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Jon H. Kaas - One of the best experts on this subject based on the ideXlab platform.
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the evolution and functions of nuclei of the visual Pulvinar in primates
The Journal of Comparative Neurology, 2017Co-Authors: Mary K. L. Baldwin, Pooja Balaram, Jon H. KaasAbstract: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.
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c fos expression in the visual system of tree shrews after monocular inactivation
The Journal of Comparative Neurology, 2017Co-Authors: Toru Takahata, Jon H. KaasAbstract:Tree shrews possess an unusual segregation of ocular inputs to sublayers rather than columns in the primary visual cortex (V1). In this study, the lateral geniculate nucleus (LGN), superior colliculus (SC), Pulvinar, and V1 were examined for changes in c-FOS, an immediate-early gene, expression after 1 or 24 hours of monocular inactivation with tetrodotoxin (TTX) in tree shrews. Monocular inactivation greatly reduced gene expression in LGN layers related to the blocked eye, whereas normally high to moderate levels were maintained in the layers that receive inputs from the intact eye. The SC and caudal Pulvinar contralateral to the blocked eye had greatly (SC) or moderately (Pulvinar) reduced gene expressions reflective of dependence on the contralateral eye. c-FOS expression in V1 was greatly reduced contralateral to the blocked eye, with most of the expression that remained in upper layer 4a and lower 4b and lower layer 6 regions. In contrast, much of V1 contralateral to the active eye showed normal levels of c-FOS expression, including the inner parts of sublayers 4a and 4b and layers 2, 3, and 6. In some cases, upper layer 4a and lower 4b showed a reduction of gene expression. Layers 5 and sublayer 3c had normally low levels of gene expression. The results reveal the functional dominance of the contralateral eye in activating the SC, Pulvinar, and V1, and the results from V1 suggest that the sublaminar organization of layer 4 is more complex than previously realized. J. Comp. Neurol. 525:151-165, 2017. © 2016 Wiley Periodicals, Inc.
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projections of the superior colliculus to the Pulvinar in prosimian galagos otolemur garnettii and vglut2 staining of the visual Pulvinar
The Journal of Comparative Neurology, 2013Co-Authors: Mary K. L. Baldwin, Pooja Balaram, Jon H. KaasAbstract:An understanding of the organization of the Pulvinar complex in prosimian primates has been somewhat elusive due to the lack of clear architectonic divisions. In the current study, we revealed features of the organization of the Pulvinar complex in galagos by examining superior colliculus (SC) projections to this structure and comparing them with staining patterns of the vesicular glutamate transporter, VGLUT2. Cholera toxin subunit β (CTB), fluroruby (FR) and wheat germ agglutinin conjugated with horseradish peroxidase (WGA-HRP) were placed in topographically different locations within the SC. Our results showed multiple topographically organized patterns of projections from the SC to several divisions of the Pulvinar complex. At least two topographically distributed projections were found within the lateral region of the Pulvinar complex, and two less obvious topographical projection patterns were found within the caudomedial region, in zones that stain darkly for VGLUT2. The results, considered in relation to recent observations in tree shrews and squirrels, suggest that parts of the organizational scheme of the Pulvinar complex in primates are present in rodents and other mammals.
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superior colliculus connections with visual thalamus in gray squirrels sciurus carolinensis evidence for four subdivisions within the Pulvinar complex
The Journal of Comparative Neurology, 2011Co-Authors: Mary K. L. Baldwin, Peiyan Wong, Jamie L Reed, Jon H. KaasAbstract:As diurnal rodents with a well-developed visual system, squirrels provide a useful comparison of visual system organization with other highly visual mammals such as tree shrews and primates. Here, we describe the projection pattern of gray squirrel superior colliculus (SC) with the large and well-differentiated Pulvinar complex. Our anatomical results support the conclusion that the Pulvinar complex of squirrels consists of four distinct nuclei. The caudal (C) nucleus, distinct in cytochrome oxidase (CO), acetylcholinesterase (AChE), and vesicular glutamate transporter-2 (VGluT2) preparations, received widespread projections from the ipsilateral SC, although a crude retinotopic organization was suggested. The caudal nucleus also received weaker projections from the contralateral SC. The caudal nucleus also projects back to the ipsilateral SC. Lateral (RLl) and medial (RLm) parts of the previously defined rostral lateral Pulvinar (RL) were architectonically distinct, and each nucleus received its own retinotopic pattern of focused ipsilateral SC projections. The SC did not project to the rostral medial (RM) nucleus of the Pulvinar. SC injections also revealed ipsilateral connections with the dorsal and ventral lateral geniculate nuclei, nuclei of the pretectum, and nucleus of the brachium of the inferior colliculus and bilateral connections with the parabigeminal nuclei. Comparisons with other rodents suggest that a variously named caudal nucleus, which relays visual inputs from the SC to temporal visual cortex, is common to all rodents and possibly most mammals. RM and RL divisions of the Pulvinar complex also appear to have homologues in other rodents.
