- Email: [email protected]
P15. Evaluation and comparison of 3D-ultrasound of the median nerve with common 2D-ultrasound
e94
Society Proceedings / Clinical Neurophysiology 126 (2015) e63–e170
Two distinct anatomical otolith pathways within the thalamo-cortical vestibular network were proposed in patients with thalamic infarctions who presented with contra- or ipsiversive tilts of the subjective visual vertical (SVV) (Dieterich and Brandt, 1993; Baier et al., submitted for publication). Aim of this study was to investigate the dendato-thalamo-cortical pathways in association with otolith dysfunction by means of DTI (diffusion tensor imaging) based on the regions found in a recent patient study using statistical lesion-behavior mapping (Baier et al., submitted for publication). Methods: Twenty-four healthy volunteers (11 females; aged 20– 4 years, mean age 28.2 ± 6.3 years) were measured in a 3 Tesla MRI (Erlangen, Siemens, Verio). The data was analyzed with FSL. For the examination of the dendato-thalamo-cortical pathways we calculated voxelbased DTI tractography between the dendate nuclei, vestibular nuclei, the thalamic regions defined in the patients with thalamic infarctions (Baier et al., submitted for publication) and the cortex. Results: At group level the data-driven DTI tractography showed that the dendato-thalamo-cortical pathways connected to ipsiversive SVV tilts projected ipsilaterally from the dendate and vestibular nuclei to the cortex via the caudate nucleus. Thalamus regions connected to contraversive SVV tilts received input from the contralateral cerebellar hemispheres, the dendate and vestibular nucleus crossing either in the pons or mesencephalon and reaching the cortex via the putamen. Discussion: These data verify that there are two distinct anatomical otolith signal-processing pathways within a dendato-thalamo-cortical vestibular network. This supports results of earlier PET- and fMRI-studies with caloric and galvanic stimulation in humans (Dieterich and Brandt, 2008). Therefore, our data support the existence of two functionally distinct dendato-thalamo-cortical vestibular pathways leading - when damaged - either to a vestibular tone imbalance to the ipsiversive or to the contraversive side. Acknowledgements: Supported by the Support Program for Research and Teaching (FöFoLeLMU), Graduate School of Systemic Neuroscience (GSN), the German Foundation for Neurology (Deutsche Stiftung Neurologie) and the German Federal Ministry of Education and Research (German Center for Vertigo and Balance Disorders -IFBLMU, Grant code 01 EO 0901).
we want to compare high-resolution 3D-US with 2D-US for the examination of the median nerve. Methods: In 22 healthy probands 3D-US of both median nerves was performed by 2 examiners (Ex1, Ex2) using an 18 MHz linear transducer (Toshiba Aplio 500) connected to the Curefab CS (Curefab Technologies GmbH, Munich, Germany). A single virtual 3D-stack of the ventral forearm ranging from the distal wrist crease to 20 cm in proximal direction was generated. Subsequently, cross section area (CSA) of each median nerve was determined by common 2D-US in 3 randomly assigned distances (1–20 cm) proximal to the distal wrist crease. Finally, for each median nerve CSA was measured in the 3D-stack at the same distances as for 2D-US. Furthermore, quality of 3D-US was evaluated with a semi-quantitative scale (1: good quality, nerve and fibre structures can be depicted axially and horizontally; 2: sufficient quality, CSA measurement is possible, but horizontal visualisation of fibre structures is limited by blurry view or too much artefacts; 3: poor quality, CSA measurement is not possible). While 3D-US of the median nerve was done by 2 examiners, CSA measurements and evaluation of quality were done by 1 examiner. Results: CSA of the median nerve from 3D-US was 0.8 mm2 (Ex1) respectively 0.5 mm2 (Ex2) smaller than CSA obtained by 2D-US. Applying intraclass correlation coefficient, interrater agreement was moderate with 0.68. 88% of CSA from 3D-US differed by just ±1 mm2 between examiners. Quality assessment showed a good quality of 3D-data in 55% (Ex1) and 45% (Ex2), a sufficient quality in 39% and 48% and a poor quality with missing CSA analysis in just 6% respectively 7%. Furthermore, for 2D- and 3D-US, there was a significant inverse correlation between the distance from the wrist and the median nerve’s CSA (Pearson r = 0.32–0.36, each p < 0:05). Conclusion: Although it is technically challenging to scan the median nerve over a distance of 20 cm without interruption, 3D-US showed a moderate to good agreement with conventional 2D-US examination. Contrary to 2D-US, 3D-US allows measurements of CSA exactly perpendicular to the nerve’s course, thus yielding more accurate results. Therefore, we propose, that 3D-US of nerves is a promising diagnostic tool to minimise time effort by separating data acquisition from subsequent data analysis since the virtual 3D-stack contains all information for a profound offline evaluation; in addition 3D-US facilitates comparability of follow-up examinations.
