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1.
Brain ; 147(7): 2522-2529, 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38289871

ABSTRACT

Lesions in the language-dominant ventral occipitotemporal cortex (vOTC) can result in selective impairment of either reading or naming, resulting in alexia or anomia. Yet, functional imaging studies that show differential activation for naming and reading do not reveal activity exclusively tuned to one of these inputs. To resolve this dissonance in the functional architecture of the vOTC, we used focused stimulation to the vOTC in 49 adult patients during reading and naming, and generated a population-level, probabilistic map to evaluate if reading and naming are clearly dissociable within individuals. Language mapping (50 Hz, 2829 stimulations) was performed during passage reading (216 positive sites) and visual naming (304 positive sites). Within the vOTC, we isolated sites that selectively disrupted reading (24 sites in 11 patients) or naming (27 sites in 12 patients), and those that disrupted both processes (75 sites in 21 patients). The anteromedial vOTC had a higher probability of producing naming disruption, while posterolateral regions resulted in greater reading-specific disruption. Between them lay a multi-modal region where stimulation disrupted both reading and naming. This work provides a comprehensive view of vOTC organization-the existence of a heteromodal cortex critical to both reading and naming, along with a causally dissociable unimodal naming cortex, and a reading-specific visual word form area in the vOTC. Their distinct roles as associative regions may thus relate to their connectivity within the broader language network that is disrupted by stimulation, more than to highly selective tuning properties. Our work also implies that pre-surgical mapping of both reading and naming is essential for patients requiring vOTC resections, as these functions are not co-localized, and such mapping may prevent the occurrence of unexpected deficits.


Subject(s)
Brain Mapping , Occipital Lobe , Reading , Temporal Lobe , Humans , Male , Female , Middle Aged , Occipital Lobe/diagnostic imaging , Occipital Lobe/physiopathology , Adult , Temporal Lobe/physiopathology , Temporal Lobe/diagnostic imaging , Brain Mapping/methods , Aged , Magnetic Resonance Imaging , Young Adult , Language , Photic Stimulation/methods
2.
Addict Biol ; 29(6): e13405, 2024 06.
Article in English | MEDLINE | ID: mdl-38837586

ABSTRACT

AIMS: Abuse of methamphetamine has aroused concern worldwide. Stimulant use and sexual behaviours have been linked in behavioural and epidemiological studies. Although methamphetamine-related neurofunctional differences are reported in previous studies, only few studies have examined neurofunctional changes related to methamphetamine and sexual cues in methamphetamine dependence from short- to long-term abstinence. METHODS: Neurofunctional changes were measured using a cue-reactivity task involving methamphetamine, sexual, and neutral cues in 20 methamphetamine abusers who were evaluated after a short- (1 week to 3 months) and long-term (10-15 months) abstinence. RESULTS: Five brain regions mainly involved in the occipital lobe and the parietal lobe were found with the group-by-condition interaction. Region-of-interest analyses found higher sexual-cue-related activation than other two activations in all five brain regions in the long-term methamphetamine abstinence group while no group differences were found. Negative relationships between motor impulsivity and methamphetamine- or sexual-cue-related activations in the left middle occipital gyrus, the superior parietal gyrus and the right angular gyrus were found. CONCLUSIONS: The findings suggested that methamphetamine abstinence may change the neural response of methamphetamine abusers to methamphetamine and sexual cues, and the neurofunction of the five brain regions reported in this study may partly recover with long-term methamphetamine abstinence. Given the use and relapse of methamphetamine for sexual purposes, the findings of this study may have particular clinical relevance.


Subject(s)
Amphetamine-Related Disorders , Cues , Methamphetamine , Sexual Behavior , Humans , Amphetamine-Related Disorders/physiopathology , Male , Adult , Sexual Behavior/drug effects , Magnetic Resonance Imaging , Parietal Lobe/physiopathology , Parietal Lobe/drug effects , Female , Occipital Lobe/physiopathology , Brain/physiopathology , Brain/drug effects , Central Nervous System Stimulants/pharmacology , Young Adult , Impulsive Behavior/drug effects , Brain Mapping/methods , Time Factors
3.
Cereb Cortex ; 31(7): 3353-3362, 2021 06 10.
Article in English | MEDLINE | ID: mdl-33611348

ABSTRACT

Dynamically allocating neural resources to salient features or objects within our visual space is fundamental to making rapid and accurate decisions. Impairments in such visuospatial abilities have been consistently documented in the clinical literature on individuals with cerebral palsy (CP), although the underlying neural mechanisms are poorly understood. In this study, we used magnetoencephalography (MEG) and oscillatory analysis methods to examine visuospatial processing in children with CP and demographically matched typically developing (TD) children. Our results indicated robust oscillations in the theta (4-8 Hz), alpha (8-14 Hz), and gamma (64-80 Hz) frequency bands in the occipital cortex of both groups during visuospatial processing. Importantly, the group with CP exhibited weaker cortical oscillations in the theta and gamma frequency bands, as well as slower response times and worse accuracy during task performance compared to the TD children. Furthermore, we found that weaker theta and gamma oscillations were related to greater visuospatial performance deficits across both groups. We propose that the weaker occipital oscillations seen in children with CP may reflect poor bottom-up processing of incoming visual information, which subsequently affects the higher-order visual computations essential for accurate visual perception and integration for decision-making.


