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1.
Acta Neurochir (Wien) ; 166(1): 299, 2024 Jul 18.
Article de Anglais | MEDLINE | ID: mdl-39020068

RÉSUMÉ

BACKGROUND: Frontal lobe epilepsy is pharmacoresistant in 30% of cases, constituting 10-20% of epilepsy surgeries. For cases of no lesional epilepsy (negative MRI), frontal lobectomy is a crucial treatment, historically involving Frontal Anatomical Lobectomy (AFL) with a 33.3% complication risk and 55.7% seizure control. METHODS: We describe Frontal Functional Lobectomy (FFL), in which the boundaries are defined on the patient's functional cortico-subcortical areas, recognized with advanced intraoperative technologies such as tractography and navigated transcranial magnetic stimulation (nTMS). CONCLUSIONS: The FFL allows for a broader resection with a lower rate of postoperative complications than the AFL.


Sujet(s)
Épilepsie pharmacorésistante , Épilepsie du lobe frontal , Lobe frontal , Humains , Épilepsie du lobe frontal/chirurgie , Épilepsie du lobe frontal/imagerie diagnostique , Épilepsie pharmacorésistante/chirurgie , Épilepsie pharmacorésistante/imagerie diagnostique , Lobe frontal/chirurgie , Lobe frontal/imagerie diagnostique , Procédures de neurochirurgie/méthodes , Stimulation magnétique transcrânienne/méthodes , Résultat thérapeutique , Neuronavigation/méthodes
2.
Neurology ; 103(3): e209606, 2024 Aug 13.
Article de Anglais | MEDLINE | ID: mdl-38976821

RÉSUMÉ

BACKGROUND AND OBJECTIVES: Neural computations underlying gait disorders in Parkinson disease (PD) are multifactorial and involve impaired expression of stereotactic locomotor patterns and compensatory recruitment of cognitive functions. This study aimed to clarify the network mechanisms of cognitive contribution to gait control and its breakdown in patients with PD. METHODS: Patients with PD were instructed to walk at a comfortable pace on a mat with pressure sensors. The characterization of cognitive-motor interplay was enhanced by using a gait with a secondary cognitive task (dual-task condition) and a gait without additional tasks (single-task condition). Participants were scanned using 3-T MRI and 123I-ioflupane SPECT. RESULTS: According to gait characteristics, cluster analysis assisted by a nonlinear dimensionality reduction technique, t-distributed stochastic neighbor embedding, categorized 56 patients with PD into 3 subpopulations. The preserved gait (PG) subgroup (n = 23) showed preserved speed and variability during gait, both with and without additional cognitive load. Compared with the PG subgroup, the mildly impaired gait (MIG) subgroup (n = 16) demonstrated deteriorated gait variability with additional cognitive load and impaired speed and gait variability without additional cognitive load. The severely impaired gait (SIG) subgroup (n = 17) revealed the slowest speed and highest gait variability. In addition, group differences were found in attention/working memory and executive function domains, with the lowest performance in the SIG subgroup than in the PG and MIG subgroups. Using resting-state functional MRI, the SIG subgroup demonstrated lower functional connectivity of the left and right frontoparietal network (FPN) with the caudate than the PG subgroup did (left FPN, d = 1.21, p < 0.001; right FPN, d = 1.05, p = 0.004). Cortical thickness in the FPN and 123I-ioflupane uptake in the striatum did not differ among the 3 subgroups. By contrast, the severity of Ch4 density loss was significantly correlated with the level of functional connectivity degradation of the FPN and caudate (left FPN-caudate, r = 0.27, p = 0.04). DISCUSSION: These findings suggest that the functional connectivity of the FPN with the caudate, as mediated by the cholinergic Ch4 projection system, underlies the compensatory recruitment of attention and executive function for damaged automaticity in gait in patients with PD.


Sujet(s)
Troubles neurologiques de la marche , Imagerie par résonance magnétique , Maladie de Parkinson , Tomographie par émission monophotonique , Humains , Maladie de Parkinson/physiopathologie , Maladie de Parkinson/imagerie diagnostique , Maladie de Parkinson/complications , Mâle , Femelle , Sujet âgé , Troubles neurologiques de la marche/étiologie , Troubles neurologiques de la marche/physiopathologie , Troubles neurologiques de la marche/imagerie diagnostique , Adulte d'âge moyen , Lobe frontal/imagerie diagnostique , Lobe frontal/physiopathologie , Corps strié/imagerie diagnostique , Corps strié/physiopathologie , Lobe pariétal/imagerie diagnostique , Lobe pariétal/physiopathologie , Réseau nerveux/imagerie diagnostique , Réseau nerveux/physiopathologie , Voies nerveuses/physiopathologie , Voies nerveuses/imagerie diagnostique , Noyau basal de Meynert/physiopathologie , Noyau basal de Meynert/imagerie diagnostique , Nortropanes
3.
PLoS One ; 19(7): e0298110, 2024.
Article de Anglais | MEDLINE | ID: mdl-38968195

