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1.
Anesthesiology ; 134(2): 202-218, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33433619

RESUMO

BACKGROUND: Nitrous oxide produces non-γ-aminobutyric acid sedation and psychometric impairment and can be used as scientific model for understanding mechanisms of progressive cognitive disturbances. Temporal complexity of the electroencephalogram may be a sensitive indicator of these effects. This study measured psychometric performance and the temporal complexity of the electroencephalogram in participants breathing low-dose nitrous oxide. METHODS: In random order, 20, 30, and 40% end-tidal nitrous oxide was administered to 12 participants while recording 32-channel electroencephalogram and psychometric function. A novel metric quantifying the spatial distribution of temporal electroencephalogram complexity, comprised of (1) absolute cross-correlation calculated between consecutive 0.25-s time samples; 2) binarizing these cross-correlation matrices using the median of all channels as threshold; (3) using quantitative recurrence analysis, the complexity in temporal changes calculated by the Shannon entropy of the probability distribution of the diagonal line lengths; and (4) overall spatial extent and intensity of brain complexity, was quantified by calculating median temporal complexity of channels whose complexities were above 1 at baseline. This region approximately overlay the brain's default mode network, so this summary statistic was termed "default-mode-network complexity." RESULTS: Nitrous oxide concentration correlated with psychometric impairment (r = 0.50, P < 0.001). Baseline regional electroencephalogram complexity at midline was greater than in lateral temporal channels (1.33 ± 0.14 bits vs. 0.81 ± 0.12 bits, P < 0.001). A dose of 40% N2O decreased midline (mean difference [95% CI], 0.20 bits [0.09 to 0.31], P = 0.002) and prefrontal electroencephalogram complexity (mean difference [95% CI], 0.17 bits [0.08 to 0.27], P = 0.002). The lateral temporal region did not change significantly (mean difference [95% CI], 0.14 bits [-0.03 to 0.30], P = 0.100). Default-mode-network complexity correlated with N2O concentration (r = -0.55, P < 0.001). A default-mode-network complexity mixed-effects model correlated with psychometric impairment (r2 = 0.67; receiver operating characteristic area [95% CI], 0.72 [0.59 to 0.85], P < 0.001). CONCLUSIONS: Temporal complexity decreased most markedly in medial cortical regions during low-dose nitrous oxide exposures, and this change tracked psychometric impairment.


Assuntos
Disfunção Cognitiva/induzido quimicamente , Disfunção Cognitiva/fisiopatologia , Eletroencefalografia/métodos , Óxido Nitroso/efeitos adversos , Lobo Temporal/efeitos dos fármacos , Lobo Temporal/fisiopatologia , Adulto , Anestésicos Inalatórios/efeitos adversos , Estudos Cross-Over , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Psicometria , Método Simples-Cego , Adulto Jovem
2.
BMJ Case Rep ; 13(12)2020 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-33370980

RESUMO

We illustrate a case of post-traumatic recurrent transient prosopagnosia in a paediatric patient with a right posterior inferior temporal gyrus haemorrhage seen on imaging and interictal electroencephalogram abnormalities in the right posterior quadrant. Face recognition area mapping with magnetoencephalography (MEG) and functional MRI (fMRI) was performed to clarify the relationship between the lesion and his prosopagnosia, which showed activation of the right fusiform gyrus that colocalised with the lesion. Lesions adjacent to the right fusiform gyrus can result in seizures presenting as transient prosopagnosia. MEG and fMRI can help to attribute this unique semiology to the lesion.


Assuntos
Hemorragia Cerebral/diagnóstico , Procedimentos Neurocirúrgicos , Prosopagnosia/etiologia , Convulsões/diagnóstico , Lobo Temporal/diagnóstico por imagem , Mapeamento Encefálico , Hemorragia Cerebral/complicações , Hemorragia Cerebral/cirurgia , Criança , Eletroencefalografia , Reconhecimento Facial/fisiologia , Humanos , Imagem por Ressonância Magnética , Masculino , Prosopagnosia/diagnóstico , Prosopagnosia/fisiopatologia , Prosopagnosia/cirurgia , Convulsões/etiologia , Convulsões/fisiopatologia , Convulsões/cirurgia , Lobo Temporal/fisiopatologia , Resultado do Tratamento
3.
Medicine (Baltimore) ; 99(46): e23116, 2020 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-33181681

RESUMO

A recent paper in the journal Neuroreport suggested that, upon source localization, the semantic P600 localizes to executive function areas, that is, outside language. But is this true for all types of linguistic P600? We report a cross-sectional source localization study of a classical (agreement) syntactic paradigm.The results show a clear localization to the temporal lobe, in classical language areas.The P600 is probably not a unitary phenomenon in term of source localization, and the question whether it localizes within or outside the language system depends on the type of P600.