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VGLUT2 mRNA and protein expression in the visual thalamus and midbrain of prosimian galagos (Otolemur garnetti)
Dove Medical Press, 2011Co-Authors: Pooja Balaram, Toru Takahata, Jon H. KaasAbstract:Pooja Balaram1, Toru Takahata1, Jon H Kaas1,21Department of Psychology, 2Department of Cell and Molecular Biology, Vanderbilt University, Nashville, TN, USAAbstract: Vesicular glutamate transporters (VGLUTs) control the storage and presynaptic release of glutamate in the central nervous system, and are involved in the majority of glutamatergic transmission in the brain. Two VGLUT isoforms, VGLUT1 and VGLUT2, are known to characterize complementary distributions of glutamatergic neurons in the rodent brain, which suggests that they are each responsible for unique circuits of excitatory transmission. In rodents, VGLUT2 is primarily utilized in thalamocortical circuits, and is strongly expressed in the primary sensory nuclei, including all areas of the visual thalamus. The distribution of VGLUT2 in the visual thalamus and midbrain has yet to be characterized in primate species. Thus, the present study describes the expression of VGLUT2 mRNA and protein across the visual thalamus and superior colliculus of prosimian galagos to provide a better understanding of glutamatergic transmission in the primate brain. VGLUT2 is strongly expressed in all six layers of the dorsal lateral geniculate nucleus, and much less so in the intralaminar zones, which correspond to retinal and superior collicular inputs, respectively. The parvocellular and magnocellular layers expressed VGLUT2 mRNA more densely than the koniocellular layers. A patchy distribution of VGLUT2 positive terminals in the Pulvinar complex possibly reflects inputs from the superior colliculus. The upper superficial granular layers of the superior colliculus, with inputs from the retina, most densely expressed VGLUT2 protein, while the lower superficial granular layers, with projections to the Pulvinar, most densely expressed VGLUT2 mRNA. The results are consistent with the conclusion that retinal and superior colliculus projections to the thalamus depend highly on the VGLUT2 transporter, as do cortical projections from the magnocellular and parvocellular layers of the lateral geniculate nucleus and neurons of the Pulvinar complex.Keywords: lateral geniculate nucleus, superior colliculus, Pulvinar, primate, glutamat
R G Will - One of the best experts on this subject based on the ideXlab platform.