Subject(s)
Attention/physiology , Brain Waves/physiology , Cerebral Palsy/physiopathology , Occipital Lobe/physiopathology , Spatial Processing/physiology , Adolescent , Child , Female , Humans , Magnetoencephalography , Male
4.
Cereb Cortex ; 31(5): 2505-2522, 2021 03 31.
Article in English | MEDLINE | ID: mdl-33338212

ABSTRACT

Congenital blindness has been shown to result in behavioral adaptation and neuronal reorganization, but the underlying neuronal mechanisms are largely unknown. Brain rhythms are characteristic for anatomically defined brain regions and provide a putative mechanistic link to cognitive processes. In a novel approach, using magnetoencephalography resting state data of congenitally blind and sighted humans, deprivation-related changes in spectral profiles were mapped to the cortex using clustering and classification procedures. Altered spectral profiles in visual areas suggest changes in visual alpha-gamma band inhibitory-excitatory circuits. Remarkably, spectral profiles were also altered in auditory and right frontal areas showing increased power in theta-to-beta frequency bands in blind compared with sighted individuals, possibly related to adaptive auditory and higher cognitive processing. Moreover, occipital alpha correlated with microstructural white matter properties extending bilaterally across posterior parts of the brain. We provide evidence that visual deprivation selectively modulates spectral profiles, possibly reflecting structural and functional adaptation.


Subject(s)
Auditory Pathways/physiopathology , Blindness/physiopathology , Frontal Lobe/physiopathology , Visual Pathways/physiopathology , Adult , Auditory Pathways/diagnostic imaging , Auditory Pathways/physiology , Blindness/diagnostic imaging , Diffusion Tensor Imaging , Female , Frontal Lobe/diagnostic imaging , Frontal Lobe/physiology , Humans , Magnetic Resonance Imaging , Magnetoencephalography , Male , Middle Aged , Neuronal Plasticity/physiology , Occipital Lobe/diagnostic imaging , Occipital Lobe/physiology , Occipital Lobe/physiopathology , Visual Pathways/diagnostic imaging , Visual Pathways/physiology , White Matter/diagnostic imaging , White Matter/physiology , White Matter/physiopathology , Young Adult
5.
Neuroimage ; 225: 117481, 2021 01 15.
Article in English | MEDLINE | ID: mdl-33122115

ABSTRACT

Brain disorders tend to impact on many different regions in a typical way: alterations do not spread randomly; rather, they seem to follow specific patterns of propagation that show a strong overlap between different pathologies. The insular cortex is one of the brain areas more involved in this phenomenon, as it seems to be altered by a wide range of brain diseases. On these grounds we thoroughly investigated the impact of brain disorders on the insular cortices analyzing the patterns of their structural co-alteration. We therefore investigated, applying a network analysis approach to meta-analytic data, 1) what pattern of gray matter alteration is associated with each of the insular cortex parcels; 2) whether or not this pattern correlates and overlaps with its functional meta-analytic connectivity; and, 3) the behavioral profile related to each insular co-alteration pattern. All the analyses were repeated considering two solutions: one with two clusters and another with three. Our study confirmed that the insular cortex is one of the most altered cerebral regions among the cortical areas, and exhibits a dense network of co-alteration including a prevalence of cortical rather than sub-cortical brain regions. Regions of the frontal lobe are the most involved, while occipital lobe is the less affected. Furthermore, the co-alteration and co-activation patterns greatly overlap each other. These findings provide significant evidence that alterations caused by brain disorders are likely to be distributed according to the logic of network architecture, in which brain hubs lie at the center of networks composed of co-altered areas. For the first time, we shed light on existing differences between insula sub-regions even in the pathoconnectivity domain.


