References of "Garraux, Gaëtan"
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See detailLarge-scale replication and heterogeneity in Parkinson disease genetic loci.
Sharma, Manu; Ioannidis, John P. A.; Aasly, Jan O. et al

in Neurology (2012), 79(7), 659-67

OBJECTIVE: Eleven genetic loci have reached genome-wide significance in a recent meta-analysis of genome-wide association studies in Parkinson disease (PD) based on populations of Caucasian descent. The ... [more ▼]

OBJECTIVE: Eleven genetic loci have reached genome-wide significance in a recent meta-analysis of genome-wide association studies in Parkinson disease (PD) based on populations of Caucasian descent. The extent to which these genetic effects are consistent across different populations is unknown. METHODS: Investigators from the Genetic Epidemiology of Parkinson's Disease Consortium were invited to participate in the study. A total of 11 SNPs were genotyped in 8,750 cases and 8,955 controls. Fixed as well as random effects models were used to provide the summary risk estimates for these variants. We evaluated between-study heterogeneity and heterogeneity between populations of different ancestry. RESULTS: In the overall analysis, single nucleotide polymorphisms (SNPs) in 9 loci showed significant associations with protective per-allele odds ratios of 0.78-0.87 (LAMP3, BST1, and MAPT) and susceptibility per-allele odds ratios of 1.14-1.43 (STK39, GAK, SNCA, LRRK2, SYT11, and HIP1R). For 5 of the 9 replicated SNPs there was nominally significant between-site heterogeneity in the effect sizes (I(2) estimates ranged from 39% to 48%). Subgroup analysis by ethnicity showed significantly stronger effects for the BST1 (rs11724635) in Asian vs Caucasian populations and similar effects for SNCA, LRRK2, LAMP3, HIP1R, and STK39 in Asian and Caucasian populations, while MAPT rs2942168 and SYT11 rs34372695 were monomorphic in the Asian population, highlighting the role of population-specific heterogeneity in PD. CONCLUSION: Our study allows insight to understand the distribution of newly identified genetic factors contributing to PD and shows that large-scale evaluation in diverse populations is important to understand the role of population-specific heterogeneity. [less ▲]

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See detailDu coaching physique pour mieux endurer la maladie de Parkinson
Garraux, Gaëtan ULg

in Mouvements (2012), 12(2), 41-50

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See detailConstruction and validation of the Dynamic Parkinson Gait Scale (DYPAGS).
Cremers, Julien ULg; PHAN BA, Remy ULg; DELVAUX, Valérie ULg et al

in Parkinsonism & Related Disorders (2012)

The dynamic evaluation of Parkinson's disease (PD)-related episodic gait disturbances in routine is challenging. Therefore, the aim of our study was to assess the reliability/validity of the Dynamic ... [more ▼]

The dynamic evaluation of Parkinson's disease (PD)-related episodic gait disturbances in routine is challenging. Therefore, the aim of our study was to assess the reliability/validity of the Dynamic Parkinson Gait Scale (DYPAGS) composed of eight relevant items for the objective quantification of PD gait features: walking forwards/backwards/with dual-task, turning to both sides, imaginary obstacle avoidance with both legs and passing through narrow spaces. The scale was validated on thirty-five patients with mild to severe parkinsonism in their habitual "on-state". A shorter 6 item-version was designed on the basis of a principal component analysis. No significant floor/ceiling effect was detected. The internal consistency was excellent. The levels of interrater agreement, precision and minimal detectable change were adequate. The criterion-related validity was demonstrated by strong correlations with the DYPAGS scores and those at the gait subscales of the Tinetti Mobility Test and MDS-UPDRS. The construct validity was assessed by moderate-strong correlations with the Freezing of Gait Questionnaire, mobility index of the PD Questionnaire (PDQ-39), disease duration and levodopa equivalent daily doses. Statistical analyses using the coefficient of determination showed that both DYPGAS versions were superior to the other instruments to identify patients with gait disturbances with poorer response to dopaminergic treatment. Full and short DYPAGS are reliable instruments for the quantification of "on" PD-related episodic gait disturbances. The full version is sensitive to detect subtle disturbances in mild parkinsonism. The shorter one is easily administered and reliably quantifies gait disturbances in moderate to severe parkinsonism. We recommend their use for research and clinical practice. [less ▲]

