Frontal Temporal Areas Research Articles

Topological abnormalities of the morphometric similarity network of the cerebral cortex in schizophrenia

A morphometric similarity (MS) network can be constructed using multiple magnetic resonance imaging parameters of each cortical region. An MS network can be used to assess the similarity between cortical regions. Although MS networks can detect microstructural alterations and capture connections between histologically similar cortical areas, the influence of schizophrenia on the topological characteristics of MS networks remains unclear. We obtained T1- and diffusion-weighted images of 239 healthy controls and 190 individuals with schizophrenia to construct the MS network. Group comparisons of the mean MS of the cortical regions and subnetworks were performed. The strengths of the connections between the cortical regions and the global and nodal network indices were compared between the groups. Clinical associations with the network indices were tested using Spearman’s rho. Compared with healthy controls, individuals with schizophrenia had significant group differences in the mean MS of several cortical regions and subnetworks. Individuals with schizophrenia had both superior and inferior strengths of connections between cortical regions compared with those of healthy controls. We observed regional abnormalities of the MS network in individuals with schizophrenia regarding lower centrality values of the pars opercularis, superior frontal, and superior temporal areas. Specific nodal network measures of the right pars opercularis and left superior temporal areas were associated with illness duration in individuals with schizophrenia. We identified regional abnormalities of the MS network in schizophrenia with the left superior temporal area possibly being a key region in topological organization and cortical connections.

Neural Correlates of Motor/Tactile Imagery and Tactile Sensation in a BCI paradigm: A High-Density EEG Source Imaging Study.

Complementary to brain-computer interface (BCI) based on motor imagery (MI) task, sensory imagery (SI) task provides a way for BCI construction using brain activity from somatosensory cortex. The underlying neurophysiological correlation between SI and MI was unclear and difficult to measure through behavior recording. In this study, we investigated the underlying neurodynamic of motor/tactile imagery and tactile sensation tasks through a high-density electroencephalogram (EEG) recording, and EEG source imaging was used to systematically explore the cortical activation differences and correlations between the tasks. In the experiment, participants were instructed to perform the left and right hand tasks in MI paradigm, sensory stimulation (SS) paradigm and SI paradigm. The statistical results demonstrated that the imagined MI and SI tasks differed from each other within ipsilateral sensorimotor scouts, frontal and right temporal areas in α bands, whereas real SS and imagined SI showed a similar activation pattern. The similarity between SS and SI may provide a way to train the BCI system, while the difference between MI and SI may provide a way to integrate the discriminative information between them to enhance BCI performance. The combination of the tasks and its underlying neurodynamic would provide a new approach for BCI designation for a wider application. BCI studies concentrate on the hybrid decoding method combining MI or SI with SS, but the underlining neurophysiological correlates between them were unclear. MI and SI differed from each other within the ipsilateral sensorimotor cortex in alpha bands. This is a first study to investigate the neurophysiological relationship between MI and SI through an EEG source imaging approach from high-density EEG recording.

Neural Oscillations and Functional Significances for Prioritizing Dual-Task Walking in Parkinson's Disease.

Task prioritization involves allocating brain resources in a dual-task scenario, but the mechanistic details of how prioritization strategies affect dual-task walking performance for Parkinson's disease (PD) are little understood. We investigated the performance benefits and corresponding neural signatures for people with PD during dual-task walking, using gait-prioritization (GP) and manual-prioritization (MP) strategies. Participants (N = 34) were asked to hold two inter-locking rings while walking and to prioritize either taking big steps (GP strategy) or separating the two rings (MP strategy). Gait parameters and ring-touch time were measured, and scalp electroencephalograph was performed. Compared with the MP strategy, the GP strategy yielded faster walking speed and longer step length, whereas ring-touch time did not significantly differ between the two strategies. The MP strategy led to higher alpha (8-12 Hz) power in the posterior cortex and beta (13-35 Hz) power in the left frontal-temporal area, but the GP strategy was associated with stronger network connectivity in the beta band. Changes in walking speed and step length because of prioritization negatively correlated with changes in alpha power. Prioritization-related changes in ring-touch time correlated negatively with changes in beta power but positively with changes in beta network connectivity. A GP strategy in dual-task walking for PD can enhance walking speed and step length without compromising performance in a secondary manual task. This strategy augments attentional focus and facilitates compensatory reinforcement of inter-regional information exchange.