Subject(s)
Brain Diseases/physiopathology , Cerebral Cortex/physiopathology , Nerve Net/physiopathology , Brain/physiopathology , Brain Mapping , Connectome , Gray Matter/physiopathology , Humans , Magnetic Resonance Imaging , Nerve Net/physiology , Occipital Lobe/physiopathology
6.
Neuroimage ; 233: 117911, 2021 06.
Article in English | MEDLINE | ID: mdl-33711483

ABSTRACT

It is widely accepted that impairment in visual perception impedes children's reading development, and further studies have demonstrated significant enhancement in reading fluency after visual perceptual training. However, the mechanism of the neural linkage between visual perception and reading is unclear. The purpose of this study was to examine the intrinsic functional relationship between visual perception (indexed by the texture discrimination task,TDT) and reading ability (character reading and reading fluency) in Chinese children with developmental dyslexia (DD) and those with typical development (TD). The resting-state functional connectivity (RSFC) between the primary visual cortex (V1, BA17) and the entire brain was analyzed. In addition, how RSFC maps are associated with TDT performance and reading ability in the DD and TD groups was examined. The results demonstrated that the strength of the RSFC between V1 and the left middle frontal gyrus (LMFG, BA9/BA46) was significantly correlated with both the threshold (SOA) of the TDT and reading fluency in TD children but not in DD children. Moreover, LMFG-V1 resting-state connectivity played a mediating role in the association of visual texture discrimination and reading fluency, but not in character reading, in TD children. In contrast, this mediation was absent in DD children, albeit their strengths of RSFC between V1 and the left middle frontal gyrus (LMFG) were comparable to those for the TD group. These findings indicate that typically developing children use the linkage of the RSFC between the V1 and LMFG for visual perception skills, which in turn promote fluent reading; in contrast, children with dyslexia, who had higher TDT thresholds than TD children, could not take advantage of their frontal-occipital connectivity to improve reading fluency abilities. These findings suggest that visual perception plays an important role in reading skills and that children with developmental dyslexia lack the ability to use their frontal-occipital connectivity to link visual perception with reading fluency.


Subject(s)
Dyslexia/physiopathology , Frontal Lobe/physiopathology , Nerve Net/physiopathology , Occipital Lobe/physiopathology , Reading , Visual Perception/physiology , Child , China/epidemiology , Discrimination Learning/physiology , Dyslexia/diagnostic imaging , Dyslexia/epidemiology , Female , Frontal Lobe/diagnostic imaging , Humans , Magnetic Resonance Imaging/methods , Male , Nerve Net/diagnostic imaging , Occipital Lobe/diagnostic imaging , Photic Stimulation/methods
7.
Neuroimage ; 236: 118023, 2021 08 01.
Article in English | MEDLINE | ID: mdl-33862241

ABSTRACT

Studies of occipital cortex plasticity in blindness provide insight into how intrinsic constraints interact with experience to determine cortical specialization. We tested the cognitive nature and anatomical origins of occipital responses during non-verbal, non-spatial auditory tasks. In a go/no-go task, congenitally blind (N=23) and sighted (N=24) individuals heard rapidly occurring (<1/s) non-verbal sounds and made one of two button presses (frequent-go 50%, infrequent-go 25%) or withheld a response (no-go, 25%). Rapid and frequent button presses heighten response selection/inhibition demands on the no-go trials: In sighted and blind adults a right-lateralized prefrontal (PFC) network responded most to no-go trials, followed by infrequent-go and finally frequent-go trials. In the blind group only, a right-lateralized occipital network showed the same response profile and the laterality of occipital and PFC responses was correlated across blind individuals. A second experiment with spoken sentences and equations (N=16) found that no-go responses in occipital cortex are distinct from previously identified occipital responses to spoken language. Finally, in resting-state data (N=30 blind, N=31 blindfolded sighted), no-go responsive 'visual' cortex of blind relative to sighted participants was more synchronized with PFC and less synchronized with primary auditory and sensory-motor cortices. No-go responsive occipital cortex showed higher resting-state correlations with no-go responsive PFC than language responsive inferior frontal cortex. We conclude that in blindness, a right-lateralized occipital network responds to non-verbal executive processes, including response selection. These results suggest that connectivity with fronto-parietal executive networks is a key mechanism for plasticity in blindness.


Subject(s)
Auditory Perception/physiology , Blindness/congenital , Blindness/physiopathology , Executive Function/physiology , Inhibition, Psychological , Nerve Net/physiopathology , Neuronal Plasticity/physiology , Occipital Lobe/physiopathology , Prefrontal Cortex/physiopathology , Psychomotor Performance/physiology , Adult , Blindness/diagnostic imaging , Brain Mapping , Female , Functional Laterality/physiology , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Nerve Net/diagnostic imaging , Occipital Lobe/diagnostic imaging , Prefrontal Cortex/diagnostic imaging , Speech Perception/physiology
8.
Neuroimage ; 226: 117570, 2021 02 01.
Article in English | MEDLINE | ID: mdl-33221445