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Diagnosing Variant Creutzfeldt-Jakob Disease with the Pulvinar Sign: MR Imaging Findings in 86 Neuropathologically Confirmed Cases
2014Co-Authors: Donald A Collie, James W. Ironside, Richard Knight, Sarah Cooper, Robin Sellar, David M. Summers, Martin Zeidler, R G WillAbstract:BACKGROUND AND PURPOSE: Variant Creutzfeldt-Jakob disease (vCJD) is a rare but important cause of dementia and death in young patients and is causally linked to bovine spongiform encephalopathy. Symmetrical hyperintensity in the Pulvinar (posterior) nuclei of the thalamus (Pulvinar sign) on brain MR images was described as a specific, noninvasive, diagnostic sign of vCJD in a previous small series. This purpose of this larger study was to evaluate this sign prospectively and further define the MR imaging characteristics of vCJD. METHODS: As part of the ongoing surveillance program in the United Kingdom, MR images of suspected cases of vCJD were collected during a 6-year period. All available images were assessed prospectively by one observer for the presence of the Pulvinar sign. Images of neuropathologically confirmed cases were then assessed independently by two neuroradiologists for the degree of hyperintensity of the Pulvinar on images of different MR sequences, and for the presence of abnormal hyperintensity in other areas of the brain. Discrepancies were reviewed jointly and a consensus opinion formed. RESULTS: Prospective analysis identified the Pulvinar sign in 74 of 82 cases of vCJD. In the retrospective study, the Pulvinar sign, as defined by hyperintensity of the Pulvinar relative to th
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diagnosing variant creutzfeldt jakob disease with the Pulvinar sign mr imaging findings in 86 neuropathologically confirmed cases
American Journal of Neuroradiology, 2003Co-Authors: Donald A Collie, James W. Ironside, Richard Knight, M Zeidler, Sarah Cooper, Robin Sellar, David Summers, R G WillAbstract:BACKGROUND AND PURPOSE: Variant Creutzfeldt-Jakob disease (vCJD) is a rare but important cause of dementia and death in young patients and is causally linked to bovine spongiform encephalopathy. Symmetrical hyperintensity in the Pulvinar (posterior) nuclei of the thalamus (Pulvinar sign) on brain MR images was described as a specific, noninvasive, diagnostic sign of vCJD in a previous small series. This purpose of this larger study was to evaluate this sign prospectively and further define the MR imaging characteristics of vCJD. METHODS: As part of the ongoing surveillance program in the United Kingdom, MR images of suspected cases of vCJD were collected during a 6-year period. All available images were assessed prospectively by one observer for the presence of the Pulvinar sign. Images of neuropathologically confirmed cases were then assessed independently by two neuroradiologists for the degree of hyperintensity of the Pulvinar on images of different MR sequences, and for the presence of abnormal hyperintensity in other areas of the brain. Discrepancies were reviewed jointly and a consensus opinion formed. RESULTS: Prospective analysis identified the Pulvinar sign in 74 of 82 cases of vCJD. In the retrospective study, the Pulvinar sign, as defined by hyperintensity of the Pulvinar relative to the anterior putamen, was present on seven (9%) of 75 T1-weighted, 77 (71%) of 108 T2-weighted, 47 (81%) of 58 proton density-weighted, and 30 (100%) of 30 fluid-attenuated inversion-recovery (FLAIR) images. Diffusion-weighted images were available in two cases and were positive for the Pulvinar sign in one. Other features were hyperintensity of the dorsomedial thalamic nuclei (93%), caudate head (40%), and periaqueductal gray matter (83%) on FLAIR images. CONCLUSION: In the appropriate clinical context, demonstration of the Pulvinar sign on MR images is a highly accurate diagnostic sign for vCJD. FLAIR sequence is more sensitive than other sequences. Positive MR images may obviate more invasive diagnostic tests in most cases.
Mary K. L. Baldwin - One of the best experts on this subject based on the ideXlab platform.
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the evolution and functions of nuclei of the visual Pulvinar in primates
The Journal of Comparative Neurology, 2017Co-Authors: Mary K. L. Baldwin, Pooja Balaram, Jon H. KaasAbstract: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.
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projections of the superior colliculus to the Pulvinar in prosimian galagos otolemur garnettii and vglut2 staining of the visual Pulvinar
The Journal of Comparative Neurology, 2013Co-Authors: Mary K. L. Baldwin, Pooja Balaram, Jon H. KaasAbstract:An understanding of the organization of the Pulvinar complex in prosimian primates has been somewhat elusive due to the lack of clear architectonic divisions. In the current study, we revealed features of the organization of the Pulvinar complex in galagos by examining superior colliculus (SC) projections to this structure and comparing them with staining patterns of the vesicular glutamate transporter, VGLUT2. Cholera toxin subunit β (CTB), fluroruby (FR) and wheat germ agglutinin conjugated with horseradish peroxidase (WGA-HRP) were placed in topographically different locations within the SC. Our results showed multiple topographically organized patterns of projections from the SC to several divisions of the Pulvinar complex. At least two topographically distributed projections were found within the lateral region of the Pulvinar complex, and two less obvious topographical projection patterns were found within the caudomedial region, in zones that stain darkly for VGLUT2. The results, considered in relation to recent observations in tree shrews and squirrels, suggest that parts of the organizational scheme of the Pulvinar complex in primates are present in rodents and other mammals.
