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Wim J. G. Oyen - One of the best experts on this subject based on the ideXlab platform.
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tumor to Cervical Spinal Cord standardized uptake ratio sur improves the reproducibility of f 18 fdg pet based tumor segmentation in head and neck squamous cell carcinoma in a multicenter setting
Radiotherapy and Oncology, 2019Co-Authors: Sven Van Den Bosch, Tim Dijkema, Marielle E.p. Philippens, Chris H J Terhaard, Frank Hoebers, Johannes H A M Kaanders, Wim J. G. OyenAbstract:Abstract Background In quantitative FDG-PET data analysis, normalization of the standardized uptake value (SUV) with an internal image-derived standard improves its reproducibility. In this study, the Cervical Spinal Cord is proposed as an internal standard that is within the field of view of the radiotherapy planning PET/CT-scan in head and neck cancer. The aim is to evaluate if the tumor to Cervical Spinal Cord standardized uptake ratio (SUR) can improve the reproducibility of a model to determine the metabolic tumor volume (MTV) on FDG-PET/CT in a multicenter setting. Materials and methods Ninety-five radiotherapy planning FDG-PET/CT-scans of patients with head and neck cancer were analyzed using the Bland–Altman method to evaluate differences in FDG-uptake in the Cervical Spinal Cord and the mediastinal blood pool. Non-linear regression analysis was used to determine the optimal MTV using the gross tumor volume (GTV) as ground truth and a spatial overlap-index as statistical validation metric. Reproducibility was evaluated using the Bland-Altman method and external validation was performed in an independent dataset consisting of 62 patients. Results Bland–Altman’s analyses demonstrated equivalence of FDG-uptake in the mediastinal blood pool and the Cervical Spinal Cord. Reproducibility of the models improved when using SUR instead of SUV. These results were confirmed in the validation cohort. Conclusion The use of the tumor to Cervical Spinal Cord SUR instead of SUV improves the reproducibility of a model to determine the MTV on FDG-PET/CT in a multicenter setting. This study indicates that SUR may be preferred over SUV based approaches.
Shawn J Bird - One of the best experts on this subject based on the ideXlab platform.
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posterior Cervical Spinal Cord infarction following vertebral artery dissection
Neurology, 1997Co-Authors: Christina Bergqvist, Olafur Thorarensen, H I Goldberg, Shawn J BirdAbstract:There are only two reported cases of unilateral posterior Cervical Spinal Cord infarction as a result of vertebral artery dissection. We describe the first reported case of bilateral posterior Spinal Cord infarction caused by vertebral artery dissection.
Carlos B Mantilla - One of the best experts on this subject based on the ideXlab platform.
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localized delivery of brain derived neurotrophic factor expressing mesenchymal stem cells enhances functional recovery following Cervical Spinal Cord injury
Journal of Neurotrauma, 2015Co-Authors: Heather M Gransee, Gary C Sieck, Wen Zhi Zhan, Carlos B MantillaAbstract:Abstract Neurotrophins, such as brain-derived neurotrophic factor (BDNF), are important in modulating neuroplasticity and promoting recovery after Spinal Cord injury. Intrathecal delivery of BDNF enhances functional recovery following unilateral Spinal Cord hemisection (SH) at C2, a well-established model of incomplete Cervical Spinal Cord injury. We hypothesized that localized delivery of BDNF-expressing mesenchymal stem cells (BDNF-MSCs) would promote functional recovery of rhythmic diaphragm activity after SH. In adult rats, bilateral diaphragm electromyographic (EMG) activity was chronically monitored to determine evidence of complete SH at 3 days post-injury, and recovery of rhythmic ipsilateral diaphragm EMG activity over time post-SH. Wild-type, bone marrow-derived MSCs (WT-MSCs) or BDNF-MSCs (2×105 cells) were injected intraSpinally at C2 at the time of injury. At 14 days post-SH, green fluorescent protein (GFP) immunoreactivity confirmed MSCs presence in the Cervical Spinal Cord. Functional recov...