ABSTRACT

Reading comprehension is a complex task that depends on multiple cognitive and linguistic processes. According to the updated Simple View of Reading framework, in adults, individual variation in reading comprehension can be largely explained by combined variance in three component abilities: (1) decoding accuracy, (2) fluency, and (3) language comprehension. Here we asked whether the neural correlates of the three components are different in adults with dyslexia as compared to typically-reading adults and whether the relative contribution of these correlates to reading comprehension is similar in the two groups. We employed a novel naturalistic fMRI reading task to identify the neural correlates of individual differences in the three components using whole-brain and literature-driven regions-of-interest approaches. Across all participants, as predicted by the Simple View framework, we found distinct patterns of associations with linguistic and domain-general regions for the three components, and that the left-hemispheric neural correlates of language comprehension in the angular and posterior temporal gyri made the largest contributions to explaining out-of-scanner reading comprehension performance. These patterns differed between the two groups. In typical adult readers, better fluency was associated with greater activation of left occipitotemporal regions, better comprehension with lesser activation in prefrontal and posterior parietal regions, and there were no significant associations with decoding. In adults with dyslexia, better fluency was associated with greater activation of bilateral inferior parietal regions, better comprehension was associated with greater activation in some prefrontal clusters and lower in others, and better decoding skills were associated with lesser activation of bilateral prefrontal and posterior parietal regions. Extending the behavioral findings of skill-level differences in the relative contribution of the three components to reading comprehension, the relative contributions of the neural correlates to reading comprehension differed based on dyslexia status. These findings reveal some of the neural correlates of individual differences in the three components and the underlying mechanisms of reading comprehension deficits in adults with dyslexia.


Subject(s)
Brain/diagnostic imaging , Comprehension , Dyslexia/diagnostic imaging , Language , Reading , Adolescent , Adult , Brain/physiology , Brain/physiopathology , Brain Mapping , Case-Control Studies , Dyslexia/physiopathology , Female , Functional Neuroimaging , Humans , Magnetic Resonance Imaging , Male , Occipital Lobe/diagnostic imaging , Occipital Lobe/physiology , Occipital Lobe/physiopathology , Parietal Lobe/diagnostic imaging , Parietal Lobe/physiology , Parietal Lobe/physiopathology , Prefrontal Cortex/diagnostic imaging , Prefrontal Cortex/physiology , Prefrontal Cortex/physiopathology , Temporal Lobe/diagnostic imaging , Temporal Lobe/physiology , Temporal Lobe/physiopathology , Young Adult
9.
Headache ; 61(10): 1562-1567, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34841519

ABSTRACT

OBJECTIVE: To analyze occipital bending (OB) frequency in patients with migraine with visual aura compared with those without aura. BACKGROUND: A unique type of asymmetry in the human brain in which one occipital pole crosses the midline and bends over the other pole is called OB. OB frequency has been shown to be related to major psychiatric diseases. Hence, it may suggest more than an anatomical variation. Structural differences in the brain have been demonstrated but unequivocally between patients with migraine with aura and without aura. OB is newly recognized, and we aimed to evaluate its frequency among patients with migraine. METHODS: For this retrospective cohort study, we reviewed our records from 2016 to 2021 from a database of the outpatient headache clinic of Koç University Hospital. RESULTS: We found 84 patients with migraine who fulfilled diagnostic criteria for migraine with aura and migraine without aura and also had cranial magnetic resonance imaging. The median age of the population was 40 (IQR, 32-52). The female-to-male ratio of participants was 2:1. A quarter of the patients had visual aura. The prevalence of OB in patients with migraine in our retrospective study was 33.3% (28/84). Between our study groups, OB was significantly higher in patients with migraine with visual aura (57.1%, 12 out of 21 patients) than in those without aura (25.4%, 16 out of 63), (odds ratio 3.9 (95% confidence interval 1.4 to 11.0), p = 0.015). CONCLUSION: OB frequency is two times higher in patients with migraine with visual aura. It may have pathophysiological implications.


Subject(s)
Migraine with Aura/physiopathology , Occipital Lobe/physiopathology , Adult , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Migraine Disorders/physiopathology , Retrospective Studies , Turkey
10.
Cereb Cortex ; 30(11): 5617-5625, 2020 10 01.
Article in English | MEDLINE | ID: mdl-32515826

ABSTRACT

In autism spectrum disorder (ASD), the complexity-specific hypothesis explains that atypical visual processing is attributable to selective functional changes in visual pathways. We investigated dendritic microstructures and their associations with functional connectivity (FC). Participants included 28 individuals with ASD and 29 typically developed persons. We explored changes in neurite orientation dispersion and density imaging (NODDI) and brain areas whose FC was significantly correlated with NODDI parameters in the explored regions of interests. Individuals with ASD showed significantly higher orientation dispersion index (ODI) values in the left occipital gyrus (OG) corresponding to the secondary visual cortex (V2). FC values between the left OG and the left middle temporal gyrus (MTG) were significantly negatively correlated with mean ODI values. The mean ODI values in the left OG were significantly positively associated with low registration of the visual quadrants of the Adolescent/Adult Sensory Profile (AASP), resulting in a significant positive correlation with passive behavioral responses of the AASP visual quadrants; additionally, the FC values between the left OG and the left MTG were significantly negatively associated with reciprocal social interaction. Our results suggest that abnormal V2 dendritic arborization is associated with atypical visual processing by altered intermediation in the ventral visual pathway.