Assuntos
Mapeamento Encefálico/métodos , Potenciais Evocados/fisiologia , Idioma , Semântica , Lobo Temporal , Adulto , Compreensão/fisiologia , Eletroencefalografia/métodos , Fenômenos Eletromagnéticos , Feminino , Humanos , Masculino , Estimulação Luminosa/métodos , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/fisiopatologia , Tomografia/métodos
4.
PLoS One ; 15(8): e0235810, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32810171

RESUMO

Anomia is common in Primary Progressive Aphasia (PPA), and there is considerable evidence that semantic problems (as opposed to impaired access to output word phonology) exist in many PPA individuals irrespective of their strict subtype, including a loss of representations from semantic memory, which is typical for people with the semantic variant of PPA. In this manuscript we present a straightforward novel clinical algorithm that quantifies this degree of semantic storage impairment. We sought to produce an algorithm by employing tasks that would measure key elements of semantic storage loss: a) whether an unrecalled name could be retrieved with cues; b) if performance for items was consistent across tasks; and c) the degree to which a participant's performance was related to general severity of cognitive impairment rather than semantic loss. More specifically, these tasks were given to 28 individuals with PPA (12 participants had a clinical diagnosis of atypical Alzheimer's Disease with the logopenic variant of PPA; the remaining 16 participants received a clinical diagnosis of Frontotemporal dementia (11 were classified as the non-fluent variant of PPA and five were the semantic variant of PPA). Scores from these tasks produced a single omnibus semantic memory storage loss score (SSL score) for each person that ranged from 0.0 to 1.0, with scores closer to 0 more indicative of semantic storage loss. Indeed, supporting the hypothesis that our scores measure the degree of semantic storage loss, we found participants with the semantic variant of PPA had the lowest scores, and SSL scores could predict the degree of hypometabolism in the anterior temporal lobe; even when only people with the logopenic variant of PPA were examined. Thus, these scores show promise quantitating the degree of a person's semantic representation loss.


Assuntos
Afasia Primária Progressiva/fisiopatologia , Doenças Neurodegenerativas/fisiopatologia , Semântica , Lobo Temporal/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/complicações , Doença de Alzheimer/metabolismo , Doença de Alzheimer/fisiopatologia , Afasia Primária Progressiva/etiologia , Afasia Primária Progressiva/metabolismo , Feminino , Demência Frontotemporal/complicações , Demência Frontotemporal/metabolismo , Demência Frontotemporal/fisiopatologia , Humanos , Masculino , Doenças Neurodegenerativas/complicações , Doenças Neurodegenerativas/metabolismo , Testes Neuropsicológicos , Tomografia por Emissão de Pósitrons , Lobo Temporal/metabolismo
5.
J Headache Pain ; 21(1): 47, 2020 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-32375638

RESUMO

BACKGROUND: Migraine is a severe and disabling brain disorder, and the exact neurological mechanisms remain unclear. Migraineurs have altered pain perception, and headache attacks disrupt their sensory information processing and sensorimotor integration. The altered functional connectivity of sub-regions of sensorimotor brain areas with other brain cortex associated with migraine needs further investigation. METHODS: Forty-eight migraineurs without aura during the interictal phase and 48 age- and sex-matched healthy controls underwent resting-state functional magnetic resonance imaging scans. We utilized seed-based functional connectivity analysis to investigate whether patients exhibited abnormal functional connectivity between sub-regions of sensorimotor brain areas and cortex regions. RESULTS: We found that patients with migraineurs without aura exhibited disrupted functional connectivities between the sensorimotor areas and the visual cortex, temporal cortex, posterior parietal lobule, prefrontal areas, precuneus, cingulate gyrus, sensorimotor areas proper and cerebellum areas compared with healthy controls. In addition, the clinical data of the patients, such as disease duration, pain intensity and HIT-6 score, were negatively correlated with these impaired functional connectivities. CONCLUSION: In patients with migraineurs without aura, the functional connectivities between the sensorimotor brain areas and other brain regions was reduced. These disrupted functional connectivities might contribute to abnormalities in visual processing, multisensory integration, nociception processing, spatial attention and intention and dysfunction in cognitive evaluation and modulation of pain. Recurrent headache attacks might lead to the disrupted network between primary motor cortex and temporal regions and between primary somatosensory cortex and temporal regions. Pain sensitivity and patient quality of life are closely tied to the abnormal functional connectivity between sensorimotor regions and other brain areas.


Assuntos
Imagem por Ressonância Magnética/métodos , Enxaqueca sem Aura/diagnóstico por imagem , Córtex Motor/diagnóstico por imagem , Rede Nervosa/diagnóstico por imagem , Córtex Somatossensorial/diagnóstico por imagem , Lobo Temporal/diagnóstico por imagem , Adulto , Mapeamento Encefálico/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Enxaqueca sem Aura/fisiopatologia , Córtex Motor/fisiopatologia , Rede Nervosa/fisiopatologia , Dor/diagnóstico por imagem , Dor/fisiopatologia , Qualidade de Vida , Córtex Somatossensorial/fisiopatologia , Lobo Temporal/fisiopatologia , Adulto Jovem
6.
PLoS One ; 15(5): e0233224, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32428025

