References of "SALMON, Eric"
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See detail[18F]UCB-H as a new PET radiotracer for Synaptic vesicle protein 2A: A first clinical trial.
Bahri, Mohamed Ali ULg; Stifkens, M; Bastin, Christine ULg et al

in Tijdschrift voor Nucleaire Geneeskunde (2015, May 09), 37(3), 1457-1458

The synaptic vesicle protein 2A (SV2A) is widely distributed in the brain and has been demonstrated to be involved in vesicle trafficking. The critical role of SV2A in proper nervous system function is ... [more ▼]

The synaptic vesicle protein 2A (SV2A) is widely distributed in the brain and has been demonstrated to be involved in vesicle trafficking. The critical role of SV2A in proper nervous system function is shown, e.g., by the fact that it is a binding site and the primary mechanism of the antiepileptic drug levetiracetam. This drug has recently been suggested to reduce synaptic deficits in a mouse model for Alzheimer’s disease. We here aimed to investigate the cerebral distribution of [18F]UCB-H, which has a high affinity with the SV2A. Dynamic PET data of the head of 4 healthy volunteers were acquired over 100 minutes after injection of 170.4 ± 24.9 MBq of GMP produced [18F]UCB-H. The arterial input function (IF) was obtained by blood sampling but also derived from the dynamic data using the correlation coefficient method. Blood data revealed a consistent amount of [18F]UCB-H in whole blood and plasma indicating a very low degree of binding of the tracer to the red blood cells. The unchanged fraction of [18F]UCB-H in plasma showed a bi-exponential behavioral decrease with a starting fraction of 92% of the injected amount of the tracer, measured at 3 min post injection. This fraction decreased to about 50% at 10 min post injection. The image-derived arterial IFs showed to be very similar to the measured ones with a peak-ratio around 0.91 and an area-under-curve ratio about 0.98. The PET images showed a high and rapid uptake of [18F]UCB-H in the grey matter structures, matching the known ubiquitous distribution of the SV2A in the brain. The kinetics of the tracer in the brain was characterized by an initial high uptake phase followed by rapid washout. For the three standard compartmental models (1-tissue, 2-tissue, and Logan Plot), similar results were obtained with both the measured and image-derived IFs. Nevertheless the two-tissue compartment model fitted the experimental data best and provided a total distribution volume of the [18F]UCB-H in the brain greater than 7 mL/cm3 and a specific distribution volume around 3 mL/cm3. Our results suggest that [18F]UCB-H is a good candidate as radiotracer for brain SV2A proteins and could be used for human studies (dosimetry has already been reported elsewhere). Image-derived IF showed to be useful for quantitative studies without the need to the arterial blood sampling. This new tracer could help to assess SV2A modifications in neurological pathologies such as Alzheimer’s disease. [less ▲]

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See detailRetirement age and the age of onset of Alzheimer’s disease: Results from the ICTUS study
Grotz, Catherine ULg; Letenneur, Luc; Bonsang, Eric ULg et al

in PLoS ONE (2015), 10(2), 0115056

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See detail[18F]UCB-H as a new PET radiotracer for Synaptic vesicle protein 2A: A first clinical trial
Bahri, Mohamed Ali ULg; Stifkens, Mathieu; Bastin, Christine ULg et al

Poster (2015, January 27)

SV2A is widely distributed in the brain and has been demonstrated to be involved in vesicle trafficking. The critical role of SV2A in proper nervous system function is shown, e.g., by the fact that it is ... [more ▼]

SV2A is widely distributed in the brain and has been demonstrated to be involved in vesicle trafficking. The critical role of SV2A in proper nervous system function is shown, e.g., by the fact that it is a binding site and the primary mechanism of levetiracetam. Levetiracetam is an antiepileptic drug which has recently been suggested to reduce synaptic deficits in a mouse model for Alzheimer’s disease. We here aimed to investigate the cerebral distribution of [18F]UCB-H, which has a high affinity with the SV2A. Dynamic PET data of the head of 4 healthy volunteers were acquired over 100 minutes after injection of 170.4 ± 24.9 MBq of GMP produced [18F]UCB-H. The arterial input function (IF) was obtained by blood sampling. The IF was also derived from the dynamic data using the correlation coefficient method. Blood data revealed a consistent amount of [18F]UCB-H in whole blood and plasma indicating a very low degree of binding of the tracer to the red blood cells. The image-derived arterial IFs were showed to be very similar to the measured ones with a peak-ratio around 0.91 and an area-under-curve ratio about 0.98. The [18F]UCB-H PET data showed a high and rapid uptake in the grey matter structures, matching the known ubiquitous distribution of the SV2A in the brain. The kinetics of the tracer in the brain was characterized by an initial high uptake phase followed by rapid washout allowing the standard compartmental modeling (1-tissue, 2-tissue, and Logan Plot). The three models gave similar results with both the measured and image-derived IFs. The total distribution volume of the tracer in the brain was greater than 7 mL/cm3. Our results suggest that [18F]UCB-H is a good candidate as radiotracer for brain SV2A proteins and could be used for human studies. Image-derived IF showed to be useful for quantitative studies without the need to the arterial blood sampling. SV2A modifications may consequently be assessed in neurological pathologies such as Alzheimer’s disease. [less ▲]