Brain connectome-based imaging markers for identifiable signature of migraine with and without aura.

Cortical spreading depression (CSD) has been considered the prominent theory for migraine with aura (MwA). However, it is also argued that CSD can exist in patients in a silent state, and not manifest as aura. Thus, the MwA classification based on aura may be questionable. This study aimed to capture whole-brain connectome-based imaging markers with identifiable signatures for MwA and migraine without aura (MwoA). A total of 88 migraine patients (32 MwA) and 49 healthy controls (HC) underwent a diffusion tensor imaging and resting-state functional magnetic resonance imaging scan. The whole-brain structural connectivity (SC) and functional connectivity (FC) analysis was employed to extract imaging features. The extracted features were subjected to an all-relevant feature selection process within cross-validation loops to pinpoint attributes demonstrating substantial efficacy for patient categorization. Based on the identified features, the predictive ability of the random forest classifiers constructed with the 88 migraine patients' sample was tested using an independent sample of 32 migraine patients (eight MwA). Compared to MwoA and HC, MwA showed two reduced SC and six FC (five increased and one reduced) features [all P<0.01, after false discovery rate (FDR) correction], involving frontal areas, temporal areas, visual areas, amygdala, and thalamus. A total of four imaging features were significantly correlated with clinical rating scales in all patients (r=-0.38 to 0.47, P<0.01, after FDR correction). The predictive ability of the random forest classifiers achieved an accuracy of 78.1% in the external sample to identify MwA. The whole-brain connectivity features in our results may serve as connectome-based imaging markers for MwA identification. The alterations of SC and FC strength provide possible evidence in further understanding the heterogeneity and mechanism of MwA which may help for patient-specific decision-making.

Topographical pattern of blood‐brain barrier impairment in preclinical and clinical Alzheimer’s disease

AbstractBackgroundWhile blood‐brain barrier (BBB) damage in some brain regions has been suggested in Alzheimer’s disease (AD) dementia and mild cognitive impairment (MCI), the topographical pattern of BBB impairment associated with AD process in whole brain level is still poorly understood. Using high‐resolution 3‐dimensional (3D) dynamic contrast‐enhanced (DCE) scans of BBB permeability (K trans) for the whole brain, we aimed to reveal topographical pattern of BBB impairment related to Alzheimer’s disease (AD) including preclinical as well as clinically impaired state.MethodNinety‐one participants were included in the study [45 cognitively normal (CN) older adults, 24 individuals with mild cognitive impairment (MCI), and 22 patients with AD dementia]. Comprehensive clinical and neuropsychological assessments were administered to all participants. High‐resolution DCE‐ as well as T1‐weighted‐MRI scans were obtained in addition to amyloid‐PET scans. Amyloid‐beta (Ab) positivity was obtained using previously established cut‐offs. Preprocessing of K trans maps incorporated FreeSurfer‐based (v6.0) segmentation to ensure exclusion of the voxels within cerebrospinal fluid (CSF) spaces. Voxel‐wise analyses were conducted using SPM12 implemented in MATLAB 2018b.ResultSubtle BBB impairment, as measured by K trans map images based on high‐resolution 3D DCE‐MRI, was observed at multiple brain regions even in preclinical AD (i.e., Ab‐positive CN) as well as AD with cognitive impairment (i.e., Ab‐positive MCI and AD). The brain regions with impaired K trans closely corresponded to the AD‐signature regions (Figure). Compared to Ab‐negative CN, Ab‐positive CN showed increased breakdown of BBB in the precuneus, posterior‐cingulate cortex, and medial temporal lobe. Moreover, compared to Ab‐negative CN, Ab‐positive MCI and AD patients showed increased breakdown of BBB in more diffuse regions including bilateral frontal, parietal and inferior temporal areas. In contrast, when using low‐resolution BBB images for the same participants, BBB damage was not detected in preclinical AD and observed at only limited brain regions in AD with cognitive impairment.ConclusionWe demonstrated topographical pattern of BBB impairment associated with preclinical AD as well as AD with cognitive impairment through technically advanced high‐resolution DCE‐MRI. The findings suggest that subtle BBB changes detectable from high‐resolution DCE‐MRI has potential as a biomarkers for detection and monitoring of BBB impairment in whole AD continuum.

