Publications by authors named "Leandro Viçosa Bonetti"

9 Publications

  • Page 1 of 1

Whole-body vibration therapy does not improve the peripheral nerve regeneration in experimental model.

J Musculoskelet Neuronal Interact 2021 03;21(1):68-78

Post graduation Program in Neuroscience, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Rio Grande do Sul, Brazil.

Objectives: Whole-body vibration (WBV) is commonly used to improve motor function, balance and functional performance, but its effects on the body are not fully understood. The main objective was to evaluate the morphometric and functional effects of WBV in an experimental nerve regeneration model.

Methods: Wistar rats were submitted to unilateral sciatic nerve crush and treated with WBV (4-5 weeks), started at 3 or 10 days after injury. Functional performances were weekly assessed by sciatic functional index, horizontal ladder rung walking and narrow beam tests. Nerve histomorphometry analysis was assessed at the end of the protocol.

Results: Injured groups, sedentary and WBV started at 3 days, had similar functional deficits. WBV, regardless of the start time, did not alter the histomorphometry parameters in the regeneration process.

Conclusions: The earlier therapy did not change the expected and natural recovery after the nerve lesion, but when the WBV starts later it seems to impair function parameter of recovery.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8020024PMC
March 2021

Changes in Oxyhemoglobin Concentration in the Prefrontal Cortex during Cognitive-Motor Dual Tasks in People with Chronic Obstructive Pulmonary Disease.

COPD 2020 06 22;17(3):289-296. Epub 2020 May 22.

Physical Therapy, University of Toronto, Toronto, Ontario, Canada.

Cognitive and motor impairment are well documented in chronic obstructive pulmonary disease (COPD) patients, but their relationship has not been studied. This study evaluated and compared cognitive and motor performance during dual tasks and related dorsolateral prefrontal cortex (PFC) changes in oxygenated hemoglobin (ΔOHb), a proxy measure of neural activity, in patients with COPD and age-matched healthy individuals. Participants performed three single tasks: (1) backwards spelling cognitive task; (2) 30 m preferred paced walk; (3) 30 m fast walk, and two dual tasks: (4) preferred paced walk + backwards spelling; (5) fast paced walk + backwards spelling. The ΔOHb from left and right dorsolateral PFC were measured using functional near-infrared spectroscopy. Gait velocity was measured using a Zeno walkway. Compared to healthy adults ( = 20), patients with COPD ( = 15) had higher ΔOHb during single preferred (-0.344 ± 0.185 vs. 0.325 ± 0.208 µM;  = 0.011) and fast paced walk (-0.249 ± 0.120 vs. 0.486 ± 0.182 µM;  = 0.001) in right PFC. Among healthy adults, ΔOHb were higher bilaterally during preferred paced walking dual versus single task (right: 0.096 ± 0.159 vs. -0.344 ± 0.185 µM,  = 0.013; left: 0.114 ± 0.150 vs. -0.257 ± 0.175 µM,  = 0.049) and in right PFC during fast walking dual versus single task (0.102 ± 0.228 vs. -0.249 ± 0.120,  = 0.021). Patients with COPD did not increase OHb during dual versus single tasks. Patients with COPD exhibited slower velocity than older adults during all walking tasks. The lack of further increase in OHb from single to dual tasks in patients with COPD, may indicate reduced cognitive-motor capacity and contribute to poorer motor performance limiting safe ambulation. Dual tasking rehabilitation may improve neural efficiency to offset these risks.
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http://dx.doi.org/10.1080/15412555.2020.1767561DOI Listing
June 2020

The effect of mental tracking task on spatiotemporal gait parameters in healthy younger and middle- and older aged participants during dual tasking.

Exp Brain Res 2019 Dec 26;237(12):3123-3132. Epub 2019 Sep 26.

Department of Physical Therapy, University of Toronto, Toronto, ON, Canada.

To evaluate the effect of dual tasking that combines walking with a mental tracking task on spatiotemporal gait parameters in younger and older adults. After completing the International Physical Activity Questionnaire (IPAQ), participants performed single tasks: preferred paced walk (PPW); fast paced walk (FPW); single-leg stance (SLS); spelling backwards cognitive task (CT). Thereafter, dual tasks: PPW + CT; FPW + CT; SLS + CT. Spatiotemporal gait parameters and the durations of SLS and SLS + CT were measured. Twenty younger and 20 older adults participated. The IPAQ scores were similar in both groups. Compared to the single task, stride length was shorter, stride time was longer, and stride length and time variability were higher during the PPW and FPW dual tasks in both groups. Older age was associated with shorter stride length during PPW and FPW, and longer stride time during FPW dual compared to single tasks. The older group exhibited shorter times during SLS and SLS + CT compared to younger group. Despite similar self-reported fitness, older age is associated with shorter stride length and longer stride time during FPW dual tasks as well as short times during SLS + CT, which may indicate diminished balance and posture stability.
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http://dx.doi.org/10.1007/s00221-019-05659-zDOI Listing
December 2019

Oxyhemoglobin changes in the prefrontal cortex in response to cognitive tasks: a systematic review.

