scholarly journals MR-safe multisegmental vibration device for cortical mapping of paraspinal afferent input

2021 ◽  
Author(s):  
Louis Schibli ◽  
Robert Gandia ◽  
Roger Buck ◽  
Philipp Staempfli ◽  
Michael Meier ◽  
...  
Keyword(s):  
Afferent Input ◽  
Cortical Mapping ◽  
Vibrotactile Stimulation ◽  
Stimulation Parameters ◽  
Mr Safe

<p>The objective of this study was to develop an MR-safe stimulation device (pneumatic vibration device, pneuVID) that can apply vibrotactile stimulation to different thoracolumbar segments and to characterize stimulation parameters such as the amplitude and its stability for two relevant frequencies (20Hz/80Hz). This is the first apparatus specifically designed for paraspinal tissue vibration on different segmental levels in an MR environment. </p>

scholarly journals MR-safe multisegmental vibration device for cortical mapping of paraspinal afferent input

2021 ◽  
Author(s):  
Louis Schibli ◽  
Robert Gandia ◽  
Roger Buck ◽  
Philipp Staempfli ◽  
Michael Meier ◽  
...  
Keyword(s):  
Afferent Input ◽  
Cortical Mapping ◽  
Vibrotactile Stimulation ◽  
Stimulation Parameters ◽  
Mr Safe

<p>The objective of this study was to develop an MR-safe stimulation device (pneumatic vibration device, pneuVID) that can apply vibrotactile stimulation to different thoracolumbar segments and to characterize stimulation parameters such as the amplitude and its stability for two relevant frequencies (20Hz/80Hz). This is the first apparatus specifically designed for paraspinal tissue vibration on different segmental levels in an MR environment. </p>

Sympathetic responses to cardiopulmonary vagal afferent stimulation during development

1999 ◽  
Vol 277 (4) ◽  
pp. H1311-H1316 ◽  
Author(s):  
David C. Merrill ◽  
Jeffrey L. Segar ◽  
Oliva J. McWeeny ◽  
Jean E. Robillard
Keyword(s):  
Afferent Input ◽  
Afferent Stimulation ◽  
Renal Sympathetic Nerve Activity ◽  
Stimulation Parameters ◽  
Vagal Afferent ◽  
Delayed Maturation ◽  
Frequency Of Stimulation ◽  
One Way Anova ◽  
Renal Sympathetic

Previous work in our laboratory has demonstrated impairment of cardiopulmonary reflex control of renal sympathetic nerve activity (RSNA) during the newborn period. The present study was designed to test the hypothesis that this delayed maturation is secondary to incomplete central integration of vagal afferent input. Term fetal (135–140 days; n = 6), newborn (3–7 days of age; n = 8), and young adult (6–8 wk old; n = 8) sheep anesthetized with α-chloralose underwent vagal afferent nerve stimulation. All animals had undergone prior sinoaortic denervation to eliminate influences from the arterial baroreceptors. After determination of optimal stimulation parameters, RSNA responses to gradual increases in stimulation frequency (1.0–16 Hz) were recorded and compared by one-way ANOVA. RSNA decreased progressively with increased frequency of stimulation in all three groups of animals. When comparing the three groups at any given frequency of stimulation, reflex withdrawal of RSNA tended to be more pronounced in newborn lambs ( P< 0.05 for 1 and 4 Hz). Heart rate (HR) was also noted to decrease significantly with vagal afferent stimulation in each of the groups, but no significant differences in the reflex decreases in HR were noted among the three groups of animals. These results demonstrate that central integration of vagal afferent input is intact in fetal and newborn sheep. These results suggest that the delayed maturation of cardiopulmonary reflex-mediated changes in RSNA seen early in development appears to depend on intrinsic alterations in baroreceptor function rather than incomplete central integration.

scholarly journals Six-Month Lower-Leg Sensory Stimulation Augments Neural Network Connectivity Associated With Improved Gait

