Performance of intraoperative neurocognitive tests during awake surgery for patients with diffuse low-grade glioma.

Despite great advancements and the diffusion of awake surgery for brain tumors, the literature shows that the tests applied during the procedure are heterogeneous and non-standardized. This prospective, observational, descriptive study collected data on intraoperative brain mapping and the performance of multiple neurocognitive tests in 51 awake surgeries for diffuse low-grade glioma. Frequency of use and rate of intraoperative findings of different neurocognitive tests were analyzed. Patients mean age at the time of surgery was 35.1 (20-57) years. We performed 26 (51.0%) surgeries on the left hemisphere (LH) and 25 (49.0%) on the right hemisphere (RH). Significant differences were observed between the total number of functional findings (cortical and subcortical) identified in the LH and RH (p = 0.004). In subcortical findings alone, the differences remained significant (p = 0.0004). The RH subcortical region showed the lowest number of intraoperative findings, and this was correlated with functional outcome: Karnofsky performance scale at five days (p = 0.022), three months (p = 0.002) and one year (p = 0.002) post-surgery. On average, more tests were used to map the RH, with a lower frequency of both cortical and subcortical functional findings. Even though subcortical findings were less frequent than cortical findings, they were crucial to defining the resection margins. Based on the intraoperative findings, frequency of use, and rate of findings per use of the tests analyzed, the most relevant tests for each hemisphere for awake brain mapping were identified.

Effect of transcranial direct current stimulation in the initial weeks post-stroke: a pilot randomized study

ABSTRACT Objective This study aimed at assessing the alterations in upper limb motor impairment and connectivity between motor areas following the post-stroke delivery of cathodal transcranial direct current stimulation sessions. Methods Modifications in the Fugl-Meyer Assessment scores, connectivity between the primary motor cortex of the unaffected and affected hemispheres, and between the primary motor and premotor cortices of the unaffected hemisphere were compared prior to and following six sessions of cathodal transcranial direct current stimulation application in 13 patients (active = 6; sham = 7); this modality targets the primary motor cortex of the unaffected hemisphere early after a stroke. Results Clinically relevant distinctions in Fugl-Meyer Assessment scores (≥9 points) were observed more frequently in the Sham Group than in the Active Group. Between-group differences in the alterations in Fugl-Meyer Assessment scores were not statistically significant (Mann-Whitney test, p=0.133). ROI-to-ROI correlations between the primary motor cortices of the affected and unaffected hemispheres post-therapeutically increased in 5/6 and 2/7 participants in the Active and Sham Groups, respectively. Between-group differences in modifications in connectivity between the aforementioned areas were not statistically significant. Motor performance enhancements were more frequent in the Sham Group compared to the Active Group. Conclusion The results of this hypothesis-generating investigation suggest that heightened connectivity may not translate into early clinical benefits following a stroke and will be crucial in designing larger cohort studies to explore mechanisms underlying the impacts of this intervention. ClinicalTrials.gov Identifier: NCT02455427.

High-beta oscillations at EEG resting state and hyperconnectivity of pain circuitry in fibromyalgia: an exploratory cross-sectional study.

Background: Electroencephalography (EEG) has identified neural activity in specific brain regions as a potential indicator of the neural signature of chronic pain. This study compared the lagged coherence connectivity between regions of interest (ROIs) associated with the pain connectome in women with fibromyalgia (FM) and healthy women (HC). Methods: We evaluated 64 participants (49 FM and 15 HC) during resting-state EEG sessions under both eyes open (EO) and eyes closed (EC) conditions. In addition to EEG measurements, we assessed clinical and psychological symptoms and serum levels of brain-derived neurotrophic factor (BDNF). The connectivity between eight ROIs was computed across eight different EEG frequencies. Results: The FM group demonstrated increased connectivity between the left dorsolateral prefrontal cortex (DLPFC) and right anterior cingulate cortex (ACC), specifically in the beta-3 frequency band (t = 3.441, p = 0.044). When comparing the EO and EC conditions, FM patients exhibited heightened interhemispheric connectivity between insular areas (t = 3.372, p = 0.024) and between the left insula (INS) and right DLPFC (t = 3.695, p = 0.024) within the beta-3 frequency band. In the EC condition, there was a negative correlation between pain disability and connectivity in the beta-3 frequency band between the left ACC and the left primary somatosensory cortex (SI; r = -0.442, p = 0.043). In the EO condition, there was a negative correlation between central sensitization severity and lagged coherence connectivity in the alpha-2 frequency band between the right ACC and left SI (r = 0.428, p = 0.014). Moreover, in the EO-EC comparison, the lagged coherence connection between the left DLPFC and right INS, indexed by the gamma frequency band, showed a negative correlation with serum BDNF levels (r = -0.506, p = 0.012). Conclusion: These findings indicate that increased connectivity between different pain processing circuits, particularly in the beta-3 frequency band during rest, may serve as neural biomarkers for the chronic pain brain signature associated with neuroplasticity and the severity of FM symptoms.

