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1.
Schizophr Res ; 271: 394-401, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38729789

RESUMO

BACKGROUND: Schizophrenia (SZ) is characterized by disconnected cerebral networks. Recent studies have shown that functional connectivity between the cerebellar dorsal dentate nucleus (dDN) and cerebrum is correlated with psychotic symptoms, and processing speed in SZ patients. Dynamic effective connectivity (dEC) is a reliable indicator of brain functional status. However, the dEC between the dDN and cerebrum in patients with SZ remains largely unknown. METHODS: Resting-state functional MRI data, symptom severity, and cognitive performance were collected from 74 SZ patients and 53 healthy controls (HC). Granger causality analysis and sliding time window methods were used to calculate dDN-based dEC maps for all subjects, and k-means clustering was performed to obtain several dEC states. Finally, between-group differences in dynamic effective connectivity variability (dECV) and clinical correlations were obtained using two-sample t-tests and correlation analysis. RESULTS: We detected four dEC states from the cerebrum to the right dDN (IN states) and three dEC states from the right dDN to the cerebrum (OUT states), with SZ group having fewer transitions in the OUT states. SZ group had increased dECV from the right dDN to the right middle frontal gyrus (MFG) and left lingual gyrus (LG). Correlations were found between the dECV from the right dDN to the right MFG and symptom severity and between the dECV from the right dDN to the left LG and working memory performance. CONCLUSIONS: This study reveals a dynamic causal relationship between cerebellar dDN and the cerebrum in SZ and provides new evidence for the involvement of cerebellar neural circuits in neurocognitive functions in SZ.


Assuntos
Núcleos Cerebelares , Disfunção Cognitiva , Conectoma , Imageamento por Ressonância Magnética , Esquizofrenia , Humanos , Esquizofrenia/diagnóstico por imagem , Esquizofrenia/fisiopatologia , Esquizofrenia/patologia , Masculino , Feminino , Núcleos Cerebelares/diagnóstico por imagem , Núcleos Cerebelares/fisiopatologia , Adulto , Disfunção Cognitiva/fisiopatologia , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/etiologia , Cérebro/diagnóstico por imagem , Cérebro/fisiopatologia , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/fisiopatologia , Pessoa de Meia-Idade
2.
Sci Rep ; 14(1): 11287, 2024 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-38760449

RESUMO

Spectrum power analysis in the low frequency oscillations (LFO) region of functional near infrared spectroscopy (fNIRS) is a promising method to deliver information about brain activation and therefore might be used for prognostication in patients with disorders of consciousness in the neurocritical care unit alongside with established methods. In this study, we measure the cortical hemodynamic response measured by fNIRS in the LFO region following auditory and somatosensory stimulation in healthy subjects. The significant hemodynamic reaction in the contralateral hemisphere correlation with the physiologic electric response suggests neurovascular coupling. In addition, we investigate power spectrum changes in steady state measurements of cerebral death patients and healthy subjects in the LFO region, the frequency of the heartbeat and respiration. The spectral power within the LFO region was lower in the patients with cerebral death compared to the healthy subjects, whereas there were no differences in spectral power for physiological activities such as heartbeat and respiration rate. This finding indicates the cerebral origin of our low frequency measurements. Therefore, LFO measurements are a potential method to detect brain activation in patients with disorders of consciousness and cerebral death. However, further studies in patients are needed to investigate its potential clinical use.


Assuntos
Morte Encefálica , Cérebro , Acoplamento Neurovascular , Espectroscopia de Luz Próxima ao Infravermelho , Humanos , Masculino , Feminino , Adulto , Idoso , Morte Encefálica/diagnóstico por imagem , Hemodinâmica , Prognóstico , Cérebro/irrigação sanguínea , Cérebro/diagnóstico por imagem , Frequência Cardíaca , Taxa Respiratória
3.
Ann Neurol ; 95(5): 941-950, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38362961