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See detailPartial trisomy 4q associated with young-onset dopa-responsive parkinsonism.
Garraux, Gaëtan ULg; CABERG, Jean-Hubert ULg; Vanbellinghen, Jean-Francois et al

in Archives of Neurology (2012), 69(3), 398-400

OBJECTIVE: To describe a patient who developed a young-onset, dopa-responsive parkinsonism linked to a de novo heterozygous interstitial duplication 4q. DESIGN: Case report. SETTING: Movement Disorder ... [more ▼]

OBJECTIVE: To describe a patient who developed a young-onset, dopa-responsive parkinsonism linked to a de novo heterozygous interstitial duplication 4q. DESIGN: Case report. SETTING: Movement Disorder Outpatient Clinic at the University Hospital Centre, Liege, Belgium. Patient A 31-year-old woman. MAIN OUTCOME MEASURES: Clinical, neuroimaging, and genetic data. RESULTS: The duplicated region contains 150 known genes, including the alpha-synuclein (SNCA) gene locus. Motor and 6-[(18)F]fluoro-L-dopa positron emission tomography features are similar to those previously reported in heterozygote SNCA duplication carriers. Altered expression of other genes contained in the duplicated region may contribute to clinical features that are uncommon in the phenotypic spectrum of SNCA multiplications such as delayed developmental psychomotor milestones during infancy and musculoskeletal abnormalities. CONCLUSION: This case report provides new insights on the genetic basis of parkinsonism. [less ▲]

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See detailBrain energization in response to deep brain stimulation of subthalamic nuclei in Parkinson's disease.
Garraux, Gaëtan ULg; Bahri, Mohamed Ali ULg; Lemaire, Christian ULg et al

in Journal of Cerebral Blood Flow & Metabolism (2011)

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an effective treatment in a subgroup of medically refractory patients with Parkinson's disease (PD). Here, we compared resting-state (18)F ... [more ▼]

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an effective treatment in a subgroup of medically refractory patients with Parkinson's disease (PD). Here, we compared resting-state (18)F-fluorodeoxyglucose (FDG) positron emission tomography images in the stimulator off (DBS_OFF) and on (DBS_ON) conditions in eight PD patients in an unmedicated state, on average 2 years after bilateral electrode implantation. Global standardized uptake value (SUV) significantly increased by approximately 11% in response to STN-DBS. To avoid any bias in the voxel-based analysis comparing DBS_ON and DBS_OFF conditions, individual scan intensity was scaled to a region where FDG-SUV did not differ significantly between conditions. The resulting FDG-SUV ratio (FDG-SUVR) was found to increase in many regions in response to STN-DBS including the target area of surgery, caudate nuclei, primary sensorimotor, and associative cortices. Contrary to previous studies, we could not find any regional decrease in FDG-SUVR. These findings were indirectly supported by comparing the extent of areas with depressed FDG-SUVR in DBS_OFF and DBS_ON relatively to 10 normal controls. Altogether, these novel results support the prediction that the effect of STN-DBS on brain activity in PD is unidirectional and consists in an increase in many subcortical and cortical regions.Journal of Cerebral Blood Flow & Metabolism advance online publication, 6 April 2011; doi:10.1038/jcbfm.2011.41. [less ▲]

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See detailAutomatic Stimulus-Induced Medial Premotor Cortex Activation without Perception or Action
D'Ostilio, Kevin ULg; Garraux, Gaëtan ULg

in PLoS ONE (2011), 6(2),

Who has ever been surprised to return to the bowl of salted peanuts without realizing it, even after having eating a moderate number and deciding to stop? Using rapid event-related functional magnetic ... [more ▼]

