J. Jabre - Academia.edu (original) (raw)
Papers by J. Jabre
Electroencephalography and Clinical Neurophysiology, 1985
Physiology, Engineering, and Noninvasive Applications, 2004
Supplements to Clinical neurophysiology, 2000
... Over the recent past we have learnt a lot about the direct CM connections in man and other pr... more ... Over the recent past we have learnt a lot about the direct CM connections in man and other primates (Porter and Lemon 1993). ... P., Hagan, PJ., Phillips, eG and Powell, TPS Mapping by microstimulation of overlapping projections from area 4 to motor units of the baboon's hand. ...
Supplements to Clinical neurophysiology, 2000
Electroencephalography and clinical neurophysiology, 1997
We used the EMG precision decomposition technique to resolve complex EMG signals and derive infor... more We used the EMG precision decomposition technique to resolve complex EMG signals and derive information about the firing times of a family of motor units (MUs) and the force they produce. The active units shared a common behavior among their firing rates, a concept described by DeLuca et al. and termed the 'common drive'. This 'common' behavior was extracted as the average of the firing rates of MUs and found to track the subject's force trajectory. In this paper, we propose the existence of functional cortico-motoneuronal connections which provide for a large number of combinations between affector cortical motoneurons (CMNs) and effector spinal motoneurons (SMNs) for the generation of a purposeful movement. We argue that these connections provide the essential link between volition and movement and function as a 'volitional unit' which consists of the CMNs, the SMNs and the anatomical and interneuronal connections between them.
Journal of rehabilitation research and development, 1997
A surface electromyographic (EMG) procedure for classifying muscle impairments in persons with lo... more A surface electromyographic (EMG) procedure for classifying muscle impairments in persons with low back pain (LBP) is described. The procedure was studied using a device, the Back Analysis System (BAS), to acquire and process EMG signals from six bilateral muscle sites during sustained isometric contractions designed to progressively fatigue the lower back. Back muscle impairment was determined on the basis of the different ways in which the EMG median frequency parameters change as a function of contraction duration and muscle site. The article describes a series of studies that have been useful in developing an automated procedure for identifying back muscle impairment by comparing individual test results to a normative database. To date, the research results have produced multivariate discriminant functions that have identified two muscle impairment categories associated with deconditioning and imbalances secondary to LBP. We have found that the functions can distinguish individu...
Electromyography and clinical neurophysiology
We have found that the presence of a Tinel's sign is often pervasive in subjects with periphe... more We have found that the presence of a Tinel's sign is often pervasive in subjects with peripheral neuropathy and/or risk factors for developing it. There is a paucity of research dealing with the usefulness of Tinel's sign as it relates to peripheral neuropathy (PN). The following investigation was carried out to determine if multiple Tinel's sign or MTS can be used to identify patients with an underlying PN or with risk factors for developing a PN. A total of 102 subjects were enrolled in the study prospectively. We found MTS to have a sensitivity of 79% with a specificity of 42% in detecting peripheral neuropathy and a sensitivity of 76% with a specificity of 44% in determining the presence of risk factors for developing a peripheral neuropathy. We conclude that MTS can be a fairly sensitive indicator of PN or risk factors.
Electroencephalography and Clinical Neurophysiology, 1990
Muscle & Nerve, 1995
ABSTRACT
Journal of Physiology-Paris, 1999
We set out to decompose the EMG signal into its constituent motor unit action potential component... more We set out to decompose the EMG signal into its constituent motor unit action potential components to track motor unit firing rates with a high degree of accuracy and extract their average firing rate. We were able to show that this average firing rate tracks the subject's force trajectory from beginning to end. We propose that this average firing rate is a volitional control signal pointing to the existence of a 'volitional unit'. This volitional unit has to do with the projection of a group of functionally related cortico-motoneurons on a group of spinal motoneurons in the motoneuronal pool of a muscle. Our study of motor unit firing patterns during their steady state showed that spinal motoneurons respond to a descending central input in a Gaussian manner. We have further shown that the central drive itself, as represented by the average firing rate of the active motor units, also displays a Gaussian firing behavior. We have also described the existence of a 'translation factor', highly correlated to the motor unit size, which is unique to each spinal motoneuron and determines the motoneuronal response, and its resulting firing rate, to the descending inputs. As for force generation, we have shown that expressing the twitch force of a motor unit in a dynamic fashion using the 'electrotwitch' concept of firing rate x macro area, approximates motor unit force output better and accounts for firing rate related force changes more effectively than force estimates based on the mechanical twitch. 0 Elsevier, Paris EMG I motor control / motor unit / motoneurons / cortico-motoneuronal connections
Journal of Endocrinological Investigation, 2007
Environmental Research, 1997
This paper summarizes the findings gleaned from detailed clinical examinations of three groups of... more This paper summarizes the findings gleaned from detailed clinical examinations of three groups of residents who were exposed to trichloroethylene in well water. Also summarized are diagnostic findings for peripheral neuropathy. A detailed description of the neuropsychological test results is included, as well as a summary of domain-specific findings and diagnostic outcomes. A high rate of cognitive deficits of the type seen in patients with central nervous system dysfunction attributable to solvent exposure was seen. In addition, there was a clear developmental trend: subjects who were younger at the time of TCE exposure showed deficits in a larger variety of cognitive realms than did subjects who had already reached adulthood by the time of exposure. In particular, language deficits were seen in the younger, but not older, exposed subjects.
