-
The American Journal of Case Reports Dec 2020BACKGROUND Wernicke's encephalopathy (WE), a commonly misdiagnosed and underdiagnosed pathology, presents with altered mental status, ataxia, and ophthalmoplegia. WE is... (Review)
Review
BACKGROUND Wernicke's encephalopathy (WE), a commonly misdiagnosed and underdiagnosed pathology, presents with altered mental status, ataxia, and ophthalmoplegia. WE is most commonly caused by excessive alcohol use, but also has diverse nonalcoholic etiologies. Here we describe 2 cases of nonalcoholic WE with different etiologies that were initially misdiagnosed due to lack of correlation of magnetic resonance imaging (MRI) findings with clinical information. CASE REPORT Patient A, a 50-year-old woman with recent gastric sleeve surgery, presented with horizontal gaze-evoked nystagmus, ataxia, and altered mental status. MRI fluid-attenuated inversion recovery (FLAIR) revealed isolated bilateral, symmetrical, thalamic hyperintensities, initially diagnosed as variant Creutzfeldt-Jakob disease. A review of imaging and clinical presentation provided an alternate diagnosis of nonalcoholic WE secondary to nutritional deficiency. Intravenous (IV) thiamine improved symptoms with resolution of MRI findings 6 months later. Patient B, a 64-year-old woman, presented with nausea, vomiting, dizziness, altered mental status, and weight loss. MRI FLAIR revealed isolated bilateral, symmetrical, thalamic hyperintensities, initially determined to be ischemia, prompting stroke management. A diagnosis of nonalcoholic WE was suggested, given the patient's low thiamine levels and history of malnutrition, and was confirmed by her excellent therapeutic response to IV thiamine. CONCLUSIONS Nonalcoholic WE remains a challenging diagnosis because of the variable clinical presentation, myriad of underlying etiologies, and lack of standardized diagnostic laboratory tests. A multidisciplinary approach with close collaboration between the radiologist and clinical care team is critical to narrow down the differential and initiate correct management. WE is a reversible disease with catastrophic consequences if it is not recognized and treated promptly.
Topics: Female; Hockey; Humans; Magnetic Resonance Imaging; Middle Aged; Pulvinar; Thiamine; Wernicke Encephalopathy
PubMed: 33380716
DOI: 10.12659/AJCR.928272 -
Trends in Neurosciences Feb 2024The pulvinar nucleus of the thalamus is a crucial component of the visual system and plays significant roles in sensory processing and cognitive integration. The... (Review)
Review
The pulvinar nucleus of the thalamus is a crucial component of the visual system and plays significant roles in sensory processing and cognitive integration. The pulvinar's extensive connectivity with cortical regions allows for bidirectional communication, contributing to the integration of sensory information across the visual hierarchy. Recent findings underscore the pulvinar's involvement in attentional modulation, feature binding, and predictive coding. In this review, we highlight recent advances in clarifying the pulvinar's circuitry and function. We discuss the contributions of the pulvinar to signal modulation across the global cortical network and place these findings within theoretical frameworks of cortical processing, particularly the global neuronal workspace (GNW) theory and predictive coding.
Topics: Humans; Pulvinar; Thalamus; Visual Perception; Attention; Sensation
PubMed: 38143202
DOI: 10.1016/j.tins.2023.11.008 -
Neurology Feb 2015
Review
Topics: Animals; Attention; Brain; Cognition; Humans; Neural Pathways; Pulvinar; Visual Perception
PubMed: 25609762
DOI: 10.1212/WNL.0000000000001276 -
The Journal of Neuroscience : the... Feb 2023Distributed cortical regions show differential responses to visual objects belonging to different domains varying by animacy (e.g., animals vs tools), yet it remains...