RESUMO

OBJECTIVE: To investigate the relationship between neurocognitive deficits and structural changes on brain magnetic resonance imaging in people living with HIV (PLWH) with good virological control on combination antiretroviral therapy, compared with socioeconomically matched control participants recruited from the same communities. METHODS: Brain magnetic resonance imaging scans, and clinical and neuropsychological data were obtained from virologically controlled PLWH (viral load of <50 c/mL and at least 1 year of combination antiretroviral therapy) and socioeconomically matched control participants. Magnetic resonance imaging was carried out on 3 T scanner with 8-channel head coils and segmented using Classification using Derivative-based Features. Multiple regression analysis was performed to examine the association between brain volume and various clinical and neuropsychiatric parameters adjusting for age, race, and sex. To evaluate longitudinal changes in brain volumes, a random coefficient model was used to evaluate the changes over time (age) adjusting for sex and race. RESULTS: The cross-sectional study included 164 PLWH and 51 controls, and the longitudinal study included 68 PLWH and 20 controls with 2 or more visits (mean 2.2 years, range 0.8-5.1 years). Gray matter (GM) atrophy rate was significantly higher in PLWH compared with control participants, and importantly, the GM and global atrophy was associated with the various neuropsychological domain scores. Higher volume of white matter hyperintensities were associated with increased atherosclerotic cardiovascular disease risk score, and decreased executive functioning and memory domain scores in PLWH. INTERPRETATION: These findings suggest ongoing neurological damage even in virologically controlled participants, with significant implications for clinical management of PLWH. ANN NEUROL 2024;95:941-950.


Assuntos
Substância Cinzenta , Infecções por HIV , Transtornos Neurocognitivos , Substância Branca , Humanos , Estudos Transversais , Infecções por HIV/complicações , Infecções por HIV/diagnóstico por imagem , Infecções por HIV/patologia , Infecções por HIV/terapia , Transtornos Neurocognitivos/diagnóstico por imagem , Substância Branca/diagnóstico por imagem , Substância Branca/patologia , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/patologia , Adulto , Pessoa de Meia-Idade , Masculino , Feminino , Cérebro/diagnóstico por imagem , Cérebro/patologia , Estudos Longitudinais
4.
Stroke Vasc Neurol ; 9(3): 306-317, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38336368

RESUMO

BACKGROUND: Acupuncture involving the limb region may be effective for stroke rehabilitation clinically, but the visualised and explanatory evidence is limited. Our objectives were to assess the specific effects of acupuncture for ischaemic stroke (IS) patients with hemiparesis and investigate its therapy-driven modification in functional connectivity. METHODS: IS patients were randomly assigned (2:1) to receive 10 sessions of hand-foot 12 needles acupuncture (HA, n=30) or non-acupoint (NA) acupuncture (n=16), enrolling gender-matched and age-matched healthy controls (HCs, n=34). The clinical outcomes were the improved Fugl-Meyer Assessment scores including upper and lower extremity (ΔFM, ΔFM-UE, ΔFM-LE). The neuroimaging outcome was voxel-mirrored homotopic connectivity (VMHC). Static and dynamic functional connectivity (sFC, DFC) analyses were used to study the neuroplasticity reorganisation. RESULTS: 46 ISs (mean(SD) age, 59.37 (11.36) years) and 34 HCs (mean(SD) age, 52.88 (9.69) years) were included in the per-protocol analysis of clinical and neuroimaging. In clinical, ΔFM scores were 5.00 in HA group and 2.50 in NA group, with a dual correlation between ΔFM and ΔVMHC (angular: r=0.696, p=0.000; cerebellum: r=-0.716, p=0.000) fitting the linear regression model (R2=0.828). In neuroimaging, ISs demonstrated decreased VMHC in bilateral postcentral gyrus and cerebellum (Gaussian random field, GRF corrected, voxel p<0.001, cluster p<0.05), which fitted the logistic regression model (AUC=0.8413, accuracy=0.7500). Following acupuncture, VMHC in bilateral superior frontal gyrus orbital part was increased with cerebro-cerebellar changes, involving higher sFC between ipsilesional superior frontal gyrus orbital part and the contralesional orbitofrontal cortex as well as cerebellum (GRF corrected, voxel p<0.001, cluster p<0.05). The coefficient of variation of VMHC was decreased in bilateral posterior cingulate gyrus (PPC) locally (GRF corrected, voxel p<0.001, cluster p<0.05), with integration states transforming into segregation states overall (p<0.05). There was no acupuncture-related adverse event. CONCLUSIONS: The randomised clinical and neuroimaging trial demonstrated acupuncture could promote the motor recovery and modified cerebro-cerebellar VMHC via bilateral static and dynamic reorganisations for IS patients with hemiparesis.