Who has ever been surprised to return to the bowl of salted peanuts without realizing it, even after having eating a moderate number and deciding to stop? Using rapid event-related functional magnetic resonance imaging (fMRI) in healthy volunteers, we investigated the neural correlates of automatic processes induced by subliminal stimuli. We demonstrated that the automatic activation of motor programs elicited unconsciously in the medial premotor cortex was normally restricted to specific contexts set by the environment, but can occur below the threshold of awareness even when no movement was executed. This novel finding expands our view on brain mechanisms underlying unconscious motor control and provides new evidence that activation of the motor preparation system and consciousness are not obligatory linked. [less ▲]

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See detailLa demence chez le patient parkinsonien: facteurs de risque, diagnostic et traitement.
BAKAY, Sara ULg; BECHET, Sophie ULg; BARJONA MORGADO DE MOURA, Aude ULg et al

in Revue Médicale de Liège (2011), 66(2), 75-81

Aside from limb tremor, bradykinesia, rigidity and gait disturbances, Parkinson's disease (PD) is also characterized by non-motor symptoms. A cognitive decline can occur early in the disease course and ... [more ▼]

Aside from limb tremor, bradykinesia, rigidity and gait disturbances, Parkinson's disease (PD) is also characterized by non-motor symptoms. A cognitive decline can occur early in the disease course and undoubtedly impact of the patient's quality of life. Dementia affects 80% of patients 20 years after disease onset but a small subgroup of patients remain free of dementia even after decades with PD. Risk factors and diagnosis of dementia can be easily assessed using bed-side clinical instruments. Advances in genetics and imagery will allow improving the diagnosis and therapeutic strategy dementia in Parkinson's disease. [less ▲]

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See detailGait feature extraction in Parkinson's disease using low-cost accelerometers
Stamatakis, Julien; Cremers, Julien ULg; Maquet, Didier ULg et al

Poster (2011)

The clinical hallmarks of Parkinson’s disease (PD) are movement poverty and slowness (i.e. bradykinesia), muscle rigidity, limb tremor or gait disturbances. Parkinson’s gait include slowness, shuffling ... [more ▼]

The clinical hallmarks of Parkinson’s disease (PD) are movement poverty and slowness (i.e. bradykinesia), muscle rigidity, limb tremor or gait disturbances. Parkinson’s gait include slowness, shuffling, short steps, freezing of gait (FoG) and/or asymmetries in gait. There are currently no validated clinical instruments or device that allow a full characterization of gait disturbances in PD. As a step towards this goal, a four accelerometer-based system is proposed to increase the number of parameters that can be extracted to characterize parkinsonian gait disturbances such as FoG or gait asymmetries. After developing the hardware, an algorithm has been developed, that automatically epoched the signals on a stride-by-stride basis and quantified, among others, the gait velocity, the stride time,the stance and swing phases, the single and double support phases or the maximum acceleration at toe-off, as validated by visual inspection of video recordings during the task. The results obtained in a PD patient and an healthy volunteer are presented. The FoG detection will be improved using time-frequency analysis and the system is about to be validated with a state-of-the-art 3D movement analysis system. [less ▲]

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See detailBrain perfusion patterns in familial frontotemporal lobar degeneration.
Seelaar, H.; Papma, J. M.; Garraux, Gaëtan ULg et al

in Neurology (2011), 77(4), 384-92

OBJECTIVE: Frontotemporal lobar degeneration (FTLD) is a clinically, genetically, and pathologically heterogeneous disorder. The aim of this study was to compare clinical features and perfusion patterns ... [more ▼]