Distributed cortical regions show differential responses to visual objects belonging to different domains varying by animacy (e.g., animals vs tools), yet it remains unclear whether this is an organization principle also applying to the subcortical structures. Combining multiple fMRI activation experiments (two main experiments and six validation datasets; 12 females and 9 males in the main Experiment 1; 10 females and 10 males in the main Experiment 2), resting-state functional connectivity, and task-based dynamic causal modeling analysis in human subjects, we found that visual processing of images of animals and tools elicited different patterns of response in the pulvinar, with robust left lateralization for tools, and distinct, bilateral (with rightward tendency) clusters for animals. Such domain-preferring activity distribution in the pulvinar was associated with the magnitude with which the voxels were intrinsically connected with the corresponding domain-preferring regions in the cortex. The pulvinar-to-right-amygdala path showed a one-way shortcut supporting the perception of animals, and the modulation connection from pulvinar to parietal showed an advantage to the perception of tools. These results incorporate the subcortical regions into the object processing network and highlight that domain organization appears to be an overarching principle across various processing stages in the brain. Viewing objects belonging to different domains elicited different cortical regions, but whether the domain organization applied to the subcortical structures (e.g., pulvinar) was unknown. Multiple fMRI activation experiments revealed that object pictures belonging to different domains elicited differential patterns of response in the pulvinar, with robust left lateralization for tool pictures, and distinct, bilateral (with rightward tendency) clusters for animals. Combining the resting-state functional connectivity and dynamic causal modeling analysis on task-based fMRI data, we found domain-preferring activity distribution in the pulvinar aligned with that in cortical regions. These results highlight the need for coherent visual theories that explain the mechanisms underlying the domain organization across various processing stages.
Topics: Male; Female; Animals; Humans; Pulvinar; Magnetic Resonance Imaging; Brain; Brain Mapping; Amygdala
PubMed: 36596697
DOI: 10.1523/JNEUROSCI.0613-22.2022 -
The Journal of Comparative Neurology Oct 2017In this review, we outline the history of our current understanding of the organization of the pulvinar complex of mammals. We include more recent evidence from our own... (Review)
Review
In this review, we outline the history of our current understanding of the organization of the pulvinar complex of mammals. We include more recent evidence from our own studies of both New and Old World monkeys, prosimian galagos, and close relatives of primates, including tree shrews and rodents. Based on cumulative evidence, we provide insights into the possible evolution of the visual pulvinar complex, as well as the possible co-evolution of the inferior pulvinar nuclei and temporal cortical visual areas within the MT complex.
Topics: Animals; Biological Evolution; Humans; Primates; Pulvinar; Visual Pathways; Visual Perception
PubMed: 28653446
DOI: 10.1002/cne.24272 -
Vision (Basel, Switzerland) Apr 2020The cortical visual hierarchy communicates in different oscillatory ranges. While gamma waves influence the feedforward processing, alpha oscillations travel in the...
The cortical visual hierarchy communicates in different oscillatory ranges. While gamma waves influence the feedforward processing, alpha oscillations travel in the feedback direction. Little is known how this oscillatory cortical communication depends on an alternative route that involves the pulvinar nucleus of the thalamus. We investigated whether the oscillatory coupling between the primary visual cortex (area 17) and area 21a depends on the transthalamic pathway involving the pulvinar in cats. To that end, visual evoked responses were recorded in areas 17 and 21a before, during and after inactivation of the pulvinar. Local field potentials were analyzed with Wavelet and Granger causality tools to determine the oscillatory coupling between layers. The results indicate that cortical oscillatory activity was enhanced during pulvinar inactivation, in particular for area 21a. In area 17, alpha band responses were represented in layers II/III. In area 21a, gamma oscillations, except for layer I, were significantly increased, especially in layer IV. Granger causality showed that the pulvinar modulated the oscillatory information between areas 17 and 21a in gamma and alpha bands for the feedforward and feedback processing, respectively. Together, these findings indicate that the pulvinar is involved in the mechanisms underlying oscillatory communication along the visual cortex.