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motoneuron bdnf trkb signaling enhances functional recovery after Cervical Spinal Cord injury
Experimental Neurology, 2013Co-Authors: Carlos B Mantilla, Heather M Gransee, Wen Zhi Zhan, Gary C SieckAbstract:A C2 Cervical Spinal Cord hemisection (SH) interrupts descending inspiratory-related drive to phrenic motoneurons located between C3 and C5 in rats, paralyzing the ipsilateral hemidiaphragm muscle. There is gradual recovery of rhythmic diaphragm muscle activity ipsilateral to Cervical Spinal Cord injury over time, consistent with neuroplasticity and strengthening of spared, contralateral descending premotor input to phrenic motoneurons. Brain-derived neurotrophic factor (BDNF) signaling through the tropomyosin related kinase receptor subtype B (TrkB) plays an important role in neuroplasticity following Spinal Cord injury. We hypothesized that 1) increasing BDNF/TrkB signaling at the level of the phrenic motoneuron pool by intrathecal BDNF delivery enhances functional recovery of rhythmic diaphragm activity after SH, and 2) inhibiting BDNF/TrkB signaling by quenching endogenous neurotrophins with the soluble fusion protein TrkB-Fc or by knocking down TrkB receptor expression in phrenic motoneurons using intrapleurally-delivered siRNA impairs functional recovery after SH. Diaphragm EMG electrodes were implanted bilaterally to verify complete hemisection at the time of SH and 3 days post-SH. After SH surgery in adult rats, an intrathecal catheter was placed at C4 to chronically infuse BDNF or TrkB-Fc using an implanted mini-osmotic pump. At 14 days post-SH, all intrathecal BDNF treated rats (n = 9) displayed recovery of ipsilateral hemidiaphragm EMG activity, compared to 3 out of 8 untreated SH rats (p < 0.01). During eupnea, BDNF treated rats exhibited 76 ± 17% of pre-SH root mean squared EMG vs. only 5 ± 3% in untreated SH rats (p < 0.01). In contrast, quenching endogenous BDNF with intrathecal TrkB-Fc treatment completely prevented functional recovery up to 14 days post-SH (n = 7). Immunoreactivity of the transcription factor cAMP response element-binding protein (CREB), a downstream effector of TrkB signaling, increased in phrenic motoneurons following BDNF treatment (n = 6) compared to artificial cerebroSpinal fluid treatment (n = 6; p < 0.001). Intrapleural injections of non-sense or TrkB siRNA were administered after SH to specifically target phrenic motoneurons. At 14 days post-SH, none out of 9 TrkB siRNA treated rats displayed functional recovery compared to 5 out of 9 non-sense siRNA treated rats. These results indicate that BDNF/TrkB signaling in phrenic motoneuron pool plays a critical role in functional recovery after Cervical Spinal Cord injury.
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novel method for physiological recruitment of diaphragm motor units after upper Cervical Spinal Cord injury
Journal of Applied Physiology, 2009Co-Authors: Gary C Sieck, Carlos B MantillaAbstract:each year, approximately 11,000 people in the United States suffer Cervical Spinal Cord injury that results in partial or complete diaphragm muscle paralysis with an annual expense of more than $3 billion. Those unable to maintain adequate ventilation due to diaphragm muscle paralysis become
Kunze Lee - One of the best experts on this subject based on the ideXlab platform.
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the therapeutic effectiveness of delayed fetal Spinal Cord tissue transplantation on respiratory function following mid Cervical Spinal Cord injury
Neurotherapeutics, 2017Co-Authors: Chiaching Lin, Sihrong Lai, Yuhan Shao, Chunlin Chen, Kunze LeeAbstract:Respiratory impairment due to damage of the Spinal respiratory motoneurons and interruption of the descending drives from brainstem premotor neurons to Spinal respiratory motoneurons is the leading cause of morbidity and mortality following Cervical Spinal Cord injury. The present study was designed to evaluate the therapeutic effectiveness of delayed transplantation of fetal Spinal Cord (FSC) tissue on respiratory function in rats with mid-Cervical Spinal Cord injury. Embryonic day-14 rat FSC tissue was transplanted into a C4 Spinal Cord hemilesion cavity in adult male rats at 1 week postinjury. The histological results showed that FSC-derived grafts can survive, fill the lesion cavity, and differentiate into neurons and astrocytes at 8 weeks post-transplantation. Some FSC-derived graft neurons exhibited specific neurochemical markers of neurotransmitter (e.g., serotonin, noradrenalin, or acetylcholine). Moreover, a robust expression of glutamatergic and γ-aminobutyric acid-ergic fibers was observed within FSC-derived grafts. Retrograde tracing results indicated that there was a connection between FSC-derived grafts and host phrenic nucleus. Neurophysiological reCording of the phrenic nerve demonstrated that phrenic burst amplitude ipsilateral to the lesion was significantly greater in injured animals that received FSC transplantation than in those that received buffer transplantation under high respiratory drives. These results suggest that delayed FSC transplantation may have the potential to repair the injured Spinal Cord and promote respiratory functional recovery after mid-Cervical Spinal Cord injury.