RÉSUMÉ

Neuroimaging studies have suggested an important role for the default mode network (DMN) in disorders of consciousness (DoC). However, the extent to which DMN connectivity can discriminate DoC states-unresponsive wakefulness syndrome (UWS) and minimally conscious state (MCS)-is less evident. Particularly, it is unclear whether effective DMN connectivity, as measured indirectly with dynamic causal modelling (DCM) of resting EEG can disentangle UWS from healthy controls and from patients considered conscious (MCS+). Crucially, this extends to UWS patients with potentially "covert" awareness (minimally conscious star, MCS*) indexed by voluntary brain activity in conjunction with partially preserved frontoparietal metabolism as measured with positron emission tomography (PET+ diagnosis; in contrast to PET- diagnosis with complete frontoparietal hypometabolism). Here, we address this gap by using DCM of EEG data acquired from patients with traumatic brain injury in 11 UWS (6 PET- and 5 PET+) and in 12 MCS+ (11 PET+ and 1 PET-), alongside with 11 healthy controls. We provide evidence for a key difference in left frontoparietal connectivity when contrasting UWS PET- with MCS+ patients and healthy controls. Next, in a leave-one-subject-out cross-validation, we tested the classification performance of the DCM models demonstrating that connectivity between medial prefrontal and left parietal sources reliably discriminates UWS PET- from MCS+ patients and controls. Finally, we illustrate that these models generalize to an unseen dataset: models trained to discriminate UWS PET- from MCS+ and controls, classify MCS* patients as conscious subjects with high posterior probability (pp > .92). These results identify specific alterations in the DMN after severe brain injury and highlight the clinical utility of EEG-based effective connectivity for identifying patients with potential covert awareness.


Sujet(s)
Troubles de la conscience , Conscience , Électroencéphalographie , Lobe pariétal , Humains , Mâle , Femelle , Adulte , Électroencéphalographie/méthodes , Adulte d'âge moyen , Lobe pariétal/physiopathologie , Lobe pariétal/imagerie diagnostique , Troubles de la conscience/physiopathologie , Troubles de la conscience/imagerie diagnostique , Conscience/physiologie , Tomographie par émission de positons , Lobe frontal/imagerie diagnostique , Lobe frontal/physiopathologie , Lésions traumatiques de l'encéphale/physiopathologie , Lésions traumatiques de l'encéphale/imagerie diagnostique , État végétatif persistant/physiopathologie , État végétatif persistant/imagerie diagnostique , Études de cohortes , Études cas-témoins , Jeune adulte , Réseau nerveux/physiopathologie , Réseau nerveux/imagerie diagnostique
4.
Hum Brain Mapp ; 45(10): e26759, 2024 Jul 15.
Article de Anglais | MEDLINE | ID: mdl-38989632

RÉSUMÉ

The inferior frontal sulcus (ifs) is a prominent sulcus on the lateral frontal cortex, separating the middle frontal gyrus from the inferior frontal gyrus. The morphology of the ifs can be difficult to distinguish from adjacent sulci, which are often misidentified as continuations of the ifs. The morphological variability of the ifs and its relationship to surrounding sulci were examined in 40 healthy human subjects (i.e., 80 hemispheres). The sulci were identified and labeled on the native cortical surface meshes of individual subjects, permitting proper intra-sulcal assessment. Two main morphological patterns of the ifs were identified across hemispheres: in Type I, the ifs was a single continuous sulcus, and in Type II, the ifs was discontinuous and appeared in two segments. The morphology of the ifs could be further subdivided into nine subtypes based on the presence of anterior and posterior sulcal extensions. The ifs was often observed to connect, either superficially or completely, with surrounding sulci, and seldom appeared as an independent sulcus. The spatial variability of the ifs and its various morphological configurations were quantified in the form of surface spatial probability maps which are made publicly available in the standard fsaverage space. These maps demonstrated that the ifs generally occupied a consistent position across hemispheres and across individuals. The normalized mean sulcal depths associated with the main morphological types were also computed. The present study provides the first detailed description of the ifs as a sulcal complex composed of segments and extensions that can be clearly differentiated from adjacent sulci. These descriptions, together with the spatial probability maps, are critical for the accurate identification of the ifs in anatomical and functional neuroimaging studies investigating the structural characteristics and functional organization of this region in the human brain.


Sujet(s)
Cartographie cérébrale , Imagerie par résonance magnétique , Humains , Mâle , Femelle , Adulte , Cartographie cérébrale/méthodes , Lobe frontal/anatomie et histologie , Lobe frontal/imagerie diagnostique , Jeune adulte , Traitement d'image par ordinateur/méthodes , Probabilité
5.
Neurology ; 103(2): e209619, 2024 Jul 23.
Article de Anglais | MEDLINE | ID: mdl-38900994

RÉSUMÉ

Cocaine-induced midline destructive lesions (CIMDL) are a rare complication of chronic intranasal cocaine use involving the centrofacial mucosal structures, often with nasal septum perforation and, in severe cases, involvement of neurocranial structures. Patients present with nasal obstruction, epistaxis, facial pain, nasal ulcerative lesions with crusting, and septal and palate perforation causing dysphagia and nasal reflux. CNS involvement is uncommon.We report a 47-year-old man with a history of nasal cocaine use who developed a subacute frontal syndrome secondary to cribriform plate destruction complicated by bilateral frontal lobe empyema and abscesses and extensive white matter involvement. The frequent presence of serum antineutrophil cytoplasmic antibodies (ANCA) in CIMDL makes this uncommon presentation challenging to differentiate from localized granulomatosis with polyangiitis. While ANCA antibodies may play a role in CIMDL, immunosuppression is not indicated and may lead to iatrogenesis.CIMDL should be considered in patients with isolated frontal lobe syndrome. Eliciting a history of cocaine use and obtaining toxicologic studies are essential in the diagnosis of CIMDL.