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See detailBiodistribution and radiation dosimetry for the novel SV2A radiotracer [18F]UCB-H: First-in-human study.
Bretin, Florian ULg; Bahri, Mohamed Ali ULg; BERNARD, Claire ULg et al

in Molecular Imaging & Biology (2015), 17

Abstract- [18F]UCB-H is a novel radiotracer with a high affinity for SV2A, a protein expressed in synaptic vesicles. SV2A is the binding site of levetiracetam, a “first in class” antiepileptic drug with a ... [more ▼]

Abstract- [18F]UCB-H is a novel radiotracer with a high affinity for SV2A, a protein expressed in synaptic vesicles. SV2A is the binding site of levetiracetam, a “first in class” antiepileptic drug with a distinct but still poorly understood mechanism of action. The objective of this study was to determine the biodistribution and radiation dosimetry of [18F]UCB-H in a human clinical trial and to establish injection limits according to biomedical research guidelines. Additionally, the clinical radiation dosimetry results were compared to estimations in previously published preclinical data. Dynamic whole body PET/CT imaging was performed over approximately 110 minutes on five healthy male volunteers after injection of 144.5 ± 7.1 MBq (range, 139.1 – 156.5 MBq) of [18F]UCB-H. Major organs were delineated on CT images and time-activity curves were obtained from co-registered dynamic PET emission scans. Time-integrated activity coefficients were calculated as area under the curve using trapezoidal numerical integration. Urinary excretion data based on PET-activities including voiding was simulated using the dynamic bladder module of OLINDA/EXM. The radiation dosimetry was calculated using OLINDA/EXM. The effective dose to the OLINDA/EXM 70 kg standard male was 1.54E-02 ± 6.84E-04 mSv/MBq, with urinary bladder wall, gallbladder wall and the liver receiving the highest absorbed dose. The brain, the tracer’s main organ of interest, received an absorbed dose of 1.89E-02 ± 2.32E-03 mGy/MBq. This first human dosimetry study of [18F]UCB-H indicated that the tracer shows similar radiation burdens to widely used common clinical tracers. Single injections of at maximum 672 MBq for USA practice and 649 MBq for European practice keep radiation exposure below recommended limits. Recently published preclinical dosimetry data extrapolated from mice provided satisfactory prediction of total body and effective dose, but showed significant differences in organ absorbed doses compared to human data. [less ▲]

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See detailLe syndrome dysexécutif pour les nuls
Adam, Stéphane; SALMON, Eric ULg; GILLAIN, Sophie ULg et al

Conference (2015, January 15)

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See detailFunctional Alterations in Order Short-Term Memory Networks in Adults With Dyslexia
Martinez Perez, Trecy ULg; Poncelet, Martine ULg; Salmon, Eric ULg et al

in Developmental Neuropsychology (2015), 40(7-8), 407-429

Dyslexia is characterized not only by reading impairment but also by short-term memory (STM) deficits, and this particularly for the retention of serial order information. Here, we explored the functional ... [more ▼]

Dyslexia is characterized not only by reading impairment but also by short-term memory (STM) deficits, and this particularly for the retention of serial order information. Here, we explored the functional neural correlates associated with serial order STM performance of adults with dyslexia for verbal and visual STM tasks. Relative to a group of age-matched controls, the dyslexic group showed abnormal activation in a network associated with order STM encompassing the right intraparietal and superior frontal sulcus, and this for both verbal and visual order STM conditions. This study highlights long-lasting alterations in non-language neural substrates and processes in dyslexia. [less ▲]

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See detailBrain metabolic dysfunction in Capgras delusion during Alzheimer’s disease: a positron emission tomography study
Jedidi, Haroun ULg; Daury, Noémy; Rémi, Capa et al

in American Journal of Alzheimer's Disease & Other Dementias (2015), 30(7), 699-706

Capgras delusion is characterized by the misidentification of people and by the delusional belief that the misidentified persons have been replaced by impostors, generally perceived as persecutors. Since ... [more ▼]

Capgras delusion is characterized by the misidentification of people and by the delusional belief that the misidentified persons have been replaced by impostors, generally perceived as persecutors. Since little is known regarding the neural correlates of Capgras syndrome, the cerebral metabolic pattern of a patient with probable Alzheimer’s disease (AD) and Capgras syndrome was compared with those of 24 healthy elderly subjects and 26 AD patients without delusional syndrome. Compared to the healthy and AD groups, the patient had significant hypometabolism in frontal and posterior midline structures. In light of current neural models of face perception, our patient’s Capgras syndrome may be related to impaired recognition of a familiar face, subserved by the posterior cingulate/precuneus cortex, and impaired reflection about personally relevant knowledge related to a face, subserved by the dorsomedial prefrontal cortex. [less ▲]

