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Deutschländer A, La Fougere C, Xiong G, Bötzel K, Gründer G, Cumming P. Therapeutic Occupancy of the D2/3-preferring Dopamine Receptor Agonist Pramipexol Parkinson's Disease ([18F]-fallypride PET study). KLIN NEUROPHYSIOL 2012. [DOI: 10.1055/s-0032-1301629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Hüfner K, Stephan T, Flanagin V, Deutschländer A, Dera T, Karch C, Linn J, Glasauer S, Dieterich M, Strupp M, Brandt T. Cerebellar and Visual Gray Matter Brain Volume Increases in Congenital Nystagmus. KLIN NEUROPHYSIOL 2010. [DOI: 10.1055/s-0030-1250968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Deutschländer A, Hüfner K, Stephan T, Flanagin V, Glasauer S, Dera T, Jahn K, Fesl G, Dieterich M, Strupp M, Brandt T. Does the oculomotor vermis generate congenital nystagmus? KLIN NEUROPHYSIOL 2010. [DOI: 10.1055/s-0030-1250859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Hüfner K, Stephan T, Flanagin VL, Deutschländer A, Stein A, Kalla R, Dera T, Fesl G, Jahn K, Strupp M, Brandt T. Differential effects of eyes open or closed in darkness on brain activation patterns in blind subjects. Neurosci Lett 2009; 466:30-4. [PMID: 19766168 DOI: 10.1016/j.neulet.2009.09.010] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2009] [Revised: 09/10/2009] [Accepted: 09/11/2009] [Indexed: 11/27/2022]
Abstract
In functional brain imaging, specific task conditions can be compared to a reference condition which is often eyes-open or eyes-closed in darkness without the execution of a specific task. Previous fMRI studies in sighted subjects have shown that eyes-open in darkness, without visual stimulation, increases the relative activity in cortical ocular motor and attentional areas ("exteroceptive" state; contrast OPEN>CLOSED). By contrast, eyes-closed causes a relative signal increase in sensory systems ("interoceptive" state; contrast CLOSED>OPEN). In the present study we used fMRI to determine whether these differential brain activity states can also be found in congenitally blind subjects: there were intragroup differences between the OPEN and CLOSED conditions. These differences were, however, less pronounced and occurred in other areas than in sighted controls. The contrast OPEN>CLOSED revealed a relative signal increase in the left frontal eye field, the middle occipital gyrus bilaterally and in the anterior cingulum. Relative signal increases in occipital cortex areas and the anterior cingulum were also apparent for this contrast in the intergroup comparison (congenitally totally blind subjects vs. sighted controls). They reflect the increased attentional load or arousal during the eyes-open condition and could be indicative of a functional reorganization of the occipital cortex in the blind. The contrast CLOSED>OPEN in the congenitally totally blind subjects lead to relative activations in the somatosensory cortex bilaterally, the middle temporal gyrus on the left and the frontal gyri on the right. These activations are residues of the "interoceptive" state found in sighted controls.
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Affiliation(s)
- K Hüfner
- Department of Neurology, Klinikum Grosshadern, Ludwig-Maximilians University, 81377 Munich, Germany.
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Hüfner K, Stephan T, Flanagin VL, Deutschländer A, Kalla R, Dera T, Fesl G, Strupp M, Brandt T. The Resting Brain in Blind Subjects: Differential Effects of Eyes Open and Closed in Darkness. Neuroimage 2009. [DOI: 10.1016/s1053-8119(09)70954-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Deutschländer A, Stephan T, Hüfner K, Wagner J, Wiesmann M, Strupp M, Brandt T, Jahn K. Imagined locomotion in the blind: an fMRI study. Neuroimage 2009. [DOI: 10.1016/s1053-8119(09)71848-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Hüfner K, Stephan T, Flanagin V, Kalla R, Deutschländer A, Glasauer S, Fesl G, Strupp M, Brandt T. The resting brain in blind subjects – an fMRI study with eyes open and closed in darkness. KLIN NEUROPHYSIOL 2009. [DOI: 10.1055/s-0029-1216235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Deutschländer A, Stephan T, Hüfner K, Wagner J, Wiesmann M, Strupp M, Brandt T, Jahn K. Imagined locomotion in the blind: an functional magnetic resonance imaging study. KLIN NEUROPHYSIOL 2009. [DOI: 10.1055/s-0029-1216236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Hüfner K, Stephan T, Kalla R, Deutschländer A, Wagner J, Holtmannspötter M, Schulte-Altedorneburg G, Strupp M, Brandt T, Glasauer S. Structural and functional MRIs disclose cerebellar pathologies in idiopathic downbeat nystagmus. Neurology 2007; 69:1128-35. [PMID: 17846412 DOI: 