Search Results (100)

Major depressive disorder is a mental health condition characterized by ongoing feelings of sadness, trouble focusing or making decisions, and a frequent sense of fatigue or hopelessness that lasts for a prolonged period. If left undiagnosed, it can have serious consequences, including suicide. This study proposes a 3D convolutional neural network model to detect major depressive disorder using 3D grey matter images from magnetic resonance imaging. The proposed 3D convolutional architecture comprises multiple hierarchical convolutional and pooling layers, designed to automatically learn spatial patterns from magnetic resonance imaging data. The model was optimized via Bayesian hyperparameter tuning, achieving an accuracy of 72.26%, an area under the receiver operating characteristic curve of 0.80, and an area under the precision–recall curve of 0.81 on a large multisite dataset comprising 1276 patients and 1104 healthy controls. Gradient-weighted class activation mapping is utilized to find brain regions associated with major depressive disorder. From this study, six regions were identified, namely, the frontal lobe, parietal lobe, temporal lobe, thalamus, insular cortex and corpus callosum which may be affected by major depressive disorder. Full article

Long-term physical training is known to induce brain plasticity, yet how these neural adaptations evolve across different stages of training remains underexplored. This two-year longitudinal study investigated the stage-dependent effects of endurance running on brain structure and resting-state function in healthy college students. Thirty participants were recruited into three groups based on their endurance training level: high-level runners, moderate-level runners, and sedentary controls. All participants underwent baseline and two-year follow-up MRI scans, including T1-weighted structural imaging and resting-state fMRI. The results revealed that the high-level runners exhibited a significant increase in degree centrality (DC) in the left dorsolateral prefrontal cortex (DLPFC). In the moderate-level group, more widespread changes were observed, including increased gray matter volume (GMV) in bilateral prefrontal cortices, medial frontal regions, the right insula, the right putamen, and the right temporo-parieto-occipital junction, along with decreased GMV in the posterior cerebellum. Additionally, DC decreased in the left thalamus and increased in the right temporal lobe and bilateral DLPFC; the fractional amplitude of low-frequency fluctuations (fALFF) in the right precentral gyrus was also elevated. These brain regions are involved in executive control, sensorimotor integration, and motor coordination, which may suggest potential functional implications for cognitive and motor performance; however, such interpretations should be viewed cautiously given the modest sample size and study duration. No significant changes were found in the control group. These findings demonstrate that long-term endurance training induces distinct patterns of brain plasticity at different training stages, with more prominent and widespread changes occurring during earlier phases of training. Full article

We previously reported that the fathers of the Bien Hoa birth cohort in Vietnam showed altered brain regional gray matter volumes, as measured by magnetic resonance imaging, and social anxiety traits associated with perinatal dioxin exposure. In the present study, we aimed to compare gray matter volumes and social anxiety scale scores between dioxin-exposed fathers in Bien Hoa and unexposed controls in an unsprayed area. Fat-based bioassay-toxic equivalency levels in serum were used to indicate dioxin exposure in adulthood. Results indicated that the longer Bien Hoa residency group (≥30 years) exposed to dioxins during the perinatal period and early childhood showed higher gray matter volumes in the right and left temporal lobes than controls. However, no significant differences in temporal lobe gray matter volumes were found between the shorter Bien Hoa residency group (<30 years) and controls. Furthermore, the longer, but not shorter, Bien Hoa residency group showed higher social–emotional subscale scores than controls. Additionally, fat-based bioassay-toxic equivalency levels were inversely correlated with gray matter volumes in several right temporal gyri. These findings suggest biphasic life stage-dependent adverse effects of dioxin exposure: perinatal dioxin exposure increases gray matter volumes, especially in the temporal lobe, which leads to neurodevelopmental disorders with socio-emotional disturbances, whereas dioxin exposure after brain development decreases cortical gray matter volumes, possibly leading to cognitive dysfunction. Full article