Subject(s)
Autism Spectrum Disorder/physiopathology , Neurites/pathology , Occipital Lobe/physiopathology , Visual Perception/physiology , Adult , Brain Mapping/methods , Diffusion Tensor Imaging , Female , Humans , Image Interpretation, Computer-Assisted , Male , Visual Pathways/physiopathology
11.
Bull Exp Biol Med ; 171(3): 317-321, 2021 Jul.
Article in English | MEDLINE | ID: mdl-34297291

ABSTRACT

We analyzed interrelations between the cerebral blood flow, cardiac output, and condition of the brain substance in 530 patients with ischemic stroke. Dependencies between the linear blood flow velocities in all arteries supplying the brain, as well as between the total volume blood flow through the internal carotid arteries and left ventricular stroke volume were revealed. The severity of atrophy was maximum in the parietal lobes (median 1.5 (1.0; 2.0)) and minimum in the occipital lobes (median 0.5 (0; 1.0)). Temporal lobes cortical atrophy significantly correlated with changes in the limbic system and in the periventricular and deep white matter; a significant weak inverse correlation of this parameter with blood flow in the middle cerebral artery was also found. Changes in the periventricular white matter (but not in deep white matter) demonstrated a significant inverse correlation with blood flow in the middle and anterior cerebral arteries.


Subject(s)
Cerebrovascular Circulation , Ischemic Stroke/physiopathology , Occipital Lobe/physiopathology , Temporal Lobe/physiopathology , White Matter/physiopathology , Adult , Aged , Aged, 80 and over , Anterior Cerebral Artery/diagnostic imaging , Anterior Cerebral Artery/physiopathology , Basilar Artery/diagnostic imaging , Basilar Artery/physiopathology , Blood Flow Velocity , Carotid Artery, Internal/diagnostic imaging , Carotid Artery, Internal/physiopathology , Female , Humans , Ischemic Stroke/diagnostic imaging , Limbic System/diagnostic imaging , Limbic System/physiopathology , Magnetic Resonance Angiography , Male , Middle Aged , Middle Cerebral Artery/diagnostic imaging , Middle Cerebral Artery/physiopathology , Neuroimaging , Occipital Lobe/diagnostic imaging , Posterior Cerebral Artery/diagnostic imaging , Posterior Cerebral Artery/physiopathology , Prospective Studies , Stroke Volume , Temporal Lobe/diagnostic imaging , Vertebral Artery/diagnostic imaging , Vertebral Artery/physiopathology , White Matter/diagnostic imaging
12.
J Neurovirol ; 26(4): 590-601, 2020 08.
Article in English | MEDLINE | ID: mdl-32572834

ABSTRACT

Although neuropsychological studies of human immunodeficiency virus (HIV)-infected patients have demonstrated heterogeneity in neurocognitive impairment and neuroimaging studies have reported diverse brain regions affected by HIV, it remains unclear whether individual differences in neurocognitive impairment are underpinned by their neural bases. Here, we investigated spatial distribution patterns of correlation between neurocognitive function and regional gray matter (GM) volume across patients with HIV. Thirty-one combination antiretroviral therapy-treated HIV-infected Japanese male patients and 33 age- and sex-matched healthy controls were included in the analysis after strict exclusion criteria, especially for substance use. Fifteen neurocognitive tests were used, and volumetric magnetic resonance imaging was performed. We used voxel-based morphometry to compare GM volume between groups and identify regional GM volumes that correlated with neurocognitive tests across patients. Using the Frascati criteria, 10 patients were diagnosed with asymptomatic neurocognitive impairment, while the others were not diagnosed with HIV-associated neurocognitive disorders. Patients showed a significantly lower performance in five neurocognitive tests as well as significantly reduced GM volume relative to controls, with volume-reduced regions spread diffusely across the whole brain. Different aspects of neurocognitive impairment (i.e., figural copy, finger tapping, and Pegboard) were associated with different GM regions. Our findings suggest a biological background constituting heterogeneity of neurocognitive impairment in HIV infection and support the clinical importance of considering individual differences for tailor-made medicine for people living with HIV.


