scholarly journals An Engineering Model to Test for Sensory Reweighting: Nonhuman Primates Serve as a Model for Human Postural Control and Vestibular Dysfunction

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Lara A. Thompson ◽  
Csilla Haburcakova ◽  
Adam D. Goodworth ◽  
Richard F. Lewis

Quantitative animal models are critically needed to provide proof of concept for the investigation of rehabilitative balance therapies (e.g., invasive vestibular prostheses) and treatment response prior to, or in conjunction with, human clinical trials. This paper describes a novel approach to modeling the nonhuman primate postural control system. Our observation that rhesus macaques and humans have even remotely similar postural control motivates the further application of the rhesus macaque as a model for studying the effects of vestibular dysfunction, as well as vestibular prosthesis-assisted states, on human postural control. Previously, system identification methodologies and models were only used to describe human posture. However, here we utilized pseudorandom, roll-tilt balance platform stimuli to perturb the posture of a rhesus monkey in normal and mild vestibular (equilibrium) loss states. The relationship between rhesus monkey trunk sway and platform roll-tilt was determined via stimulus–response curves and transfer function results. A feedback controller model was then used to explore sensory reweighting (i.e., changes in sensory reliance), which prevented the animal from falling off of the tilting platform. Conclusions involving sensory reweighting in the nonhuman primate for a normal sensory state and a state of mild vestibular loss led to meaningful insights. This first-phase effort to model the balance control system in nonhuman primates is essential for future investigations toward the effects of invasive rehabilitative (balance) technologies on postural control in primates, and ultimately, humans.

1974 ◽  
Vol 11 (2) ◽  
pp. 165-171 ◽  
Author(s):  
F. W. Chandler ◽  
C. S. Callaway ◽  
S. R. Adams

A juvenile Rhesus monkey died suddenly while being conditioned for tissue culture studies. A diagnosis of necrotizing pancreatitis associated with adenovirus was made on the basis of the demonstration by electron microscopy of paracrystalline arrays of viral particles and granular and fibrillar inclusions in necrotic pancreatic acinar cells. This is the first description of necrotizing pancreatitis in a nonhuman primate. Adenovirus should be considered in the etiology of pancreatitis in nonhuman primates.


CommonHealth ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 31-36
Author(s):  
Kwadwo Osei Appiah-Kubi ◽  
Anne Galgon ◽  
Ryan Tierney ◽  
Richard Lauer ◽  
W. Geoffrey Wright

Background: Postural stability depends on the integration of multisensory inputs to drive motor outputs. When visual and somatosensory input is available and reliable, this reduces the postural control system’s reliance on the vestibular system. Despite this, vestibular loss can still cause severe postural dysfunction (1,2). Training one or more of the three sensory systems can alter sensory weighting and change postural behavior. Vestibular activation exercises, including horizontal and vertical headshaking, influence vestibular-ocular and -motor responses and have been showed to be effective in vestibular rehabilitation (3–8).   Purpose/Hypothesis: To assess sensory reweighting of postural control processing and vestibular-ocular and -motor responses after concurrent vestibular activation with postural training. It was hypothesized that the effect of this training would significantly alter the pattern of sensory weighting by changing the ratio of visual, somatosensory and vestibular dependence needed to maintain postural stability, and significantly decrease vestibular responses. Methods: Forty-two young healthy individuals (22 females; 23.0+3.9 years; 1.6+0.1 meters) were randomly assigned into four groups: 1) visual feedback weight shift training (WST) coupled with an active horizontal headshake (HHS), 2) same WST with vertical headshake (VHS), 3) WST with no headshake (NHS) and 4) no training/headshake control (CTL) groups. The headshake groups performed an intensive body WST together with horizontal or vertical rhythmic headshake at 80 to 120 beats/minute. The NHS group performed the WST with no headshake while the controls did not perform any training. Five 15-minute training sessions were performed on consecutive days for one week with the weight shift exercises involving upright limits of stability activities on a flat surface, foam or rocker board (Fig. 1). All groups performed baseline- and post-assessments including sensory organization test (SOT) and force platform ramp perturbations, coupled with electromyographic (EMG) recordings. A video head impulse test was also used to record horizontal vestibulo-ocular reflex (VOR) gain. A between- and within-group repeated measures ANOVA was used to analyze five COP sway variables, the equilibrium and composite scores and sensory ratios of the SOT as well as EMG signals and horizontal VOR gain. Similarly, COP variables, EMG, as well as vestibular reflex data (vertical VOR, vestibulo-collic reflex [VCR] and vestibulo-spinal [VSR] gains) during ramp perturbations were analyzed. Alpha level was set at p<.05. Results: The training showed a significant somatosensory downweighting (p=.050) in the headshake groups compared to the other groups. Training also showed significant decreased horizontal VOR gain (p=.040), faster automatic postural response (p=.003) (Figs. 2-4) with improved flexibility (p=.010) in the headshake groups. Muscle activation pattern in medial gastrocnemius (p=.033) was significantly decreased in the headshake. Conclusion: The concurrent vestibular activation and weight shift training modifies vestibular-dependent responses after the training intervention as evidenced in somatosensory downweighting, decreased VOR gain, better postural flexibility and faster automatic postural response. Findings suggest this is predominantly due to vestibular adaptation and habituation of VOR, VCR and VSR which induced sensory reweighting. Clinical relevance: Findings may be used to guide the development of a vestibular-postural rehabilitation intervention in impaired neurological populations, such as with vestibular disorders or sensory integration problems.


