referred to as simple generative tasks (SGTs), and tasks also involving sentence-level processing, referred to as sentence-level language tasks (SLTs). Specifically, we aimed to investigate the extent and laterality of activation and frontal-temporal connectivity during these language tasks and their relationship to clinical language measures. Thirty-one patients with TLE (18 patients with left TLE and 13 patients with right TLE) performed four language tasks during an fMRI scan, two SGTs and two SLTs. We found significantly greater activity for SLTs over SGTs in bilateral inferior frontal and middle temporal gyri and the left temporal pole. Sentence-level language tasks also showed greater lateralization compared with SGTs. Finally, we found that while activation extent did not correlate with clinical language tests, the degree of left frontal-temporal connectivity was significantly correlated with naming and semantic fluency performance. These correlations also were more robust for SLTs than for SGTs. Taken together, these results provide a compelling argument for including some form of SLTs in fMRI language lateralization protocols for TLE as they allow for better characterization of language networks, particularly in the temporal lobes which are at risk in surgery.


Assuntos
Epilepsia do Lobo Temporal/diagnóstico , Lateralidade Funcional/fisiologia , Idioma , Lobo Temporal/fisiopatologia , Adulto , Mapeamento Encefálico , Epilepsia , Epilepsia do Lobo Temporal/fisiopatologia , Feminino , Humanos , Testes de Linguagem , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos
18.
Epilepsy Behav ; 31: 220-7, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24210456

RESUMO

Predicting postsurgery memory decline is crucial to clinical decision-making for individuals with mesial temporal lobe epilepsy (mTLE) who are candidates for temporal lobe excisions. Extensive neuropsychological testing is critical to assess risk, but the numerous test scores it produces can make deriving a formal prediction of cognitive change quite complex. In order to benefit from the information contained in comprehensive memory assessment, we used principal component analysis (PCA) to simplify neuropsychological test scores (presurgical and pre- to postsurgical change) obtained from a cohort of 56 patients with mTLE into a few easily interpretable latent components. We next performed discriminant analyses using presurgery latent components to categorize seizure laterality and then regression analyses to assess how well presurgery latent components could predict postsurgery memory decline. Finally, we validated the predictive power of these regression models in an independent sample of 18 patients with mTLE. Principal component analysis identified three significant latent components that reflected IQ, verbal memory, and visuospatial memory, respectively. Together, the presurgery verbal and visuospatial memory components classified 80% of patients with mTLE correctly according to their seizure laterality. Furthermore, the presurgery verbal memory component predicted postsurgery verbal memory decline, while the presurgery visuospatial memory component predicted visuospatial memory decline. These regression models also predicted postsurgery memory decline successfully in the independent cohort of patients with mTLE. Our results demonstrate the value of data reduction techniques in identifying cognitive metrics that can characterize laterality of damage and risk of postoperative decline.


Assuntos
Transtornos da Memória/diagnóstico , Transtornos da Memória/etiologia , Análise Multivariada , Complicações Pós-Operatórias/fisiopatologia , Adulto , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/etiologia , Epilepsia do Lobo Temporal/cirurgia , Feminino , Lateralidade Funcional , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Procedimentos Neurocirúrgicos/efeitos adversos , Valor Preditivo dos Testes , Análise de Componente Principal , Reprodutibilidade dos Testes , Estudos Retrospectivos
19.
Camb Q Healthc Ethics ; 23(3): 361-8, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24865371

RESUMO

Vulnerability is an important criterion to assess the ethical justification of the inclusion of participants in research trials. Currently, vulnerability is often understood as an attribute inherent to a participant by nature of a diagnosed condition. Accordingly, a common ethical concern relates to the participant's decisionmaking capacity and ability to provide free and informed consent. We propose an expanded view of vulnerability that moves beyond a focus on consent and the intrinsic attributes of participants. We offer specific suggestions for how relational aspects and the dynamic features of vulnerability could be more fully captured in current discussions and research practices.


Assuntos
Estimulação Encefálica Profunda/ética , Ética em Pesquisa , Consentimento Livre e Esclarecido/ética , Seleção de Pacientes/ética , Ensaios Clínicos como Assunto , Tomada de Decisões/ética , Humanos , Transtornos Mentais/terapia , Medição de Risco
20.
Pain ; 2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38551888

RESUMO

ABSTRACT: Rodents and human studies indicate that the hippocampus, a brain region necessary for memory processing, responds to noxious stimuli. However, the hippocampus has yet to be considered a key brain region directly involved in the human pain experience. One approach to answer this question is to perform quantitative sensory testing on patients with hippocampal damage-ie, medial temporal lobe epilepsy. Some case studies and case series have performed such tests in a handful of patients with various types of epilepsy and have reported mixed results. Here, we aimed to determine whether mechanical pain sensitivity was altered in patients diagnosed with temporal lobe epilepsy. We first investigated whether mechanical pain sensitivity in patients with temporal lobe epilepsy differs from that of healthy individuals. Next, in patients with temporal lobe epilepsy, we evaluated whether the degree of pain sensitivity is associated with the degree of hippocampal integrity. Structural integrity was based on hippocampal volume, and functional integrity was based on verbal and visuospatial memory scores. Our findings show that patients with temporal lobe epilepsy have lower mechanical pain sensitivity than healthy individuals. Only left hippocampal volume was positively associated with mechanical pain sensitivity-the greater the hippocampal damage, the lower the sensitivity to mechanical pain. Hippocampal measures of functional integrity were not significantly associated with mechanical pain sensitivity, suggesting that the mechanisms of hippocampal pain processing may be different than its memory functions. Future studies are necessary to determine the mechanisms of pain processing in the hippocampus.

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