Search results for " Neurophysiological"

Decreased lower limb muscle recruitment contributes to the inability of older adults to recover with a single step following a forward loss of balance

2013

In response to a balance disturbance, older individuals often require multiple steps to prevent a fall. Reliance on multiple steps to recover balance is predictive of a future fall, so studies should determine the mechanisms underlying differences between older adults who can and cannot recover balance with a single step. This study compared neural activation parameters of the major leg muscles during balance recovery from a sudden forward loss of balance in older individuals capable of recovering with a single step and those who required multiple steps to regain balance. Eighty-one healthy, community dwelling adults aged 70±3 participated. Loss of balance was induced by releasing participa…

Revision Rate of Misplaced Pedicle Screws of the Thoracolumbar Spine-Comparison of Three-Dimensional Fluoroscopy Navigation with Freehand Placement: …

2017

BACKGROUND Recent studies have shown higher accuracy rates of image-guided pedicle screw placement compared to freehand (FH) placement. However, data focusing on the impact of spinal navigation on the rate of revision surgeries caused by misplaced pedicle screws (PS) are scarce. OBJECTIVE This study is aimed at identifying the rate of revision surgeries for misplaced PS comparing three-dimensional (3D) fluoroscopy navigation (3DFL) with FH PS placement. METHODS A retrospective analysis was conducted of 2232 patients (mean age, 65.3 ± 13.5 years) with 13,703 implanted PS who underwent instrumentation of the thoracolumbar spine between 2007 and 2015. Group 1 received surgery with use of 3DFL …

The Etiology of Muscle Fatigue Differs between Two Electrical Stimulation Protocols

2016

International audience; Purpose: This study aimed at investigating the mechanisms involved in the force reduction induced by two electrical stimulation (ES) protocols that were designed to activate motor units differently. Methods: The triceps surae of 11 healthy subjects (8 men; age, similar to 28 yr) was activated using ES applied over the tibial nerve. Two ES protocols (conventional [CONV]: 20 Hz, 0.05 ms vs wide-pulse high-frequency [WPHF]: 80 Hz, 1 ms) were performed and involved 40 trains (6 s on-6 s off) delivered at an intensity (I-ES) evoking 20% of maximal voluntary contraction. To analyze the mechanical properties of the motor units activated at I-ES, force-frequency relation was…

Sevoflurane-induced reduction of bispectral index does not affect human cerebral microcirculation

2015

Contemporary spinal cord protection during thoracic and thoracoabdominal aortic surgery and endovascular aortic repair: a position paper of the vascu…

2015

Ischaemic spinal cord injury (SCI) remains the Achilles heel of open and endovascular descending thoracic and thoracoabdominal repair. Neurological outcomes have improved coincidentially with the introduction of neuroprotective measures. However, SCI (paraplegia and paraparesis) remains the most devastating complication. The aim of this position paper is to provide physicians with broad information regarding spinal cord blood supply, to share strategies for shortening intraprocedural spinal cord ischaemia and to increase spinal cord tolerance to transitory ischaemia through detection of ischaemia and augmentation of spinal cord blood perfusion. This study is meant to support physicians cari…

Extracorporeal Stimulation of Sacral Nerve Roots for Observation of Pelvic Autonomic Nerve Integrity: Description of a Novel Methodological Setup.

2017

Introduction: Neurophysiologic monitoring can improve autonomic nerve sparing during critical phases of rectal cancer surgery. Objectives: To develop a system for extracorporeal stimulation of sacral nerve roots. Methods: Dedicated software controlled a ten-electrode stimulation array by switching between different electrode configurations and current levels. A built-in impedance and current level measurement assessed the effectiveness of current injection. Intra-anal surface electromyography (sEMG) informed on targeting the sacral nerve roots. All tests were performed on five pig specimens. Results: During switching between electrode configurations, the system delivered 100% of the set cur…

Isolated Pediatric Intramedullary Schwannoma: Case Report and Review of Literature

2018

Background: Intramedullary (IM) schwannomas are rare entities representing 0.3%−1% of intramedullary tumors and 1.1% of spinal schwannomas. Beside many theories proposed, their rare occurrence might be related to the absence of Schwann cells in the spinal cord. Pediatric IM schwannomas are uncommon, and in the absence of neurofibromatosis they are extremely rare. To date, few cases have been reported in the literature. Case Description: We describe the case of an 8-year-old female affected by a progressive paraparesis. Neuroradiologic investigations showed an oval-shaped mass at the level of T10-T11. The patient underwent surgery, performed under neurophysiologic monitoring. The patient was…

Modeling the pelvic region for non-invasive pelvic intraoperative neuromonitoring

2016

Abstract Finite element analysis (FEA) of electric current distribution in the pelvis minor may help to assess the usability of non-invasive surface stimulation for continuous pelvic intraoperative neuromonitoring. FEA requires generation of quality volumetric tetrahedral mesh geometry. This study proposes the generation of a suitable mesh based on MRI data. The resulting volumetric mesh models the autonomous nerve structures at risk during total mesorectal excision. The model also contains the bone, cartilage, fat, skin, muscle tissues of the pelvic region, and a set of electrodes for surface stimulation. The model is ready for finite element analysis of the discrete Maxwell’s equations.

Navigated Transcranial Magnetic Stimulation Motor Mapping Usefulness in the Surgical Management of Patients Affected by Brain Tumors in Eloquent Area…

2021

Background: The surgical strategy for brain glioma has changed, shifting from tumor debulking to a more careful tumor dissection with the aim of a gross-total resection, extended beyond the contrast-enhancement MRI, including the hyperintensity on FLAIR MR images and defined as supratotal resection. It is possible to pursue this goal thanks to the refinement of several technological tools for pre and intraoperative planning including intraoperative neurophysiological monitoring (IONM), cortico-subcortical mapping, functional MRI (fMRI), navigated transcranial magnetic stimulation (nTMS), intraoperative CT or MRI (iCT, iMR), and intraoperative contrast-enhanced ultrasound. This systematic re…

EMERGING ROLE OF ULTRASOUND IMAGING ASSOCIATED TO CLINICAL NEUROPHYSIOLOGY AS A SUPPLEMENTARY DIAGNOSTICS TECHNIQUE OF PERIPHERAL NERVES PATHOLOGIES:…

2013

PURPOSE: to show the relevance of peripheral nerve ultrasound imaging as a supplementary technique in a clinical neurophysiological evaluation. METHODS: peripheral nerves ultrasound (US) examination was performed in patients with a medical history of nerve entrapment and/or post-traumatic neuropathy but with clinical or neurophysiological unusual findings. A 10-18 MHz transducer was used. RESULTS: we recruited 50 patients with clinical evidence of peripheral neuropathies (25M, 25F): 24 median nerves, 1 anterior interosseous, 14 ulnar, 3 brachial plexus, 2 posterior interosseus, 1 superficial radial, 1 superficial peroneal and 4 common peroneal nerves. Overall 20/50 patients had a history of…