Background: Developmental dyslexia (DD) is the most common form of specific learning disorders (SLDs). From a neurocognitive point of view, dyslexic reading is associated with atypical neurofunctional patterns in the left hemisphere, mainly in the posterior areas linked to lexical access and phonological processing. Nowadays, rehabilitation treatments do not aim to fix the disorder but rather improve adaptive skills. On the other hand, the transcranial direct current stimulation (tDCS) has recently gained popularity in this field. In fact, a few studies have documented enhanced accuracy and speed after the tDCS over the parietal cortex, although the results were mainly limited to non-word reading. Methods: We conducted a single-case study employing an innovative multifocal eight-channel tDCS aimed at increasing the reading network activity in the left hemisphere and inhibiting the contralateral areas. The participant was a 9-year-old boy with a diagnosis of severe mixed-type specific learning disorder. The high-definition multifocal tDCS was administered over key areas of the frontal, temporal, parietal, and occipital lobes (four 3.14 cm² electrodes per hemisphere) in conjunction with tachistoscope training over a span of 10 weeks, with three sessions per week for a total of thirty sessions. Standardized assessments of reading were carried out at the beginning, at the end of the treatment, and at one- and six-month follow-up. Results: The treatment led to a 77% improvement in the accuracy of passage reading and an 83% improvement in the reading of high-frequency short words, with stable results at the 1- and 6-month follow-up. By contrast, in line with the severity of the disorder, there were only slight improvements in the speed parameter. Conclusions: This is the first study to document such remarkable improvements in reading in a case of severe SLD: if confirmed, these promising findings could pave the way for an effective, non-invasive rehabilitation for SLDs using multifocal tDCS. However, future studies are needed to overcome the limitations of single-case studies, such as the lack of control conditions and quantifiable analysis. Full article

Background: Congenital anosmia (CA) is a rare condition characterized by a lifelong inability to perceive odors, which significantly affects daily life and may be linked to broader neurodevelopmental alterations. This study aimed to investigate structural brain differences in patients with CA using MRI, focusing on gray matter (GM) and white matter (WM) changes and their implications for neurodevelopment. Methods: This retrospective study included 28 patients with CA and 28 age- and gender-matched healthy controls. Patients with CA were diagnosed at a single medical center between 1 January 2001 and 30 August 2024. Controls were randomly selected from an imaging database and had no history of olfactory dysfunction. Brain Magnetic Resonance Imaging (MRI)was analyzed using volumetric analysis in SPM12.GM and WM volumes were quantified across 11 anatomical brain regions based on theWFU_PickAtlas toolbox, including frontal, temporal, parietal, occipital, limbic, sub-lobar, cerebellum (anterior/posterior), midbrain, the pons, and the frontal–temporal junction. Left–right hemispheric comparisons were also conducted. Results: Patients with CA exhibited significantly smaller GM volumes compared to healthy controls (560.6 ± 114.7 cc vs. 693.7 ± 96.3 cc, p < 0.001) but larger WM volumes (554.2 ± 75.4 cc vs. 491.1 ± 79.7 cc, p = 0.015). Regionally, GM reductions were observed in the frontal (131.9 ± 33.7 cc vs. 173.7 ± 27.0 cc, p < 0.001), temporal (81.1 ± 18.4 cc vs. 96.5 ± 14.1 cc, p = 0.001), parietal (52.4 ± 15.2 cc vs. 77.2 ± 12.4 cc, p < 0.001), sub-lobar (57.8 ± 9.7 cc vs. 68.2 ± 10.2 cc, p = 0.001), occipital (39.1 ± 13.0 cc vs. 57.8 ± 8.9 cc, p < 0.001), and midbrain (2.0 ± 0.5 cc vs. 2.3 ± 0.4 cc, p = 0.006) regions. Meanwhile, WM increases were notable in the frontal(152.0 ± 19.9 cc vs. 139.2 ± 24.0 cc, p = 0.027), temporal (71.5 ± 11.5 cc vs. 60.8 ± 9.5 cc, p = 0.001), parietal (75.8 ± 12.4 cc vs. 61.9 ± 11.5 cc, p < 0.001), and occipital (58.7 ± 10.3 cc vs. 41.9 ± 7.9 cc, p < 0.001) lobes. A separate analysis of the left and right hemispheres revealed similar patterns of reduced GM and increased WM volumes in patients with CA across both sides. An exception was noted in the right cerebellum-posterior, where patients with CA showed significantly greater WM volume (5.625 ± 1.667 cc vs. 4.666 ± 1.583 cc, p = 0.026). Conclusions: This study demonstrates widespread structural brain differences in individuals with CA, including reduced GM and increased WM volumes across multiple cortical and sub-lobar regions. These findings suggest that congenital olfactory deprivation may impact brain maturation beyond primary olfactory pathways, potentially reflecting altered synaptic pruning and increased myelination during early neurodevelopment. The involvement of the cerebellum further implies potential adaptations beyond motor functions. These structural differences may serve as potential neuroimaging markers for monitoring CA-associated cognitive or emotional comorbidities. Full article