RESUMO

Epidemiological evidence shows an association between hearing loss and dementia in elderly people. However, the mechanisms that connect hearing impairments and cognitive decline are still unknown. Here we propose that a suprathreshold auditory-nerve impairment is associated with cognitive decline and brain atrophy. METHODS: audiological, neuropsychological, and brain structural 3-Tesla MRI data were obtained from elders with different levels of hearing loss recruited in the ANDES cohort. The amplitude of waves I (auditory nerve) and V (midbrain) from auditory brainstem responses were measured at 80 dB nHL. We also calculated the ratio between wave V and I as a proxy of suprathreshold brainstem function. RESULTS: we included a total of 101 subjects (age: 73.5 ± 5.2 years (mean ± SD), mean education: 9.5 ± 4.2 years, and mean audiogram thresholds (0.5-4 kHz): 25.5 ± 12.0 dB HL). We obtained reliable suprathreshold waves V in all subjects (n = 101), while replicable waves I were obtained in 92 subjects (91.1%). Partial Spearman correlations (corrected by age, gender, education and hearing thresholds) showed that reduced suprathreshold wave I responses were associated with thinner temporal and parietal cortices, and with slower processing speed as evidenced by the Trail-Making Test-A and digit symbol performance. Non-significant correlations were obtained between wave I amplitudes and other cognitive domains. CONCLUSIONS: These results evidence that reduced suprathreshold auditory nerve responses in presbycusis are associated with slower processing speed and brain structural changes in temporal and parietal regions.


Assuntos
Percepção Auditiva/fisiologia , Disfunção Cognitiva/metabolismo , Presbiacusia/fisiopatologia , Estimulação Acústica , Idoso , Idoso de 80 Anos ou mais , Audiometria de Tons Puros , Limiar Auditivo/fisiologia , Encéfalo/fisiopatologia , Nervo Coclear/fisiologia , Disfunção Cognitiva/etiologia , Potenciais Evocados Auditivos do Tronco Encefálico/fisiologia , Feminino , Audição/fisiologia , Humanos , Masculino , Ruído , Lobo Parietal/fisiopatologia , Presbiacusia/metabolismo , Lobo Temporal/fisiopatologia
7.
Sci Rep ; 10(1): 6744, 2020 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-32317774

RESUMO

Non-pharmacological treatment (NPT) improves cognitive functions and behavioural disturbances in patients with dementia, but the underlying neural mechanisms are unclear. In this observational study, 21 patients with dementia received NPTs for several months. Patients were scanned using magnetoencephalography twice during the NPT period to evaluate NPT effects on resting-state brain activity. Additionally, cognitive functions and behavioural disturbances were measured using the Mini-Mental State Examination (MMSE-J) and a short version of the Dementia Behaviour Disturbance Scale (DBD-13) at the beginning and the end of the NPT period. In contrast to the average DBD-13 score, the average MMSE-J score improved after the NPT period. Magnetoencephalography data revealed a reduced alpha activity in the right temporal lobe and fusiform gyrus, as well as an increased low-gamma activity in the right angular gyrus. DBD-13 score changes were correlated with beta activity in the sensorimotor area. These findings corroborate previous studies confirming NPT effects on brain activity in healthy participants and people at risk of dementia. Our results provide additional evidence that brains of patients with dementia have the capacity for plasticity, which may be responsible for the observed NPT effects. In dementia, NPT might lead to improvements in the quality of life.


Assuntos
Doença de Alzheimer/terapia , Terapia Cognitivo-Comportamental/métodos , Demência Vascular/terapia , Horticultura Terapêutica/métodos , Lobo Parietal/fisiopatologia , Lobo Temporal/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Ritmo alfa/fisiologia , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/fisiopatologia , Ritmo beta/fisiologia , Cognição/fisiologia , Demência Vascular/diagnóstico por imagem , Demência Vascular/fisiopatologia , Exercício Físico/psicologia , Feminino , Ritmo Gama/fisiologia , Humanos , Magnetoencefalografia , Masculino , Testes de Estado Mental e Demência , Cuidados de Enfermagem/métodos , Lobo Parietal/diagnóstico por imagem , Qualidade de Vida/psicologia , Desempenho de Papéis , Lobo Temporal/diagnóstico por imagem
8.
Brain ; 143(4): 1261-1277, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32236540

RESUMO

Frontotemporal dysconnectivity is a key pathology in schizophrenia. The specific nature of this dysconnectivity is unknown, but animal models imply dysfunctional theta phase coupling between hippocampus and medial prefrontal cortex (mPFC). We tested this hypothesis by examining neural dynamics in 18 participants with a schizophrenia diagnosis, both medicated and unmedicated; and 26 age, sex and IQ matched control subjects. All participants completed two tasks known to elicit hippocampal-prefrontal theta coupling: a spatial memory task (during magnetoencephalography) and a memory integration task. In addition, an overlapping group of 33 schizophrenia and 29 control subjects underwent PET to measure the availability of GABAARs expressing the α5 subunit (concentrated on hippocampal somatostatin interneurons). We demonstrate-in the spatial memory task, during memory recall-that theta power increases in left medial temporal lobe (mTL) are impaired in schizophrenia, as is theta phase coupling between mPFC and mTL. Importantly, the latter cannot be explained by theta power changes, head movement, antipsychotics, cannabis use, or IQ, and is not found in other frequency bands. Moreover, mPFC-mTL theta coupling correlated strongly with performance in controls, but not in subjects with schizophrenia, who were mildly impaired at the spatial memory task and no better than chance on the memory integration task. Finally, mTL regions showing reduced phase coupling in schizophrenia magnetoencephalography participants overlapped substantially with areas of diminished α5-GABAAR availability in the wider schizophrenia PET sample. These results indicate that mPFC-mTL dysconnectivity in schizophrenia is due to a loss of theta phase coupling, and imply α5-GABAARs (and the cells that express them) have a role in this process.