OBJECTIVE: Frontotemporal lobar degeneration (FTLD) is a clinically, genetically, and pathologically heterogeneous disorder. The aim of this study was to compare clinical features and perfusion patterns on SPECT of patients with familial FTLD-TAR DNA binding protein 43 kDa (TDP) and MAPT mutations. METHODS: Patients were included if they had MAPT or GRN mutations, positive family history with pathologically proven FTLD in the patient or first-degree relative, or were part of FTD-MND families. All patients and 10 age- and gender-matched controls underwent measurement of brain perfusion using (99m)Tc-HMPAO SPECT. We used SPM8 to perform image processing and voxel-based group analyses (p < 0.001). Gender and age were included as nuisance variables in the design matrices. RESULTS: Of the 29 patients with familial FTLD, 19 had familial FTLD-TDP (GRN mutations in 6), and 10 had MAPT mutations. At clinical presentation, familial FTLD-TDP patients were older at onset (p = 0.030) and had more memory deficits (p = 0.011), whereas patients with MAPT had more naming deficits (p < 0.001) and obsessive-compulsive behavior (p = 0.001). The between-groups SPECT analyses revealed significantly less perfusion in the right frontal lobe, precuneus, cuneus, and inferior parietal lobule in familial FTLD-TDP, whereas significantly less perfusion was found in the left temporal and inferior frontal gyri in MAPT. Post hoc analysis of familial FTLD-TDP with unknown genetic defect vs MAPT revealed less perfusion in the right frontal and parietal lobe. CONCLUSION: Familial FTLD-TDP shows relatively more posterior hypoperfusion, including the precuneus and inferior parietal lobule, possibly related to significant memory impairment. Patients with MAPT were characterized by impaired perfusion of the temporal regions and naming deficits. [less ▲]

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See detailHemispheric specialization during mental imagery of brisk walking.
Cremers, Julien ULg; Dessoullieres, Aurélie; Garraux, Gaëtan ULg

in Human Brain Mapping (2011)

OBJECTIVES: Brisk walking, a sensitive test to evaluate gait capacity in normal and pathological aging such as parkinsonism, is used as an alternative to classical fitness program for motor rehabilitation ... [more ▼]

OBJECTIVES: Brisk walking, a sensitive test to evaluate gait capacity in normal and pathological aging such as parkinsonism, is used as an alternative to classical fitness program for motor rehabilitation and may help to decrease the risk of cognitive deterioration observed with aging. In this study, we aimed to identify brain areas normally involved in its control. METHODS: We conducted a block-design blood oxygen level dependent function magnetic resonance imaging (BOLD fMRI) experiment in 18 young healthy individuals trained to imagine themselves in three main situations: brisk walking in a 25-m-long corridor, standing or lying. Imagined walking time (IWT) was measured as a control of behavioral performance during fMRI. RESULTS: The group mean IWT was not significantly different from the actual walking time measured during a training session prior to the fMRI study. Compared with other experimental conditions, mental imagery (MI) of brisk walking was associated with stronger activity in frontal and parietal regions mainly on the right, and cerebellar hemispheres, mainly on the left. Presumed imagined walking speed (2.3 +/- 0.4 m/s) was positively correlated with activity levels in the right dorsolateral prefrontal cortex and posterior parietal lobule along with the vermis and the left cerebellar hemisphere. INTERPRETATIONS: A new finding in this study is that MI of brisk walking in young healthy individuals strongly involves processes lateralized in right fronto-parietal regions along with left cerebellum. These results show that brisk walking might be a non automatic locomotor activity requiring a high-level supraspinal control. Hum Brain Mapp, 2011. (c) 2011 Wiley-Liss, Inc. [less ▲]

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See detailIs posterior cerebral hypometabolism always predicitve of dementia in Parkinson's disease?
Deville, Benjamin ULg; Lemaire, Christian ULg; Degueldre, Christian ULg et al

Poster (2010, June 08)

In Parkinson's disease, altered activity in posterior associative cortices has often been associated with dementia. It remains to be determined if this pattern is a reliable marker of a progression toward ... [more ▼]