Intra and inter-individual variability in functional connectomes of patients with First Episode of Psychosis.

Patients with Schizophrenia may show different clinical presentations, not only regarding inter-individual comparisons but also in one specific subject over time. In fMRI studies, functional connectomes have been shown to carry valuable individual level information, which can be associated with cognitive and behavioral variables. Moreover, functional connectomes have been used to identify subjects within a group, as if they were fingerprints. For the particular case of Schizophrenia, it has been shown that there is reduced connectome stability as well as higher inter-individual variability. Here, we studied inter and intra-individual heterogeneity by exploring functional connectomes' variability and related it with clinical variables (PANSS Total scores and antipsychotic's doses). Our sample consisted of 30 patients with First Episode of Psychosis and 32 Healthy Controls, with a test-retest approach of two resting-state fMRI scanning sessions. In our patients' group, we found increased deviation from healthy functional connectomes and increased intragroup inter-subject variability, which was positively correlated to symptoms' levels in six subnetworks (visual, somatomotor, dorsal attention, ventral attention, frontoparietal and DMN). Moreover, changes in symptom severity were positively related to changes in deviation from healthy functional connectomes. Regarding intra-subject variability, we were unable to replicate previous findings of reduced connectome stability (i.e., increased intra-subject variability), but we found a trend suggesting that result. Our findings highlight the relevance of variability characterization in Schizophrenia, and they can be related to evidence of Schizophrenia patients having a noisy functional connectome.

Exploring clinical outcomes in patients with idiopathic/inherited isolated generalized dystonia and stimulation of the subthalamic region / Explorando os desfechos clínicos em pacientes com distonia idiopática/hereditária generalizada isolada submetidos a estimulação da região subtalâmica

Abstract Background Deep Brain Stimulation (DBS) is an established treatment option for refractory dystonia, but the improvement among the patients is variable. Objective To describe the outcomes of DBS of the subthalamic region (STN) in dystonic patients and to determine whether the volume of tissue activated (VTA) inside the STN or the structural connectivity between the area stimulated and different regions of the brain are associated with dystonia improvement. Methods The response to DBS was measured by the Burke-Fahn-Marsden Dystonia Rating Scale (BFM) before and 7 months after surgery in patients with generalized isolated dystonia of inherited/idiopathic etiology. The sum of the two overlapping STN volumes from both hemispheres was correlated with the change in BFM scores to assess whether the area stimulated inside the STN affects the clinical outcome. Structural connectivity estimates between the VTA (of each patient) and different brain regions were computed using a normative connectome taken from healthy subjects. Results Five patients were included. The baseline BFM motor and disability subscores were 78.30 ± 13.55 (62.00-98.00) and 20.60 ± 7.80 (13.00-32.00), respectively. Patients improved dystonic symptoms, though differently. No relationships were found between the VTA inside the STN and the BFM improvement after surgery (p = 0.463). However, the connectivity between the VTA and the cerebellum structurally correlated with dystonia improvement (p = 0.003). Conclusions These data suggest that the volume of the stimulated STN does not explain the variance in outcomes in dystonia. Still, the connectivity pattern between the region stimulated and the cerebellum is linked to outcomes of patients.