Assuntos
Terapia por Acupuntura , Cerebelo , AVC Isquêmico , Paresia , Recuperação de Função Fisiológica , Humanos , Feminino , Masculino , Pessoa de Meia-Idade , Idoso , AVC Isquêmico/fisiopatologia , AVC Isquêmico/terapia , AVC Isquêmico/diagnóstico por imagem , AVC Isquêmico/diagnóstico , Resultado do Tratamento , Cerebelo/fisiopatologia , Cerebelo/diagnóstico por imagem , Paresia/fisiopatologia , Paresia/etiologia , Paresia/terapia , Paresia/diagnóstico por imagem , Imageamento por Ressonância Magnética , Cérebro/diagnóstico por imagem , Cérebro/fisiopatologia , Plasticidade Neuronal , Adulto , Avaliação da Deficiência , Fatores de Tempo , Reabilitação do Acidente Vascular Cerebral , Estado Funcional
5.
J Anat ; 243(4): 690-696, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37218094

RESUMO

The human cerebral cortex is highly convoluted forming patterns of gyri separated by sulci. The cerebral sulci and gyri are fundamental in cortical anatomy as well as neuroimage processing and analysis. Narrow and deep cerebral sulci are not fully discernible either on the cortical or white matter surface. To cope with this limitation, I propose a new sulci presentation method that employs the inner cortical surface for sulci examination from the inside of the cerebrum. The method has four steps, construct the cortical surface, segment and label the sulci, dissect (open) the cortical surface, and explore the fully exposed sulci from the inside. The inside sulcal maps are created for the left and right lateral, left and right medial, and basal hemispheric surfaces with the sulci parcellated by color and labeled. These three-dimensional sulcal maps presented here are probably the first of this kind created. The proposed method demonstrates the full course and depths of sulci, including narrow, deep, and/or convoluted sulci, which has an educational value and facilitates their quantification. In particular, it provides a straightforward identification of sulcal pits which are valuable markers in studying neurologic disorders. It enhances the visibility of sulci variations by exposing branches, segments, and inter-sulcal continuity. The inside view also clearly demonstrates the sulcal wall skewness along with its variability and enables its assessment. Lastly, this method exposes the sulcal 3-hinges introduced here.


Assuntos
Cérebro , Substância Branca , Humanos , Cérebro/diagnóstico por imagem , Córtex Cerebral/anatomia & histologia , Substância Branca/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos
6.
Oper Neurosurg (Hagerstown) ; 25(1): 3-10, 2023 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-37083688

RESUMO

BACKGROUND: Understanding the anatomy of the human cerebrum, cerebellum, and brainstem and their 3-dimensional (3D) relationships is critical for neurosurgery. Although 3D photogrammetric models of cadaver brains and 2-dimensional images of postmortem brain slices are available, neurosurgeons lack free access to 3D models of cross-sectional anatomy of the cerebrum, cerebellum, and brainstem that can be simulated in both augmented reality (AR) and virtual reality (VR). OBJECTIVE: To create 3D models and AR/VR simulations from 2-dimensional images of cross-sectionally dissected cadaveric specimens of the cerebrum, cerebellum, and brainstem. METHODS: The Klingler method was used to prepare 3 cadaveric specimens for dissection in the axial, sagittal, and coronal planes. A series of 3D models and AR/VR simulations were then created using 360° photogrammetry. RESULTS: High-resolution 3D models of cross-sectional anatomy of the cerebrum, cerebellum, and brainstem were obtained and used in creating AR/VR simulations. Eleven axial, 9 sagittal, and 7 coronal 3D models were created. The sections were planned to show important deep anatomic structures. These models can be freely rotated, projected onto any surface, viewed from all angles, and examined at various magnifications. CONCLUSION: To our knowledge, this detailed study is the first to combine up-to-date technologies (photogrammetry, AR, and VR) for high-resolution 3D visualization of the cross-sectional anatomy of the entire human cerebrum, cerebellum, and brainstem. The resulting 3D images are freely available for use by medical professionals and students for better comprehension of the 3D relationship of the deep and superficial brain anatomy.