Sujet(s)
Troubles liés à la cocaïne , Lobe frontal , Humains , Mâle , Adulte d'âge moyen , Lobe frontal/anatomopathologie , Lobe frontal/imagerie diagnostique , Troubles liés à la cocaïne/complications , Cocaïne/effets indésirables
6.
Nat Commun ; 15(1): 4802, 2024 Jun 05.
Article de Anglais | MEDLINE | ID: mdl-38839745

RÉSUMÉ

Staying engaged is necessary to maintain goal-directed behaviors. Despite this, engagement exhibits continuous, intrinsic fluctuations. Even in experimental settings, animals, unlike most humans, repeatedly and spontaneously move between periods of complete task engagement and disengagement. We, therefore, looked at behavior in male macaques (macaca mulatta) in four tasks while recording fMRI signals. We identified consistent autocorrelation in task disengagement. This made it possible to build models capturing task-independent engagement. We identified task general patterns of neural activity linked to impending sudden task disengagement in mid-cingulate gyrus. By contrast, activity centered in perigenual anterior cingulate cortex (pgACC) was associated with maintenance of performance across tasks. Importantly, we carefully controlled for task-specific factors such as the reward history and other motivational effects, such as response vigor, in our analyses. Moreover, we showed pgACC activity had a causal link to task engagement: transcranial ultrasound stimulation of pgACC changed task engagement patterns.


Sujet(s)
Gyrus du cingulum , Macaca mulatta , Imagerie par résonance magnétique , Récompense , Animaux , Mâle , Gyrus du cingulum/physiologie , Gyrus du cingulum/imagerie diagnostique , Lobe frontal/physiologie , Lobe frontal/imagerie diagnostique , Comportement animal/physiologie , Cartographie cérébrale , Motivation/physiologie
7.
J Alzheimers Dis ; 100(1): 357-374, 2024.
Article de Anglais | MEDLINE | ID: mdl-38875035

RÉSUMÉ

Background: Executive dysfunction in mild cognitive impairment (MCI) has been associated with gray matter atrophy. Prior studies have yielded limited insight into associations between gray matter volume and executive function in early and late amnestic MCI (aMCI). Objective: To examine the relative importance of predictors of executive function at 24 months and relationships between baseline regional gray matter volume and executive function performance at 24-month follow-up in non-demented older adults. Methods: 147 participants from the Alzheimer's Disease Neuroimaging Initiative (mean age = 70.6 years) completed brain magnetic resonance imaging and neuropsychological testing and were classified as cognitively normal (n = 49), early aMCI (n = 60), or late aMCI (n = 38). Analyses explored the importance of demographic, APOEɛ4, biomarker (p-tau/Aß42, t-tau/Aß42), and gray matter regions-of-interest (ROI) variables to 24-month executive function, whether ROIs predicted executive function, and whether relationships varied by baseline diagnostic status. Results: Across all participants, baseline anterior cingulate cortex and superior parietal lobule volumes were the strongest predictors of 24-month executive function performance. In early aMCI, anterior cingulate cortex volume was the strongest predictor and demonstrated a significant interaction such that lower volume related to worse 24-month executive function in early aMCI. Educational attainment and inferior frontal gyrus volume were the strongest predictors of 24-month executive function performance for cognitively normal and late aMCI groups, respectively. Conclusions: Baseline frontoparietal gray matter regions were significant predictors of executive function performance in the context of aMCI and may identify those at risk of Alzheimer's disease. Anterior cingulate cortex volume may predict executive function performance in early aMCI.


Sujet(s)
Vieillissement , Dysfonctionnement cognitif , Fonction exécutive , Substance grise , Imagerie par résonance magnétique , Tests neuropsychologiques , Humains , Mâle , Femelle , Fonction exécutive/physiologie , Substance grise/imagerie diagnostique , Substance grise/anatomopathologie , Sujet âgé , Dysfonctionnement cognitif/imagerie diagnostique , Dysfonctionnement cognitif/psychologie , Dysfonctionnement cognitif/anatomopathologie , Vieillissement/physiologie , Vieillissement/anatomopathologie , Études de suivi , Lobe pariétal/imagerie diagnostique , Lobe pariétal/anatomopathologie , Lobe frontal/imagerie diagnostique , Lobe frontal/anatomopathologie , Adulte d'âge moyen , Sujet âgé de 80 ans ou plus , Taille d'organe
8.
Medicina (B Aires) ; 84(3): 592-596, 2024.
Article de Espagnol | MEDLINE | ID: mdl-38907981

RÉSUMÉ

The frontal aslant tract (FAT) connects the supplementary motor area (SMA) with the pars opercularis. Its role in language and its implications in glioma surgery remain under discussion. We present an anatomosurgical study of three cases with surgical resolution. Three patients with gliomas in the left frontal lobe were operated on using an awake patient protocol with cortical and subcortical mapping techniques, conducting motor and language evaluations. Tractography was performed using DSI Studio software. All three patients showed intraoperative language inhibition through subcortical stimulation of the FAT. Resection involving the FAT correlated with language deficits in all cases and movement initiation deficits in two cases. All patients recovered from their deficits at six months postoperatively. In conclusion, the tract has been successfully reconstructed, showing both anatomical and functional complexity, supporting the idea of its mapping and preservation in glioma surgery. Future interdisciplinary studies are necessary to determine the transient or permanent nature of the deficits.