Assuntos
Vias Neurais/fisiopatologia , Córtex Pré-Frontal/fisiopatologia , Esquizofrenia/fisiopatologia , Lobo Temporal/fisiopatologia , Ritmo Teta/fisiologia , Adulto , Feminino , Humanos , Magnetoencefalografia , Masculino , Vias Neurais/metabolismo , Tomografia por Emissão de Pósitrons , Córtex Pré-Frontal/metabolismo , Receptores de GABA-A/metabolismo , Esquizofrenia/metabolismo , Lobo Temporal/metabolismo
9.
Brain ; 143(4): 1233-1248, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32252068

RESUMO

Human episodic memory critically depends on subregions of the medial temporal lobe, which are part of functional brain systems such as the anterior-temporal and the posterior-medial system. Here we analysed how Alzheimer's pathology affects functional connectivity within these systems. Data from 256 amyloid-ß-negative cognitively unimpaired, 103 amyloid-ß-positive cognitively unimpaired, and 83 amyloid-ß-positive individuals with mild cognitive impairment were analysed. Amyloid-ß and tau pathology were measured using the CSF amyloid-ß42/40 ratio and phosphorylated tau, respectively. We found that amyloid-ß-positive cognitively unimpaired individuals were mainly characterized by decreased functional connectivity between the medial temporal lobe and regions in the anterior-temporal system, most prominently between left perirhinal/entorhinal cortices and medial prefrontal cortex. Furthermore, correlation analysis in this group revealed decreasing functional connectivity between bilateral perirhinal/entorhinal cortices, anterior hippocampus and posterior-medial regions with increasing levels of phosphorylated tau. The amyloid-ß-positive individuals with mild cognitive impairment mostly exhibited reduced connectivity between the medial temporal lobe and posterior-medial regions, predominantly between the anterior hippocampus and posterior cingulate cortex. In addition, they showed hyperconnectivity within the medial temporal lobe and its immediate proximity. Lower medial temporal-cortical functional connectivity networks resulting from the group comparisons of cognitively unimpaired individuals were associated with reduced memory performance and more rapid longitudinal memory decline as shown by linear mixed-effects regression analysis. Finally, we found that reduced medial temporal-cortical connectivity in mildly cognitively impaired individuals was related to reduced entorhinal thickness and white matter integrity of the parahippocampal cingulum and the fornix. No such relationships were found in cognitively unimpaired individuals. In conclusion, our findings show that the earliest changes in preclinical Alzheimer's disease might involve decreased connectivity within the anterior-temporal system, and early changes in connectivity might be related to memory impairment, but not to structural changes. With disease progression and increased tau pathology, medial temporal functional connectivity with posterior-medial regions seems to be increasingly impaired. In individuals with mild cognitive impairment, reduced functional connectivity is associated with structural brain changes as well as the emergence of locally increased connectivity patterns. Thus, functional connectivity between the medial temporal lobe and the anterior-temporal and posterior-medial system could serve as stage-specific functional markers in early Alzheimer's disease.


Assuntos
Doença de Alzheimer/patologia , Memória Episódica , Vias Neurais/patologia , Lobo Temporal/patologia , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/fisiopatologia , Cognição/fisiologia , Progressão da Doença , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Lobo Temporal/fisiopatologia
10.
Psychiatry Res Neuroimaging ; 299: 111059, 2020 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-32135406

RESUMO

This study explored imaging predictors of electroconvulsive therapy (ECT) outcome in schizophrenia patients based on pre-treatment functional connectivity (FC) within regions with strong ECT electric fields distribution. Forty-seven patients received standard antipsychotic drugs combined with ECT as well as two brain imaging sessions. Regions of interest (ROI) with strong electric field distribution were determined by ECT simulation. Using baseline functional connectivity between ROIs, a model was constructed to predict the percentage reduction of Positive and Negative Syndrome Scale (PANSS) scores. The strong electric fields were distributed in the orbital prefrontal lobe, medial temporal lobe, and other parts of the temporal lobe. Ten functional connectivity features within the electric field distribution areas showed a predictive ability for ECT outcome. The correlation coefficient between the predictive and real values of cross-validation was 0.7165. Among the predictive features, ECT induced a significant decrease in functional connectivity between the right amygdala and the left hippocampus. These results suggest that pretreatment functional connectivity patterns in brain regions with strong electric field distributions during ECT could be potential predictors of the efficacy of ECT augmentation in schizophrenia. These findings may help to improve individualized clinical treatment in the future.