Assuntos
Tronco Encefálico , Cérebro , Humanos , Anatomia Transversal , Cerebelo , Cérebro/diagnóstico por imagem , Cadáver
10.
Cerebellum ; 22(5): 781-789, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35933493

RESUMO

Major depressive disorder (MDD) is a serious and widespread psychiatric disorder. Previous studies mainly focused on cerebrum functional connectivity, and the sample size was relatively small. However, functional connectivity is undirected. And, there is increasing evidence that the cerebellum is also involved in emotion and cognitive processing and makes outstanding contributions to the symptomology and pathology of depression. Therefore, we used a large sample size of resting-state functional magnetic resonance imaging (rs-fMRI) data to investigate the altered effective connectivity (EC) among the cerebellum and other cerebral cortex in patients with MDD. Here, from the perspective of data-driven analysis, we used two different atlases to divide the whole brain into different regions and analyzed the alterations of EC and EC networks in the MDD group compared with healthy controls group (HCs). The results showed that compared with HCs, there were significantly altered EC in the cerebellum-neocortex and cerebellum-basal ganglia circuits in MDD patients, which implied that the cerebellum may be a potential biomarker of depressive disorders. And, the alterations of EC brain networks in MDD patients may provide new insights into the pathophysiological mechanisms of depression.


Assuntos
Cérebro , Transtorno Depressivo Maior , Humanos , Transtorno Depressivo Maior/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Encéfalo , Cérebro/diagnóstico por imagem , Cerebelo/diagnóstico por imagem
11.
Cereb Cortex ; 32(22): 5175-5190, 2022 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-35213687

RESUMO

Multiple areas in the cerebellum have been reported to be engaged in reading. However, how these regions cooperate with the reading-related areas in the cerebrum remains unclear. Here, brain images of fifty-two adults were acquired via functional magnetic resonance imaging. By comparing the cerebellar activation across three localization tasks targeting orthographic, phonological, and semantic processing, we first identified three different reading-related areas in the cerebellum, biased toward orthography, phonology, and semantics, respectively. Then, functional connectivity (FC) analyses demonstrated that the mean FC between functionally corresponding areas across the cerebrum and cerebellum was greater than that between noncorresponding areas during silent word reading. FC patterns of functionally corresponding areas could significantly predict reading speed, with the FC driven from orthographic and semantic areas contributing the most. Effective FC analyses further showed that orthographic and semantic areas in the cerebellum had selective and direct connectivity to areas in the cerebrum with similar functional specificity. These results suggest that reading-related areas vary in their functions to reading, and cooperation between areas with corresponding functions was greater than that between noncorresponding areas. These findings emphasize the importance of functional cooperation between the cerebrum and cerebellum during reading from a new perspective.


Assuntos
Cerebelo , Cérebro , Leitura , Mapeamento Encefálico , Cerebelo/diagnóstico por imagem , Cerebelo/fisiologia , Cérebro/diagnóstico por imagem , Cérebro/fisiologia , Imageamento por Ressonância Magnética , Semântica , Humanos , Adulto
12.
Hum Brain Mapp ; 43(4): 1449-1462, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34888973

RESUMO

Aberrant affective neural processing and negative emotional bias are trait-marks of major depression disorders (MDDs). However, most research on biased emotional perception in depression has only focused on unimodal experimental stimuli, the neural basis of potentially biased emotional processing of multimodal inputs remains unclear. Here, we addressed this issue by implementing an audiovisual emotional task during functional MRI scanning sessions with 37 patients with MDD and 37 gender-, age- and education-matched healthy controls. Participants were asked to distinguish laughing and crying sounds while being exposed to faces with different emotional valences as background. We combined general linear model and psychophysiological interaction analyses to identify abnormal local functional activity and integrative processes during audiovisual emotional processing in MDD patients. At the local neural level, MDD patients showed increased bias activity in the ventromedial prefrontal cortex (vmPFC) while listening to negative auditory stimuli and concurrently processing visual facial expressions, along with decreased dorsolateral prefrontal cortex (dlPFC) activity in both the positive and negative visual facial conditions. At the network level, MDD exhibited significantly decreased connectivity in areas involved in automatic emotional processes and voluntary control systems during perception of negative stimuli, including the vmPFC, dlPFC, insula, as well as the subcortical regions of posterior cingulate cortex and striatum. These findings support a multimodal emotion dysregulation hypothesis for MDD by demonstrating that negative bias effects may be facilitated by the excessive ventral bottom-up negative emotional influences along with incapability in dorsal prefrontal top-down control system.