(1) Background: Evidence from non-human animal and spaceflight analog studies have suggested that traveling to outer space could have a significant impact on the structural properties of the hippocampus, a brain region within the medial temporal lobe that is critical for learning and memory. Here, we tested this hypothesis in a group of astronauts who participated in a six-month mission in the International Space Station (ISS). (2) Methods: We collected magnetic resonance imaging (MRI) scans from a sample of 17 (9 males, 8 females) astronauts before and after the ISS mission, and calculated percent gray matter volume changes in the whole hippocampus and its (anterior, body, and posterior) subregions in both hemispheres. (3) Following the six-month mission in the ISS, we found a significantly decreased volume in the whole left hippocampus; in addition, when looking at subregions separately, we detected a significantly decreased volume in the anterior subregion of the left hippocampus and the body subregion of the right hippocampus. We also found a significantly decreased volume in the whole right hippocampus of male astronauts as compared to female astronauts. (4) Conclusions: This study, providing the very first evidence of hippocampal volumetric changes in astronauts following a six-month mission to the ISS, could have significant implications for cognitive performance during future long-duration spaceflights. Full article

We present a rare case of a 16-year-old male who was admitted with bilateral tinnitus and subsequently underwent magnetic resonance imaging (MRI) and digital subtraction angiography (DSA) for further evaluation. The left internal carotid (ICA) artery had a normal caliber but ended as a stump at the C7 segment, with a network of filiform vessels from both the stump and right posterior communicating artery (PComm). The right PComm was hypertrophic and the right posterior cerebral artery (PCA) was mainly supplied by the right ICA. The right ICA’s bifurcation and the initial middle cerebral artery (MCA) segment were absent, while the MCA trunk was hypoplastic. The right PCA and pial branches vascularized the temporal lobe, with collaterals between the PCA and MCA. The left ICA was slightly enlarged with double fenestration at the left A1 segment. The right A1 segment of the anterior cerebral artery had double fenestration and while several diagnoses were considered, no single diagnosis fully explained all clinical findings. A thorough review of the existing literature yielded no comparable cases, highlighting the uniqueness of this presentation. This case emphasizes the complexity of cerebral vascular anomalies and the challenges associated with diagnosing such rare conditions, underscoring the need for careful assessment. Full article