SLEEP MICROARCHITECTURE IN MILD COGNITIVE IMPAIRMENT: A HIGH‐DENSITY EEG STUDY

AbstractBackgroundSleep disturbance and sleep disorders are potential risk factors for dementia. Adults with mild cognitive impairment (MCI) are at increased risk of developing dementia and many report disturbed sleep. Altered sleep neurophysiology including deficits in sleep spindles and slow wave activity (SWA) during NREM sleep have been reported in MCI, though studies are sparse. These NREM EEG oscillations are crucial for overnight memory consolidation and optimal daytime functioning. Abnormal EEG activity during sleep in MCI may adversely impact sleep‐dependent memory processes and cognitive trajectory. This study is the first to examine sleep microarchitecture using high‐density EEG technology in MCI.MethodOlder adults with multi‐domain MCI (n = 19, mean age 68.5 years) and cognitively‐intact controls (n = 22, 69 years) had 256‐channel high‐density EEG recordings during overnight polysomnography and resting wakefulness. Declarative (word paired associates) and procedural (finger tapping) memory tasks were administered before and after sleep. Neuropsychological testing and brain MRI scans were also performed. After artefact processing, spectral analysis was performed for high‐density EEG recordings. Topographical power maps were calculated for standard frequency ranges for NREM sleep (N2 and N3 (slow wave sleep)). Maps were compared between groups using normalized power (z‐scores computed for each subject).ResultThe MCI group had worse declarative (% retention, MCI vs Controls: 84.2 ± 16.6 vs. 94.5 ± 7.8, p = 0.024) and procedural (% early improvement: 92.9 ± 11.0 vs. 103.0 ± 12.0%, p = 0.017) overnight memory consolidation than the controls. Topographic analysis of high‐density EEG data revealed a regional increase in SWA (1‐4.5Hz) EEG power during N3 in a cluster of 18 electrodes overlying the centroparietal cortex in the MCI group (cluster mean t‐value = 3.11, p = 0.0036, uncorrected) and a regional reduction in SWA in the left frontal (5 channels, t = ‐3.75, p&lt;0.001) and right temporal areas (5 channels, t = ‐3.46, p = 0.001), Figure 1.ConclusionOvernight memory consolidation was impaired in this MCI population. Regional differences in SWA during deep sleep were present in distinct brain regions and may indicate pathology. Future analysis exploring associations between EEG abnormalities with underlying brain structures may provide mechanistic insights into the impact of altered sleep neurophysiology on cognitive outcomes in MCI.

Topographical pattern of blood‐brain barrier impairment in preclinical and clinical Alzheimer’s disease