Assuntos
Antipsicóticos/uso terapêutico , Eletroconvulsoterapia/métodos , Esquizofrenia/tratamento farmacológico , Esquizofrenia/terapia , Adulto , Encéfalo/fisiopatologia , Feminino , Hipocampo/fisiopatologia , Humanos , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Córtex Pré-Frontal/fisiopatologia , Esquizofrenia/fisiopatologia , Lobo Temporal/fisiopatologia
11.
J Neurosci ; 40(11): 2269-2281, 2020 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-32015023

RESUMO

A prominent hypothesis regarding the pathophysiology of autism is that an increase in the balance between neural excitation and inhibition results in an increase in neural responses. However, previous reports of population-level response magnitude in individuals with autism have been inconsistent. Critically, network interactions have not been considered in previous neuroimaging studies of excitation and inhibition imbalance in autism. In particular, a defining characteristic of cortical organization is its hierarchical and interactive structure; sensory and cognitive systems are comprised of networks where later stages inherit and build upon the processing of earlier input stages, and also influence and shape earlier stages by top-down modulation. Here we used the well established connections of the human visual system to examine response magnitudes in a higher-order motion processing region [middle temporal area (MT+)] and its primary input region (V1). Simple visual stimuli were presented to adult individuals with autism spectrum disorders (ASD; n = 24, mean age 23 years, 8 females) and neurotypical controls (n = 24, mean age 22, 8 females) during fMRI scanning. We discovered a strong dissociation of fMRI response magnitude between region MT+ and V1 in individuals with ASD: individuals with high MT+ responses had attenuated V1 responses. The magnitude of MT+ amplification and of V1 attenuation was associated with autism severity, appeared to result from amplified suppressive feedback from MT+ to V1, and was not present in neurotypical controls. Our results reveal the potential role of altered hierarchical network interactions in the pathophysiology of ASD.SIGNIFICANCE STATEMENT An imbalance between neural excitation and inhibition, resulting in increased neural responses, has been suggested as a pathophysiological pathway to autism, but direct evidence from humans is lacking. In the current study we consider the role of interactions between stages of sensory processing when testing increased neural responses in individuals with autism. We used the well known hierarchical structure of the visual motion pathway to demonstrate dissociation in the fMRI response magnitude between adjacent stages of processing in autism: responses are attenuated in a primary visual area but amplified in a subsequent higher-order area. This response dissociation appears to rely on enhanced suppressive feedback between regions and reveals a previously unknown cortical network alteration in autism.


Assuntos
Percepção de Movimento/fisiologia , Rede Nervosa/fisiopatologia , Lobo Temporal/fisiopatologia , Adulto , Transtorno do Espectro Autista/fisiopatologia , Mapeamento Encefálico , Movimentos Oculares/fisiologia , Feminino , Movimentos da Cabeça/fisiologia , Humanos , Imagem por Ressonância Magnética , Masculino , Inibição Neural/fisiologia , Estimulação Luminosa , Desempenho Psicomotor/fisiologia , Adulto Jovem
12.
J Autism Dev Disord ; 50(8): 2765-2778, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32006272

RESUMO

The neurobiology of autism spectrum disorder remains poorly understood. The present study addresses this knowledge gap by examining the relationship between functional brain connectivity and Autism Diagnostic Observation Schedule (ADOS) scores using publicly available data from the Autism Brain Imaging Data Exchange (ABIDE) database (N = 107). This relationship was tested across all brain voxels, without a priori assumptions, using a novel statistical approach. ADOS scores were primarily associated with decreased connectivity to right temporoparietal junction, right anterior insula, and left fusiform gyrus (p < 0.05, corrected). Seven large-scale brain networks influenced these associations. Findings largely encompassed brain regions involved in processing socially relevant information, highlighting the importance of these processes in autism spectrum disorder.


Assuntos
Transtorno do Espectro Autista/fisiopatologia , Encéfalo/fisiopatologia , Vias Neurais/fisiopatologia , Adolescente , Mapeamento Encefálico , Córtex Cerebral/fisiopatologia , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino , Neuroimagem , Lobo Temporal/fisiopatologia
13.
Brain ; 143(3): 844-861, 2020 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-32068789