Depression has become one of the most common mental illnesses, causing severe physical and mental harm. To clarify the impact of brain region segmentation on the detection accuracy of moderate-to-severe major depressive disorder (MDD) and identify the optimal brain region for detecting MDD using electroencephalography (EEG), this study compared eight traditional single-machine learning algorithms with a hybrid machine learning model based on a stacking ensemble technique. The hybrid model employed K-nearest neighbors (KNN), decision tree (DT), and Extreme Gradient Boosting (XGBoost) as base learners and used a DT as the meta-learner. Compared with traditional single methods, the hybrid approach significantly improved detection accuracy by leveraging the strengths of different algorithms. In addition, this study divided the brain regions into the left and right temporal lobes and extracted both linear and nonlinear features to comprehensively capture the complexity and dynamic behavior of EEG signals, enhancing the model’s ability to distinguish features across different brain regions. The experimental results showed that among the eight traditional machine learning methods, the KNN classifier achieved the highest detection accuracy of 96.97% in the left temporal lobe region. In contrast, the stacking hybrid learning model further increased the detection accuracy to 98.07%, significantly outperforming the single models. Moreover, the analysis of the brain region segmentation revealed that the left temporal lobe exhibited higher discriminative power in detecting MDD, highlighting its important role in the neurobiology of depression. This study provides a solid foundation for developing more efficient and portable methods for detecting depression, offering new perspectives and approaches for EEG-based MDD detection, and contributing to the improvement in objectivity and precision in depression diagnosis. Full article

Introduction: Neurodegenerative diseases like progressive supranuclear palsy (PSP) present challenges concerning their diagnosis. Neuroimaging using magnetic resonance (MRI) may add diagnostic value. However, modern techniques such as volumetric assessment using Voxel-Based Morphometry (VBM), although proven to be more accurate and superior compared to MRI, have not gained popularity among scientists in the investigation of neurological disorders due to their higher cost and time-consuming applications. Conventional brain MRI methods may present a quick, practical, and easy-to-use imaging rating tool for the differential diagnosis of PSP. The purpose of this study is to evaluate a string of existing visual MRI rating scales and signs regarding their impact for the diagnosis of PSP. Materials and Methods: The population study consisted of 30 patients suffering from PSP and 72 healthy controls. Each study participant underwent a brain MRI, which was subsequently examined by two independent researchers in a double-blinded fashion. Fifteen visual rating scales and signs were evaluated, including pontine atrophy, cerebellar atrophy, midbrain atrophy, aqueduct of Sylvius enlargement, cerebellar peduncle hyperintensities, enlargement of the fourth ventricle (100% sensitivity and 71% specificity) and left temporal lobe atrophy (97% sensitivity and 78% specificity). Conclusions: Enlargement of the Sylvius aqueduct, enlargement of the fourth ventricle and atrophy of both temporal lobes together with the presence of morning glory and hummingbird signs can be easily and quickly distinguished and identified by an experienced radiologist without involving any complex analysis, making them useful tools for PSP diagnosis. MRI visual scale measurements could be added to the diagnostic criteria of PSP and may serve as an alternative to highly technical and more sophisticated quantification methods. Full article

Background: Carotid web (CaW) usually presents as a shelf-like intimal flap at the beginning of the internal carotid artery. It has been proven that CaW is associated with ischemic stroke, particularly in young patients without other risk factors. This case report aimed to describe the carotid web that causes ischemic stroke due to embolic complications. Moreover, both pathologies were successfully treated with endovascular techniques in the presented case study. Methods: A 59-year-old male presented to the neurological department with motor aphasia, right-sided weakness, and hypoesthesia. Computer tomography (CT) of the head and computed tomography angiography (CTA) of the aortic arch and intracranial arteries were performed. Due to the unknown onset of the presented stroke symptoms, diagnostics were extended to magnetic resonance (MR), and based on this, the patient qualified for immediate mechanical thrombectomy (according to the DAWN trial protocol). Intraoperative digital subtraction angiography (DSA) revealed embolism material in the left middle cerebral artery (segment M1). The artery was recanalized via aspiration thrombectomy using the Penumbra system, and complete restoration of flow was obtained (according to the TICI scale). In addition, DSA revealed the presence of CaW changes in the left internal carotid artery (LICA). In the control CT scanning, an acute ischemic area in the left temporal lobe was found. After the treatment, the patient demonstrated complete neurological improvement from his initial presentation. He qualified for carotid artery stenting of the LICA, which was postponed to a later period due to the presence of an area of infarction. The angioplasty with stenting was performed 6 months later, and a carotid antiembolic “mesh” stent (Roadsaver, Terumo) was implanted into the LICA across the carotid web. Conclusions: CaW should be considered in the case of stroke resulting from unknown causes. The presented case study demonstrated that both carotid web and ischemic stroke pathologies can be effectively treated with emerging endovascular techniques. Full article