In Parkinson's disease, altered activity in posterior associative cortices has often been associated with dementia. It remains to be determined if this pattern is a reliable marker of a progression toward dementia in patients without demonstratable dementia. In this retrospective analysis, we used positron emission tomography to study resting-state cerebral fluodeoxyglucose uptake in 8 healthy controls and 8 Parkinson's disease patients who did not have evidence of dementia at the time of assessment. For those patients, clinical follow up was available and we know that they did not meet dementia criteria on average 10,37 years after assessment. The results show that patients had reduced fluodeoxyglucose uptake mostly localised in the right hemisphere and including precuneus, superior temporal, middle temporal and inferior parietal cortices. It also includes right insula. These cerebral activity predominating in posterior cortices is present in non-demened patients but is not always predictive of dementia within the 10,34 years. [less ▲]

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See detailAmbulatory monitoring of energy expenditure and physical activity levels using the SenseWear ArmbandTM system in Parkinson’s disease
Rodriguez de la Cruz, Carlos ULg; Bury, Thierry ULg; Le Scanff, Steren et al

in Movement Disorders : Official Journal of the Movement Disorder Society (2010, June), 25(S2), 355-356

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See detailGait analysis during an original walking test: Comparison between control subjects and patients with Parkinson’s disease
Maquet, Didier ULg; Croisier, Jean-Louis ULg; Robert, Fanny et al

in Movement Disorders : Official Journal of the Movement Disorder Society (2010, June), 25(Suppl 2), 355

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See detailGait analysis using a wearable accelerometer system: Comparison between control subjects and patients with Parkinson’s disease
Maquet, Didier ULg; Croisier, Jean-Louis ULg; Robert, Fanny et al

in Movement Disorders : Official Journal of the Movement Disorder Society (2010, June), 25(S2), 355

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See detailFinger Tapping feature extraction in Parkinson's disease using low-cost accelerometers
Stamatakis, Julien; Cremers, Julien ULg; Macq, Benoït et al

in Proceedings 10th IEEE International Conference on Information Technology and Applications in Biomedicine (ITAB 2010) (2010)

The clinical hallmarks of Parkinson's disease (PD) are movement poverty and slowness (i.e. bradykinesia), muscle rigidity and limb tremor. The physicians usually quantify these motor disturbances by ... [more ▼]

The clinical hallmarks of Parkinson's disease (PD) are movement poverty and slowness (i.e. bradykinesia), muscle rigidity and limb tremor. The physicians usually quantify these motor disturbances by assigning a severity score according to validated but time-consuming clinical scales such as the Unified Parkinson's Disease Rating Scale (UPDRS) - part III. These clinical ratings are however prone to subjectivity and inter-rater variability. The PD medical community is therefore looking for a faster and more objective rating method. As a first step towards this goal, a tri-axial accelerometer-based system is proposed as patients are engaged in a repetitive finger tapping task, which is classically used to assess bradykinesia in the UPDRS-III. After developing the hardware, an algorithm has been developed, that automatically epoched the signal on a trial-by-trial basis and quantified, among others, movement speed, amplitude, hesitations or halts as validated by visual inspection of video recordings during the task. The results obtained in a PD patient and an healthy volunteer are presented. Preliminary results show that PD patients and healthy volunteers have different features profiles, so that a classifier could be set up to predict objective UPDRS-III scores. [less ▲]

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See detailAutomatic brain image reading for the differential diagnosis between atypical parkinsonian syndromes & Parkinson's disease
Garraux, Gaëtan ULg; Phillips, Christophe ULg; Lemaire, Christian ULg et al

in Movement Disorders : Official Journal of the Movement Disorder Society (2010), 25(7), 379-379

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See detailAutomatic stimulus-induced medial premotor cortex activation without perception or action
D'Ostilio, Kevin ULg; Garraux, Gaëtan ULg

Poster (2010)

Evidence from functional imaging studies suggests that well-established stimulus-action associations may induce an automatic activation of the motor preparation system even when there is no intention to ... [more ▼]