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superior colliculus connections with visual thalamus in gray squirrels sciurus carolinensis evidence for four subdivisions within the Pulvinar complex
The Journal of Comparative Neurology, 2011Co-Authors: Mary K. L. Baldwin, Peiyan Wong, Jamie L Reed, Jon H. KaasAbstract:As diurnal rodents with a well-developed visual system, squirrels provide a useful comparison of visual system organization with other highly visual mammals such as tree shrews and primates. Here, we describe the projection pattern of gray squirrel superior colliculus (SC) with the large and well-differentiated Pulvinar complex. Our anatomical results support the conclusion that the Pulvinar complex of squirrels consists of four distinct nuclei. The caudal (C) nucleus, distinct in cytochrome oxidase (CO), acetylcholinesterase (AChE), and vesicular glutamate transporter-2 (VGluT2) preparations, received widespread projections from the ipsilateral SC, although a crude retinotopic organization was suggested. The caudal nucleus also received weaker projections from the contralateral SC. The caudal nucleus also projects back to the ipsilateral SC. Lateral (RLl) and medial (RLm) parts of the previously defined rostral lateral Pulvinar (RL) were architectonically distinct, and each nucleus received its own retinotopic pattern of focused ipsilateral SC projections. The SC did not project to the rostral medial (RM) nucleus of the Pulvinar. SC injections also revealed ipsilateral connections with the dorsal and ventral lateral geniculate nuclei, nuclei of the pretectum, and nucleus of the brachium of the inferior colliculus and bilateral connections with the parabigeminal nuclei. Comparisons with other rodents suggest that a variously named caudal nucleus, which relays visual inputs from the SC to temporal visual cortex, is common to all rodents and possibly most mammals. RM and RL divisions of the Pulvinar complex also appear to have homologues in other rodents.
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cortical connections of the visual Pulvinar complex in prosimian galagos otolemur garnetti
The Journal of Comparative Neurology, 2009Co-Authors: Peiyan Wong, Christine E Collins, Mary K. L. Baldwin, Jon H. KaasAbstract:The present study focuses on determining the cortical and tectal connections with subdivisions of the visual Pulvinar in prosimian galagos. Traditionally, the Pulvinar complex of primates has been divided into inferior (PI), lateral (PL), and medial (PM) regions (Stepniewska and Kaas, 1997; Stepniewska et al., 1999; Kaas and Lyon, 2007; Jones, 2007). The inferior Pulvinar, once thought to be a single nucleus, has been divided into four nuclei in monkeys that can be distinguished by histochemical differences and patterns of projections to areas of visual cortex (for review see Kaas and Lyon, 2007). In monkeys, the most lateral part of PI, the large central lateral nucleus (PIcl), projects to primary and secondary visual areas, V1 and V2, as well as the dorsolateral visual area (DL or V4), whereas a smaller, medial nucleus (PIm) projects to the middle temporal visual area, MT. The posterior (PIp) and central medial (PIcm) nuclei receive inputs from the superior colliculus and project to areas of the dorsal stream of visual processing that are connected with MT. The lateral Pulvinar largely consists of a large ventral lateral nucleus (PLvl) that projects to V1, V2, and DL(V4). A dorsomedial nucleus (PLdm) is sometimes distinguished as part of the lateral Pulvinar, but its connections with prefrontal and inferior parietal cortex suggest that it more appropriately should be considered part of the medial Pulvinar, which has widespread connections that are not strictly visual. An anterior or oral Pulvinar is associated with somatosensory cortex and clearly is not part of the visual Pulvinar. The visual Pulvinar (also called the lateral posterior nucleus or the lateral posterior Pulvinar complex) appears to be organized somewhat differently in carnivores, rodents (Jones, 2007), and even tree shrews (Lyon et al., 2003), and common (homologous) nuclei have been difficult to identify. Understanding of the visual Pulvinar organization in primates has largely been based on studies of New and Old World monkeys (see e.g., Allman et al., 1972; Gattass et al., 1978; Lin and Kaas, 1979; Bender, 1981; Ungerleider et al., 1983; Boussaoud et al., 1992; Cusick et al., 1993; Gutierrez et al., 1995; Gutierrez and Cusick, 1997; Stepniewska and Kaas, 1997; Stepniewska et al., 1999, 2000; Gray et al., 1999; Adams et al., 2000; O’Brien et