Objective: Temporal lobe epilepsy (TLE) constitutes the most common drug-refractory epilepsy syndrome. Tailored approaches are required, as TLE originates from extrahippocampal lesions in about one-quarter of surgical candidates. Despite high success rates in seizure control, concern persists regarding postoperative memory decline after lesionectomy. We investigated the associations between structural connectivity and postoperative memory performance in extrahippocampal TLE surgery. Methods: In total, 55 patients (25 females, 30 males; mean age 29.8 ± 14.5 years; epilepsy duration 7.9 ± 10.5 years, 31 left, 24 right TLE) with extrahippocampal TLE undergoing hippocampal-sparing surgery were evaluated with standardized pre- and postoperative neuropsychological testing. Lesion volumes intersected with Human Connectome Project-derived tractography data were employed to assess the structural connectivity integrity via voxel-based and connectome-informed lesion–symptom mapping to identify cortical and white matter structures associated with cognitive outcomes. Results: Post-surgery, the widespread structural disconnection of several major white matter pathways was found, correlating with verbal memory and delayed recall. Additionally, the structural disconnection of the ipsilateral temporal lobe white matter was further associated with hippocampal atrophy. Conclusions: Our study highlights the role of structural connectivity alterations in postoperative memory decline in extrahippocampal TLE surgery. These findings expand the traditional understanding of hippocampal integrity in memory function towards the importance of broader structural networks. Individualized, connectome-informed surgical approaches might protect neurocognitive function. Full article

Continuous metrics of cerebral autoregulation (CA) assessment have been developed using various multimodal cerebral physiological monitoring devices. However, CA regional disparity remains unclear in states of health and disease. Leveraging existing archived data sources, we preliminarily evaluated regional hemispheric disparity in CA using the near infrared spectroscopy (NIRS)-derived cerebral oximetry index (COx/COx-a). Along with bilateral NIRS, regional cerebral oxygen saturation, arterial blood pressure, cerebral perfusion pressure, and bilateral COx/COx-a were derived using three different temporal resolutions—10 s, 1 min, and 5 min—based on non-overlapping mean values. The regional disparity between hemispheres was evaluated based on median and median absolute deviation. Further, patient-level autoregressive integrative moving average models were calculated for each signal stream and used to generate personalized vector autoregressive models. Multi-variate cerebral physiologic relationships between hemispheres were assessed via impulse response functions and Granger causality analyses. Data from 102 healthy control volunteers, 27 spinal surgery patients, and 95 TBI patients (varying in frontal lobe pathology impacting the optode path; 64 without bifrontal lobe pathology, 15 without left frontal lobe pathology, 11 without right frontal lobe pathology, and 5 with bifrontal lobe pathology) were retrospectively analyzed. For subjects with or without cranial pathology, no difference in COx/COx-a was found between hemispheres regardless of the analytic method. In TBI patients without pathology underneath the NIRS sensor, distant parenchymal injury does not seem to have an effect on the CA of uninjured frontal lobes. Further work is required to characterize regional disparities with multi-channel CA measurements in healthy and disease states. Full article