Subject(s)
Anti-HIV Agents/therapeutic use , Cognitive Dysfunction/physiopathology , Gray Matter/physiopathology , HIV Infections/physiopathology , Adult , Antiretroviral Therapy, Highly Active , Asymptomatic Diseases , Attention/drug effects , Case-Control Studies , Cognitive Dysfunction/diagnostic imaging , Cognitive Dysfunction/drug therapy , Cognitive Dysfunction/virology , Executive Function/drug effects , Gray Matter/diagnostic imaging , Gray Matter/drug effects , Gray Matter/virology , Gyrus Cinguli/diagnostic imaging , Gyrus Cinguli/drug effects , Gyrus Cinguli/physiopathology , Gyrus Cinguli/virology , HIV Infections/diagnostic imaging , HIV Infections/drug therapy , HIV Infections/virology , Hippocampus/diagnostic imaging , Hippocampus/drug effects , Hippocampus/physiopathology , Hippocampus/virology , Humans , Magnetic Resonance Imaging , Male , Memory/drug effects , Mental Status and Dementia Tests , Middle Aged , Motor Skills/drug effects , Neuroimaging/methods , Occipital Lobe/diagnostic imaging , Occipital Lobe/drug effects , Occipital Lobe/physiopathology , Occipital Lobe/virology , Parietal Lobe/diagnostic imaging , Parietal Lobe/drug effects , Parietal Lobe/physiopathology , Parietal Lobe/virology , Prefrontal Cortex/diagnostic imaging , Prefrontal Cortex/drug effects , Prefrontal Cortex/physiopathology , Prefrontal Cortex/virology , Severity of Illness Index , Speech/drug effects
13.
Am J Med Genet A ; 182(11): 2761-2764, 2020 11.
Article in English | MEDLINE | ID: mdl-32902107

ABSTRACT

Bi-allelic loss-of-function variants in LAMC3, encoding extracellular matrix protein laminin gamma 3, represent a rare cause of occipital polymicrogyria with epilepsy, developmental delay and cognitive impairment. So far, only five families have been reported. We now identified a novel, homozygous splice variant in LAMC3 in an individual with an unusual manifestation of cortical malformation. She presented with polymicrogyria in the frontal but not the occipital lobes, with adult-onset seizures and normal psychomotor development and cognition. Additionally, ictal asystole, requiring implantation of a pacemaker, and nonepileptic seizures occurred. This case expands the spectrum of LAMC3-associated cortical malformation phenotypes to frontal only polymicrogyria and adult-onset of epilepsy.


Subject(s)
Epilepsy/pathology , Laminin/genetics , Occipital Lobe/physiopathology , Phenotype , Polymicrogyria/pathology , RNA Splicing , Seizures/pathology , Adult , Age of Onset , Epilepsy/genetics , Female , Humans , Male , Pedigree , Polymicrogyria/genetics , Seizures/genetics
14.
J Psychiatry Neurosci ; 45(2): 98-107, 2020 03 01.
Article in English | MEDLINE | ID: mdl-31509362

ABSTRACT

Background: Patients with obsessive­compulsive disorder (OCD) employ ritualistic behaviours to reduce or even neutralize the anxiety provoked by their obsessions. The presence of excessive rumination and indecision has motivated the view of OCD as a disorder of decision-making. Most studies have focused on the "cold," cognitive aspects of decision-making. This study expands current understanding of OCD by characterizing the abnormalities associated with affective, or "hot" decision-making. Methods: We performed a functional MRI study in a sample of 34 patients with OCD and 33 sex- and age-matched healthy controls, during which participants made 2-choice gambles taking varying levels of risk. Results: During risky decisions, patients showed significantly reduced task-related activation in the posterior cingulum, lingual gyrus and anterior cingulate cortex. We identified significant group × risk interactions in the calcarine cortex, precuneus, amygdala and anterior cingulate cortex. During the outcome phase, patients with OCD showed stronger activation of the orbitofrontal cortex, anterior cingulate cortex and putamen in response to unexpected losses. Limitations: The group of patients not receiving medication was very small (n = 5), which precluded us from assessing the effect of medication on risk-taking behaviour in these patients. Conclusion: Obsessive­compulsive disorder is associated with abnormal brain activity patterns during risky decision-making in a set of brain regions that have been consistently implicated in the processing of reward prediction errors. Alterations in affective "hot" processes implicated in decision-making may contribute to increased indecisiveness and intolerance to uncertainty in patients with OCD.


Subject(s)
Amygdala/diagnostic imaging , Decision Making , Gyrus Cinguli/diagnostic imaging , Obsessive-Compulsive Disorder/diagnostic imaging , Occipital Lobe/diagnostic imaging , Parietal Lobe/diagnostic imaging , Risk-Taking , Adult , Amygdala/physiopathology , Brain/diagnostic imaging , Brain/physiopathology , Female , Functional Neuroimaging , Gyrus Cinguli/physiopathology , Humans , Magnetic Resonance Imaging , Male , Neural Pathways/diagnostic imaging , Neural Pathways/physiopathology , Obsessive-Compulsive Disorder/physiopathology , Occipital Lobe/physiopathology , Parietal Lobe/physiopathology , Reward , Young Adult
15.
Neurocase ; 26(3): 171-174, 2020 06.
Article in English | MEDLINE | ID: mdl-32378454

ABSTRACT

A 63-year-old woman was referred for visuospatial difficulties. The clinical and neuropsychological examination in association with imaging and biomarkers led to a diagnosis of posterior cortical atrophy (PCA). The patient, an amateur watercolor artist, continued to paint throughout her disease and her paintings illustrate in an original way the progression of her disorders. At an advanced stage, the evolution of neurovisual disorders is difficult to evaluate in patients. While studies have shown changes in artistic style in neurodegenerative diseases, none of them concerned PCA. Artistic production enables a different approach to trying to understand the progression of disorders.