El tracto oblicuo frontal (TOF) conecta el área motora suplementaria (AMS) con la pars opercularis. Su rol en el lenguaje y su implicancia en la cirugía de gliomas siguen en discusión. Presentamos un estudio anatomoquirúrgico de tres casos con resolución quirúrgica. Se operaron tres pacientes con gliomas en el lóbulo frontal izquierdo utilizando protocolo de paciente despierto con técnicas de mapeo cortical y subcortical realizando evaluación motora y del lenguaje. Las tractografías fueron realizadas con el software DSI Studio. Los tres pacientes presentaron inhibición intraoperatoria del lenguaje mediante la estimulación subcortical de TOF. La resección en contacto con el TOF se correlacionó con déficits del lenguaje en todos los casos y en dos casos déficits en la iniciación del movimiento. Todos los pacientes recuperaron su déficit a los seis meses postoperatorios. En conclusión, se ha logrado reconstruir al tracto. Éste presenta una complejidad anatómica y funcional, que apoya la idea de su mapeo y preservación en la cirugía de gliomas. Futuros estudios interdisciplinarios son necesarios para determinar el carácter transitorio o permanente de los déficits.


Sujet(s)
Tumeurs du cerveau , Lobe frontal , Gliome , Humains , Tumeurs du cerveau/chirurgie , Tumeurs du cerveau/imagerie diagnostique , Tumeurs du cerveau/anatomopathologie , Gliome/chirurgie , Gliome/imagerie diagnostique , Gliome/anatomopathologie , Mâle , Lobe frontal/chirurgie , Lobe frontal/imagerie diagnostique , Adulte d'âge moyen , Femelle , Adulte , Procédures de neurochirurgie/méthodes , Cartographie cérébrale/méthodes , Cortex moteur/imagerie diagnostique , Cortex moteur/chirurgie , Cortex moteur/anatomie et histologie , Imagerie par tenseur de diffusion
9.
Sci Rep ; 14(1): 14135, 2024 06 19.
Article de Anglais | MEDLINE | ID: mdl-38898075

RÉSUMÉ

Numerous prospective biomarkers are being studied for their ability to diagnose various stages of Alzheimer's disease (AD). High-density electroencephalogram (EEG) methods show promise as an accurate, economical, non-invasive approach to measuring the electrical potentials of brains associated with AD. Event-related potentials (ERPs) may serve as clinically useful biomarkers of AD. Through analysis of secondary data, the present study examined the performance and distribution of N4/P6 ERPs across the frontoparietal network (FPN) using EEG topographic mapping. ERP measures and memory as a function of reaction time (RT) were compared between a group of (n = 63) mild untreated AD patients and a control group of (n = 73) healthy age-matched adults. Based on the literature presented, it was expected that healthy controls would outperform patients in peak amplitude and mean component latency across three parameters of memory when measured at optimal N4 (frontal) and P6 (parietal) locations. It was also predicted that the control group would exhibit neural cohesion through FPN integration during cross-modal tasks, thus demonstrating healthy cognitive functioning consistent with older healthy adults. By targeting select frontal and parietal EEG reference channels based on N4/P6 component time windows and positivity, our findings demonstrated statistically significant group variations between controls and patients in N4/P6 peak amplitudes and latencies during cross-modal testing. Our results also support that the N4 ERP might be stronger than its P6 counterpart as a possible candidate biomarker. We conclude through topographic mapping that FPN integration occurs in healthy controls but is absent in AD patients during cross-modal memory tasks.


Sujet(s)
Maladie d'Alzheimer , Marqueurs biologiques , Électroencéphalographie , Potentiels évoqués , Lobe frontal , Lobe pariétal , Humains , Maladie d'Alzheimer/physiopathologie , Maladie d'Alzheimer/diagnostic , Mâle , Femelle , Électroencéphalographie/méthodes , Sujet âgé , Lobe pariétal/physiopathologie , Potentiels évoqués/physiologie , Lobe frontal/physiopathologie , Lobe frontal/imagerie diagnostique , Adulte d'âge moyen , Temps de réaction/physiologie , Études cas-témoins , Cartographie cérébrale/méthodes , Sujet âgé de 80 ans ou plus , Mémoire/physiologie
10.
J Behav Addict ; 13(2): 576-586, 2024 Jun 26.
Article de Anglais | MEDLINE | ID: mdl-38935433

RÉSUMÉ

Background: Changes in brain structural connections appear to be important in the pathophysiology of substance use disorders, but their role in behavioral addictions, such as gambling disorder (GD), is unclear. GD also offers a model to study addiction mechanisms without pharmacological confounding factors. Here, we used multimodal MRI data to examine the integrity of white matter connections in individuals with GD. We hypothesized that the affected areas would be in the fronto-striatal-thalamic circuit. Methods: Twenty individuals with GD (mean age: 64 years, GD duration: 15.7 years) and 40 age- and sex-matched healthy controls (HCs) underwent detailed clinical examinations together with brain 3T MRI scans (T1, T2, FLAIR and DWI). White matter (WM) analysis involved fractional anisotropy and lesion load, while gray matter (GM) analysis included voxel- and surface-based morphometry. These measures were compared between groups, and correlations with GD-related behavioral characteristics were examined. Results: Individuals with GD showed reduced WM integrity in the left and right frontal parts of the corona radiata and corpus callosum (pFWE < 0.05). WM gambling symptom severity (SOGS score) was negatively associated to WM integrity in these areas within the left hemisphere (p < 0.05). Individuals with GD also exhibited higher WM lesion load in the left anterior corona radiata (pFWE < 0.05). GM volume in the left thalamus and GM thickness in the left orbitofrontal cortex were reduced in the GD group (pFWE < 0.05). Conclusions: Similar to substance addictions, the fronto-striatal-thalamic circuit is also affected in GD, suggesting that this circuitry may have a crucial role in addictions, independent of pharmacological substances.