Assuntos
Percepção Auditiva/fisiologia , Mapeamento Encefálico , Cérebro/fisiologia , Transtorno Depressivo Maior/fisiopatologia , Emoções/fisiologia , Reconhecimento Facial/fisiologia , Percepção Social , Adulto , Cérebro/diagnóstico por imagem , Transtorno Depressivo Maior/diagnóstico por imagem , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade
13.
Medicine (Baltimore) ; 100(52): e28389, 2021 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-34967372

RESUMO

RATIONALE: Cerebral air embolism from portal venous gas rarely occurs due to invasive procedures (e.g., endoscopic procedures, liver biopsy, or percutaneous transhepatic biliary drainage) that disrupt the gastrointestinal or hepatobiliary structures. Here, we report a rare case of fatal cerebral air embolism following a series of percutaneous transhepatic biliary drainage tube insertions. PATIENT CONCERNS: A 50-year-old woman with a history of cholecystectomy, liver wedge resection, and hepaticojejunostomy for gallbladder cancer presented with altered mental status 1 week after percutaneous transhepatic biliary drainage tube placement. DIAGNOSES: Extensive cerebral air embolism and acute cerebral infarction. INTERVENTIONS: Brain computed tomography and magnetic resonance imaging, hyperbaric oxygen therapy, medical therapy. OUTCOMES: Despite the use of hyperbaric oxygen therapy and medical treatment including vasopressors, the patient eventually died due to massive systemic air embolism. LESSONS: To date, there have been no reports of cerebral air embolism due to percutaneous transhepatic biliary drainage with pronounced radiologic images. We reviewed previously reported fatal cases associated with endoscopic hepatobiliary procedures and assessed the possible mechanisms and potential causes of air embolism.


Assuntos
Procedimentos Cirúrgicos do Sistema Biliar , Circulação Cerebrovascular , Cérebro/irrigação sanguínea , Embolia Aérea , Neoplasias da Vesícula Biliar/cirurgia , Veia Porta , Procedimentos Cirúrgicos do Sistema Biliar/efeitos adversos , Cérebro/diagnóstico por imagem , Procedimentos Cirúrgicos do Sistema Digestório/efeitos adversos , Drenagem/efeitos adversos , Embolia Aérea/diagnóstico por imagem , Embolia Aérea/etiologia , Embolia Aérea/terapia , Evolução Fatal , Feminino , Hepatectomia , Humanos , Oxigenoterapia Hiperbárica , Fígado/cirurgia , Pessoa de Meia-Idade , Veia Porta/diagnóstico por imagem
14.
Bull Exp Biol Med ; 171(6): 691-694, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34709517

RESUMO

The reactions of microcirculation parameters of symmetrical areas of the human head to hypoxic loads were studied. The study was conducted in 10 healthy male volunteers aged 18-19 years. Short-term hypoxia was modeled using a ReOxy Cardio normobaric device (S. A. Aimediq). Synchronous measurements of microcirculation parameters in symmetrical temporal regions of the head at the basal state and immediately after short-term hypoxic exposure were carried out by the method of laser Doppler flowmetry. We evaluated statistical characteristics of perfusion of both sides, as well as regression characteristics of the relationship between changes in the microcirculation parameters and the initial values of these parameters. It was shown that the reaction of the microcirculation parameters in symmetrical regions of the head to hypoxia depends on the initial microcirculation parameters in ipsi- and contralateral sides. 3D graphs were constructed and regression equations describing these relationships were formulated. A new method of geometric sensing is proposed, which allows predicting the direction of reactions to hypoxic effects. The obtained data illustrate the specificity of regulation of microcirculation of paired organs determined by the presence of functional asymmetry. A new method of geometric zoning is proposed, which allows solving the problems of personalized assessments of the state of the microcirculation system in patients.


Assuntos
Circulação Cerebrovascular/fisiologia , Cérebro/diagnóstico por imagem , Lateralidade Funcional/fisiologia , Hipóxia/diagnóstico por imagem , Microcirculação/fisiologia , Adolescente , Cérebro/irrigação sanguínea , Cérebro/fisiologia , Voluntários Saudáveis , Humanos , Hipóxia/fisiopatologia , Fluxometria por Laser-Doppler , Masculino , Análise de Regressão , Adulto Jovem
15.
J Neurol Neurosurg Psychiatry ; 92(11): 1197-1205, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34168085