Author(s):  
Lara A. Thompson ◽  
Csilla Haburcakova ◽  
Richard F. Lewis

The purpose of this paper is to describe novel experiments and methodologies utilizing a distinctive balance platform system to investigate postural responses for moderate to severe vestibular loss and invasive vestibular prosthesis-assisted nonhuman primates (rhesus monkeys). For several millions of vestibular loss sufferers in the U.S., daily living is severely affected in that common everyday tasks, such as getting out of bed at night, maintaining balance on a moving bus, or walking on an uneven surface, may cause a loss of stability leading to falls and injury. Aside from loss of balance, blurred vision and vertigo (perceived spinning sensation) are also debilitating in vestibular-impaired individuals. Although the need for vestibular rehabilitative solutions is apparent, postural responses for a broad range of peripheral vestibular function, and for various stationary and moving support conditions, have not been systematically investigated. For the investigation of implants and prostheses that are being developed toward implementation in humans, nonhuman primates are a key component. The measurement system used in this research was unique. Our platform system facilitated the study of rhesus monkey posture for stationary support surface conditions (quiet stance and head turns) and for dynamic support surface conditions (pseudorandom roll tilts of the support surface). Further, the platform system was used to systematically study postural responses that will serve as baseline measures for future vestibular-focused human and nonhuman primate posture studies.


2008 ◽  
Vol 51 (3) ◽  
pp. 129-137 ◽  
Author(s):  
Jitka Jančová

Past studies of postural control during standing have employed wide range of procedures including the outcome measures use to quantify postural control, the duration of the sample collected, sampling frequency and methods for data processing. Due to these differences there remains little, if any, common grounds for comparisons between studies to establish a concrete understanding of the features and bouns which characterize normal healthy postural control. This article deals with terms such as reliability and repeatability of stabilometric measurements, stabilometric data quantification and analysis. To clear up those terms is suggested, by the author of this paper, very important. The stabilometric measurements remain, nevertheless, different when dealing with aging adults. Though, we notes some alterations of the aging systems, this article is not entirely dedicated to the seniors population. Measurements of COP and technical notes remain the main axis of present paper.


2019 ◽  
Vol 7 (2) ◽  
pp. 61-68
Author(s):  
Igor E. Nikityuk ◽  
Elizaveta L. Kononova ◽  
Maksim S. Nikitin ◽  
Konstantin A. Afonichev

Relevance. Treatment of children with post-burn foot deformities is an important task of reconstructive plastic surgery. The scars formed on the back surface of the feet, even with adequate surgical approach, in the acute period of thermal injury, further often lead to deformities of the entire foot, which leads to a derangement of its support function. The importance of the problem lies in the fact that with the growth of the child, secondary abnormal changes develop on the part of the joints of the lower extremities and the spine, leading to impaired locomotor function, including deviations in the body balance control system. Purpose of the study. To study postural stability in children with post-burn foot deformities before and after surgical treatment. Material and methods. The stabilometric study was conducted in 12 patients with post-burn cicatricial foot deformity, the average age of the patients was 9.8 ± 0.93 years old. The control group consisted of 12 children of the same age with no signs of orthopedic abnormality. To assess the results, the methods of descriptive statistics with the inclusion of correlation and regression analysis were used. Results. In patients with post-burn cicatricial deformity of the foot at the pre-treatment stage, a compensatory redistribution of the static load towards the intact lower limb was revealed. Analysis of postural control indicators in patients of the main group showed an abnormal increase in the synchronization of the system of body balance control. After reconstructive operations on the affected foot, symmetry of the distribution of the load and restoration of the support of the limb of the affected side were noted. Correlation analysis revealed a pronounced decrease in abnormal hypersynchronization between stabilometric parameters, which may indicate a trend towards normalization of the postural control strategy in patients after treatment. Conclusion. Elimination of post-burn foot deformity contributed to the restoration of its anatomical shape and was accompanied by pronounced positive dynamics in the state of the system of vertical balance of the patient’s body.


2021 ◽  
Vol 30 (1) ◽  
pp. 55-60
Author(s):  
Julia Fischer

Studies of nonhuman primate communication are often motivated by the desire to shed light on the evolution of speech. In contrast to human speech, the vocal repertoires of nonhuman primates are evolutionarily highly conserved. Within species-specific constraints, calls may vary in relation to the internal state of the caller or social experience. Receivers can use signalers’ calls to predict upcoming events or behavioral dispositions. Yet nonhuman primates do not appear to express or comprehend communicative or informative intent. Signalers are sensitive to the relation between their own actions and receivers’ responses, and thus, signaling behavior can be conceived as goal directed. Receivers’ ability to integrate information from multiple sources renders the system flexible and powerful. Researchers who take a linguistic or biological perspective on nonhuman primate communication should be aware of the strengths and limitations of their approaches. Both benefit from a focus on the mechanisms that underpin signaling and responses to signals.


2016 ◽  
Vol 21 (4) ◽  
pp. 195-202 ◽  
Author(s):  
Jessica Vitkovic ◽  
Carmen Le ◽  
Su-Ling Lee ◽  
Ross A. Clark

This study investigated the hypothesis that a hearing ‘map' of our surroundings is used to maintain balance control. We investigated the effects of sound on postural sway using centre of pressure analysis in 50 subjects with normal hearing, 28 with hearing loss and 19 with vestibular dysfunction. The acoustic environments utilized sound cues that were either present or absent. It was found that auditory cues are utilized by subjects with normal hearing to improve postural sway. The ability to utilize sound for postural control is diminished when there is a hearing loss, but this appears to be overcome by the use of a hearing aid. Patients with additional vestibular deficits exploit auditory cues to a greater degree, suggesting that sensory weighting to enhance the use of auditory cues may be applied when there is diminished sensory redundancy.


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