Sujet(s)
Jeu de hasard , Substance grise , Imagerie par résonance magnétique , Substance blanche , Humains , Mâle , Adulte d'âge moyen , Substance grise/imagerie diagnostique , Substance grise/anatomopathologie , Substance blanche/imagerie diagnostique , Substance blanche/anatomopathologie , Jeu de hasard/imagerie diagnostique , Jeu de hasard/anatomopathologie , Jeu de hasard/physiopathologie , Femelle , Sujet âgé , Imagerie multimodale , Lobe frontal/imagerie diagnostique , Lobe frontal/anatomopathologie , Thalamus/imagerie diagnostique , Thalamus/anatomopathologie
11.
Alzheimers Res Ther ; 16(1): 119, 2024 05 31.
Article de Anglais | MEDLINE | ID: mdl-38822365

RÉSUMÉ

BACKGROUND: Autopsy work reported that neuronal density in the locus coeruleus (LC) provides neural reserve against cognitive decline in dementia. Recent neuroimaging and pharmacological studies reported that left frontoparietal network functional connectivity (LFPN-FC) confers resilience against beta-amyloid (Aß)-related cognitive decline in preclinical sporadic and autosomal dominant Alzheimer's disease (AD), as well as against LC-related cognitive changes. Given that the LFPN and the LC play important roles in attention, and attention deficits have been observed early in the disease process, we examined whether LFPN-FC and LC structural health attenuate attentional decline in the context of AD pathology. METHODS: 142 participants from the Harvard Aging Brain Study who underwent resting-state functional MRI, LC structural imaging, PiB(Aß)-PET, and up to 5 years of cognitive follow-ups were included (mean age = 74.5 ± 9.9 years, 89 women). Cross-sectional robust linear regression associated LC integrity (measured as the average of five continuous voxels with the highest intensities in the structural LC images) or LFPN-FC with Digit Symbol Substitution Test (DSST) performance at baseline. Longitudinal robust mixed effect analyses examined associations between DSST decline and (i) two-way interactions of baseline LC integrity (or LFPN-FC) and PiB or (ii) the three-way interaction of baseline LC integrity, LFPN-FC, and PiB. Baseline age, sex, and years of education were included as covariates. RESULTS: At baseline, lower LFPN-FC, but not LC integrity, was related to worse DSST performance. Longitudinally, lower baseline LC integrity was associated with a faster DSST decline, especially at PiB > 10.38 CL. Lower baseline LFPN-FC was associated with a steeper decline on the DSST but independent of PiB. At elevated PiB levels (> 46 CL), higher baseline LFPN-FC was associated with an attenuated decline on the DSST, despite the presence of lower LC integrity. CONCLUSIONS: Our findings demonstrate that the LC can provide resilience against Aß-related attention decline. However, when Aß accumulates and the LC's resources may be depleted, the functioning of cortical target regions of the LC, such as the LFPN-FC, can provide additional resilience to sustain attentional performance in preclinical AD. These results provide critical insights into the neural correlates contributing to individual variability at risk versus resilience against Aß-related cognitive decline.


Sujet(s)
Maladie d'Alzheimer , Locus ceruleus , Imagerie par résonance magnétique , Lobe pariétal , Humains , Femelle , Mâle , Maladie d'Alzheimer/imagerie diagnostique , Maladie d'Alzheimer/psychologie , Maladie d'Alzheimer/physiopathologie , Sujet âgé , Locus ceruleus/imagerie diagnostique , Locus ceruleus/anatomopathologie , Imagerie par résonance magnétique/méthodes , Lobe pariétal/imagerie diagnostique , Sujet âgé de 80 ans ou plus , Attention/physiologie , Lobe frontal/imagerie diagnostique , Lobe frontal/physiopathologie , Tomographie par émission de positons , Études transversales , Voies nerveuses/imagerie diagnostique , Voies nerveuses/physiopathologie , Dysfonctionnement cognitif/imagerie diagnostique , Dysfonctionnement cognitif/physiopathologie , Dysfonctionnement cognitif/psychologie , Tests neuropsychologiques
12.
Behav Brain Funct ; 20(1): 16, 2024 Jun 26.
Article de Anglais | MEDLINE | ID: mdl-38926731