AbstractBackgroundWhile blood‐brain barrier (BBB) damage in some brain regions has been suggested in Alzheimer’s disease (AD) dementia and mild cognitive impairment (MCI), the topographical pattern of BBB impairment associated with AD process in whole brain level is still poorly understood. Using high‐resolution 3‐dimensional (3D) dynamic contrast‐enhanced (DCE) scans of BBB permeability (Ktrans) for the whole brain, we aimed to reveal topographical pattern of BBB impairment related to Alzheimer’s disease (AD) including preclinical as well as clinically impaired state.MethodNinety‐one participants were included in the study [45 cognitively normal (CN) older adults, 24 individuals with mild cognitive impairment (MCI), and 22 patients with AD dementia]. Comprehensive clinical and neuropsychological assessments were administered to all participants. High‐resolution DCE‐ as well as T1‐weighted‐MRI scans were obtained in addition to amyloid‐PET scans. Amyloid‐beta (Ab) positivity was obtained using previously established cut‐offs. Preprocessing of Ktrans maps incorporated FreeSurfer‐based (v6.0) segmentation to ensure exclusion of the voxels within cerebrospinal fluid (CSF) spaces. Voxel‐wise analyses were conducted using SPM12 implemented in MATLAB 2018b.ResultSubtle BBB impairment, as measured by Ktrans map images based on high‐resolution 3D DCE‐MRI, was observed at multiple brain regions even in preclinical AD (i.e., Ab‐positive CN) as well as AD with cognitive impairment (i.e., Ab‐positive MCI and AD). The brain regions with impaired Ktrans closely corresponded to the AD‐signature regions (Figure). Compared to Ab‐negative CN, Ab‐positive CN showed increased breakdown of BBB in the precuneus, posterior‐cingulate cortex, and medial temporal lobe. Moreover, compared to Ab‐negative CN, Ab‐positive MCI and AD patients showed increased breakdown of BBB in more diffuse regions including bilateral frontal, parietal and inferior temporal areas. In contrast, when using low‐resolution BBB images for the same participants, BBB damage was not detected in preclinical AD and observed at only limited brain regions in AD with cognitive impairment.ConclusionWe demonstrated topographical pattern of BBB impairment associated with preclinical AD as well as AD with cognitive impairment through technically advanced high‐resolution DCE‐MRI. The findings suggest that subtle BBB changes detectable from high‐resolution DCE‐MRI has potential as a biomarkers for detection and monitoring of BBB impairment in whole AD continuum.

Isolated Frontosphenoidal Synostosis: Early Clinical Management of a Rare Condition With Distraction Osteogenesis

Isolated frontosphenoidal synostosis (FSS) is an extremely rare pathology in which premature fusion of the frontal and sphenoid bones produces asymmetry of the forehead in a newborn or young child. If left untreated, these children may suffer significant esthetic and neurologic symptoms. Therefore, surgery is time-sensitive and necessary for correction. This report details the case of a male infant who presented to clinic at 3 months of age with unilateral, isolated FSS. Clinical features of this patient included an asymmetric forehead with flattening of the right frontal temporal area, indentation of the right temporal sphenoid area, and inferiorly displaced right orbit. Previous reports have been in older patients who were treated with open fronto-orbital advancement. With the patient’s early presentation, the primary surgical approach deployed here included anterior cranial vault remodeling with right distractor placement and fronto-orbital osteotomy. Four months following the procedure, the patient returned with increased right-sided hypoglobus and enophthalmos. CT imaging revealed a pseudomeningocele, secondary to a dural tear. Consequently, the 7-month-old underwent a second surgery, which included fronto-orbital advancement reconstruction. The child remains stable with improved forehead symmetry at 11 months of age. Due to the rare nature of FSS, treatment options are limited and traditional in their approach. This report aims to contribute additional clinical insights and treatment guidance to the growing body of literature surrounding FSS.

QEEG‐based differentiation between Alzheimer’s disease with or without alpha synucleinopathy

