Manto M.,FNRS |
van den Braber N.,Moog |
Grimaldi G.,Neurologie |
Sensors | Year: 2010
The pathophysiological assessment of joint properties and voluntary motion in neurological patients remains a challenge. This is typically the case in cerebellar patients, who exhibit dysmetric movements due to the dysfunction of cerebellar circuitry. Several tools have been developed, but so far most of these tools have remained confined to laboratories, with a lack of standardization. We report on a new device which combines the use of electromyographic (EMG) sensors with haptic technology for the dynamic investigation of wrist properties. The instrument is composed of a drivetrain, a haptic controller and a signal acquisition unit. Angular accuracy is 0.00611 rad, nominal torque is 6 N·m, maximal rotation velocity is 34.907 rad/sec, with a range of motion of -1.0472 to +1.0472 rad. The inertia of the motor and handgrip is 0.004 kg·m2. This is the first standardized myohaptic instrument allowing the dynamic characterization of wrist properties, including under the condition of artificial damping. We show that cerebellar patients are unable to adapt EMG activities when faced with an increase in damping while performing fast reversal movements. The instrument allows the extraction of an electrophysiological signature of a cerebellar deficit. © 2010 by the authors.
Tombeux C.,CHU de Liege |
Melon P.,CHU de Liege |
Close P.,Center Hospitalier Chretien Of Liege |
Magne J.,FNRS |
Pierard L.A.,Service de cardiologie
Revue Medicale de Liege | Year: 2011
Documented ventricular tachyarrhythmias or related symptoms need meticulous cardiac investigations. The mechanism of ventricular arrhythmia must be defined. The prognosis is related to underlying cardiac electrical or structural disorders. In the absence of cardiovascular abnormalities, the prognosis is good. no disqualification to competitive activity is required in most cases. Assessment of the risk of sudden death remains a continuing challenge in athletes. This article reviews the diagnostic and therapeutic approaches of ventricular arrhythmias encountered in trained athletes.
Lavita S.I.,University of Medicine and Pharmacy, Cluj-Napoca |
Aro R.,University of Mons |
Kiss B.,University of Medicine and Pharmacy, Cluj-Napoca |
Manto M.,FNRS |
And 2 more authors.
Cerebellum | Year: 2016
Essential tremor (ET) is one of the most prevalent neurological disorders in the world. Environmental factors have been implicated in the pathogenesis of ET. In particular, epidemiological studies have suggested that neurotoxic agents, especially β-carboline alkaloids (βCAs), might be generated through Maillard-type reaction. βCAs are molecules which are members of a large group of heterocyclic amines (HCAs, the so-called products of cooking meat). βCAs are highly tremorogenic in animals, producing a marked generalized action tremor soon after systemic administration in a wide range of laboratory animals such as mice, rats and monkeys. Administration of βCAs remains currently the main experimental model of ET. We review the pathogenesis of ET, with a focus on the biochemistry of βCAs, their occurrence and biological activity, their endogenous biosynthesis, their formation in food, their toxicokinetics and their neurotoxicity. We highlight open questions regarding the effects of βCAs in humans. © 2015, Springer Science+Business Media New York.
Manto M.U.,FNRS |
Jissendi P.,Service de Neuroradiologie
Frontiers in Neuroanatomy | Year: 2012
The study of the links and interactions between development and motor learning has noticeable implications for the understanding and management of neurodevelopmental disorders. This is particularly relevant for the cerebellum which is critical for sensorimotor learning. The olivocerebellar pathway is a key pathway contributing to learning of motor skills. Its developmental maturation and remodeling are being unraveled. Advances in genetics have led to major improvements in our appraisal of the genes involved in cerebellar development, especially studies in mutant mice. Cerebellar neurogenesis is compartmentalized in relationship with neurotransmitter fate. The Engrailed-2 gene is a major actor of the specification of cerebellar cell types and late embryogenic morphogenesis. Math1, expressed by the rhombic lip, is required for the genesis of glutamatergic neurons. Mutants deficient for the transcription factor Ptf1a display a lack of Purkinje cells and gabaergic interneurons. Rora gene contributes to the developmental signaling between granule cells and Purkinje neurons. The expression profile of sonic hedgehog in postnatal stages determines the final size/shape of the cerebellum. Genes affecting the development impact upon the physiological properties of the cerebellar circuits. For instance, receptors are developmentally regulated and their action interferes directly with developmental processes. Another field of research which is expanding relates to very preterm neonates. They are at risk for cerebellar lesions, which may themselves impair the developmental events. Very preterm neonates often show sensori-motor deficits, highlighting another major link between impaired developments and learning deficiencies. Pathways playing a critical role in cerebellar development are likely to become therapeutical targets for several neurodevelopmental disorders.
Moreno J.A.,National Autonomous University of Mexico |
Dochain D.,FNRS |
Dochain D.,Catholic University of Louvain
Proceedings of the IEEE Conference on Decision and Control | Year: 2013
We propose a discontinuous observer able to estimate in finite time both unmeasured states and the unknown input of a SISO nonlinear second order system. The only requirements are the observability of both the states and the unknown input, and that the unknown input is a uniformly Lipschitz time function. We illustrate the method in a biological reactor that models the functioning of aWasteWater Treatment Plant (WWTP), for which the problem of estimating the unknown input is of practical relevance. For concreteness of the presentation we restrict the treatment to second order systems, but the idea can be extended to a more general context. ©2013 IEEE.