al., 2001; Shipp, 2001; Weller et al., 2002; Cola et al., 2005), where major similarities in architectonic subdivisions and connection patterns are evident. However, little is known about the organization of the visual Pulvinar in other primates. Broader comparisons across mammalian taxa might result in a fuller understanding of common and variable features of visual Pulvinar organization across the major branches of the primate radiation. Toward this end, we sought to reveal patterns of visual Pulvinar connections in a member of the prosimian radiation, the Otolemur garnetti. The primate order has three major branches, the prosimians, the tarsiers, and the anthropoid primates that include monkeys, apes, and humans. In general, the skull and brain shapes of extant prosimian (strepsirrhine) primates resemble those of the earliest primate fossils (Radinsky, 1977; Jerison, 1979), suggesting that, in some respects, prosimian brains have changed the least in primate evolution. An initial separation of the two main branches of early prosimians into lemuriforms and lorisiforms occurred in Africa 50 – 80 million years ago. The lemuriform ancestor invaded Madagascar to initiate the highly varied radiation of lemurs (Horvath and Willard, 2007), and lorisiforms divided into lorisides and galagosides (Roos et al., 2004). The galagos, including Otolemur garnetti (formerly Galago garnetti), remained in Africa, whereas one of the two lorisid lineages migrated to Asia. Most of what is known about the organization of prosimian brains comes from studies of galagos. Previously, several papers have described some aspects of Pulvinar connections in galagos (Glendenning et al., 1975; Raczkowski and Diamond, 1978, 1980, 1981; Symonds and Kaas, 1978; Carey et al., 1979; Wall et al., 1982). The present results, together with previous findings, allow a more comprehensive understanding of Pulvinar organization in galagos as well as a comparison with what is now known about Pulvinar organization in monkeys. The major conclusion stemming from this comparison is that the inferior Pulvinar of galagos, and perhaps other prosimians, has fewer subdivisions than in monkeys, and cortical connections with various visual cortical areas are not as segregated. The cortical areas investigated in the present study include V1 and V2, areas common to most mammals, and MT, an area characteristic of all primates with no obvious homologue in other mammals (Kaas, 2004). In addition, we describe superior colliculus projections to the Pulvinar.
Donald A Collie - One of the best experts on this subject based on the ideXlab platform.
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Post-mortem magnetic resonance imaging in patients with suspected prion disease: Pathological confirmation, sensitivity, specificity and observer reliability. A national registry.
'Public Library of Science (PLoS)', 2018Co-Authors: Lorna M Gibson, James W. Ironside, Richard Knight, Robin Sellar, Donald A Collie, David Summers, Francesca M Chappell, Jonathan Best, Joanna M WardlawAbstract:The relationship between magnetic resonance imaging (MRI) and clinical variables in patients suspected to have Creutzfeldt-Jakob Disease (CJD) is uncertain. We aimed to determine which MRI features of CJD (positive or negative), previously described in vivo, accurately identify CJD, are most reliably detected, vary with disease duration, and whether combined clinical and imaging features increase diagnostic accuracy for CJD. Prospective patients suspected of having CJD were referred to the National CJD Research and Surveillance Unit between 1994-2004; post-mortem, brains were sent for MRI and histopathology. Two neuroradiologists independently assessed MRI for atrophy, white matter hyperintensities, and caudate, lentiform and Pulvinar signals, blind to histopathological diagnosis and clinical details. We examined differences in variable frequencies using Fisher's exact tests, and associations between variables and CJD in logistic regression models. Amongst 200 cases, 118 (59%) with a histopathological diagnosis of CJD and 82 (41%) with histopathological diagnoses other than CJD, a logistic regression model including age, disease duration at death, atrophy, white matter hyperintensities, bright or possibly bright caudate, and present Pulvinar sign correctly classified 81% of cases as CJD versus not CJD. Pulvinar sign alone was not independently associated with an increased likelihood of histopathologically-confirmed CJD (of any subtype) or sporadic CJD after adjustment for age at death, disease duration, atrophy, white matter hyperintensities or caudate signal; despite the large sample, data sparsity precluded investigation of the association of Pulvinar sign with variant CJD. No imaging feature varied significantly with disease duration. Of the positive CJD signs, neuroradiologists most frequently agreed on the presence or absence of atrophy (agreements in 169/200 cases [84.5%]). Combining patient age, and disease duration, with absence of atrophy and white matter hyperintensities and presence of increased caudate signal and Pulvinar sign predicts CJD with good accuracy. Autopsy remains essential