RESUMO

The loss and recovery of language functions are still incompletely understood. This longitudinal functional MRI study investigated the neural mechanisms underlying language recovery in patients with post-stroke aphasia putting particular emphasis on the impact of lesion site. To identify patterns of language-related activation, an auditory functional MRI sentence comprehension paradigm was administered to patients with circumscribed lesions of either left frontal (n = 17) or temporo-parietal (n = 17) cortex. Patients were examined repeatedly during the acute (≤1 week, t1), subacute (1-2 weeks, t2) and chronic phase (>6 months, t3) post-stroke; healthy age-matched control subjects (n = 17) were tested once. The separation into two patient groups with circumscribed lesions allowed for a direct comparison of the contributions of distinct lesion-dependent network components to language reorganization between both groups. We hypothesized that activation of left hemisphere spared and perilesional cortex as well as lesion-homologue cortex in the right hemisphere varies between patient groups and across time. In addition, we expected that domain-general networks serving cognitive control independently contribute to language recovery. First, we found a global network disturbance in the acute phase that is characterized by reduced functional MRI language activation including areas distant to the lesion (i.e. diaschisis) and subsequent subacute network reactivation (i.e. resolution of diaschisis). These phenomena were driven by temporo-parietal lesions. Second, we identified a lesion-independent sequential activation pattern with increased activity of perilesional cortex and bilateral domain-general networks in the subacute phase followed by reorganization of left temporal language areas in the chronic phase. Third, we observed involvement of lesion-homologue cortex only in patients with frontal but not temporo-parietal lesions. Fourth, irrespective of lesion location, language reorganization predominantly occurred in pre-existing networks showing comparable activation in healthy controls. Finally, we detected different relationships of performance and activation in language and domain-general networks demonstrating the functional relevance for language recovery. Our findings highlight that the dynamics of language reorganization clearly depend on lesion location and hence open new perspectives for neurobiologically motivated strategies of language rehabilitation, such as individually-tailored targeted application of neuro-stimulation.


Assuntos
Afasia/fisiopatologia , Lobo Frontal/fisiopatologia , Idioma , Lobo Parietal/fisiopatologia , Recuperação de Função Fisiológica/fisiologia , Acidente Vascular Cerebral/fisiopatologia , Lobo Temporal/fisiopatologia , Estudos de Casos e Controles , Lobo Frontal/patologia , Neuroimagem Funcional , Humanos , Testes de Linguagem , Estudos Longitudinais , Imagem por Ressonância Magnética , Vias Neurais/fisiopatologia , Lobo Parietal/patologia , Acidente Vascular Cerebral/complicações , Lobo Temporal/patologia
14.
Clin Neurophysiol ; 131(3): 609-615, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31972504

RESUMO

OBJECTIVE: To determine the relationship between seizure onset, sleep stage and focal cortical dysplasia type 2 (FCD2) location in sleep related epilepsy (SRE). METHODS: We reviewed scalp video-EEG data of 77 patients with SRE among 130 surgically treated patients with histologically confirmed FCD2. Seizure onset was classified as occurring during NREM, REM and after arousal. RESULTS: Sleep recordings were available for 65 patients (37 males, 7-49 years old). FCD2 was located in frontal lobe in 46 (71%) and in extra-frontal regions in 19, including the temporal lobe in 6. MRI was negative/doubtful in 35 cases. Interictal rhythmic/pseudorhythmic spike rate increased from 31% during waking to 65% during sleep. Seizure onset occurred from NREM in 46 cases (71%), mostly from stage 2, and after arousal in 14 (22%). Seizures occurring from NREM/REM sleep were significantly more frequent in frontal (89%) compared to extra-frontal location (42%), whilst arousal preceded seizure onset more often in extra-frontal (58%) compared to frontal location (7%). CONCLUSIONS: NREM seizure onset is the most common ictal pattern in SRE due to frontal FCD2 whereas preceding arousal points to extra-frontal regions. SIGNIFICANCE: Sleep recordings may help for FCD2 localisation and suggest topography dependent impact on sleep related epileptic networks.


Assuntos
Epilepsia/fisiopatologia , Lobo Frontal/fisiopatologia , Malformações do Desenvolvimento Cortical do Grupo I/fisiopatologia , Sono/fisiologia , Lobo Temporal/fisiopatologia , Adolescente , Adulto , Criança , Eletroencefalografia , Epilepsia/complicações , Epilepsia/cirurgia , Feminino , Humanos , Masculino , Malformações do Desenvolvimento Cortical do Grupo I/complicações , Malformações do Desenvolvimento Cortical do Grupo I/cirurgia , Pessoa de Meia-Idade , Período Pré-Operatório , Adulto Jovem
15.
Brain Connect ; 10(1): 39-50, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31984759

RESUMO

Understanding how global brain networks are affected in epilepsy may elucidate the pathogenesis of seizures and its accompanying neurobehavioral comorbidities. We investigated functional changes within neural networks in temporal lobe epilepsy (TLE) using graph theory analysis of resting-state connectivity. Twenty-seven TLE presurgical patients (age 41.0 ± 12.3 years) and 85 age, gender, and handedness equivalent healthy controls (HCs; age 39.7 ± 16.9 years) were enrolled. Eyes-closed resting-state functional magnetic resonance image scans were analyzed to compare network properties and functional connectivity (FC) changes. TLE subjects showed significantly higher global efficiency, lower clustering coefficient ratio, and lower shortest path lengths ratio than HCs, as an indication of a more synchronized, yet less segregated network. A trend of functional reorganization with a shift of network hubs to the contralateral hemisphere was noted in TLE subjects. Support vector machine (SVM) with linear kernel was trained to separate between neural networks in TLE and HC subjects based on graph measurements. SVM analysis allowed separation between TLE and HC networks with 80.66% accuracy using eight features of graph measurements. Support vector regression (SVR) was used to predict neurocognitive performance from graph metrics. An SVR linear predictor showed discriminative prediction accuracy for four key neurocognitive variables in TLE (absolute R value range: 0.61-0.75). Despite TLE, our results showed both local and global network topology differences that reflect widespread alterations in FC in TLE. Network differences are discriminative between TLE and HCs using data-driven analysis and predicted severity of neurocognitive sequelae in our cohort.