RESUMO

OBJECTIVE: Cerebellar disease burden and cerebro-cerebellar connectivity alterations are poorly characterised in amyotrophic lateral sclerosis (ALS) despite the likely contribution of cerebellar pathology to the clinical heterogeneity of the condition. METHODS: A prospective imaging study has been undertaken with 271 participants to systematically evaluate cerebellar grey and white matter alterations, cerebellar peduncle integrity and cerebro-cerebellar connectivity in ALS. Participants were stratified into four groups: (1) patients testing positive for GGGGCC repeat expansions in C9orf72, (2) patients carrying an intermediate-length repeat expansion in ATXN2, (3) patients without established ALS-associated mutations and (4) healthy controls. Additionally, the cerebellar profile of a single patient with ALS who had an ATXN2 allele length of 62 was evaluated. Cortical thickness, grey matter and white matter volumes were calculated in each cerebellar lobule complemented by morphometric analyses to characterise genotype-associated atrophy patterns. A Bayesian segmentation algorithm was used for superior cerebellar peduncle volumetry. White matter diffusivity parameters were appraised both within the cerebellum and in the cerebellar peduncles. Cerebro-cerebellar connectivity was assessed using deterministic tractography. RESULTS: Cerebellar pathology was confined to lobules I-V of the anterior lobe in patients with sporadic ALS in contrast to the considerable posterior lobe and vermis disease burden identified in C9orf72 mutation carriers. Patients with intermediate ATXN2 expansions did not exhibit significant cerebellar pathology. CONCLUSIONS: Focal rather than global cerebellar degeneration characterises ALS. Pathognomonic ALS symptoms which are typically attributed to other anatomical regions, such as dysarthria, dysphagia, pseudobulbar affect, eye movement abnormalities and cognitive deficits, may be modulated, exacerbated or partially driven by cerebellar changes in ALS.


Assuntos
Esclerose Lateral Amiotrófica/diagnóstico por imagem , Cerebelo/diagnóstico por imagem , Cérebro/diagnóstico por imagem , Genótipo , Idoso , Esclerose Lateral Amiotrófica/genética , Proteína C9orf72/genética , Imagem de Tensor de Difusão , Feminino , Substância Cinzenta/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Vias Neurais/diagnóstico por imagem , Estudos Prospectivos , Substância Branca/diagnóstico por imagem
16.
Elife ; 102021 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-34096502

RESUMO

Traditionally, research unraveling seasonal neuroplasticity in songbirds has focused on the male song control system and testosterone. We longitudinally monitored the song behavior and neuroplasticity in male and female starlings during multiple photoperiods using Diffusion Tensor and Fixel-Based techniques. These exploratory data-driven whole-brain methods resulted in a population-based tractogram confirming microstructural sexual dimorphisms in the song control system. Furthermore, male brains showed hemispheric asymmetries in the pallium, whereas females had higher interhemispheric connectivity, which could not be attributed to brain size differences. Only females with large brains sing but differ from males in their song behavior by showing involvement of the hippocampus. Both sexes experienced multisensory neuroplasticity in the song control, auditory and visual system, and cerebellum, mainly during the photosensitive period. This period with low gonadal hormone levels might represent a 'sensitive window' during which different sensory and motor systems in the cerebrum and cerebellum can be seasonally re-shaped in both sexes.


Assuntos
Cerebelo/fisiologia , Cérebro/fisiologia , Plasticidade Neuronal , Estorninhos/fisiologia , Vocalização Animal , Animais , Percepção Auditiva , Cerebelo/diagnóstico por imagem , Cerebelo/metabolismo , Cérebro/diagnóstico por imagem , Cérebro/metabolismo , Imagem de Tensor de Difusão , Estradiol/sangue , Feminino , Masculino , Atividade Motora , Fotoperíodo , Estações do Ano , Caracteres Sexuais , Estorninhos/sangue , Testosterona/sangue , Percepção Visual
17.
Rev. bras. neurol ; 57(2): 8-13, abr.-jun. 2021. tab, ilus
Artigo em Inglês | LILACS | ID: biblio-1280767

RESUMO

Dementia is a syndrome characterized by a decline of two or more cognitive functions, affecting social or professional life. Alzheimer's Disease is a neurodegenerative disorder that represents 53% of dementia cases; memory loss, inability to recognize faces, impaired judgement, disorientation and confusion are possible common symptoms. Vascular Dementia is responsible for 42% of dementia cases, due to cerebrovascular pathologies, and the clinical aspects are related to the extension and location of the brain injury. Lewy Bodies Dementia is a neurodegenerative disorder that represents 15% of dementia cases, and its symptoms include visual hallucinations, parkinsonism and fluctuating cognitive decline. Frontotemporal dementia is a group of clinical syndromes, divided in Behavioral-variant, characterized by disinhibition, compulsions, apathy, aberrant sexual behavior and executive dysfunction; and Primary Progressive Aphasia, which is subdivided in Nonfluentvariant and Semantic-variant. Vitamin B12 deficiency is a reversible cause of dementia, with a wide clinical feature, that includes psychiatric symptoms such as depression and irritability, hematological symptoms related to anemia (e.g. dyspnea and fatigue), and neurological symptoms including dementia and neuropathy. Normal pressure hydrocephalus is also reversible, presenting forgetfulness, changes in mood, decline of executive functions, reduced attention, and a lack of interest in daily activities as symptoms. The radiological findings vary depending on the etiology of dementia. For that reason, understanding neuroimaging and clinical aspects is important to diagnose effectively.