AbstractBackgroundAs existence of alpha synucleniopathy could affect progression of cognitive impairment in Alzheimer’s disease (AD), it’s very important to differentiate comorbidity of alpha synucleniopathy in AD to predict progression. To develop affordable EEG‐based discriminating machine‐learning(ML) algorithm for existence of alpha synucleniopathy, we explore differences between AD with vs without it.MethodBased on pattern of cognitive impairment and 3 types of PET scan [18F‐Florbetaben brain amyloid‐beta, FDG, DAT‐PET] , dementia due to Alzheimer’s disease [pure ADD] or Lewy Body (pure LBD) or mixed type (AD with LB disease) were clinically classified.We measured 19ch resting state EEG based on international 10‐20. Quantitative analysis of EEG was done by iSyncBrain®.ResultPure ADD showed the characteristics that general EEG slowing with low total power, relative delta enhancement and desynchronized alpha with low amplitude. Pure LBD showed the pattern of slow alpha peak frequency with intact synchronization, relatively higher EEG total power and frontotemporal theta enhancement. Compared to pure ADD, ADD with LB showed mixed pattern of ADD and LDB. Total power was higher, alpha wave showed intact synchronization but theta power was rather enhanced at frontal(Fz; p‐value &lt; 0.05) and bilateral temporal(T3,5, T4,6; p‐value &lt; 0.05) area that was reported as characteristic pattern of progressive type of AD by previous studies.ConclusionThese findings imply that ADD could have different EEG oscillation characteristics according to the Lewybody disease. Next step, we will develop the machine‐learning algorithm to discriminate the Lewybody disease based on specific EEG features and validate it.

Atypical prosopagnosia following right hemispheric stroke: A 23-year follow-up study with M.T.

ABSTRACT Most findings on prosopagnosia to date suggest preserved voice recognition in prosopagnosia (except in cases with bilateral lesions). Here we report a follow-up examination on M.T., suffering from acquired prosopagnosia following a large unilateral right-hemispheric lesion in frontal, parietal, and anterior temporal areas excluding core ventral occipitotemporal face areas. Twenty-three years after initial testing we reassessed face and object recognition skills [Henke, K., Schweinberger, S. R., Grigo, A., Klos, T., & Sommer, W. (1998). Specificity of face recognition: Recognition of exemplars of non-face objects in prosopagnosia. Cortex, 34(2), 289–296]; [Schweinberger, S. R., Klos, T., & Sommer, W. (1995). Covert face recognition in prosopagnosia – A dissociable function? Cortex, 31(3), 517–529] and additionally studied voice recognition. Confirming the persistence of deficits, M.T. exhibited substantial impairments in famous face recognition and memory for learned faces, but preserved face matching and object recognition skills. Critically, he showed substantially impaired voice recognition skills. These findings are congruent with the ideas that (i) prosopagnosia after right anterior temporal lesions can persist over long periods > 20 years, and that (ii) such lesions can be associated with both facial and vocal deficits in person recognition.

Morphometric similarity deviations in stimulant use disorder point towards abnormal brain ageing

Chronic drug use negatively impacts ageing, resulting in diminished health and quality of life. However, little is known about biomarkers of abnormal ageing in stimulant drug users. Using morphometric similarity network mapping, a novel approach to structural connectomics, we first mapped cross-sectional morphometric similarity trajectories of ageing in the publicly available Rockland Sample (20–80 years of age, n = 665). We then compared morphometric similarity and neuropsychological function between non-treatment-seeking, actively using patients with stimulant use disorder (n = 183, mean age: 35.6 years) and healthy control participants (n = 148, mean age: 36.0 years). The significantly altered mean regional morphometric similarity was found in 43 cortical regions including the inferior and orbital frontal gyri, pre/postcentral gyri and anterior temporal, superior parietal and occipital areas. Deviations from normative morphometric similarity trajectories in patients with stimulant use disorder suggested abnormal brain ageing. Furthermore, deficits in paired associates learning were consistent with neuropathology associated with both ageing and stimulant use disorder. Morphometric similarity mapping provides a promising biomarker for ageing in health and disease and may complement existing neuropsychological markers of age-related cognitive decline. Neuropathological ageing mechanisms in stimulant use disorder warrant further investigation to develop more age-appropriate treatments for older people addicted to stimulant drugs.