Clinical Neurophysiology, 2010
This chapter describes internet electromyography (EMG) associated within telemedicine. Medicine i... more This chapter describes internet electromyography (EMG) associated within telemedicine. Medicine is being revolutionized every day by the Internet, both for practitioners—who communicate with each other and update their knowledge—and for patients who obtain information and network through it. The development of general medical sites was quickly followed by neuroscience sites and eventually by exclusive neurophysiology EMG sites. Clinical neurophysiology (CN) lends itself well to various aspects of TeleMedicine (TM). Summaries of EEG, EMG and evoked potential findings are often presented as graphs or pictures, which are well suited for digital transmission. Clinical neurophysiology (CN) lends itself well to various aspects of TM. The laboratory also has contacts with other EMG laboratories in the world using identical recording equipment. E-mail, net meeting, authoring web pages, video conferencing, video chatting, digital literature, and databases for the neurophysiologist are all part and parcel of telemedicine. Positive aspects of transmission of biosignals are time saving; remote colleagues may obtain immediate consultations, improved quality, on call possibilities for EEG and easy international collaboration. Combination of biosignal and picture transmission is used for discussion of specific cases, participation in morning case reviews, educational purposes, business meetings, and faster CN service.
Electroencephalography and Clinical Neurophysiology, 1985
Physiology, Engineering, and Noninvasive Applications, 2004
Supplements to Clinical neurophysiology, 2000
... Over the recent past we have learnt a lot about the direct CM connections in man and other pr... more ... Over the recent past we have learnt a lot about the direct CM connections in man and other primates (Porter and Lemon 1993). ... P., Hagan, PJ., Phillips, eG and Powell, TPS Mapping by microstimulation of overlapping projections from area 4 to motor units of the baboon's hand. ...
Supplements to Clinical neurophysiology, 2000
Electroencephalography and clinical neurophysiology, 1997
We used the EMG precision decomposition technique to resolve complex EMG signals and derive infor... more We used the EMG precision decomposition technique to resolve complex EMG signals and derive information about the firing times of a family of motor units (MUs) and the force they produce. The active units shared a common behavior among their firing rates, a concept described by DeLuca et al. and termed the 'common drive'. This 'common' behavior was extracted as the average of the firing rates of MUs and found to track the subject's force trajectory. In this paper, we propose the existence of functional cortico-motoneuronal connections which provide for a large number of combinations between affector cortical motoneurons (CMNs) and effector spinal motoneurons (SMNs) for the generation of a purposeful movement. We argue that these connections provide the essential link between volition and movement and function as a 'volitional unit' which consists of the CMNs, the SMNs and the anatomical and interneuronal connections between them.
Journal of rehabilitation research and development, 1997
A surface electromyographic (EMG) procedure for classifying muscle impairments in persons with lo... more A surface electromyographic (EMG) procedure for classifying muscle impairments in persons with low back pain (LBP) is described. The procedure was studied using a device, the Back Analysis System (BAS), to acquire and process EMG signals from six bilateral muscle sites during sustained isometric contractions designed to progressively fatigue the lower back. Back muscle impairment was determined on the basis of the different ways in which the EMG median frequency parameters change as a function of contraction duration and muscle site. The article describes a series of studies that have been useful in developing an automated procedure for identifying back muscle impairment by comparing individual test results to a normative database. To date, the research results have produced multivariate discriminant functions that have identified two muscle impairment categories associated with deconditioning and imbalances secondary to LBP. We have found that the functions can distinguish individu...