10.1212/01.wnl.0000276953.00969.48] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Neurologic disorders in which the etiology and pathogenesis are not yet understood are termed idiopathic. Downbeat nystagmus (DBN) is a frequent eye movement disorder that clinically manifests with oscillopsia and postural instability. Forty percent of patients with DBN are classified as having idiopathic DBN, because no underlying pathology can be demonstrated by conventional MRI or laboratory tests. METHODS We evaluated gray matter brain volumes of 11 patients with idiopathic DBN and compared them to those of healthy controls using voxel-based morphometry. In a second, functional MRI experiment, patients and controls performed downward smooth pursuit eye movements (DOWN), which were then compared with straight-ahead fixation of a stationary target (MID). RESULTS Small areas of localized gray matter atrophy were detected in the lateral cerebellar hemispheres (lobule VI) and ocular motor vermis of patients with idiopathic DBN, but not in the flocculus and paraflocculus. The functional imaging data, however, revealed reduced activation in the parafloccular lobule and in the ponto-medullary brainstem of the patients when they performed smooth pursuit eye movements downwards. CONCLUSIONS The applied specialized imaging and data analysis techniques disclosed pathologies in an idiopathic eye movement disorder. The focal atrophy found in the vermal and lateral cerebellar regions in downbeat nystagmus (DBN) may lead to deficits in smooth pursuit eye movement initiation, which in turn causes hypofunction of the parafloccular lobe, associated with DBN. Our data are in line with experiments in primates showing that ablation of the floccular and parafloccular lobes disrupts smooth pursuit and causes DBN.
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Affiliation(s)
- K Hüfner
- Department of Neurology, Klinikum Grosshadern, Neurologisches Forschungshaus, Munich, Germany.
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Deutschländer A, Jahn K, Strupp M, Brandt T. Pulse-synchronous rotational and vertical pendular eye movements in superior canal dehiscence syndrome. Eur J Neurol 2007; 14:e29. [PMID: 17222087 DOI: 10.1111/j.1468-1331.2006.01556.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Jahn K, Deutschländer A, Stephan T, Kalla R, Wiesmann M, Strupp M, Brandt T. Supraspinale Kontrolle der Lokomotion beim Menschen im fMRT. Akt Neurol 2007. [DOI: 10.1055/s-2007-987498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Deutschländer A, Stephan T, Wiesmann M, Wagner J, Hüfner K, Strupp M, Brandt T, Jahn K. Brain activation patterns during imagined locomotion in blind subjects. Akt Neurol 2007. [DOI: 10.1055/s-2007-987684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Deutschländer A, Marx E, Stephan T, Riedel E, Wiesmann M, Dieterich M, Brandt T. Asymmetric modulation of human visual cortex activity during 10° lateral gaze (fMRI study). Neuroimage 2005; 28:4-13. [PMID: 16005247 DOI: 10.1016/j.neuroimage.2005.06.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2004] [Revised: 03/30/2005] [Accepted: 06/01/2005] [Indexed: 11/21/2022] Open
Abstract
We used BOLD fMRI to study the differential effects of the direction of gaze on the visual and the ocular motor systems. Fixation of a target straight ahead was compared to fixation of a target 10 degrees to the right and 10 degrees to the left from gaze straight ahead, and to eyes open in complete darkness in thirteen healthy volunteers. While retinotopic coordinates remained the same in all fixation conditions, the fixation target shifted with respect to a head-centered frame of reference. During lateral fixation, deactivations in higher-order visual areas (one ventral cluster in the lingual and fusiform gyri and one dorsal cluster in the postero-superior cuneus) and, as a trend, activations in early visual cortical areas were found predominantly in the hemisphere contralateral to the fixation target. We propose that visual processing is performed predominantly in the hemisphere contralateral to gaze direction, even during small gaze shifts into one visual hemifield. The excitability of visual neurons may be modulated depending on eye position to construct a head-centered frame of reference from a retinotopic input, thus allowing perceptual stability of space during eye movements. A further finding was that BOLD signal increases in fronto-parietal ocular motor and attentional structures were more pronounced during lateral than central fixation.
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Affiliation(s)
- A Deutschländer
- Department of Neurology, Klinikum Grosshadern, Munich, Germany.
