A 65-year-old woman with progressive visuospatial dysfunction for 2 years complained of later-onset associated memory impairment. MRI revealed diffuse cerebrocortical atrophy, which was especially severe in both parieto-occipital regions but spared the calcarine and pericalcarine cortices. Examination 5 years after onset revealed left visual hemi-neglect, oculomotor apraxia, optic ataxia, simultanagnosia, verbal alexia, lexical and spatial agraphia, and anterograde amnesia. This patient's disorder is considered in the context of previous reports on the array of cognitive disturbances associated with posterior cortical atrophy (pCA). Special emphasis is made on her reading and writing disturbances, because their prevalence and range of individual variability have not been established in pCA. This array of neuropsychological manifestations may help to distinguish among different clinical and etiological types of pCA, and to elucidate the pathophysiology of a syndrome that has been associated with conditions as diverse as Alzheimer's disease, subcortical gliosis, and prion diseases. The parameters described in our case may thus help to address these issues in clinico-pathological studies with large numbers of patients with pCA.
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Convolutional neural networks (CNNs) have been shown to be state-of-the-art models for visual cortical neurons. Cortical neurons in the primary visual cortex are sensitive to contextual information mediated by extensive horizontal and feedback connections. Standard CNNs integrate global contextual information to model contextual modulation via two mechanisms: successive convolutions and a fully connected readout layer.
View Article and Find Full Text PDFLayer 1 of V1 has been shown to receive locomotion-related signals from the dorsal lateral geniculate (dLGN) and lateral posterior (LP) thalamic nuclei ( ). Inputs from the dLGN terminate in M2+ patches while inputs from LP target M2- interpatches ( ) suggesting that motion related signals are processed in distinct networks. Here, we investigated by calcium imaging in head-fixed awake mice whether L2/3 neurons underneath L1 M2+ and M2- modules are differentially activated by locomotion, and whether distinct networks of feedback connections from higher cortical areas to L1 may contribute to these differences.
View Article and Find Full Text PDFBiol Psychiatry Cogn Neurosci Neuroimaging
March 2025
Department of Psychiatry, Indiana University School of Medicine, Indianapolis, Indiana; Adolescent Behavioral Health Research Program, Indiana University School of Medicine, Indianapolis, Indiana.
Introduction: Children with externalizing disorders (EDs) often have difficulties with impulsivity and emotion regulation. These constructs have been associated with dysfunction in the recruitment of reward processing circuits and striatal connectivity with cortical networks. However, it is unclear to what extent co-presentations of impulsivity and emotion regulation are associated with differences in striatocortical connectivity.
View Article and Find Full Text PDFBMC Oral Health
March 2025
Department of Implantology, Hospital of Stomatology, Jilin University, Changchun, China.
Background: Finite element analysis was used to predict the risk of bone plate fracture and the expected bone augmentation effect of a new alveolar bone splitting technique in the mandibular posterior region for different alveolar crest widths, different alveolar bone densities, different root incision widths, and different insertion depths of bone expansion instrumentation.
Methods: The jaw models of the mandibular posterior region were constructed by computer-aided software and surgical incisions and bone expansion instruments were prepared on the models, after which the alveolar bone splitting procedure was simulated by finite element analysis software, and the equivalent stress-strain distribution characteristics of the jaw models of each group, as well as the maximal force and the maximal displacement of the bone plate when it was fractured, were recorded.
Results: The distribution of equivalent stress and strain was mainly concentrated in the cancellous bone area at the root incision and the lower 1/3 of the buccal cortical bone plate, and there was no significant difference in the stress-strain distribution characteristics of the jaw models of each group.
Neurobiol Aging
March 2025
Department of Radiology, Mayo Clinic, Rochester, MN, USA. Electronic address:
Dementia with Lewy bodies (DLB) and posterior cortical atrophy (PCA) are neurodegenerative disorders that can overlap clinically and in patterns of regional hypometabolism and show elevated white matter hyperintensity (WMH) burden. Little is known about the regional WMH burden in DLB patients without any interference of AD pathology and how these patterns compare to PCA patients. Twenty-two amyloid-negative DLB patients, 40 amyloid-positive PCA patients, and 49 amyloid-negative cognitively unimpaired (CU) healthy individuals were recruited at Mayo Clinic, Rochester, MN.
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