References
doi:10.1016/j.clinph.2015.04.135
Baier B, Conrad J, Stephan T, Kirsch V, Vogt T, Wilting J, Müller-Forell W, Dieterich M (submitted) Vestibular Thalamus: Two distinct graviceptive pathways. submitted. Dieterich M, Brandt T. Thalamic infarctions: differential effects on vestibular function in the roll plane (35 patients). Neurology 1993;43:1732–40. Dieterich M, Brandt T. Functional brain imaging of peripheral and central vestibular disorders. Brain 2008;131:2538–52. Lopez C, Blanke O. The thalamocortical vestibular system in animals and humans. Brain Res Rev 2011;67:119–46. doi:10.1016/j.clinph.2015.04.134
P15. Evaluation and comparison of 3D-ultrasound of the median nerve with common 2D-ultrasound—J. Pelz, M. Busch, A. Weinreich, D. Saur (Universitätsklinikum Leipzig, Klinik und Poliklinik für Neurologie, Leipzig, Germany) Background: Ultrasound is still regarded as an imaging modality that considerably depends on the examiner’s experience. Additionally, storage of only single images or short video sequences restricts re-evaluation and repeated measurements. While 3D-ultrasound (3D-US) might overcome these limitations, its use is currently mainly hampered by relatively low image quality. Here,
P17. Early Huntington’s disease patients demonstrate micro-structural and functional connectivity changes in motor and basal ganglia-thalamic networks—H.-P. Müller a, J. Kassubek a, G. Grön b, M. Gorges a, G.B. Landwehrmeyer a, S.D. Süßmuth a, M. Orth a (a University of Ulm, Department of b Neurology, Ulm, Germany, University of Ulm, Section Neuropsychology and Functional Imaging, Department of Psychiatry, Ulm, Germany) Introduction: In Huntington’s disease (HD), cerebral white matter changes have been reported in a number of studies using diffusion tensor imaging (DTI) or T1-weighted magnetic resonance imaging (MRI). A key question is how brain structure changes (both grey and white matter) influence brain function. Intrinsic functional connectivity (ifc) MRI investigates intrinsic connectivity networks (ICN), i.e. large-scale distributed functionally coupled brain regions observed in the absence of a specific task. The objective of our study was to integrate structural connectivity data as assessed by DTI with ifcMRI changes in order to obtain a comprehensive picture of structural and functional changes with an emphasis on motor and basal ganglia thalamic networks.
Society Proceedings / Clinical Neurophysiology 126 (2015) e63–e170
Two distinct anatomical otolith pathways within the thalamo-cortical vestibular network were proposed in patients with thalamic infarctions who presented with contra- or ipsiversive tilts of the subjective visual vertical (SVV) (Dieterich and Brandt, 1993; Baier et al., submitted for publication). Aim of this study was to investigate the dendato-thalamo-cortical pathways in association with otolith dysfunction by means of DTI (diffusion tensor imaging) based on the regions found in a recent patient study using statistical lesion-behavior mapping (Baier et al., submitted for publication). Methods: Twenty-four healthy volunteers (11 females; aged 20– 4 years, mean age 28.2 ± 6.3 years) were measured in a 3 Tesla MRI (Erlangen, Siemens, Verio). The data was analyzed with FSL. For the examination of the dendato-thalamo-cortical pathways we calculated voxelbased DTI tractography between the dendate nuclei, vestibular nuclei, the thalamic regions defined in the patients with thalamic infarctions (Baier et al., submitted for publication) and the cortex. Results: At group level the data-driven DTI tractography showed that the dendato-thalamo-cortical pathways connected to ipsiversive SVV tilts projected ipsilaterally from the dendate and vestibular nuclei to the cortex via the caudate nucleus. Thalamus regions connected to contraversive SVV tilts received input from the contralateral cerebellar hemispheres, the dendate and vestibular nucleus crossing either in the pons or mesencephalon and reaching the cortex via the putamen. Discussion: These data verify that there are two distinct anatomical otolith signal-processing pathways within a dendato-thalamo-cortical vestibular network. This supports results of earlier PET- and fMRI-studies with caloric and galvanic stimulation in humans (Dieterich and Brandt, 2008). Therefore, our data support the existence of two functionally distinct dendato-thalamo-cortical vestibular pathways leading - when damaged - either to a vestibular tone imbalance to the ipsiversive or to the contraversive side. Acknowledgements: Supported by the Support Program for Research and Teaching (FöFoLeLMU), Graduate School of Systemic Neuroscience (GSN), the German Foundation for Neurology (Deutsche Stiftung Neurologie) and the German Federal Ministry of Education and Research (German Center for Vertigo and Balance Disorders -IFBLMU, Grant code 01 EO 0901).