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Riedel E, Marx E, Stephan T, Deutschländer A, Bruening R, Brandt T. Visual Connectivity in Cases with Unilateral Focal Cortical Dysplasia or Hemispherectomy in fMRI. KLIN NEUROPHYSIOL 2004. [DOI: 10.1055/s-2004-832138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Deutschländer A, Stephan T, Wiesmann M, Dieterich M, Brandt T. Asymmetric Hemispheric Activations during 10° Lateral Gaze (fMRI Study). KLIN NEUROPHYSIOL 2004. [DOI: 10.1055/s-2004-831951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Bense S, Deutschländer A, Stephan T, Bartenstein P, Schwaiger M, Brandt T, Dieterich M. Preserved visual-vestibular interaction in patients with bilateral vestibular failure. Neurology 2004; 63:122-8. [PMID: 15249621 DOI: 10.1212/01.wnl.0000129545.79566.6a] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND During caloric vestibular stimulation, subjects showed bilateral activation of the vestibular cortex in the posterior insula and retroinsular region as well as concurrent deactivation of visual cortex areas bilaterally. This finding was the basis for the concept of a reciprocal inhibitory interaction between the vestibular and the visual systems. OBJECTIVE To analyze the modulations of this activation and deactivation pattern in patients with loss of vestibular input, that is, in patients with bilateral vestibular failure (BVF). METHODS Modulations of regional cerebral blood flow (rCBF) in PET were measured in nine patients with BVF and compared with those in healthy volunteers using statistical group as well as single-subject analyses (Statistical Parametric Mapping 96b). RESULTS The group analysis of the BVF patients showed only one small region of activation in the posterior insula contralateral to the stimulated ear, whereas the other areas correlating with vestibular, autonomic, and ocular motor function were not activated. Furthermore, the concurrent rCBF decreases of the primary visual cortex seen in healthy volunteers were not found in the patients. These decreases seem to be dependent on an intact vestibular input with concurrent vestibular nystagmus. CONCLUSIONS The results are compatible with the concept of a reciprocal inhibitory sensorisensory interaction between the vestibular and visual systems that normally act together for orientation in space and perception of motion. This interaction appears to be preserved in the patients at a significantly lower level, that is, with less activation and less deactivation.
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Affiliation(s)
- S Bense
- Department of Neurology, Johannes Gutenberg-University of Mainz, Langenbeckstrasse 1, D-55101 Mainz, Germany.
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Abstract
A patient sought treatment for vertical oscillopsia and impaired vision during locomotion, and unsteadiness of gait. Positive fistula tests and CT of the temporal bones confirmed a diagnosis of bilateral superior canal dehiscence. An impairment of the superior canal vestibulo-ocular reflex, documented by three-dimensional search coil eye movement recordings for oblique (single) and downward pitch head motion (bilateral canal testing), is proposed to induce vertical rather than torsional-vertical oscillopsia during locomotion.
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Affiliation(s)
- A Deutschländer
- Department of Neurology, Institute of Clinical Radiology, Klinikum Grosshadern, Ludwig-Maximilians University, Munich, Germany.
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Jahn K, Deutschländer A, Stephan T, Brückmann H, Strupp M, Brandt T. Stehen, Gehen, Laufen: funktionelle MRI-Studie zu zerebralen Aktivierungen und Deaktivierungen während vorgestellter Lokomotion. KLIN NEUROPHYSIOL 2003. [DOI: 10.1055/s-2003-816455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Torres-Nagel N, Deutschländer A, Herrmann T, Arden B, Hünig T. Control of TCR V alpha-mediated positive repertoire selection and alloreactivity by differential J alpha usage and CDR3 alpha composition. Int Immunol 1997; 9:1441-52. [PMID: 9352349 DOI: 10.1093/intimm/9.10.1441] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
In rats expressing the f allele of the rat MHC (RT1f), CD8 T cells utilizing the V alpha 8.2 segment are 10-fold overselected during thymic development, resulting in V alpha 8.2 expression by 14% of mature CD8 T cells as compared to 1-2% in MHC congenic strains. In the alloreactive responses of CD8 T cells from RT1f-negative rats against RT1f, V alpha 8.2+ CD8 T cells are also preferentially expanded. Neither overselection nor alloreactivity of V alpha 8.2+ TCR require selective V beta pairing. However, RT1f alloreactive V alpha 8.2+ TCR preferentially use a related set of J alpha segments which contribute short homogeneous CDR3 alpha loops, with features suggesting peptide promiscuity, and little N additions. In contrast, only few overselected V alpha 8.2+ CD8 T cells showed an imprint of positive selection on J usage or CDR3 composition. The results demonstrate that a single V alpha segment can promote both MHC allele-specific positive selection and alloreactivity, and that the latter is more dependent on an additional contribution of CDR3 alpha, possibly by promoting reactivity with a diverse set of MHC-bound peptides or by providing additional MHC contacts.
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Affiliation(s)
- N Torres-Nagel
- Institute for Virology and Immunobiology, University of Würzburg, Germany
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Torres-Nagel N, Mehling B, Deutschländer A, Joly E, Hermann T, Hünig T. Structural requirements for T cell receptor Va mediated positive repertoire selection by and alloreactivity to MHC class I. Immunol Lett 1997. [DOI: 10.1016/s0165-2478(97)86405-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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