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Diagnosing Variant Creutzfeldt-Jakob Disease with the Pulvinar Sign: MR Imaging Findings in 86 Neuropathologically Confirmed Cases
2014Co-Authors: Donald A Collie, James W. Ironside, Richard Knight, Sarah Cooper, Robin Sellar, David M. Summers, Martin Zeidler, R G WillAbstract:BACKGROUND AND PURPOSE: Variant Creutzfeldt-Jakob disease (vCJD) is a rare but important cause of dementia and death in young patients and is causally linked to bovine spongiform encephalopathy. Symmetrical hyperintensity in the Pulvinar (posterior) nuclei of the thalamus (Pulvinar sign) on brain MR images was described as a specific, noninvasive, diagnostic sign of vCJD in a previous small series. This purpose of this larger study was to evaluate this sign prospectively and further define the MR imaging characteristics of vCJD. METHODS: As part of the ongoing surveillance program in the United Kingdom, MR images of suspected cases of vCJD were collected during a 6-year period. All available images were assessed prospectively by one observer for the presence of the Pulvinar sign. Images of neuropathologically confirmed cases were then assessed independently by two neuroradiologists for the degree of hyperintensity of the Pulvinar on images of different MR sequences, and for the presence of abnormal hyperintensity in other areas of the brain. Discrepancies were reviewed jointly and a consensus opinion formed. RESULTS: Prospective analysis identified the Pulvinar sign in 74 of 82 cases of vCJD. In the retrospective study, the Pulvinar sign, as defined by hyperintensity of the Pulvinar relative to th
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diagnosing variant creutzfeldt jakob disease with the Pulvinar sign mr imaging findings in 86 neuropathologically confirmed cases
American Journal of Neuroradiology, 2003Co-Authors: Donald A Collie, James W. Ironside, Richard Knight, M Zeidler, Sarah Cooper, Robin Sellar, David Summers, R G WillAbstract:BACKGROUND AND PURPOSE: Variant Creutzfeldt-Jakob disease (vCJD) is a rare but important cause of dementia and death in young patients and is causally linked to bovine spongiform encephalopathy. Symmetrical hyperintensity in the Pulvinar (posterior) nuclei of the thalamus (Pulvinar sign) on brain MR images was described as a specific, noninvasive, diagnostic sign of vCJD in a previous small series. This purpose of this larger study was to evaluate this sign prospectively and further define the MR imaging characteristics of vCJD. METHODS: As part of the ongoing surveillance program in the United Kingdom, MR images of suspected cases of vCJD were collected during a 6-year period. All available images were assessed prospectively by one observer for the presence of the Pulvinar sign. Images of neuropathologically confirmed cases were then assessed independently by two neuroradiologists for the degree of hyperintensity of the Pulvinar on images of different MR sequences, and for the presence of abnormal hyperintensity in other areas of the brain. Discrepancies were reviewed jointly and a consensus opinion formed. RESULTS: Prospective analysis identified the Pulvinar sign in 74 of 82 cases of vCJD. In the retrospective study, the Pulvinar sign, as defined by hyperintensity of the Pulvinar relative to the anterior putamen, was present on seven (9%) of 75 T1-weighted, 77 (71%) of 108 T2-weighted, 47 (81%) of 58 proton density-weighted, and 30 (100%) of 30 fluid-attenuated inversion-recovery (FLAIR) images. Diffusion-weighted images were available in two cases and were positive for the Pulvinar sign in one. Other features were hyperintensity of the dorsomedial thalamic nuclei (93%), caudate head (40%), and periaqueductal gray matter (83%) on FLAIR images. CONCLUSION: In the appropriate clinical context, demonstration of the Pulvinar sign on MR images is a highly accurate diagnostic sign for vCJD. FLAIR sequence is more sensitive than other sequences. Positive MR images may obviate more invasive diagnostic tests in most cases.