Evidence from functional imaging studies suggests that well-established stimulus-action associations may induce an automatic activation of the motor preparation system even when there is no intention to make the associated movement (Grezes & Decety, 2002). Here we investigated whether this automatic motor activation can also be elicited by visual stimuli that are not consciously perceived. However, previous subliminal masked experiments used supraliminal response-target in such a way that unconscious mechanisms were inferred from the accumulation of the effect of the subliminal masked stimulus and the motor response. Here, to investigate neural correlates of unconscious process induced by subliminal stimuli, we used event-related BOLD fMRI at 3T to record brain activity in 24 healthy volunteers (mean age: 21 ± 2 years) as they performed a subliminal priming task (see Eimer & Schlaghecken, 1998). In this visuomotor task, participants were asked to make speeded button presses with the left or right hand following double leftward (<< <<) or rightward (>> >>) pointing arrows, which were preceded by a masked subliminal prime of 17 ms (compatible/incompatible arrows or neutral stimulus). Reaction time analysis revealed the classical positive compatibility effect (PCE), mainly shorter reaction times for compatible (mean RT: 369±38 ms) than for incompatible (mean RT: 383± 30 ms) in comparison to neutral trials (mean RT: 375± 38 ms). In a prime identification task, subjects’ performance was at chance level for primes presented for 17 ms, suggesting that the prime was not consciously perceived in the main experiment. Theses behavioral results suggest an automatic and unconscious motor activation induced by the prime. The responded stimuli were randomly intermixed with non-responded stimuli (0 0) with the assumption that the subliminal arrow prime also elicited an automatic motor activation in these passive trials as in responded trials. Imaging analysis of these non-responded trials showed first that activation was mainly restricted to posterior brain areas when using a subliminal stimulus that has not been previously associated with a motor response. Second, when the subliminal stimulus has been strongly associated with a motor response, this activation extended to rostral brain regions classically involved in motor preparation as the SMA, the premotor cortex and the striatum (cluster level p< 0.05 corrected). This finding corroborates the involvement of a fronto-striatal network, especially of the SMA in automatic and unconscious motor activation. [less ▲]

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See detail18F-flutemetamol amyloid imaging in Alzheimer disease and mild cognitive impairment: a phase 2 trial.
Vandenberghe, R.; Van Laere, K.; Ivanoiu, A. et al

in Annals of Neurology (2010), 68(3), 319-329

Objective: The most widely studied positron emission tomography ligand for in vivo -amyloid imaging is 11CPittsburgh compound B (11C-PIB). Its availability, however, is limited by the need for an on-site ... [more ▼]

Objective: The most widely studied positron emission tomography ligand for in vivo -amyloid imaging is 11CPittsburgh compound B (11C-PIB). Its availability, however, is limited by the need for an on-site cyclotron. Validation of the 18F-labeled PIB derivative 18F-flutemetamol could significantly enhance access to this novel technology. Methods: Twenty-seven patients with early-stage clinically probable Alzheimer disease (AD), 20 with amnestic mild cognitive impairment (MCI), and 15 cognitively intact healthy volunteers (HVs) above and 10 HVs below 55 years of age participated. The primary endpoint was the efficacy of blinded visual assessments of 18F-flutemetamol scans in assigning subjects to a raised versus normal uptake category, with clinical diagnosis as the standard of truth (SOT). As secondary objectives, we determined the correlation between the regional standardized uptake value ratios (SUVRs) for 18F-flutemetamol and its parent molecule 11C-PIB in 20 of the AD subjects and 20 of the MCI patients. We also determined test-retest variability of 18F-flutemetamol SUVRs in 5 of the AD subjects. Results: Blinded visual assessments of 18F-flutemetamol scans assigned 25 of 27 scans from AD subjects and 1 of 15 scans from the elderly HVs to the raised category, corresponding to a sensitivity of 93.1% and a specificity of 93.3% against the SOT. Correlation coefficients between cortical 18F-flutemetamol SUVRs and 11C-PIB SUVRs ranged from 0.89 to 0.92. Test-retest variabilities of regional SUVRs were 1 to 4%. Interpretation: 18F-Flutemetamol performs similarly to the 11C-PIB parent molecule within the same subjects and provides high test-retest replicability and potentially much wider accessibility for clinical and research use. [less ▲]

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