Background/Objectives: Recent theories of the neurocognitive architecture of semantic memory have included a distinction between semantic control in the left inferior frontal gyrus (LIFG) and semantic representation in the left anterior temporal lobe (LATL). Support for this distinction has been found both in tasks in which high semantic selection demands have been instantiated and in tasks in which previous presentations of semantic information that compete with target information have been instantiated. Methods: In the current study, these manipulations were combined in a novel manner into a single task in which brand-name product pictures were used. Functional near-infrared spectroscopy (fNIRS) was used to measure hemodynamic activity and tensor decomposition, in addition to grand averaging, was used to analyze the fNIRS output. Results: Both analytic methods converged on the same set of findings. That is, in line with past studies, greater activity in the LIFG was observed in the competitive condition than in a repeated condition. However, unlike past studies, greater activity in the competitive condition was also observed in both the left and right anterior temporal lobes (ATLs). Conclusions: While it was possible that the novel combination of high selection and competition into a single task unlocked a semantic selection mechanism in the bilateral ATL, a number of other post-hoc explanations were offered for this unusual finding, including a re-interpretation of the high-selection task as an ad hoc categorization task. Finally, the convergence of the tensor decomposition and grand averaging approaches on the same set of findings supported tensor decomposition as a viable approach to the analysis of fNIRS data. Full article

Background: Unilateral basal ganglia calcinosis (BGC) is a rare radiological finding that can be diagnosed on computed tomography (CT) and magnetic resonance imaging (MRI) but often presents challenges for clinicians and radiologists in determining its underlying cause. So far, only a few potential causes that could explain unilateral BGC have been described in the literature. Case Report: A 54-year-old Caucasian male was admitted to a tertiary university hospital due to the sudden onset of speech impairment and right-sided weakness. The patient had no significant medical history prior to this event. Non-enhanced computed tomography (NECT) of the brain revealed no evidence of acute ischemia; CT angiography (CTA) showed acute left middle cerebral artery (MCA) M2 segment occlusion. CT perfusion (CTP) maps revealed an extensive penumbra-like lesion, which is potentially reversible upon achieving successful recanalization. However, a primary neoplastic tumor with calcifications in the basal ganglia was initially interpreted as the potential cause; therefore, acute stroke treatment with intravenous thrombolysis was contraindicated. A follow-up CT examination at 24 h revealed an ischemic lesion localized to the left insula, predominantly involving the left parietal lobe and the superior gyrus of the left temporal lobe. Subsequent gadolinium-enhanced brain MRI revealed small blood vessels draining into the subependymal periventricular veins on the left basal ganglia. Digital subtraction angiography was conducted, confirming the diagnosis of venous angioma. Conclusions: Unilateral BGC caused by venous angioma is a rare entity with unclear pathophysiological mechanisms and heterogeneous clinical presentation. It may mimic conditions such as intracerebral hemorrhage or hemorrhagic brain tumors, complicating acute stroke management, as demonstrated in this case. Surrounding tissue calcification may provide a valuable radiological clue in diagnosing venous angiomas DVAs and vascular malformations. Full article

A major scientific objective of cognitive neuroscience is to define cortico-cortical functional connections supporting cognitive functions. Here, we use an original approach combining frequency-tagging and direct electrical stimulation (DES) to test for bidirectional and cross-hemispheric category-specific modulations within the human cortical face network. A unique patient bilaterally implanted with depth electrodes in multiple face-selective cortical regions of the ventral occipito-temporal cortex (VOTC) was shown 70 s sequences of variable natural object images at a 6 Hz rate, objectively identifying deviant face-selective neural activity at 1.2 Hz (i.e., every five images). Concurrent electrical stimulation was separately applied for 10 seconds on four independently defined face-selective sites in the right and left VOTC. Upon stimulation, we observed reduced or even abolished face-selective neural activity locally and, most interestingly, at distant VOTC recording sites. Remote DES effects were found up to the anterior temporal lobe (ATL) in both forward and backward directions along the VOTC, as well as across the two hemispheres. This reduction was specific to face-selective neural activity, with the general 6 Hz visual response being mostly unaffected. Overall, these results shed light on the functional connectivity of the cortical face-selective network, supporting its non-hierarchical organization as well as bidirectional effective category-selective connections between posterior ‘core’ regions and the ATL. They also pave the way for widespread and systematic development of this approach to better understand the functional and effective connectivity of human brain networks. Full article