Resumo Antecedentes A estimulação cerebral profunda (ECP) é um tratamento estabelecido para distonias refratárias. Porém, a melhora dos pacientes é variável. Objetivo O objetivo do estudo foi descrever os desfechos da ECP da região do núcleo subtalâmico (NST) e determinar se o volume de tecido ativado (VTA) dentro do NST ou se a conectividade estrutural entre a área estimulada e diferentes regiões cerebrais estão associadas a melhora da distonia. Métodos A resposta da ECP em pacientes com distonia generalizada isolada de etiologia hereditária/idiopática foi mensurada pela escala de Burke-Fahr-Marsden Dystonia Rating Scale (BFM) antes e 7 meses após a cirurgia. A soma dos volumes do NST nos dois hemisférios foi correlacionada com a melhora nos escores do BFM para avaliar se a área estimulada dentro do NST afeta o desfecho clínico. A conectividade estrutural estimada entre o VTA de cada paciente e as diferentes regiões cerebrais foram computadas usando um conectoma normativo retirado de indivíduos saudáveis. Resultados Cinco pacientes com idade de 40,00 ± 7,30 anos foram incluídos. O BFM motor e de incapacidade basal eram de 78,30 ± 13,55 (62,00-98,00) e 20,60 ± 7,80 (13,00-32,00), respectivamente. Os pacientes melhoraram com a cirurgia, mas com variabilidade. Não houve relação entre o VTA dentro do NST e a melhora do BFM após a cirurgia (p = 0.463). Entretanto, a conectividade estrutural entre o VTA e o cerebelo correlacionaram com a melhora da distonia (p = 0.003). Conclusão Os dados sugerem que o VTA dentro do NST não explica a variabilidade do desfecho clínico na distonia. Porém, o padrão de conectividade entre a região estimulada e o cerebelo foi relacionada com o desfecho dos pacientes.

Brain morphological variability between whites and African Americans: the importance of racial identity in brain imaging research.

In a segregated society, marked by a historical background of inequalities, there is a consistent under-representation of ethnic and racial minorities in biomedical research, causing disparities in understanding genetic and acquired diseases as well as in the effectiveness of clinical treatments affecting different groups. The repeated inclusion of small and non-representative samples of the population in neuroimaging research has led to generalization bias in the morphological characterization of the human brain. A few brain morphometric studies between Whites and African Americans have reported differences in orbitofrontal volumetry and insula cortical thickness. Nevertheless, these studies are mostly conducted in small samples and populations with cognitive impairment. For this reason, this study aimed to identify brain morphological variability due to racial identity in representative samples. We hypothesized that, in neurotypical young adults, there are differences in brain morphometry between participants with distinct racial identities. We analyzed the Human Connectome Project (HCP) database to test this hypothesis. Brain volumetry, cortical thickness, and cortical surface area measures of participants identified as Whites (n = 338) or African Americans (n = 56) were analyzed. Non-parametrical permutation analysis of covariance between these racial identity groups adjusting for age, sex, education, and economic income was implemented. Results indicated volumetric differences in choroid plexus, supratentorial, white matter, and subcortical brain structures. Moreover, differences in cortical thickness and surface area in frontal, parietal, temporal, and occipital brain regions were identified between groups. In this regard, the inclusion of sub-representative minorities in neuroimaging research, such as African American persons, is fundamental for the comprehension of human brain morphometric diversity and to design personalized clinical brain treatments for this population.

Use of Connectomes in Deep Brain Stimulation for the Treatment of Obsessive-Compulsive Disorder / Uso de conectomas na estimulação cerebral profunda para tratamento de transtorno obsessivo-compulsivo

Obsessive-compulsive disorder (OCD) is a psychiatric disorder characterized by the performance of repetitive behaviors in response to an obsession, which currently ranks as the tenth cause of disability in the world. Patients who are refractory to conventional treatment are candidates for the neurosurgical treatment of deep brain stimulation (DBS). In this procedure, electrodes are implanted in specific anatomical brain targets. The present systematic literature review aimed to describe the main connectomes and associate them with their respective targets involved in DBS for the treatment of OCD, to understand the connectomes related to OCD and their contributions to DBS, and to describe the main targets used in DBS surgery for OCD. Based on the present results, the stimulated targets that showed better clinical outcomes were the anterior limb of the internal capsule, the nucleus accumbens, the subthalamic nucleus, and the ventral capsule/striatal capsule. The target associated with the worst clinical results was the posterior limb of the anterior commissure. The variable stimulation of certain regions of the brain determines different clinical results. However, an individualized investigation of the OCD patient is essential for choosing the best target for DBS.