RÉSUMÉ

BACKGROUND: An intronic deletion within intron 2 of the DCDC2 gene encompassing the entire READ1 (hereafter, READ1d) has been associated in both children with developmental dyslexia (DD) and typical readers (TRs), with interindividual variation in reading performance and motion perception as well as with structural and functional brain alterations. Visual motion perception -- specifically processed by the magnocellular (M) stream -- has been reported to be a solid and reliable endophenotype of DD. Hence, we predicted that READ1d should affect neural activations in brain regions sensitive to M stream demands as reading proficiency changes. METHODS: We investigated neural activations during two M-eliciting fMRI visual tasks (full-field sinusoidal gratings controlled for spatial and temporal frequencies and luminance contrast, and sensitivity to motion coherence at 6%, 15% and 40% dot coherence levels) in four subject groups: children with DD with/without READ1d, and TRs with/without READ1d. RESULTS: At the Bonferroni-corrected level of significance, reading skills showed a significant effect in the right polar frontal cortex during the full-field sinusoidal gratings-M task. Regardless of the presence/absence of the READ1d, subjects with poor reading proficiency showed hyperactivation in this region of interest (ROI) compared to subjects with better reading scores. Moreover, a significant interaction was found between READ1d and reading performance in the left frontal opercular area 4 during the 15% coherent motion sensitivity task. Among subjects with poor reading performance, neural activation in this ROI during this specific task was higher for subjects without READ1d than for READ1d carriers. The difference vanished as reading skills increased. CONCLUSIONS: Our findings showed a READ1d-moderated genetic vulnerability to alterations in neural activation in the ventral attentive and salient networks during the processing of relevant stimuli in subjects with poor reading proficiency.


Sujet(s)
Dyslexie , Lobe frontal , Imagerie par résonance magnétique , Perception du mouvement , Lobe pariétal , Lecture , Humains , Dyslexie/physiopathologie , Dyslexie/génétique , Mâle , Enfant , Femelle , Imagerie par résonance magnétique/méthodes , Lobe pariétal/physiopathologie , Perception du mouvement/physiologie , Lobe frontal/physiopathologie , Lobe frontal/imagerie diagnostique , Protéines associées aux microtubules/génétique , Cartographie cérébrale/méthodes , Réseau nerveux/physiopathologie , Réseau nerveux/imagerie diagnostique , Stimulation lumineuse/méthodes
13.
Commun Biol ; 7(1): 700, 2024 Jun 07.
Article de Anglais | MEDLINE | ID: mdl-38849518

RÉSUMÉ

Thalamic aphasia results from focal thalamic lesions that cause dysfunction of remote but functionally connected cortical areas due to language network perturbation. However, specific local and network-level neural substrates of thalamic aphasia remain incompletely understood. Using lesion symptom mapping, we demonstrate that lesions in the left ventrolateral and ventral anterior thalamic nucleus are most strongly associated with aphasia in general and with impaired semantic and phonemic fluency and complex comprehension in particular. Lesion network mapping (using a normative connectome based on fMRI data from 1000 healthy individuals) reveals a Thalamic aphasia network encompassing widespread left-hemispheric cerebral connections, with Broca's area showing the strongest associations, followed by the superior and middle frontal gyri, precentral and paracingulate gyri, and globus pallidus. Our results imply the critical involvement of the left ventrolateral and left ventral anterior thalamic nuclei in engaging left frontal cortical areas, especially Broca's area, during language processing.


Sujet(s)
Aphasie , Imagerie par résonance magnétique , Accident vasculaire cérébral , Thalamus , Noyaux ventraux du thalamus , Humains , Mâle , Adulte d'âge moyen , Femelle , Noyaux ventraux du thalamus/physiopathologie , Noyaux ventraux du thalamus/imagerie diagnostique , Aphasie/physiopathologie , Aphasie/étiologie , Aphasie/imagerie diagnostique , Accident vasculaire cérébral/complications , Accident vasculaire cérébral/physiopathologie , Thalamus/physiopathologie , Thalamus/imagerie diagnostique , Sujet âgé , Adulte , Connectome , Lobe frontal/physiopathologie , Lobe frontal/imagerie diagnostique , Réseau nerveux/physiopathologie , Réseau nerveux/imagerie diagnostique , Voies nerveuses/physiopathologie
14.
Behav Brain Funct ; 20(1): 10, 2024 May 03.
Article de Anglais | MEDLINE | ID: mdl-38702688

RÉSUMÉ

BACKGROUND: Episodic memory (EM) deteriorates as a result of normal aging as well as Alzheimer's disease. The neural underpinnings of such age-related memory impairments in older individuals are not well-understood. Although previous research has unveiled the association between gray matter volume (GMV) and EM in the elderly population, such findings exhibit variances across distinct age cohorts. Consequently, an investigation into the dynamic evolution of this relationship with advancing age is imperative. RESULT: The present study utilized a sliding window approach to examine how the correlation between EM and GMV varied with age in a cross-sectional sample of 926 Chinese older adults. We found that both verbal EM (VEM) and spatial EM (SEM) exhibited positive correlations with GMV in extensive areas primarily in the temporal and frontal lobes and that these correlations typically became stronger with older age. Moreover, there were variations in the strength of the correlation between EM and GMV with age, which differed based on sex and the specific type of EM. Specifically, the association between VEM and GMVs in the insula and parietal regions became stronger with age for females but not for males, whereas the association between SEM and GMVs in the parietal and occipital regions became stronger for males but not for females. At the brain system level, there is a significant age-related increase in the correlations between both types of EM and the GMV of both the anterior temporal (AT) system and the posterior medial (PM) system in male group. In females, both types of EM show stronger age-related correlations with the GMV of the AT system compared to males. CONCLUSIONS: Our study revealed a significant positive correlation between GMV in most regions associated with EM and age, particularly in the frontal and temporal lobes. This discovery offers new insights into the connection between brain structure and the diminishing episodic memory function among older individuals.


