Search results for " Neurophysiological"
showing 10 items of 20 documents
Evidence of resistance training-induced neural adaptation in older adults
2021
The deleterious effects of aging on force production are observable from the age of 40 upwards, depending on the measure. Neural mechanisms contributing to maximum force production and rate of force development have been suggested as descending drive from supraspinal centers, spinal motoneuron excitability, and corticospinal inhibition of descending drive; all of which influence motor unit recruitment and/or firing rate. Resistance-trained Master athletes offer a good source of information regarding the inevitable effects of aging despite the countermeasure of systematic resistance-training. However, most evidence of neural adaptation is derived from longitudinal intervention studies in pre…
Enhancement of human cortico-motoneuronal excitability by the selective norepinephrine reuptake inhibitor reboxetine
2002
It has been proposed that norepinephrine plays a critical role in the modulation of cortical excitability, which in turn is thought to influence functional recovery from brain lesions. The purpose of the present experiments was to determine if it is possible to modulate cortical excitability with the selective norepinephrine reuptake inhibitor reboxetine in intact humans. Recruitment curve and intracortical facilitation, assessed by transcranial magnetic stimulation, were increased after oral intake of 8 and 4 mg reboxetine, in the absence of changes in motor threshold, intracortical inhibition, M-response, F-wave or H-reflex. These results demonstrate that reboxetine enhances cortical exci…
Motor recruitment during action observation: Effect of interindividual differences in action strategy
2020
Abstract Visual processing of other’s actions is supported by sensorimotor brain activations. Access to sensorimotor representations may, in principle, provide the top-down signal required to bias search and selection of critical visual features. For this to happen, it is necessary that a stable one-to-one mapping exists between observed kinematics and underlying motor commands. However, due to the inherent redundancy of the human musculoskeletal system, this is hardly the case for multijoint actions where everyone has his own moving style (individual motor signature—IMS). Here, we investigated the influence of subject’s IMS on subjects’ motor excitability during the observation of an actor…
Does the Recruitment of Excitation and Inhibition in the Motor Cortex Differ?
2007
The level of excitability within the motor cortex can be described as a balance between excitation and inhibition, but it is unknown how well both processes correlate. To address this question, the authors measured motor cortical excitability and inhibition in healthy human subjects, comparing the recruitment of motor evoked potentials (MEPs) and the duration of the cortical silent period (CSP) after transcranial magnetic stimulation (TMS). Single-pulse "focal" TMS was applied at intensities varying between 90% and 200% of motor thresholds to the right motor cortex of 15 healthy volunteers. The peak-to peak size of MEP responses and the duration of the CSP were measured in small hand muscle…
Intraoperative brain mapping of language, cognitive functions, and social cognition in awake surgery of low-grade gliomas located in the right non-do…
2020
Abstract Objective The aim of our study was to evaluate the usefulness of cortical-subcortical intraoperative brain mapping (ioBM) in resective awake surgery of low-grade gliomas (LGG) of the right non-dominant hemisphere (RndH). It was estimated how ioBM may affect both the extent of resection and postoperative outcome of language, spatial cognition, social cognition, and executive functions including attention and working memory. Patients and Methods : Fifteen patients that underwent ioBM in resective awake surgery of LGG located on the RndH, were included. A cohort of 15 patients with the same tumour location operated under general anaesthesia without brain mapping was used as control. S…
Disrupting the right pars opercularis with electrical stimulation frees the song: case report
2015
International audience; The authors report the first case of a strikingly unusual speech impairment evoked by intraoperative electrostimulation in a 36-year-old right-handed patient, a well-trained singer, who underwent awake surgery for a right fronto-temporoinsular low-grade glioma. Functionally disrupting the pars opercularis of the right inferior frontal gyrus led the patient to automatically switch from a speaking to a singing mode of language production. Given the central role of the right pars opercularis in the inhibitory control network, the authors propose that this finding may be interpreted as possible evidence for a competitive and independent neurocognitive subnetwork devoted …
Repeated sugammadex reversal of muscle relaxation during lumbar spine surgery with intraoperative neurophysiological multimodal monitoring
2016
Intraoperative neurophysiological monitoring during spine surgery is usually acomplished avoiding muscle relaxants. A case of intraoperative sugammadex partial reversal of the neuromuscular blockade allowing adequate monitoring during spine surgery is presented. A 38 year-old man was scheduled for discectomy and vertebral arthrodesis throughout anterior and posterior approaches. Anesthesia consisted of total intravenous anesthesia plus rocuronium. Intraoperatively monitoring was needed, and the muscle relaxant reverted twice with low dose sugammadex in order to obtain adequate responses. The doses of sugammadex used were conservatively selected (0.1 mg/kg boluses increases, total dose neede…
A rare case of extra-intramedullary dorsal tanycitic ependymoma, radically removed with intraoperative neurophysiological monitoring
2015
Introduction: Tanycitic dorsal extra and intramedullary ependymoma is a rare form of tumor. From the histological point of view, these tumors show several aspects that make difficult the differential diagnosis from schwannomas and pilocytic astrocytomas. Tanycytic variant, often occurs in the thoracic tract of the spinal cord, and it is constituted by tanycites, that are typical elongated and bipolar cells that give to the tumor fibrillary aspects. Tanycitic variant has been recently characterized as a variant of ependymoma, since the 2000 World Health Organization (WHO) system. Case presentation: A 57 years old woman presented with intractable back pain often radiating to the left leg. Neu…
Transcutaneous sacral nerve stimulation for intraoperative verification of internal anal sphincter innervation.
2017
Background: The current standard for pelvic intraoperative neuromonitoring (pIONM) is based on intermittent direct nerve stimulation. This study investigated the potential use of transcutaneous sacral nerve stimulation for non‐invasive verification of pelvic autonomic nerves. Methods: A consecutive series of six pigs underwent low anterior rectal resection. For transcutaneous sacral nerve stimulation, an array of ten electrodes (cathodes) was placed over the sacral foramina (S2 to S4). Anodes were applied on the back, right and left thigh, lower abdomen, and intra‐anally. Stimulation using the novel method and current standard were performed at different phases of the experiment…
Preliminary experience with a transcranial magnetic resonance-guided focused ultrasound surgery system integrated with a 1.5-T MRI unit in a series o…
2018
OBJECTIVETranscranial magnetic resonance–guided focused ultrasound surgery (tcMRgFUS) is one of the emerging noninvasive technologies for the treatment of neurological disorders such as essential tremor (ET), idiopathic asymmetrical tremor-dominant Parkinson’s disease (PD), and neuropathic pain. In this clinical series the authors present the preliminary results achieved with the world’s first tcMRgFUS system integrated with a 1.5-T MRI unit.METHODSThe authors describe the results of tcMRgFUS in a sample of patients with ET and with PD who underwent the procedure during the period from January 2015 to September 2017. A monolateral ventralis intermedius nucleus (VIM) thalamic ablation was pe…