Bioelectric activity of the brain in 3-4 years old children in eyes-open resting state

Background. Electroencephalography is the main technique for assessing the functional state of the brain. Indications for EEG are diagnosis of paroxysmal states, prediction of the outcome of a pathological state, evaluation of bioelectrical activity if brain death is suspected. Up to 90 % of the native EEG in calm wakefulness in healthy individuals is occupied by “alpha activity”. In children in active wakefulness, the EEG pattern depends to a great extent on their age.Objective. The aim of the work was to assess EEG parameters in children aged 3–4 years in eyes-open resting state. Design and methods. 31 healthy participants aged 3–4 years were enrolled. EEG was registered for 30 minutes in a state of passive wakefulness in the supine position with open eyes. Average values of the power of the spectra for the alpha-rhythm, delta-rhythm and theta-rhythm in the frontal and temporal leads, as well as the ratio of the average power of alpha/theta and alpha/delta rhythms in the frontal and temporal leads were calculated.Results. Average power of the alpha-rhythm was significantly higher over the right frontal lobe than over the right frontal-temporal area, as well as average amplitude of it was significantly higher in F3-A1 than F7-A1, F4-A2 than F8-A2, which is associated with the articulatory praxis. Average alpha-rhythm power was significantly higher in T5-A1 than T3-A1 and T6-A2 than T4-A2, which corresponds to the recognition and naming of objects optically. Significant differences according to the total average power of the alpha- and theta-rhythms above the frontal and frontal-temporal regions reflect the relationship between the frontal cortex temporal lobes and the premotor zones, i.e. arcuate bundle, responsible for the “speech system”.Conclusion. The identified patterns can reflect the characteristics of the state of active wakefulness in a 3–4-year-old child and can be used for comparison in the future (both in the course of behavioral experiments and observation of patients with certain pathological processes).

Accent discrimination abilities during the first days of life: An fNIRS study

Humans are biologically endowed with the faculty of language. However, the way neonates can crack this complex communicative code is yet not totally understood. While phonetic discrimination has been widely investigated in neonates, less is known about the role of supra-segments patterns in the recognition of native language. Therefore, the aim of this study was to evaluate accent discrimination abilities in newborns in a sentential prosody paradigm. We used near-infared spectroscopy to investigate accent discrimination in 21 full-term born infants within the first days of life. Sentential prosody was used to investigate: (a) native accent, (b) foreign accent, and (c) flattened accent. Neonates revealed a significantly smaller hemodynamic response to native accent compared to flattened accent and foreign accent, respectively. Cluster-based permutation analysis revealed two clusters with a significant difference between the two conditions native accent and foreign accent. The first cluster covered the middle and superior frontal, middle and superior temporal, central, and parietal areas within the left hemisphere. The second cluster, located in the right hemisphere, covered inferior, middle, and superior frontal, central, middle and superior temporal areas. We therefore conclude that neonates can differentiate prosodic features like accents within the same language a few days after birth.

EEG Correlates of Middle Eastern Music Improvisations on the Ney Instrument.

The cognitive sciences have witnessed a growing interest in cognitive and neural basis of human creativity. Music improvisations constitute an ideal paradigm to study creativity, but the underlying cognitive processes remain poorly understood. In addition, studies on music improvisations using scales other than the major and minor chords are scarce. Middle Eastern Music is characterized by the additional use of microtones, resulting in a tonal–spatial system called Maqam. No EEG correlates have been proposed yet for the eight most commonly used maqams. The Ney, an end-blown flute that is popular and widely used in the Middle East was used by a professional musician to perform 24 improvisations at low, medium, and high tempos. Using the EMOTIV EPOC+, a 14-channel wireless EEG headset, brainwaves were recorded and quantified before and during improvisations. Pairwise comparisons were calculated using IBM-SPSS and a principal component analysis was used to evaluate the variability between the maqams. A significant increase of low frequency bands theta power and alpha power were observed at the frontal left and temporal left area as well as a significant increase in higher frequency bands beta-high bands and gamma at the right temporal and left parietal area. This study reveals the first EEG observations of the eight most commonly used maqam and is proposing EEG signatures for various maqams.