Sujet(s)
Vieillissement , Lobe frontal , Substance grise , Imagerie par résonance magnétique , Mémoire épisodique , Lobe temporal , Humains , Mâle , Femelle , Sujet âgé , Substance grise/imagerie diagnostique , Lobe frontal/imagerie diagnostique , Vieillissement/physiologie , Vieillissement/anatomopathologie , Lobe temporal/imagerie diagnostique , Adulte d'âge moyen , Imagerie par résonance magnétique/méthodes , Études transversales , Sujet âgé de 80 ans ou plus , Taille d'organe/physiologie
15.
Nat Commun ; 15(1): 4669, 2024 May 31.
Article de Anglais | MEDLINE | ID: mdl-38821963

RÉSUMÉ

Measures of fMRI resting-state functional connectivity (rs-FC) are an essential tool for basic and clinical investigations of fronto-limbic circuits. Understanding the relationship between rs-FC and the underlying patterns of neural activity in these circuits is therefore vital. Here we introduced inhibitory designer receptors exclusively activated by designer drugs (DREADDs) into the amygdala of two male macaques. We evaluated the causal effect of activating the DREADD receptors on rs-FC and neural activity within circuits connecting amygdala and frontal cortex. Activating the inhibitory DREADD increased rs-FC between amygdala and ventrolateral prefrontal cortex. Neurophysiological recordings revealed that the DREADD-induced increase in fMRI rs-FC was associated with increased local field potential coherency in the alpha band (6.5-14.5 Hz) between amygdala and ventrolateral prefrontal cortex. Thus, our multi-modal approach reveals the specific signature of neuronal activity that underlies rs-FC in fronto-limbic circuits.


Sujet(s)
Amygdale (système limbique) , Imagerie par résonance magnétique , Cortex préfrontal , Imagerie par résonance magnétique/méthodes , Mâle , Animaux , Cortex préfrontal/physiologie , Cortex préfrontal/imagerie diagnostique , Amygdale (système limbique)/physiologie , Amygdale (système limbique)/imagerie diagnostique , Voies nerveuses/physiologie , Lobe frontal/physiologie , Lobe frontal/imagerie diagnostique , Système limbique/physiologie , Système limbique/imagerie diagnostique , Cartographie cérébrale/méthodes , Repos/physiologie , Macaca mulatta , Drogues fabriquées clandestinement/pharmacologie , Clozapine/analogues et dérivés , Clozapine/pharmacologie , Réseau nerveux/physiologie , Réseau nerveux/imagerie diagnostique
16.
JAMA Neurol ; 81(7): 775-776, 2024 Jul 01.
Article de Anglais | MEDLINE | ID: mdl-38805232

RÉSUMÉ

This case report describes a woman with Creutzfeldt-Jakob disease with findings largely confined to the right precentral gyrus on initial imaging.


Sujet(s)
Maladie de Creutzfeldt-Jakob , Humains , Maladie de Creutzfeldt-Jakob/imagerie diagnostique , Imagerie par résonance magnétique , Mâle , Lobe frontal/imagerie diagnostique , Lobe frontal/physiopathologie , Femelle , Adulte d'âge moyen , Sujet âgé
17.
Neurocase ; 30(1): 32-38, 2024 02.
Article de Anglais | MEDLINE | ID: mdl-38752838

RÉSUMÉ

We report a patient with behavioral variant frontotemporal dementia who developed agraphia, irritability, perseverative and stereotyped behavior, and dietary changes. MRI revealed bilateral frontal convexity atrophy. Neuropsychological examination showed fluent aphasia with perseverative allographic agraphia, mild semantic impairment, and dysexecutive syndrome. Allographic agraphia featured unidirectional conversion from hiragana (cursive form of Japanese phonograms) and kanji (Japanese morphograms) to katakana (square form of Japanese phonograms), as opposed to mutual (bidirectional) conversion between hiragana and katakana in parieto-occipital gyri lesions. Furthermore, all letters of the word were converted and this whole-word conversion may be characteristic of perseverative behavior in frontotemporal dementia.


Sujet(s)
Agraphie , Démence frontotemporale , Humains , Démence frontotemporale/anatomopathologie , Démence frontotemporale/imagerie diagnostique , Démence frontotemporale/physiopathologie , Démence frontotemporale/complications , Agraphie/étiologie , Agraphie/physiopathologie , Mâle , Imagerie par résonance magnétique , Adulte d'âge moyen , Tests neuropsychologiques , Lobe frontal/imagerie diagnostique , Lobe frontal/anatomopathologie , Atrophie/anatomopathologie
18.
Schizophr Res ; 269: 123-129, 2024 Jul.
Article de Anglais | MEDLINE | ID: mdl-38772324

RÉSUMÉ

BACKGROUND: Persistent auditory verbal hallucinations (pAVHs) are a fundamental manifestation of schizophrenia (SCZ), yet the exact connection between pAVHs and brain structure remains contentious. This study aims to explore the potential correlation between pAVHs and alterations in grey matter volume (GMV) within specific brain regions among individuals diagnosed with SCZ. METHODS: 76 SCZ patients with pAVHs (pAVH group), 57 SCZ patients without AVHs (non-AVH group), and 83 healthy controls (HC group) were investigated using 3 T magnetic resonance imaging. The P3 hallucination item of the Positive and Negative Syndrome Scale was used to assess the severity of pAVHs. Voxel-based morphometry was used to analyze the GMV profile between the three groups. RESULTS: Compared to the non-AVH and HC groups, the pAVH group exhibited extensive reduction in GMV within the frontotemporal cortex. Conversely, no significant difference in GMV was observed between the non-AVH and HC groups. The severity of pAVHs showed a negative correlation with GMV in several regions, including the right fusiform, right inferior temporal, right medial orbitofrontal, right superior frontal, and right temporal pole (p = 0.0036, Bonferroni correction). Stepwise linear regression analysis revealed that GMV in the right temporal pole (ß = -0.29, p = 0.001) and right fusiform (ß = -0.21, p = 0.01) were significantly associated with the severity of pAVHs. CONCLUSIONS: Widespread reduction in GMV is observed within the frontotemporal cortex, particularly involving the right temporal pole and right fusiform, which potentially contribute to the pathogenesis of pAVHs in individuals with chronic SCZ.