Assuntos
Epilepsia do Lobo Temporal/fisiopatologia , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/fisiopatologia , Adulto , Encéfalo/fisiopatologia , Mapeamento Encefálico/métodos , Eletroencefalografia , Feminino , Humanos , Aprendizado de Máquina , Imagem por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Convulsões/fisiopatologia , Lobo Temporal/fisiopatologia
16.
PLoS One ; 15(1): e0227355, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31990937

RESUMO

Incomplete hippocampal inversion (IHI), also called hippocampal malrotation, is an atypical presentation of the hippocampus present in about 20% of healthy individuals. Here we conducted the first genome-wide association study (GWAS) in IHI to elucidate the genetic underpinnings that may contribute to the incomplete inversion during brain development. A total of 1381 subjects contributed to the discovery cohort obtained from the IMAGEN database. The incidence rate of IHI was 26.1%. Loci with P<1e-5 were followed up in a validation cohort comprising 161 subjects from the PING study. Summary statistics from the discovery cohort were used to compute IHI heritability as well as genetic correlations with other traits. A locus on 18q11.2 (rs9952569; OR = 1.999; Z = 5.502; P = 3.755e-8) showed a significant association with the presence of IHI. A functional annotation of the locus implicated genes AQP4 and KCTD1. However, neither this locus nor the other 16 suggestive loci reached a significant p-value in the validation cohort. The h2 estimate was 0.54 (sd: 0.30) and was significant (Z = 1.8; P = 0.036). The top three genetic correlations of IHI were with traits representing either intelligence or education attainment and reached nominal P< = 0.013.


Assuntos
Encefalopatias/genética , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Hipocampo/fisiopatologia , Adolescente , Aquaporina 4/genética , Encefalopatias/diagnóstico por imagem , Encefalopatias/fisiopatologia , Proteínas Correpressoras/genética , Feminino , Hipocampo/diagnóstico por imagem , Humanos , Masculino , Polimorfismo de Nucleotídeo Único/genética , Lobo Temporal/fisiopatologia
17.
Cogn Neuropsychol ; 37(1-2): 25-45, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31597512

RESUMO

Schemas capture patterns across multiple experiences, accumulating information about common event structures that guide decision making in new contexts. Schemas are an important principle of leading theories of cognitive development; yet, we know little about how children and adolescents form schemas and use schematic knowledge to guide decisions. Here, we show that the ability to acquire schematic knowledge based on the temporal regularities of events increases during childhood and adolescence. Furthermore, we show that temporally mediated schematic knowledge biases reasoning decisions in an age-dependent manner. Participants with greater temporal schematic knowledge were more likely to infer that temporally related items shared other, non-temporal properties, with adults showing the greatest relationship between schema knowledge and reasoning choices. These data indicate that the mechanisms underlying schema formation and expression are not fully developed until adulthood and may reflect the ongoing maturation of hippocampus and prefrontal cortex through adolescence.


Assuntos
Cognição/fisiologia , Lobo Temporal/fisiopatologia , Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Adulto Jovem
18.
Brain Imaging Behav ; 14(1): 19-29, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30251182

RESUMO

Substantial work associates late-life depression with hippocampal pathology. However, there is less information about differences in hippocampal subfields and other connected temporal lobe regions and how these regions may be influenced by vascular factors. Individuals aged 60 years or older with and without a DSM-IV diagnosis of Major Depressive Disorder completed clinical assessments and 3 T cranial MRI using a protocol allowing for automated measurement of medial temporal lobe subfield volumes. A subset also completed pseudo-continuous arterial spin labeling, allowing for the measurement of hippocampal cerebral blood flow. In 59 depressed and 21 never-depressed elders (mean age = 66.4 years, SD = 5.8y, range 60-86y), the depressed group did not exhibit statistically significant volumetric differences for the total hippocampus or hippocampal subfields but did exhibit significantly smaller volumes of the perirhinal cortex, specifically in the BA36 region. Additionally, age had a greater effect in the depressed group on volumes of the cornu ammonis, entorhinal cortex, and BA36 region. Finally, both clinical and radiological markers of vascular risk were associated with smaller BA36 volumes, while reduced hippocampal blood flow was associated with smaller hippocampal and cornu ammonis volumes. In conclusion, while we did not observe group differences in hippocampal regions, we observed group differences and an effect of vascular pathology on the BA36 region, part of the perirhinal cortex. This is a critical region exhibiting atrophy in prodromal Alzheimer's disease. Moreover, the observed greater effect of age in the depressed groups is concordant with past longitudinal studies reporting greater hippocampal atrophy in late-life depression.