Vestibular-Evoked Cerebral Potentials.

The human vestibular cortex has mostly been approached using functional magnetic resonance imaging and positron emission tomography combined with artificial stimulation of the vestibular receptors or nerve. Few studies have used electroencephalography and benefited from its high temporal resolution to describe the spatiotemporal dynamics of vestibular information processing from the first milliseconds following vestibular stimulation. Evoked potentials (EPs) are largely used to describe neural processing of other sensory signals, but they remain poorly developed and standardized in vestibular neuroscience and neuro-otology. Yet, vestibular EPs of brainstem, cerebellar, and cortical origin have been reported as early as the 1960s. This review article summarizes and compares results from studies that have used a large range of vestibular stimulation, including natural vestibular stimulation on rotating chairs and motion platforms, as well as artificial vestibular stimulation (e.g., sounds, impulsive acceleration stimulation, galvanic stimulation). These studies identified vestibular EPs with short latency (<20 ms), middle latency (from 20 to 50 ms), and late latency (>50 ms). Analysis of the generators (source analysis) of these responses offers new insights into the neuroimaging of the vestibular system. Generators were consistently found in the parieto-insular and temporo-parietal junction—the core of the vestibular cortex—as well as in the prefrontal and frontal areas, superior parietal, and temporal areas. We discuss the relevance of vestibular EPs for basic research and clinical neuroscience and highlight their limitations.

Microsurgical decompression of the supraorbital nerve in the treatment of chronic neuropathic pain in the frontal-temporal area

Chronic headache is common. One of the causes of frontal-temporal pain may be compression of sensory nerves from the trigeminal nerve system, for example, the supraorbital nerve. Our study involved 12 women with symptoms of supraorbital nerve neuralgia resistant to drug correction. He underwent microsurgical decompression of the supraorbital nerve. The results of the operation were assessed by the change in the level of neuropathic pain using the PainDetect questionnaire and the degree of psychosocial maladjustment of the patient according to the MIDAS questionnaire, before and after the operation. The data obtained indicate a significant decrease in the level of neuropathic pain in patients 1 month after surgery and a significant minimization of the effect of headache on the quality of life in patients 3 months after surgery. Two out of 12 women did not notice any improvement, which required repeated delayed revision and extended proximal decompression of the supraorbital nerve with dissection of m. corrugator supercilii fibers. After the myotomy, pain regression was achieved and the patients noted that they were satisfied with the result.

Incidental Verbal Semantic Processing Recruits the Fronto-temporal Semantic Control Network.

The frontoparietal semantic network, encompassing the inferior frontal gyrus and the posterior middle temporal cortex, is considered to be involved in semantic control processes. The explicit versus implicit nature of these control processes remains however poorly understood. The present study examined this question by assessing regional brain responses to the semantic attributes of an unattended stream of auditory words while participants' top-down attentional control processes were absorbed by a demanding visual search task. Response selectivity to semantic aspects of verbal stimuli was assessed via a functional magnetic resonance imaging response adaptation paradigm. We observed that implicit semantic processing of an unattended verbal stream recruited not only unimodal and amodal cortices in posterior supporting semantic knowledge areas, but also inferior frontal and posterior middle temporal areas considered to be part of the semantic control network. These results indicate that frontotemporal semantic networks support incidental semantic (control) processes.

Surface-based Cortical Morphometry, White Matter Hyperintensity, and Multidomain Cognitive Performance in Asymptomatic Carotid Stenosis