PubMed: 32290073
DOI: 10.3390/vision4020022 -
Brain Research Reviews Oct 2007The visual pulvinar is part of the dorsal thalamus, and in primates it is especially well developed. Recently, our understanding of how the visual pulvinar is subdivided... (Review)
Review
The visual pulvinar is part of the dorsal thalamus, and in primates it is especially well developed. Recently, our understanding of how the visual pulvinar is subdivided into nuclei has greatly improved as a number of histological procedures have revealed marked architectonic differences within the pulvinar complex. At the same time, there have been unparalleled advances in understanding of how visual cortex of primates is subdivided into areas and how these areas interconnect. In addition, considerable evidence supports the view that the hierarchy of interconnected visual areas is divided into two major processing streams, a ventral stream for object vision and a dorsal stream for visually guided actions. In this review, we present evidence that a subset of medial nuclei in the inferior pulvinar function predominantly as a subcortical component of the dorsal stream while the most lateral nucleus of the inferior pulvinar and the adjoining ventrolateral nucleus of the lateral pulvinar are more devoted to the ventral stream of cortical processing. These nuclei provide cortico-pulvinar-cortical interactions that spread information across areas within streams, as well as information relayed from the superior colliculus via inferior pulvinar nuclei to largely dorsal stream areas.
Topics: Animals; Humans; Primates; Thalamus; Visual Pathways
PubMed: 17433837
DOI: 10.1016/j.brainresrev.2007.02.008 -
Neuron Jan 2016While the function of the pulvinar remains one of the least explored among the thalamic nuclei despite occupying the most thalamic volume in primates, it has long been...
While the function of the pulvinar remains one of the least explored among the thalamic nuclei despite occupying the most thalamic volume in primates, it has long been suspected to play a crucial role in attentive stimulus processing. In this issue of Neuron, Zhou et al. (2016) use simultaneous pulvinar-visual cortex recordings and pulvinar inactivation to provide evidence that the pulvinar is essential for intact stimulus processing, maintenance of neuronal oscillatory dynamics, and mediating the effects of attention.
Topics: Animals; Attention; Male; Pulvinar; Vision, Ocular; Visual Cortex; Visual Pathways
PubMed: 26748085
DOI: 10.1016/j.neuron.2015.12.022 -
NeuroImage Oct 2023Spatial attention is often described as a mental spotlight that enhances information processing at the attended location. Using fMRI, we investigated background...
Spatial attention is often described as a mental spotlight that enhances information processing at the attended location. Using fMRI, we investigated background connectivity between the pulvinar and V1 in relation to focused versus diffused attention allocation, in weak and strong crowding contexts. Our findings revealed that focused attention led to enhanced correlations between the pulvinar and V1. Notably, this modulation was initiated by the pulvinar, and the strength of the modulation was dependent on the saliency of the target. These findings suggest that the pulvinar initiates information reweighting to V1, which underlies attentional selection in cluttered scenes.
Topics: Humans; Pulvinar; Cognition; Diffusion
PubMed: 37619793
DOI: 10.1016/j.neuroimage.2023.120341 -
Sheng Li Xue Bao : [Acta Physiologica... Feb 2018Superior colliculus-pulvinar-amygdala pathway is one of the subcortical visual pathways in mammalian brain. Some recent studies suggest that this pathway is involved in... (Review)
Review
Superior colliculus-pulvinar-amygdala pathway is one of the subcortical visual pathways in mammalian brain. Some recent studies suggest that this pathway is involved in processing emotion-related visual information. This review discusses the possibility that this pathway is more related to visual alert rather than simply the early visual information processing. The biological significance of this pathway is also discussed. Instead of detecting "where" or "what" the visual target is, the task of this early visual stage is to send out a warning signal, i.e., "something appears", so that the brain can be set up in a state of alert, which is important for the survival of animals. Thus, in the early visual information process, detection of new object "emerging" or "disappearing" takes priority over the acquisition of its feature information of "texture" and "shape", etc. The subcortical pathway may provide the neural basis of early visual warning in topological perception, a biological significance critical for animal survival.
Topics: Amygdala; Animals; Brain; Emotions; Humans; Perception; Pulvinar; Superior Colliculi; Visual Pathways
PubMed: 29492518
DOI: No ID Found