Subject(s)
Art , Neurodegenerative Diseases , Occipital Lobe , Parietal Lobe , Psychomotor Performance/physiology , Space Perception/physiology , Visual Perception/physiology , Disease Progression , Female , Humans , Middle Aged , Neurodegenerative Diseases/pathology , Neurodegenerative Diseases/physiopathology , Occipital Lobe/pathology , Occipital Lobe/physiopathology , Parietal Lobe/physiology , Parietal Lobe/physiopathology
16.
Brain Topogr ; 33(2): 176-190, 2020 03.
Article in English | MEDLINE | ID: mdl-31832813

ABSTRACT

The posterior parietal cortex (PPC) is a key structure for visual attention and upper limb function, two features that could be impaired after stroke, and could be implied in their recovery. If it is well established that stroke is responsible for intra- and interhemispheric connectivity troubles, little is known about those existing for the contralesional PPC. In this study, we aimed at mapping the functional (using resting state fMRI) and structural (using diffusion tensor imagery) networks from 3 subparts of the PPC of the contralesional hemisphere (the anterior intraparietal sulcus), the posterior intraparietal sulcus and the superior parieto-occipital cortex to bilateral frontal areas and ipsilesional homologous PPC parts in 11 chronic stroke patients compared to 13 healthy controls. We also aimed at assessing the relationship between connectivity and the severity of visuospatial and motor deficiencies. We showed that interhemispheric functional and structural connectivity between PPCs was altered in stroke patients compared to controls, without any specificity among seeds. Alterations of parieto-frontal intra- and interhemispheric connectivity were less observed. Neglect severity was associated with several alterations in intra- and interhemispheric connectivity, whereas we did not find any behavioral/connectivity correlations for motor deficiency. The results of this exploratory study shed a new light on the influence of the contralesional PPC in post-stroke patients, they have to be confirmed and refined in further larger studies.


Subject(s)
Motor Disorders/physiopathology , Parietal Lobe/pathology , Parietal Lobe/physiopathology , Perceptual Disorders/physiopathology , Stroke/physiopathology , Attention , Diffusion Tensor Imaging , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Occipital Lobe/physiopathology
17.
Audiol Neurootol ; 25(5): 237-248, 2020.
Article in English | MEDLINE | ID: mdl-32320979

ABSTRACT

OBJECTIVE: The present study investigated the characteristics of visual processing in the auditory-associated cortex in adults with hearing loss using event-related potentials. METHODS: Ten subjects with bilateral postlingual hearing loss were recruited. Ten age- and sex-matched normal-hearing subjects were included as controls. Visual ("sound" and "non-sound" photos)-evoked potentials were performed. The P170 response in the occipital area as well as N1 and N2 responses in FC3 and FC4 were analyzed. RESULTS: Adults with hearing loss had higher P170 amplitudes, significantly higher N2 amplitudes, and shorter N2 latency in response to "sound" and "non-sound" photo stimuli at both FC3 and FC4, with the exception of the N2 amplitude which responded to "sound" photo stimuli at FC3. Further topographic mapping analysis revealed that patients had a large difference in response to "sound" and "non-sound" photos in the right frontotemporal area, starting from approximately 200 to 400 ms. Localization of source showed the difference to be located in the middle frontal gyrus region (BA10) at around 266 ms. CONCLUSIONS: The significantly stronger responses to visual stimuli indicate enhanced visual processing in the auditory-associated cortex in adults with hearing loss, which may be attributed to cortical visual reorganization involving the right frontotemporal cortex.


Subject(s)
Auditory Cortex/physiopathology , Deafness/physiopathology , Evoked Potentials/physiology , Occipital Lobe/physiopathology , Acoustic Stimulation , Adult , Female , Humans , Male , Middle Aged , Photic Stimulation
18.
Cereb Cortex ; 29(8): 3319-3330, 2019 07 22.
Article in English | MEDLINE | ID: mdl-30137241