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 960-961
Author(s):  
Chun Liang Hsu ◽  
Ikechukwu Iloputaife ◽  
Lars Oddsson ◽  
Brad Manor ◽  
Lewis Lipsitz
Keyword(s):  
Older Adults ◽  
Lower Limb ◽  
Network Connectivity ◽  
Lower Leg ◽  
Afferent Input ◽  
Brain Network ◽  
Community Dwelling ◽  
Vibrotactile Stimulation ◽  
Post Intervention ◽  
Brain Network Connectivity

Abstract Foot sole somatosensory impairment associated with peripheral neuropathy (PN) is prevalent and a strong independent risk factor for gait disturbance and falls in older adults. A lower-limb sensory prosthesis providing afferent input related to foot sole pressure distributions via lower-leg vibrotactile stimulation has been demonstrated to improve gait in people with PN. The effects of this device on brain function related to motor control, however, remains equivocal. This study aimed to explore changes in brain network connectivity after six months of daily use of the prosthesis among individuals with diagnosed PN and balance problems. Functional Gait Assessment (FGA) and resting-state functional magnetic resonance imaging were completed before and after the intervention. Preliminary analysis on participants who have completed the study to date (N=5; mean age 76 years) indicated altered connectivity of the sensorimotor network (SMN), frontoparietal network (FPN), and the default mode network (DMN) post-intervention (Z&gt;3.11, unadjusted p&lt;0.05). Participants displayed an average improvement of 5.5 point in the FGA (Minimal Clinically Important Differences&gt;4 for community-dwelling older adults) that was correlated with connectivity changes (unadjusted p&lt;0.05). Specifically, improved FGA was associated with: 1) increased connectivity between the SMN, cerebellum, and occipital cortex; 2) increased connectivity between the FPN, cerebellum, calcarine and intracalcarine; and 3) decreased connectivity between DMN and intracalcarine. These early findings suggest that long-term use of a lower-limb sensory prosthesis may induce neuroplastic changes in brain network connectivity reflecting enhanced bottom-up sensory-attentional processing and suppression of the DMN that are relevant to gait improvements among older adults with PN.

Functional PET scanning in the assessment of cerebral arteriovenous malformations

1990 ◽  
Vol 73 (4) ◽  
pp. 615-619 ◽  
Author(s):  
Richard Leblanc ◽  
Ernst Meyer
Keyword(s):  
Brain Lesion ◽  
Pet Scan ◽  
Cortical Mapping ◽  
Precentral Gyrus ◽  
Vibrotactile Stimulation ◽  
Content Type ◽  
Positron Emission ◽  
Pet Scanning ◽  
Contralateral Hand ◽  
Hand Region

✓ A case is presented which represents the first instance of the use of functional positron emission tomography (PET) scanning to precisely localize a structural brain lesion to the precentral gyrus, and the first validation of functional PET scanning by intraoperative cortical mapping. The lesion was a 3-cm arteriovenous malformation (AVM) that had produced a generalized seizure in an otherwise asymptomatic young woman. A first, resting H215O PET scan identified the AVM. A second PET scan, performed during vibrotactile stimulation of the contralateral hand, identified the somatosensory area of the hand region and localized the AVM to that part of the precentral gyrus immediately in front of it. This relationship and localization were confirmed by cortical mapping at the time of craniotomy under local anesthesia. Functional PET scanning may prove to be useful to localize cortical lesions precisely and to help in determining preoperatively the best form of treatment for lesions, especially AVM's, in functionally important cortex.

The limits of human performance

2008 ◽  
Vol 44 ◽  
pp. 11-26 ◽  
Author(s):  
Ralph Beneke ◽  
Dieter Böning
Keyword(s):  
Human Performance ◽  
Safety Margin ◽  
Afferent Input ◽  
Metabolic Energy ◽  
Human Organism ◽  
Mechanical Resistance ◽  
As Doping ◽  
Gene And Protein Expression ◽  
Underlying Mechanisms ◽  
Biochemical Research