Carotid stenosis is a major contributor to vascular dementia. Recent studies suggest that even clinically “asymptomatic” carotid stenosis is linked with cognitive decline and neuroimaging changes. Here we examined surface-based cortical morphometry, white matter hyperintensity (WMH), and multidomain cognitive performance in unilateral severe (>70% narrowing) asymptomatic carotid stenosis (SACS). We included 24 SACS patients (19 males/5 females; 64.25 ± 7.18 years) and 24 comorbidities-matched controls (19 males/5 females; 67.16 ± 6.10 years), and measured cortical thickness, sulcal depth, gyrification, cortical complexity, and WMH loads with structural MRI images. The SACS patients exhibited: (1) thinner cortex in bilateral somatosensory/motor, bilateral inferior frontal, bilateral fusiform, and left lateral temporal areas; (2) shallower sulci in left lateral temporal, parietal, insular and somatosensory/motor areas; (3) both hyper- and hypo-gyrification in lateral temporal and frontal cortices; (4) lower complexity (fractal dimension) in left insular and right superior temporal areas. Further association analyses showed that the cortical alterations were significantly correlated with verbal memory and WMH burden in SACS. These results suggest that SACS patients present a left-dominated damage tendency, especially in the Perisylvian cortices that span across several large-scale systems of somatosensory/motor and language. Our findings also provide cortical anatomy evidence for cognitive impairment in SACS, suggesting a neuroanatomical predisposition to dementia and cerebrovascular events.

Spatiotemporal Processing of Bimodal Odor Lateralization in the Brain Using Electroencephalography Microstates and Source Localization.

The neuronal cascade related to the perception of either purely olfactory or trigeminal airborne chemicals has been investigated using electroencephalography (EEG) microstate analyses and source localization. However, most airborne chemicals are bimodal in nature, encompassing both properties. Moreover, there is an ongoing debate regarding whether there is one dominant nostril, and this could be investigated using these multichannel EEG methods. In this study, 18 right-handed, healthy participants (13 females) were monorhinally stimulated using an olfactometer with the bimodal component acetic acid during continuous EEG recording. Participants indicated the side of stimulation, the confidence in their decision, and rated the strength of the evoked perception. EEG microstate clustering determined four distinct maps and successive backfitting procedures, and source estimations revealed a network that evolved from visual-spatial processing areas to brain areas related to basic olfactory and trigeminal sensations (e.g., thalamus, cingulate cortex, insula, parahippocampal, and pre-/post-central gyri) and resulted in activation of areas involved in multisensory integration (e.g., frontal-temporal areas). Right-nostril stimulation was associated with faster microstate transition and longer involvement of the superior temporal gyrus, which was previously linked to chemical localization and provides evidence for a potential nostril dominance. The results describe for the first time the processing cascade of bimodal odor perception using microstate analyses and demonstrate its feasibility to further investigate potential nostril dominance.

Когнитивный вызванный потенциал Р300 у школьников 16–17 лет, проживающих в регионах Арктической зоны РФ

Living in adverse climatic and geographical conditions of the Arctic zone of the Russian Federation requires mobilization of the adaptive mechanisms of the central nervous system in humans. The parameters of the event-related potential P300 serve as indicators of brain bioelectric processes associated with the mechanisms of information perception and processing. This study aimed to establish the parameters of the event-related potential P300 in 16–17-year-old schoolchildren living in different regions of the Arctic zone of the Russian Federation based on a comparative analysis. The auditory event-related potential P300 was evaluated in subjects living in the Nenets Autonomus Okrug (NAO), Yamalo-Nenets Autonomous Okrug (YNAO) and the Arkhangelsk Region (AR). P300 latency and amplitude were recorded by the Encephalan-131-03 electroencephalograph (Medicom MTD, Russia) in the frontal (F3, F4), central (C4, C3), parietal (P3, P4), mid-temporal (T3, T4), and anterior temporal (F7, F8) areas of the brain using the oddball method. In schoolchildren living in AR and YNAO, the amplitude-latency parameters of P300 did not differ significantly. Subjects living in NAO, the majority of whom are representatives of the indigenous peoples of the North (the Nenets), had a longer P300 latency than their peers from other regions. Р300 amplitudes in schoolchildren from all the regions under study were statistically identical. The author comes to the conclusion that longer information processing time, according to the P300 data, reflects the adaptive psychophysiological characteristics of the population with a long historical experience of living in the North.