O transtorno obsessivo-compulsivo (TOC) é uma doença psiquiátrica caracterizada pela realização de comportamentos repetitivos em resposta a uma obsessão, que atualmente se enquadra como a décima causa de incapacidade do mundo. Pacientes refratários ao tratamento convencional são candidatos para o tratamento neurocirúrgico de estimulação cerebral profunda (ECP). Neste procedimento, eletrodos são implantados em alvos anatômicos específicos do cérebro. A presente revisão sistemática da literatura teve como objetivo descrever os principais conectomas e associá-los aos seus respectivos alvos envolvidos no ECP para o tratamento de TOC, compreender os conectomas relacionados ao TOC e suas contribuições para o ECP e descrever os principais alvos utilizados na cirurgia de ECP para TOC. Com base nos nossos resultados, os alvos estimulados que apresentaram melhores resultados clínicos foram o membro anterior da cápsula interna, o núcleo accumbens, o núcleo subtalâmico e cápsula ventral/cápsula estriatal. O alvo associado aos piores resultados clínicos foi o membro posterior da comissura anterior. A estimulação variável de determinadas regiões do cérebro determina resultados clínicos diferentes. No entanto, uma investigação individualizada do paciente com TOC é essencial para a escolha do melhor alvo para ECP.

Superficial white matter bundle atlas based on hierarchical fiber clustering over probabilistic tractography data.

The study of short association fibers is still an incomplete task due to their higher inter-subject variability and the smaller size of this kind of fibers in comparison to known long association bundles. However, their description is essential to understand human brain dysfunction and better characterize the human brain connectome. In this work, we present a multi-subject atlas of short association fibers, which was computed using a superficial white matter bundle identification method based on fiber clustering. To create the atlas, we used probabilistic tractography from one hundred subjects from the HCP database, aligned with non-linear registration. The method starts with an intra-subject clustering of short fibers (30-85 mm). Based on a cortical atlas, the intra-subject cluster centroids from all subjects are segmented to identify the centroids connecting each region of interest (ROI) of the atlas. To reduce computational load, the centroids from each ROI group are randomly separated into ten subgroups. Then, an inter-subject hierarchical clustering is applied to each centroid subgroup, followed by a second level of clustering to select the most-reproducible clusters across subjects for each ROI group. Finally, the clusters are labeled according to the regions that they connect, and clustered to create the final bundle atlas. The resulting atlas is composed of 525 bundles of superficial short association fibers along the whole brain, with 384 bundles connecting pairs of different ROIs and 141 bundles connecting portions of the same ROI. The reproducibility of the bundles was verified using automatic segmentation on three different tractogram databases. Results for deterministic and probabilistic tractography data show high reproducibility, especially for probabilistic tractography in HCP data. In comparison to previous work, our atlas features a higher number of bundles and greater cortical surface coverage.

El cerebro ¿Una máquina analógica con funcionamiento cuántico? / The brain. An analogic machine with quantum functioning?

Resumen La neurociencia moderna aborda el problema de funcionamiento global del cerebro para poder comprender los procesos neurobiológicos que subyacen a las funciones mentales, y especialmente, a la consciencia. La actividad cerebral está basada en el intercambio de información entre neuronas a través de contactos llamados sinapsis. Las neuronas forman redes de conexión entre ellas (circuitos), que están dedicados a procesar una parcela específica de información (visual, auditiva, motora…). Los circuitos establecen redes entre ellos, combinando diferentes modalidades de información para generar lo que conocemos como actividad mental. El estudio de las conexiones entre regiones corticales, que se ha llamado conectoma, está siendo abordado mediante técnicas de neuroimagen como la resonancia magnética nuclear, que aportan datos sobre la densidad de conexiones del cerebro. La capacidad del cerebro de crear nuevas conexiones en función de la experiencia (plasticidad cerebral), sugiere que el conectoma es una estructura dinámica en constante interacción con estímulos externos e internos. La pregunta sobre si el conocimiento del conectoma de un individuo nos per mitiría predecir su conducta parece que todavía no tiene respuesta clara, porque no conocemos los parámetros físicos que ligan la complejidad de las conexiones del cerebro con la aparición de las funciones mentales y de la consciencia. Por el momento, parece que la compleja e impredecible conducta no es el simple resultado de procesos lineales de interacción neuronal. La incertidumbre prima al determinismo, lo que abre la puerta a la posibilidad de un mecanismo cuántico para explicar la consciencia.