Human performance, defined by mechanical resistance and distance per time, includes human, task and environmental factors, all interrelated. It requires metabolic energy provided by anaerobic and aerobic metabolic energy sources. These sources have specific limitations in the capacity and rate to provide re-phosphorylation energy, which determines individual ratios of aerobic and anaerobic metabolic power and their sustainability. In healthy athletes, limits to provide and utilize metabolic energy are multifactorial, carefully matched and include a safety margin imposed in order to protect the integrity of the human organism under maximal effort. Perception of afferent input associated with effort leads to conscious or unconscious decisions to modulate or terminate performance; however, the underlying mechanisms of cerebral control are not fully understood. The idea to move borders of performance with the help of biochemicals is two millennia old. Biochemical findings resulted in highly effective substances widely used to increase performance in daily life, during preparation for sport events and during competition, but many of them must be considered as doping and therefore illegal. Supplements and food have ergogenic potential; however, numerous concepts are controversially discussed with respect to legality and particularly evidence in terms of usefulness and risks. The effect of evidence-based nutritional strategies on adaptations in terms of gene and protein expression that occur in skeletal muscle during and after exercise training sessions is widely unknown. Biochemical research is essential for better understanding of the basic mechanisms causing fatigue and the regulation of the dynamic adaptation to physical and mental training.

Effects of Vibrotactile Stimulation for Sustaining Performance in a Vigilance Task: A Pilot Study

2011 ◽  
Author(s):  
G. Robert Arrabito ◽  
Geoffrey Ho ◽  
Behzad Aghaei ◽  
Catherine Burns ◽  
Ming Hou
Keyword(s):  
Pilot Study ◽  
Vigilance Task ◽  
Vibrotactile Stimulation

Prolongation of mechanical hyperalgesia by non nociceptive afferent input

2005 ◽  
Vol 32 (S 4) ◽  
Author(s):  
J Schattschneider ◽  
H.K Kim ◽  
J.M Chung ◽  
R Baron
Keyword(s):  
Afferent Input ◽  
Mechanical Hyperalgesia

Phosphene perceptions and safety of chronic visual cortex stimulation in a blind subject

2020 ◽  
Vol 132 (6) ◽  
pp. 2000-2007 ◽  
Author(s):  
Soroush Niketeghad ◽  
Abirami Muralidharan ◽  
Uday Patel ◽  
Jessy D. Dorn ◽  
Laura Bonelli ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Adverse Events ◽  
Clinical Intervention ◽  
Occipital Cortex ◽  
Neuronal Population ◽  
Serious Adverse Events ◽  
Stimulation Parameters ◽  
The Right ◽  
Visual Cortical ◽  
Stimulation Of

Stimulation of primary visual cortices has the potential to restore some degree of vision to blind individuals. Developing safe and reliable visual cortical prostheses requires assessment of the long-term stability, feasibility, and safety of generating stimulation-evoked perceptions.A NeuroPace responsive neurostimulation system was implanted in a blind individual with an 8-year history of bare light perception, and stimulation-evoked phosphenes were evaluated over 19 months (41 test sessions). Electrical stimulation was delivered via two four-contact subdural electrode strips implanted over the right medial occipital cortex. Current and charge thresholds for eliciting visual perception (phosphenes) were measured, as were the shape, size, location, and intensity of the phosphenes. Adverse events were also assessed.Stimulation of all contacts resulted in phosphene perception. Phosphenes appeared completely or partially in the left hemifield. Stimulation of the electrodes below the calcarine sulcus elicited phosphenes in the superior hemifield and vice versa. Changing the stimulation parameters of frequency, pulse width, and burst duration affected current thresholds for eliciting phosphenes, and increasing the amplitude or frequency of stimulation resulted in brighter perceptions. While stimulation thresholds decreased between an average of 5% and 12% after 19 months, spatial mapping of phosphenes remained consistent over time. Although no serious adverse events were observed, the subject experienced mild headaches and dizziness in three instances, symptoms that did not persist for more than a few hours and for which no clinical intervention was required.Using an off-the-shelf neurostimulator, the authors were able to reliably generate phosphenes in different areas of the visual field over 19 months with no serious adverse events, providing preliminary proof of feasibility and safety to proceed with visual epicortical prosthetic clinical trials. Moreover, they systematically explored the relationship between stimulation parameters and phosphene thresholds and discovered the direct relation of perception thresholds based on primary visual cortex (V1) neuronal population excitation thresholds.

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