we want to compare high-resolution 3D-US with 2D-US for the examination of the median nerve. Methods: In 22 healthy probands 3D-US of both median nerves was performed by 2 examiners (Ex1, Ex2) using an 18 MHz linear transducer (Toshiba Aplio 500) connected to the Curefab CS (Curefab Technologies GmbH, Munich, Germany). A single virtual 3D-stack of the ventral forearm ranging from the distal wrist crease to 20 cm in proximal direction was generated. Subsequently, cross section area (CSA) of each median nerve was determined by common 2D-US in 3 randomly assigned distances (1–20 cm) proximal to the distal wrist crease. Finally, for each median nerve CSA was measured in the 3D-stack at the same distances as for 2D-US. Furthermore, quality of 3D-US was evaluated with a semi-quantitative scale (1: good quality, nerve and fibre structures can be depicted axially and horizontally; 2: sufficient quality, CSA measurement is possible, but horizontal visualisation of fibre structures is limited by blurry view or too much artefacts; 3: poor quality, CSA measurement is not possible). While 3D-US of the median nerve was done by 2 examiners, CSA measurements and evaluation of quality were done by 1 examiner. Results: CSA of the median nerve from 3D-US was 0.8 mm2 (Ex1) respectively 0.5 mm2 (Ex2) smaller than CSA obtained by 2D-US. Applying intraclass correlation coefficient, interrater agreement was moderate with 0.68. 88% of CSA from 3D-US differed by just ±1 mm2 between examiners. Quality assessment showed a good quality of 3D-data in 55% (Ex1) and 45% (Ex2), a sufficient quality in 39% and 48% and a poor quality with missing CSA analysis in just 6% respectively 7%. Furthermore, for 2D- and 3D-US, there was a significant inverse correlation between the distance from the wrist and the median nerve’s CSA (Pearson r = 0.32–0.36, each p < 0:05). Conclusion: Although it is technically challenging to scan the median nerve over a distance of 20 cm without interruption, 3D-US showed a moderate to good agreement with conventional 2D-US examination. Contrary to 2D-US, 3D-US allows measurements of CSA exactly perpendicular to the nerve’s course, thus yielding more accurate results. Therefore, we propose, that 3D-US of nerves is a promising diagnostic tool to minimise time effort by separating data acquisition from subsequent data analysis since the virtual 3D-stack contains all information for a profound offline evaluation; in addition 3D-US facilitates comparability of follow-up examinations.
References
doi:10.1016/j.clinph.2015.04.135
Baier B, Conrad J, Stephan T, Kirsch V, Vogt T, Wilting J, Müller-Forell W, Dieterich M (submitted) Vestibular Thalamus: Two distinct graviceptive pathways. submitted. Dieterich M, Brandt T. Thalamic infarctions: differential effects on vestibular function in the roll plane (35 patients). Neurology 1993;43:1732–40. Dieterich M, Brandt T. Functional brain imaging of peripheral and central vestibular disorders. Brain 2008;131:2538–52. Lopez C, Blanke O. The thalamocortical vestibular system in animals and humans. Brain Res Rev 2011;67:119–46. doi:10.1016/j.clinph.2015.04.134
P15. Evaluation and comparison of 3D-ultrasound of the median nerve with common 2D-ultrasound—J. Pelz, M. Busch, A. Weinreich, D. Saur (Universitätsklinikum Leipzig, Klinik und Poliklinik für Neurologie, Leipzig, Germany) Background: Ultrasound is still regarded as an imaging modality that considerably depends on the examiner’s experience. Additionally, storage of only single images or short video sequences restricts re-evaluation and repeated measurements. While 3D-ultrasound (3D-US) might overcome these limitations, its use is currently mainly hampered by relatively low image quality. Here,
P17. Early Huntington’s disease patients demonstrate micro-structural and functional connectivity changes in motor and basal ganglia-thalamic networks—H.-P. Müller a, J. Kassubek a, G. Grön b, M. Gorges a, G.B. Landwehrmeyer a, S.D. Süßmuth a, M. Orth a (a University of Ulm, Department of b Neurology, Ulm, Germany, University of Ulm, Section Neuropsychology and Functional Imaging, Department of Psychiatry, Ulm, Germany) Introduction: In Huntington’s disease (HD), cerebral white matter changes have been reported in a number of studies using diffusion tensor imaging (DTI) or T1-weighted magnetic resonance imaging (MRI). A key question is how brain structure changes (both grey and white matter) influence brain function. Intrinsic functional connectivity (ifc) MRI investigates intrinsic connectivity networks (ICN), i.e. large-scale distributed functionally coupled brain regions observed in the absence of a specific task. The objective of our study was to integrate structural connectivity data as assessed by DTI with ifcMRI changes in order to obtain a comprehensive picture of structural and functional changes with an emphasis on motor and basal ganglia thalamic networks.