Abstract Modern neuroscience addresses the problem of the global functioning of the brain in order to understand the neurobiological processes that underlie mental functions, and especially, consciousness. Brain activity is based on the exchange of infor mation between neurons through contacts or synapses. Neurons form networks of connection between them (circuits), which are dedicated to processing a specific type of information (visual, auditory, motor…). The circuits establish networks among themselves, combining different modalities of information to generate what we know as mental activity. The study of connections between cortical regions, which has been called connectome, is being approached through neuroimaging techniques such as nuclear magnetic resonance that provide data on the density of connections in the brain. The brain's ability to create new connections based on experience (brain plasticity) suggests that the connectome is a dynamic structure in constant interaction with external and internal stimuli. The question about whether knowledge of an individual's connectome would allow us to predict his or her behavior seems to have no clear answer yet, because we do not know the physical parameters that link the complexity of the brain's connections with the appearance of mental functions and consciousness. At the moment, it seems that the complex and unpredictable behavior is not the simple result of linear processes of neuronal interaction. Uncertainty prevails over determinism, which opens the door to the possibility of a quantum mechanism to explain consciousness.

[The brain. An analogic machine with quantum functioning?] / El cerebro ¿una máquina analógica con funcionamiento cuántico?

Modern neuroscience addresses the problem of the global functioning of the brain in order to understand the neurobiological processes that underlie mental functions, and especially, consciousness. Brain activity is based on the exchange of information between neurons through contacts or synapses. Neurons form networks of connection between them (circuits), which are dedicated to processing a specific type of information (visual, auditory, motor ...). The circuits establish networks among themselves, combining different modalities of information to generate what we know as mental activity. The study of connections between cortical regions, which has been called connectome, is being approached through neuroimaging techniques such as nuclear magnetic resonance that provide data on the density of connections in the brain. The brain's ability to create new connections based on experience (brain plasticity) suggests that the connectome is a dynamic structure in constant interaction with external and internal stimuli. The question about whether knowledge of an individual's connectome would allow us to predict his or her behavior seems to have no clear answer yet, because we do not know the physical parameters that link the complexity of the brain's connections with the appearance of mental functions and consciousness. At the moment, it seems that the complex and unpredictable behavior is not the simple result of linear processes of neuronal interaction. Uncertainty prevails over determinism, which opens the door to the possibility of a quantum mechanism to explain consciousness.

La neurociencia moderna aborda el problema de funcionamiento global del cerebro para poder comprender los procesos neurobiológicos que subyacen a las funciones mentales, y especialmente, a la consciencia. La actividad cerebral está basada en el intercambio de información entre neuronas a través de contactos llamados sinapsis. Las neuronas forman redes de conexión entre ellas (circuitos), que están dedicados a procesar una parcela específica de información (visual, auditiva, motora ...). Los circuitos establecen redes entre ellos, combinando diferentes modalidades de información para generar lo que conocemos como actividad mental. El estudio de las conexiones entre regiones corticales, que se ha llamado conectoma, está siendo abordado mediante técnicas de neuroimagen como la resonancia magnética nuclear, que aportan datos sobre la densidad de conexiones del cerebro. La capacidad del cerebro de crear nuevas conexiones en función de la experiencia (plasticidad cerebral), sugiere que el conectoma es una estructura dinámica en constante interacción con estímulos externos e internos. La pregunta sobre si el conocimiento del conectoma de un individuo nos permitiría predecir su conducta parece que todavía no tiene respuesta clara, porque no conocemos los parámetros físicos que ligan la complejidad de las conexiones del cerebro con la aparición de las funciones mentales y de la consciencia. Por el momento, parece que la compleja e impredecible conducta no es el simple resultado de procesos lineales de interacción neuronal. La incertidumbre prima al determinismo, lo que abre la puerta a la posibilidad de un mecanismo cuántico para explicar la consciencia.