Sujet(s)
Substance grise , Hallucinations , Imagerie par résonance magnétique , Schizophrénie , Lobe temporal , Humains , Schizophrénie/imagerie diagnostique , Schizophrénie/anatomopathologie , Hallucinations/imagerie diagnostique , Hallucinations/étiologie , Hallucinations/anatomopathologie , Hallucinations/physiopathologie , Mâle , Femelle , Adulte , Substance grise/imagerie diagnostique , Substance grise/anatomopathologie , Lobe temporal/imagerie diagnostique , Lobe temporal/anatomopathologie , Maladie chronique , Lobe frontal/imagerie diagnostique , Lobe frontal/anatomopathologie , Adulte d'âge moyen , Jeune adulte , Chine , Peuples d'Asie de l'Est
19.
Addict Biol ; 29(5): e13399, 2024 05.
Article de Anglais | MEDLINE | ID: mdl-38711213

RÉSUMÉ

Excessive use of the internet, which is a typical scenario of self-control failure, could lead to potential consequences such as anxiety, depression, and diminished academic performance. However, the underlying neuropsychological mechanisms remain poorly understood. This study aims to investigate the structural basis of self-control and internet addiction. In a cohort of 96 internet gamers, we examined the relationships among grey matter volume and white matter integrity within the frontostriatal circuits and internet addiction severity, as well as self-control measures. The results showed a significant and negative correlation between dACC grey matter volume and internet addiction severity (p < 0.001), but not with self-control. Subsequent tractography from the dACC to the bilateral ventral striatum (VS) was conducted. The fractional anisotropy (FA) and radial diffusivity of dACC-right VS pathway was negatively (p = 0.011) and positively (p = 0.020) correlated with internet addiction severity, respectively, and the FA was also positively correlated with self-control (p = 0.036). These associations were not observed for the dACC-left VS pathway. Further mediation analysis demonstrated a significant complete mediation effect of self-control on the relationship between FA of the dACC-right VS pathway and internet addiction severity. Our findings suggest that the dACC-right VS pathway is a critical neural substrate for both internet addiction and self-control. Deficits in this pathway may lead to impaired self-regulation over internet usage, exacerbating the severity of internet addiction.


Sujet(s)
Imagerie par tenseur de diffusion , Substance grise , Dépendance à Internet , Sang-froid , Substance blanche , Humains , Substance blanche/imagerie diagnostique , Substance blanche/anatomopathologie , Mâle , Dépendance à Internet/imagerie diagnostique , Dépendance à Internet/physiopathologie , Femelle , Imagerie par tenseur de diffusion/méthodes , Adulte , Jeune adulte , Substance grise/imagerie diagnostique , Substance grise/anatomopathologie , Striatum ventral/imagerie diagnostique , Striatum ventral/physiopathologie , Striatum ventral/anatomopathologie , Indice de gravité de la maladie , Voies nerveuses/imagerie diagnostique , Voies nerveuses/physiopathologie , Corps strié/imagerie diagnostique , Corps strié/anatomopathologie , Corps strié/physiopathologie , Internet , Lobe frontal/imagerie diagnostique , Lobe frontal/anatomopathologie , Lobe frontal/physiopathologie
20.
Acta Paediatr ; 113(8): 1876-1883, 2024 Aug.
Article de Anglais | MEDLINE | ID: mdl-38773283

RÉSUMÉ

AIM: Media use in children has exploded in the past several decades, most recently fuelled by portable electronic devices. This study aims to explore differences in functional brain connectivity in children during a story-listening functional MRI (fMRI) task using data collected before (1998) and after (2013) the widespread adoption of media. METHODS: Cross-sectional data were collected from English-speaking 5- to 7-year-old children at Cincinnati Children's Hospital Medical Center, USA, of a functional MRI narrative comprehension task completed in 1998 (n = 22) or 2013 (n = 25). Imaging data were processed using a graph theory approach, focusing on executive functions, language and visual processing networks supporting reading. RESULTS: Group differences suggest more efficient processing in the fronto-parietal network in the pre-media group while listening to stories. A modulation of the visual and fronto-parietal networks for the post-media exposure group was found. CONCLUSION: Further studies are needed to assess effects over time in the more exposed group to discern a causal effect of portable devices on cognitive networks.


Sujet(s)
Imagerie par résonance magnétique , Lobe pariétal , Humains , Enfant , Mâle , Femelle , Enfant d'âge préscolaire , Études transversales , Lobe pariétal/physiologie , Lobe pariétal/imagerie diagnostique , Lobe frontal/physiologie , Lobe frontal/imagerie diagnostique ,
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