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See detailPitfalls and Limitations of PET/CT in Brain Imaging.
Salmon, Eric ULg; Bernard, Claire ULg; HUSTINX, Roland ULg

in Seminars in nuclear medicine (2015), 45(6), 541-51

Neurologic applications were at the forefront of PET imaging when the technique was developed in the mid-1970s. Although oncologic indications have become prominent in terms of number of studies performed ... [more ▼]

Neurologic applications were at the forefront of PET imaging when the technique was developed in the mid-1970s. Although oncologic indications have become prominent in terms of number of studies performed worldwide, neurology remains a major field in which functional imaging provides unique information, both for clinical and research purposes. The evaluation of glucose metabolism using FDG remains the most frequent exploration, but in recent years, alternative radiotracers have been developed, including fluorinated amino acid analogues for primary brain tumor imaging and fluorinated compounds for assessing the amyloid deposits in patients with suspected Alzheimer disease. As the brain is enclosed in the skull, which presents fixed landmarks, it is relatively easy to coregister images obtained with various cross-sectional imaging methods, either functional or anatomical, with a relatively high accuracy and robustness. Nevertheless, PET in neurology has fully benefited from the advent of hybrid imaging. Attenuation and scatter correction is now much faster and equally accurate, using CT as compared with the traditional transmission scan using an external radioactive source. The perfect coregistration with the CT data, which is now systematically performed, also provides its own set of valuable information, for instance regarding cerebral atrophy. However, hybrid imaging in neurology comes with pitfalls and limitations, in addition to those that are well known, for example, blood glucose levels or psychotropic drugs that greatly affect the physiological FDG uptake. Movements of the patient's head, either during the PET acquisition or between the PET and the CT acquisitions will generate artifacts that may be very subtle yet lead to erroneous interpretation of the study. Similarly, quantitative analysis, such as voxel-based analyses, may prove very helpful in improving the diagnostic accuracy and the reproducibility of the reading, but a wide variety of artifacts may also be introduced, and should therefore be identified and corrected. [less ▲]

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See detail3D shape perception in posterior cortical atrophy: a visual neuroscience perspective
Gillebert, Céline; Schaeverbeke, J.; Bastin, Christine ULg et al

in Journal of Neuroscience (2015), 35(37), 12673-12692

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See detailFonctionnement exécutif et attentionnel consécutif à des lésions cérébrales acquises : une analyse de cas multiples
Hogge, Michael; Salmon, Eric ULg; Collette, Fabienne ULg

in Revue de Neuropsychologie, Neurosciences Cognitives et Cliniques (2015), 7(2), 71-99

Le fonctionnement exécutif a été conceptualisé comme un ensemble de processus cognitifs de haut niveau pouvant être clairement distingués, et dont le substrat cérébral se situerait au sein des régions ... [more ▼]

Le fonctionnement exécutif a été conceptualisé comme un ensemble de processus cognitifs de haut niveau pouvant être clairement distingués, et dont le substrat cérébral se situerait au sein des régions frontales. Un certain nombre de données obtenues notamment chez des patients présentant des lésions cérébrales acquises sont toutefois venues remettre en question cette conceptualisation. Dans ce contexte, nous avons administré une large batterie d’épreuves exécutives et attentionnelles à un petit groupe de patients cérébro-lésés (N=9) afin de déterminer, au moyen d’analyses de cas multiples, l’influence de la localisation et de l’étendue des lésions, ainsi que l’influence de difficultés attentionnelles, sur la survenue d’un syndrome dysexécutif. Les analyses de profils individuels semblent indiquer qu’un mauvais transfert d’information entre régions cérébrales antérieures et postérieures serait responsable de la survenue de troubles exécutifs, et que, dans certains cas, ce soient des difficultés attentionnelles qui déterminent ces déficits. Toutefois, il se pourrait également que l’atteinte de certaines régions clés (relativement focalisées) sous-tendant des processus cognitifs impliqués dans un large éventail de tâches exécutives soit responsable de la survenue d’un dysfonctionnement exécutif massif. [less ▲]

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See detailPrevalence and prognosis of Alzheimer’s disease at the mild cognitive impairment stage
Vos; VERHEY, F.; Frölich, L. et al

in Brain : A Journal of Neurology (2015), 138

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See detailRecognition of Personally Familiar Faces and Functional Connectivity in Alzheimer’s Disease
Kurth, Sophie ULg; Moyse, Evelyne ULg; Bahri, Mohamed Ali ULg et al

in Cortex : A Journal Devoted to the Study of the Nervous System & Behavior (2015), 67

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See detailImpairment of age estimation from faces in Alzheimer’s disease
Moyse, Evelyne ULg; Bastin, Christine ULg; Salmon, Eric ULg et al

in Journal of Alzheimer's Disease [=JAD] (2015), 45

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See detailThe neural basis of temporal order processing in past and future thought
D'Argembeau, Arnaud ULg; Jeunehomme, Olivier ULg; Majerus, Steve ULg et al

in Journal of Cognitive Neuroscience (2015), 27

Detailed reference viewed: 94 (22 ULg)