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the Pulvinar sign on magnetic resonance imaging in variant creutzfeldt jakob disease
The Lancet, 2000Co-Authors: M Zeidler, James W. Ironside, Simon Cousens, Richard Knight, G E Stewart, Robin Sellar, Donald A Collie, Margaretann Macleod, Alan F C Colchester, Donald M HadleyAbstract:Summary Background There is a need for an accurate non-invasive diagnostic test for variant Creutzfeldt-Jakob disease (vCJD). We investigated the sensitivity and specificity of bilateral Pulvinar high signal on magnetic resonance imaging (MRI) for the diagnosis of vCJD. Methods MRI from patients with vCJD and controls (patients with suspected CJD) were analysed. Scans were reviewed on two separate occasions by two neuroradiologists and scored for the distribution of changes, and likely final diagnosis. Scans from vCJD cases were reassessed to reach a consensus on all abnormalities. Findings We analysed 36 patients and 57 controls. vCJD patients were correctly identified based on bilateral Pulvinar high signal in 29 of 36 and 32 of 36 cases on the first assessment by the two radiologists, and 32 of 36 and 31 of 36 on their second assessment. Bilateral increased Pulvinar signal was identified in one of 57 and one of 57 controls on the first assessment and two of 57 and three of 57 controls on the second assessment. These reported changes in controls were graded as minimal/equivocal in six of seven patients and moderate in one ( Interpretation In the appropriate clinical context the MRI identification of bilaterally increased Pulvinar signal is a useful non-invasive test for the diagnosis of vCJD.
Ai Koizumi - One of the best experts on this subject based on the ideXlab platform.
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threat anticipation in Pulvinar and in superficial layers of primary visual cortex v1 evidence from layer specific ultra high field 7t fmri
eNeuro, 2019Co-Authors: Beatrice De Gelder, Ai Koizumi, Minye Zhan, Hiroshi Ban, Ikuhiro Kida, Federico De Martino, Maarten J Vaessen, Kaoru AmanoAbstract:Abstract The perceptual system gives priority to threat-relevant signals with survival value. In addition to the processing initiated by sensory inputs of threat signals, prioritization of threat signals may also include processes related to threat anticipation. These neural mechanisms remain largely unknown. Using ultra-high-field 7 tesla (7T) fMRI, we show that anticipatory processing takes place in the early stages of visual processing, specifically in the Pulvinar and V1. When anticipation of a threat-relevant fearful face target triggered false perception of not-presented target, there was enhanced activity in the Pulvinar as well as in the V1 superficial-cortical-depth (layers 1–3). The anticipatory activity was absent in the LGN or higher visual cortical areas (V2–V4). The effect in V1 was specific to the perception of fearful face targets and did not generalize to happy face targets. A preliminary analysis showed that the connectivity between the Pulvinar and V1 superficial-cortical-depth was enhanced during false perception of threat, indicating that the Pulvinar and V1 may interact in preparation of anticipated threat. The anticipatory processing supported by the Pulvinar and V1 may play an important role in non-sensory-input-driven anxiety states.
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layer specific ultra high field 7t fmri showing that threat anticipation is mediated by the Pulvinar input to the superficial layers of primary visual cortex v1
bioRxiv, 2018Co-Authors: Ai Koizumi, Beatrice De Gelder, Minye Zhan, Hiroshi Ban, Ikuhiro Kida, Federico De Martino, Kaoru AmanoAbstract:The perceptual system gives priority to threat relevant signals with survival value. Its mechanism may not only include the processing initiated in the presence of threat signals but also in the mere anticipation of such signals. Here, we show that the Pulvinar modulates activity in the early visual cortex (V1) specifically in threat anticipation. Using ultra high field 7T fMRI, we examined the layer specific interaction between V1 and the Pulvinar, while taking advantage of the fact that the directionality of such interaction is anatomically constrained in specific V1 layers. Only in anticipation of a fearful face target, but not of a control happy face target, was false perception of anticipated, yet unpresented, target face accompanied by stronger activity in the V1 superficial cortical depth (layers 1 to 3), which was preceded by pre target onset Pulvinar activity. The Pulvinar may contribute to the visual processing initiated in the anticipation of threat, and play an important role in anxiety.