Emergent dynamics in a robotic model based on the Caenorhabditis elegans connectome.

We analyze the neural dynamics and their relation with the emergent actions of a robotic vehicle that is controlled by a neural network numerical simulation based on the nervous system of the nematode Caenorhabditis elegans. The robot interacts with the environment through a sensor that transmits the information to sensory neurons, while motor neurons outputs are connected to wheels. This is enough to allow emergent robot actions in complex environments, such as avoiding collisions with obstacles. Working with robotic models makes it possible to simultaneously keep track of the dynamics of all the neurons and also register the actions of the robot in the environment in real time, while avoiding the complex technicalities of simulating a real environment. This allowed us to identify several relevant features of the neural dynamics associated with the emergent actions of the robot, some of which have already been observed in biological worms. These results suggest that some basic aspects of behaviors observed in living beings are determined by the underlying structure of the associated neural network.

Long-term stability of the cortical volumetric profile and the functional human connectome throughout childhood and adolescence.

There is compelling evidence showing that between-subject variability in several functional and structural brain features is sufficient for unique identification in adults. However, individuation of brain functional connectomes depends on the stabilization of neurodevelopmental processes during childhood and adolescence. Here, we aimed to (1) evaluate the intra-subject functional connectome stability over time for the whole brain and for large scale functional networks and (2) determine the long-term identification accuracy or 'fingerprinting' for the cortical volumetric profile and the functional connectome. For these purposes, we analysed a longitudinal cohort of 239 children and adolescents scanned in two sessions with an interval of approximately 3 years (age range 6-15 years at baseline and 9-18 years at follow-up). Corroborating previous results using short between-scan intervals in children and adolescents, we observed a moderate identification accuracy (38%) for the whole functional profile. In contrast, identification accuracy using cortical volumetric profile was 95%. Among the large-scale networks, the default-mode (26.8%), the frontoparietal (23.4%) and the dorsal-attention (27.6%) networks were the most discriminative. Our results provide further evidence for a protracted development of specific individual structural and functional connectivity profiles.

Inferring the heritability of large-scale functional networks with a multivariate ACE modeling approach.

Recent evidence suggests that the human functional connectome is stable at different timescales and is unique. These characteristics posit the functional connectome not only as an individual marker but also as a powerful discriminatory measure characterized by high intersubject variability. Among distinct sources of intersubject variability, the long-term sources include functional patterns that emerge from genetic factors. Here, we sought to investigate the contribution of additive genetic factors to the variability of functional networks by determining the heritability of the connectivity strength in a multivariate fashion. First, we reproduced and extended the connectome fingerprinting analysis to the identification of twin pairs. Then, we estimated the heritability of functional networks by a multivariate ACE modeling approach with bootstrapping. Twin pairs were identified above chance level using connectome fingerprinting, with monozygotic twin identification accuracy equal to 57.2% on average for whole-brain connectome. Additionally, we found that a visual (0.37), the medial frontal (0.31), and the motor (0.30) functional networks were the most influenced by additive genetic factors. Our findings suggest that genetic factors not only partially determine intersubject variability of the functional connectome, such that twins can be identified using connectome fingerprinting, but also differentially influence connectivity strength in large-scale functional networks.

Commute Time as a Method to Explore Brain Functional Connectomes.

Graph theory has been extensively applied to investigate complex brain networks in current neuroscience research. Many metrics derived from graph theory, such as local and global efficiencies, are based on the path length between nodes. These approaches are commonly used in analyses of brain networks assessed by resting-state functional magnetic resonance imaging, although relying on the strong assumption that information flow throughout the network is restricted to the shortest paths. In this study, we propose the utilization of commute time as a tool to investigate regional centrality on the functional connectome. Our initial hypothesis was that an alternative approach that considers alternative routes (such as commute time) could provide further information into the organization of functional networks. However, our empirical findings on the ADHD-200 database suggest that at the group level, the commute time and shortest path are highly correlated. In contrast, at the subject level, we discovered that commute time is much less susceptible to head motion artifacts when compared with metrics based on shortest paths. Given the overall similarity between the measures, we argue that commute time might be advantageous particularly for connectomic studies in populations where motion artifacts are a major issue.