Assuntos
Circulação Cerebrovascular/fisiologia , Depressão/fisiopatologia , Lobo Temporal/fisiopatologia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Atrofia/patologia , Córtex Cerebral/patologia , Depressão/metabolismo , Transtorno Depressivo Maior/metabolismo , Transtorno Depressivo Maior/fisiopatologia , Feminino , Hipocampo/patologia , Humanos , Estudos Longitudinais , Imagem por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Lobo Temporal/metabolismo
19.
Brain Lang ; 200: 104710, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31739187

RESUMO

This study used voxel-based lesion-symptom mapping to examine the cortical and white matter regions associated with language production impairments in a sample of 63 preoperative tumour patients. We identified four cognitive functions considered crucial for spoken language production: semantic-to-lexical mapping (selecting the appropriate lexical label for the intended concept); phonological encoding (retrieving the word's phonological form); articulatory-motor planning (programming the articulatory motor movements); and goal-driven language selection (exerting top-down control over the words selected for production). Each participant received a score estimating their competence on each function. We then mapped the region(s) where pathology was significantly associated with low scores. For semantic-to-lexical mapping, the critical map encompassed portions of the left posterior middle and inferior temporal gyri, extending into posterior fusiform gyrus, overlapping substantially with the territory of the inferior longitudinal fasciculus. For phonological encoding, the map encompassed the left inferior parietal lobe and posterior middle temporal gyrus, overlapping with the territory of the inferior longitudinal and posterior arcuate fasciculi. For articulatory-motor planning, the map encompassed parts of the left frontal pole, frontal operculum, and inferior frontal gyrus, and overlapped with the territory of the frontal aslant tract. Finally, the map for goal-driven language selection encompassed the left frontal pole and the anterior cingulate cortex. We compare our findings with those from other neuropsychological samples, and conclude that the study of tumour patients offers evidence that complements that available from other populations.


Assuntos
Mapeamento Encefálico , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/fisiopatologia , Transtornos da Linguagem/patologia , Transtornos da Linguagem/fisiopatologia , Fala/fisiologia , Adolescente , Adulto , Idoso , Neoplasias Encefálicas/complicações , Feminino , Lobo Frontal/patologia , Lobo Frontal/fisiopatologia , Humanos , Transtornos da Linguagem/complicações , Masculino , Pessoa de Meia-Idade , Semântica , Lobo Temporal/patologia , Lobo Temporal/fisiopatologia , Substância Branca/patologia , Substância Branca/fisiopatologia , Adulto Jovem
20.
J Neurosci ; 40(3): 682-693, 2020 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-31754015

RESUMO

Memory deficits are common in epilepsy patients. In these patients, the interictal EEG commonly shows interictal epileptiform discharges (IEDs). While IEDs are associated with transient cognitive impairments, it remains poorly understood why this is. We investigated the effects of human (male and female) hippocampal IEDs on single-neuron activity during a memory task in patients with medically refractory epilepsy undergoing depth electrode monitoring. We quantified the effects of hippocampal IEDs on single-neuron activity and the impact of this modulation on subjectively declared memory strength. Across all recorded neurons, the activity of 50 of 728 neurons were significantly modulated by IEDs, with the strongest modulation in the medial temporal lobe (33 of 416) and in particular the right hippocampus (12 of 58). Putative inhibitory neurons, as identified by their extracellular signature, were more likely to be modulated by IEDs than putative excitatory neurons (19 of 157 vs 31 of 571). Behaviorally, the occurrence of hippocampal IEDs was accompanied by a disruption of recognition of familiar images only if they occurred up to 2 s before stimulus onset. In contrast, IEDs did not impair encoding or recognition of novel images, indicating high temporal and task specificity of the effects of IEDs. The degree of modulation of individual neurons by an IED correlated with the declared confidence of a retrieval trial, with higher firing rates indicative of reduced confidence. Together, these data link the transient modulation of individual neurons by IEDs to specific declarative memory deficits in specific cell types, thereby revealing a mechanism by which IEDs disrupt medial temporal lobe-dependent declarative memory retrieval processes.SIGNIFICANCE STATEMENT Interictal epileptiform discharges (IEDs) are thought to be a cause of memory deficits in chronic epilepsy patients, but the underlying mechanisms are not understood. Utilizing single-neuron recordings in epilepsy patients, we found that hippocampal IEDs transiently change firing of hippocampal neurons and disrupted selectively the retrieval, but not encoding, of declarative memories. The extent of the modulation of the individual firing of hippocampal neurons by an IED predicted the extent of reduction of subjective retrieval confidence. Together, these data reveal a specific kind of transient cognitive impairment caused by IEDs and link this impairment to the modulation of the activity of individual neurons. Understanding the mechanisms by which IEDs impact memory is critical for understanding memory impairments in epilepsy patients.


Assuntos
Hipocampo/fisiopatologia , Transtornos da Memória/fisiopatologia , Transtornos da Memória/psicologia , Neurônios , Convulsões/fisiopatologia , Convulsões/psicologia , Adulto , Idoso , Eletroencefalografia , Epilepsia do Lobo Temporal , Feminino , Humanos , Masculino , Rememoração Mental , Pessoa de Meia-Idade , Reconhecimento Psicológico , Lobo Temporal/fisiopatologia , Adulto Jovem
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