Electromyography and clinical neurophysiology
We have found that the presence of a Tinel's sign is often pervasive in subjects with periphe... more We have found that the presence of a Tinel's sign is often pervasive in subjects with peripheral neuropathy and/or risk factors for developing it. There is a paucity of research dealing with the usefulness of Tinel's sign as it relates to peripheral neuropathy (PN). The following investigation was carried out to determine if multiple Tinel's sign or MTS can be used to identify patients with an underlying PN or with risk factors for developing a PN. A total of 102 subjects were enrolled in the study prospectively. We found MTS to have a sensitivity of 79% with a specificity of 42% in detecting peripheral neuropathy and a sensitivity of 76% with a specificity of 44% in determining the presence of risk factors for developing a peripheral neuropathy. We conclude that MTS can be a fairly sensitive indicator of PN or risk factors.
Electroencephalography and Clinical Neurophysiology, 1990
Muscle & Nerve, 1995
ABSTRACT
Journal of Physiology-Paris, 1999
We set out to decompose the EMG signal into its constituent motor unit action potential component... more We set out to decompose the EMG signal into its constituent motor unit action potential components to track motor unit firing rates with a high degree of accuracy and extract their average firing rate. We were able to show that this average firing rate tracks the subject's force trajectory from beginning to end. We propose that this average firing rate is a volitional control signal pointing to the existence of a 'volitional unit'. This volitional unit has to do with the projection of a group of functionally related cortico-motoneurons on a group of spinal motoneurons in the motoneuronal pool of a muscle. Our study of motor unit firing patterns during their steady state showed that spinal motoneurons respond to a descending central input in a Gaussian manner. We have further shown that the central drive itself, as represented by the average firing rate of the active motor units, also displays a Gaussian firing behavior. We have also described the existence of a 'translation factor', highly correlated to the motor unit size, which is unique to each spinal motoneuron and determines the motoneuronal response, and its resulting firing rate, to the descending inputs. As for force generation, we have shown that expressing the twitch force of a motor unit in a dynamic fashion using the 'electrotwitch' concept of firing rate x macro area, approximates motor unit force output better and accounts for firing rate related force changes more effectively than force estimates based on the mechanical twitch. 0 Elsevier, Paris EMG I motor control / motor unit / motoneurons / cortico-motoneuronal connections
Journal of Endocrinological Investigation, 2007
Environmental Research, 1997
This paper summarizes the findings gleaned from detailed clinical examinations of three groups of... more This paper summarizes the findings gleaned from detailed clinical examinations of three groups of residents who were exposed to trichloroethylene in well water. Also summarized are diagnostic findings for peripheral neuropathy. A detailed description of the neuropsychological test results is included, as well as a summary of domain-specific findings and diagnostic outcomes. A high rate of cognitive deficits of the type seen in patients with central nervous system dysfunction attributable to solvent exposure was seen. In addition, there was a clear developmental trend: subjects who were younger at the time of TCE exposure showed deficits in a larger variety of cognitive realms than did subjects who had already reached adulthood by the time of exposure. In particular, language deficits were seen in the younger, but not older, exposed subjects.
Clinical Neurophysiology, 2010
This chapter describes internet electromyography (EMG) associated within telemedicine. Medicine i... more This chapter describes internet electromyography (EMG) associated within telemedicine. Medicine is being revolutionized every day by the Internet, both for practitioners—who communicate with each other and update their knowledge—and for patients who obtain information and network through it. The development of general medical sites was quickly followed by neuroscience sites and eventually by exclusive neurophysiology EMG sites. Clinical neurophysiology (CN) lends itself well to various aspects of TeleMedicine (TM). Summaries of EEG, EMG and evoked potential findings are often presented as graphs or pictures, which are well suited for digital transmission. Clinical neurophysiology (CN) lends itself well to various aspects of TM. The laboratory also has contacts with other EMG laboratories in the world using identical recording equipment. E-mail, net meeting, authoring web pages, video conferencing, video chatting, digital literature, and databases for the neurophysiologist are all part and parcel of telemedicine. Positive aspects of transmission of biosignals are time saving; remote colleagues may obtain immediate consultations, improved quality, on call possibilities for EEG and easy international collaboration. Combination of biosignal and picture transmission is used for discussion of specific cases, participation in morning case reviews, educational purposes, business meetings, and faster CN service.