A demência é uma síndrome que consiste em um declínio de um ou mais domínios cognitivos, que afeta o desempenho social ou profissional do indivíduo. A Doença de Alzheimer é um transtorno neurocognitivo que representa 53% dos casos de demência; seus sintomas podem incluir perda de memória, incapacidade de reconhecer rostos familiares, julgamento comprometido desorientação e confusão mental. A Demência Vascular é responsável por 42% dos casos de demência e é causada por doenças cerebrovasculares, seus achados clínicos são relacionados com o local e com a extensão do dano cerebral. Já a Demência por Corpos de Lewy é uma doença neurocognitiva que representa 15% dos casos de demência, cujos sintomas incluem alucinações visuais, parkinsonismo e flutuação cognitiva. A Demência Frontotemporal, por sua vez, é um grupo de síndromes, que se dividem em variante comportamental ­ caracterizada por desinibição, compulsão, apatia, hipersexualidade e disfunções executivas ­ e Afasia Progressiva Primária, subdividida em variante não-fluente e variante semântica, que cursam com disfunções da linguagem. Há, ainda, a Deficiência de Vitamina B12, uma causa reversível de demência. Ela possui um quadro clínico variado, que inclui sintomas psiquiátricos, como depressão e irritabilidade, sintomas hematológicos relacionados a anemia, como dispneia e fadiga) e sintomas neurológicos, que incluem demência e neuropatias. Uma outra causa reversível é a Hidrocefalia de Pressão Normal, que se apresenta com esquecimentos, alterações de humor, perda de função executiva e redução da atenção e do interesse nas atividades cotidianas. Os achados de neuroimagem variam dependendo da etiologia da demência. Assim, compreender os aspectos clínicos e radiológicos é importante para um diagnóstico efetivo..


Assuntos
Humanos , Masculino , Feminino , Idoso , Demência Vascular/diagnóstico , Demência/complicações , Demência/epidemiologia , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/epidemiologia , Deficiência de Vitamina B 12/etiologia , Prevalência , Cérebro/diagnóstico por imagem , Neuroimagem/métodos , Disfunção Cognitiva , Testes de Estado Mental e Demência , Hidrocefalia de Pressão Normal/etiologia , Transtornos da Memória
18.
Hum Brain Mapp ; 42(12): 3760-3776, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-33991155

RESUMO

Recent studies have reported that optical indices of cerebral pulsatility are associated with cerebrovascular health in older adults. Such indices, including cerebral pulse amplitude and the pulse relaxation function (PRF), have been previously applied to quantify global and regional cerebral pulsatility. The aim of the present study was to determine whether these indices are modulated by cardiovascular status and whether they differ between individuals with low or high cardiovascular risk factors (LCVRF and HCVRF) and coronary artery disease (CAD). A total of 60 older adults aged 57-79 were enrolled in the study. Participants were grouped as LCVRF, HCVRF, and CAD. Participants were asked to walk freely on a gym track while a near-infrared spectroscopy (NIRS) device recorded hemodynamics data. Low-intensity, short-duration walking was used to test whether a brief cardiovascular challenge could increase the difference of pulsatility indices with respect to cardiovascular status. Results indicated that CAD individuals have higher global cerebral pulse amplitude compared with the other groups. Walking reduced global cerebral pulse amplitude and PRF in all groups but did not increase the difference across the groups. Instead, walking extended the spatial distribution of cerebral pulse amplitude to the anterior prefrontal cortex when CAD was compared to the CVRF groups. Further research is needed to determine whether cerebral pulse amplitude extracted from data acquired with NIRS, which is a noninvasive, inexpensive method, can provide an index to characterize the cerebrovascular status associated with CAD.