Descobertas nos estudos das afasias com imagens de Tensor de Difusão / Findings in studies of aphasia with Diffusion Tensor Images

Haja vista que as pesquisas sobre o conectoma estão causando uma mudança de paradigma no campo da neurobiologia da linguagem, esta revisão concentra-se em descobertas das neurociências sobre o conectoma humanoem relação às afasias pós-trauma ao utilizar imagens de tensor de difusão. Esta pesquisa é qualitativa, do tipo exploratória, caracterizando-se por uma revisão de literatura que compreendeu 16 artigos em língua inglesa publicados nos períodos de 2011 a 2016. Os resultados apontaram para a relação entre melhora da afasia e lateralização hemisférica; confirmaram o fascículo arqueado como uma importante via para a função da linguagem, não só na produção, como na compreensão; evidenciaram o papel funcional do fascículo uncinado no controle semântico e também indicaram a importância dos tractos temporais principalmente na compreensão da linguagem. Percebe-se que as pesquisas ainda possuem limitações principalmente quanto ao número de sujeitos investigados. Ainda faltam estudos sobre previsão de prognóstico dasafasias, bem como de mecanismos de recuperação. (AU)

Considering that research into the connectome are causing a paradigm shift in the field of neurobiology of language, this review focuses on findings of neuroscience on the human connectome in relation to post stroke aphasia using diffusion tensor imaging. This research is qualitative, exploratory, characterizedby a literature review that included 16 articles in English published in the periods 2011 to 2016. The results pointed to the relationship between aphasia improvement and hemispheric lateralization; confirmed the arcuate fasciculusas an important pathway for the function of language, not only in language production but also in understanding; evidenced the functional role of uncinatefasciculus in semantic control and indicated the importance of temporal tracts mainly in language comprehension. It is noticed that the researches still have limitations mainly regarding the number of subjects investigated. There is still alack of studies on prediction of aphasia prognosis, as well as mechanisms of recovery. (AU)

Descobertas nos estudos das afasias com imagens de Tensor de Difusão / Findings in studies of aphasia with Diffusion Tensor Images

Haja vista que as pesquisas sobre o conectoma estão causando uma mudança de paradigma no campo da neurobiologia da linguagem, esta revisão concentra-se em descobertas das neurociências sobre o conectoma humano em relação às afasias pós-trauma ao utilizar imagens de tensor de difusão. Esta pesquisa é qualitativa, do tipo exploratória, caracterizando-se por uma revisão de literatura que compreendeu 16 artigos em língua inglesa publicados nos períodos de 2011 a 2016. Os resultados apontaram para a relação entre melhora da afasia e lateralização hemisférica; confirmaram o fascículo arqueado como uma importante via para a função da linguagem, não só na produção, como na compreensão; evidenciaram o papel funcional do fascículo uncinado no controle semântico e também indicaram a importância dos tractos temporais principalmente na compreensão da linguagem. Percebe-se que as pesquisas ainda possuem limitações principalmente quanto ao número de sujeitos investigados. Ainda faltam estudos sobre previsão de prognóstico das afasias, bem como de mecanismos de recuperação.

Considering that research into the connectome are causing a paradigm shift in the field of neurobiology of language, this review focuses on findings of neuroscience on the human connectome in relation to post stroke aphasia using diffusion tensor imaging. This research is qualitative, exploratory, characterizedby a literature review that included 16 articles in English published in the periods 2011 to 2016. The results pointed to the relationship between aphasia improvement and hemispheric lateralization; confirmed the arcuate fasciculusas an important pathway for the function of language, not only in language production but also in understanding; evidenced the functional role of uncinatefasciculus in semantic control and indicated the importance of temporal tracts mainly in language comprehension. It is noticed that the researches still have limitations mainly regarding the number of subjects investigated. There is still alack of studies on prediction of aphasia prognosis, as well as mechanisms of recovery