Marielle E.p. Philippens - One of the best experts on this subject based on the ideXlab platform.
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tumor to Cervical Spinal Cord standardized uptake ratio sur improves the reproducibility of f 18 fdg pet based tumor segmentation in head and neck squamous cell carcinoma in a multicenter setting
Radiotherapy and Oncology, 2019Co-Authors: Sven Van Den Bosch, Tim Dijkema, Marielle E.p. Philippens, Chris H J Terhaard, Frank Hoebers, Johannes H A M Kaanders, Wim J. G. OyenAbstract:Abstract Background In quantitative FDG-PET data analysis, normalization of the standardized uptake value (SUV) with an internal image-derived standard improves its reproducibility. In this study, the Cervical Spinal Cord is proposed as an internal standard that is within the field of view of the radiotherapy planning PET/CT-scan in head and neck cancer. The aim is to evaluate if the tumor to Cervical Spinal Cord standardized uptake ratio (SUR) can improve the reproducibility of a model to determine the metabolic tumor volume (MTV) on FDG-PET/CT in a multicenter setting. Materials and methods Ninety-five radiotherapy planning FDG-PET/CT-scans of patients with head and neck cancer were analyzed using the Bland–Altman method to evaluate differences in FDG-uptake in the Cervical Spinal Cord and the mediastinal blood pool. Non-linear regression analysis was used to determine the optimal MTV using the gross tumor volume (GTV) as ground truth and a spatial overlap-index as statistical validation metric. Reproducibility was evaluated using the Bland-Altman method and external validation was performed in an independent dataset consisting of 62 patients. Results Bland–Altman’s analyses demonstrated equivalence of FDG-uptake in the mediastinal blood pool and the Cervical Spinal Cord. Reproducibility of the models improved when using SUR instead of SUV. These results were confirmed in the validation cohort. Conclusion The use of the tumor to Cervical Spinal Cord SUR instead of SUV improves the reproducibility of a model to determine the MTV on FDG-PET/CT in a multicenter setting. This study indicates that SUR may be preferred over SUV based approaches.
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magnetic resonance imaging of the Cervical Spinal Cord in Spinal muscular atrophy
NeuroImage: Clinical, 2019Co-Authors: Marloes Stam, Marielle E.p. Philippens, Wieke Haakma, Lidy Kuster, Martijn Froeling, Clemens Bos, Alexander Leemans, Louise A M Otto, Leonard H Van Den Berg, Jeroen HendrikseAbstract:Abstract Objective In this study we investigated the potential value of magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) in characterizing changes in the Cervical Spinal Cord and peripheral nerve roots in vivo in patients with Spinal muscular atrophy (SMA). Methods We developed an MRI protocol with 4 sequences to investigate the Cervical Spinal Cord and nerve roots on a 3 Tesla MRI system. We used 2 anatomical MRI sequences to investigate cross-sectional area (CSA) at each Spinal segment and the diameter of ventral and dorsal nerve roots, and two diffusion tensor imaging (DTI) techniques to estimate the fractional anisotropy (FA), mean (MD), axial (AD) and radial diffusivity (RD) in 10 SMA patients and 20 healthy controls. Results There were no significant differences in CSA (p > .1), although an 8.5% reduction of CSA in patients compared to healthy controls was apparent at segment C7. DTI data showed a higher AD in grey matter of patients compared to healthy controls (p = .033). Significantly lower MD, AD and RD values were found in rostral nerve roots (C3-C5) in patients (p Conclusions We showed feasibility of an advanced 3 T MRI protocol that allowed differences to be determined between patients and healthy controls, confirming the potential of this technique to assess pathological mechanisms in SMA. After further development and confirmation of findings in a larger sample, these techniques may be used to study disease course of SMA in vivo and evaluate response to survival motor neuron (SMN) augmenting therapy.