ABSTRACT

Autism spectrum disorders (ASDs) are increasingly prevalent neurodevelopmental disorders characterized by sociocommunicative impairments. Growing consensus indicates that neurobehavioral abnormalities require explanation in terms of interconnected networks. Despite theoretical speculations about increased local and reduced distal connectivity, links between local and distal functional connectivity have not been systematically investigated in ASDs. Specifically, it remains open whether hypothesized local overconnectivity may reflect isolated versus overly integrative processing. Resting state functional MRI data from 57 children and adolescents with ASDs and 51 typically developing (TD) participants were included. In regional homogeneity (ReHo) analyses, pericalcarine visual cortex was found be locally overconnected (ASD > TD). Using this region as seed in whole-brain analyses, we observed overconnectivity in distal regions, specifically middle frontal gyri, for an ASD subgroup identified through k-means clustering. While in this subgroup local occipital to distal frontal overconnectivity was associated with greater symptom severity, a second subgroup showed the opposite pattern of connectivity and symptom severity correlations. Our findings suggest that increased local connectivity in ASDs is region-specific and may be partially associated with more integrative long-distance connectivity. Results also highlight the need to test for subtypes, as differential patterns of brain-behavior links were observed in two distinct subgroups of our ASD cohort.


Subject(s)
Autistic Disorder/diagnostic imaging , Prefrontal Cortex/diagnostic imaging , Visual Cortex/diagnostic imaging , Adolescent , Autism Spectrum Disorder/diagnostic imaging , Autism Spectrum Disorder/physiopathology , Autistic Disorder/physiopathology , Case-Control Studies , Child , Communication , Female , Frontal Lobe/diagnostic imaging , Frontal Lobe/physiopathology , Functional Neuroimaging , Humans , Magnetic Resonance Imaging , Male , Neural Pathways/diagnostic imaging , Neural Pathways/physiopathology , Occipital Lobe/diagnostic imaging , Occipital Lobe/physiopathology , Prefrontal Cortex/physiopathology , Severity of Illness Index , Social Behavior , Stereotyped Behavior , Visual Cortex/physiopathology
19.
J Cogn Neurosci ; 31(7): 1065-1078, 2019 07.
Article in English | MEDLINE | ID: mdl-30938589

ABSTRACT

The task-specific principle asserts that, following deafness or blindness, the deprived cortex is reorganized in a manner such that the task of a given area is preserved even though its input modality has been switched. Accordingly, tactile reading engages the ventral occipitotemporal cortex (vOT) in the blind in a similar way to regular reading in the sighted. Others, however, show that the vOT of the blind processes spoken sentence structure, which suggests that the task-specific principle might not apply to vOT. The strongest evidence for the vOT's engagement in sighted reading comes from orthographic repetition-suppression studies. Here, congenitally blind adults were tested in an fMRI repetition-suppression paradigm. Results reveal a double dissociation, with tactile orthographic priming in the vOT and auditory priming in general language areas. Reconciling our finding with other evidence, we propose that the vOT in the blind serves multiple functions, one of which, orthographic processing, overlaps with its function in the sighted.


Subject(s)
Blindness/physiopathology , Pattern Recognition, Physiological/physiology , Reading , Sensory Aids , Touch Perception/physiology , Visual Cortex/physiopathology , Adolescent , Adult , Auditory Perception , Blindness/congenital , Brain Mapping , Humans , Magnetic Resonance Imaging , Occipital Lobe/physiopathology , Temporal Lobe/physiopathology , Visually Impaired Persons , Young Adult
20.
Neuroimage ; 190: 205-212, 2019 04 15.
Article in English | MEDLINE | ID: mdl-28927730

ABSTRACT

Autism spectrum disorder (ASD) is a prevalent neurodevelopmental disorder characterized by atypical social communication and repetitive behaviors. In this study, we applied a multimodal approach to investigate brain structural connectivity, resting state activity, and surface area, as well as their associations with the core symptoms of ASD. Data from forty boys with ASD (mean age, 11.5 years; age range, 5.5-19.5) and forty boys with typical development (TD) (mean age, 12.3; age range, 5.8-19.7) were extracted from the Autism Brain Imaging Data Exchange II (ABIDE II) for data analysis. We found significantly decreased structural connectivity, resting state brain activity, and surface area at the occipital cortex in boys with ASD compared to boys with TD. In addition, we found that resting state brain activity and surface area in the lateral occipital cortex was negatively correlated with communication scores in boys with ASD. Our results suggest that decreased structural connectivity and resting-state brain activity in the occipital cortex may impair the integration of verbal and non-verbal communication cues in boys with ASD, thereby impacting their social development.


Subject(s)
Autism Spectrum Disorder/pathology , Autism Spectrum Disorder/physiopathology , Connectome , Diffusion Tensor Imaging , Occipital Lobe/pathology , Occipital Lobe/physiopathology , Social Communication Disorder/pathology , Social Communication Disorder/physiopathology , Adolescent , Adult , Autism Spectrum Disorder/diagnostic imaging , Autism Spectrum Disorder/etiology , Child , Child, Preschool , Humans , Male , Occipital Lobe/diagnostic imaging , Social Communication Disorder/diagnostic imaging , Social Communication Disorder/etiology , Young Adult
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