Assuntos
Circulação Cerebrovascular/fisiologia , Cérebro/fisiopatologia , Doença da Artéria Coronariana/fisiopatologia , Neuroimagem Funcional , Pulso Arterial , Espectroscopia de Luz Próxima ao Infravermelho , Idoso , Cérebro/diagnóstico por imagem , Doença da Artéria Coronariana/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
19.
Hum Brain Mapp ; 42(10): 3282-3294, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33934442

RESUMO

Individual-based morphological brain networks built from T1-weighted magnetic resonance imaging (MRI) reflect synchronous maturation intensities between anatomical regions at the individual level. Autism spectrum disorder (ASD) is a socio-cognitive and neurodevelopmental disorder with high neuroanatomical heterogeneity, but the specific patterns of morphological networks in ASD remain largely unexplored at the individual level. In this study, individual-based morphological networks were constructed by using high-resolution structural MRI data from 40 young children with ASD (age range: 2-8 years) and 38 age-, gender-, and handedness-matched typically developing children (TDC). Measurements were recorded as threefold. Results showed that compared with TDC, young children with ASD exhibited lower values of small-worldness (i.e., σ) of individual-level morphological brain networks, increased morphological connectivity in cortico-striatum-thalamic-cortical (CSTC) circuitry, and decreased morphological connectivity in the cortico-cortical network. In addition, morphological connectivity abnormalities can predict the severity of social communication deficits in young children with ASD, thus confirming an associational impact at the behavioral level. These findings suggest that the morphological brain network in the autistic developmental brain is inefficient in segregating and distributing information. The results also highlight the crucial role of abnormal morphological connectivity patterns in the socio-cognitive deficits of ASD and support the possible use of the aberrant developmental patterns of morphological brain networks in revealing new clinically-relevant biomarkers for ASD.


Assuntos
Transtorno do Espectro Autista/patologia , Transtorno do Espectro Autista/fisiopatologia , Cérebro/patologia , Rede Nervosa/patologia , Tálamo/patologia , Transtorno do Espectro Autista/diagnóstico por imagem , Cérebro/diagnóstico por imagem , Criança , Pré-Escolar , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Rede Nervosa/diagnóstico por imagem , Tálamo/diagnóstico por imagem
20.
AJNR Am J Neuroradiol ; 42(7): 1231-1238, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33985952

RESUMO

BACKGROUND AND PURPOSE: The association of perivascular spaces in the centrum semiovale with amyloid accumulation among patients with Alzheimer disease-related cognitive impairment is unknown. We evaluated this association in patients with Alzheimer disease-related cognitive impairment and ß-amyloid deposition, assessed with [18F] florbetaben PET/CT. MATERIALS AND METHODS: MR imaging and [18F] florbetaben PET/CT images of 144 patients with Alzheimer disease-related cognitive impairment were retrospectively evaluated. MR imaging-visible perivascular spaces were rated on a 4-point visual scale: a score of ≥3 or <3 indicated a high or low degree of MR imaging-visible perivascular spaces, respectively. Amyloid deposition was evaluated using the brain ß-amyloid plaque load scoring system. RESULTS: Compared with patients negative for ß-amyloid, those positive for it were older and more likely to have lower cognitive function, a diagnosis of Alzheimer disease, white matter hyperintensity, the Apolipoprotein E ε4 allele, and a high degree of MR imaging-visible perivascular spaces in the centrum semiovale. Multivariable analysis, adjusted for age and Apolipoprotein E status, revealed that a high degree of MR imaging-visible perivascular spaces in the centrum semiovale was independently associated with ß-amyloid positivity (odds ratio, 2.307; 95% CI, 1.036-5.136; P = .041). CONCLUSIONS: A high degree of MR imaging-visible perivascular spaces in the centrum semiovale independently predicted ß-amyloid positivity in patients with Alzheimer disease-related cognitive impairment. Thus, MR imaging-visible perivascular spaces in the centrum semiovale are associated with amyloid pathology of the brain and could be an indirect imaging marker of amyloid burden in patients with Alzheimer disease-related cognitive impairment.


Assuntos
Doença de Alzheimer , Cérebro/diagnóstico por imagem , Disfunção Cognitiva , Sistema Glinfático/diagnóstico por imagem , Placa Amiloide/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/complicações , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides , Cérebro/patologia , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/patologia , Sistema Glinfático/patologia , Humanos , Imageamento por Ressonância Magnética/métodos , Pessoa de Meia-Idade , Placa Amiloide/patologia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Estudos Retrospectivos
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