Int J Neurosci 2019 Feb 31;129(2):195-203. Epub 2018 Oct 31.

a Department of Physical Therapy , University of Toronto , Toronto, ON , Canada.

Purpose Of The Study: the aim of this study was to synthesize PFC fNIRS outcomes on the effects of cognitive tasks compared to resting/baseline tasks in healthy adults from studies utilizing a pre/post design.

Material And Methods: original research studies were searched from seven databases (MEDLINE, EMBASE, CENTRAL, CINAHL, SCOPUS, PEDro and PubMed). Subsequently, two independent reviewers screened the titles and abstracts followed by full-text reviews to assess the studies' eligibility.

Results: eleven studies met the inclusion criteria and had data abstracted and quality assessed. Methodology varied considerably and yet cognitive tasks resulted in the ΔOHb increasing in 8 of the 11 and ΔHHb decreasing in 8 of 8 studies that reported this outcome. The cognitive tasks from 10 of the 11 studies were classified as "Working Memory" and "Verbal Fluency Tasks".

Conclusions: although, the data comparison was challenging provided the heterogeneity in methodology, the results across studies were similar.
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http://dx.doi.org/10.1080/00207454.2018.1518906DOI Listing
February 2019

The Effects of Two Different Exercise Programs on the Ultrastructural Features of the Sciatic Nerve and Soleus Muscle After Sciatic Crush.

Anat Rec (Hoboken) 2017 Sep 12;300(9):1654-1661. Epub 2017 May 12.

Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, RS, Brazil.

Peripheral nerve injuries constitute a significant medical problem and the recovery is critically dependent on post-injury treatment. In this study, following sciatic nerve crush, we investigated the effects of a 4-week endurance training program (ET) and balance and coordination training program (BCT) on the ultrastructural features of the sciatic nerve and soleus muscle. The animals were randomly divided into Sham, non-trained (NT), ET, and BCT groups each of which included three animals. Ultra-thin cross and longitudinal sections (70-85 nm) were digitized and analyzed comparatively. The electron micrographic analysis of the sciatic nerve showed similar organelles features in the injury groups (myelin debris and swelling mitochondria). Nonetheless, the ET group presented better ultrastructural features as demonstrated by the greater predominance of rounded fibers and more defined organization in the myelinated axon bundles. In the soleus muscle's analyses, the injured groups demonstrated similar organelles' features (nucleus contained highly heterochromatic nuclei and smaller mitochondria). However, ET and BCT groups showed apparently enlarged myofibril cross-sectional areas and less collagen around muscle fibers, although, the ET group displayed reduced intermyofibrillar spaces and more closely aligned myofilaments when compared with the BCT group. Based on electron micrographic analysis, our findings suggest the presence of ultrastructural differences between the Sham, NT, and the trained groups. Therefore, exercise type seems to be responsible for producing some different positive features in the trained groups, while ET seems to have a more pronounced influence on the ultrastructural features of the sciatic nerve and the soleus muscle after a crush injury. Anat Rec, 300:1654-1661, 2017. © 2017 Wiley Periodicals, Inc.
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http://dx.doi.org/10.1002/ar.23611DOI Listing
September 2017

Balance and coordination training, but not endurance training, enhances synaptophysin and neurotrophin-3 immunoreactivity in the lumbar spinal cord after sciatic nerve crush.

Muscle Nerve 2016 Apr 29;53(4):617-25. Epub 2015 Dec 29.

Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.

Introduction: Numerous rehabilitation treatments have been shown to be useful for peripheral and central restoration after (PNI).

Methods: After sciatic nerve crush, we investigated 4 weeks of endurance training (ET) and balance and coordination training (BCT) with sciatic function index, hind-paw stride length, and spinal cord dorsal horn synaptophysin and neurotrophin-3 immunoreactivity.

Results: Our results demonstrated no significant differences between the non-trained (NT), ET, and BCT groups in sciatic functional index, and in stride-length analysis, but the ET showed higher values compared with the NT group. Synaptophysin immunoreactivity was higher in the BCT group compared with the NT group, and neurotrophin-3 immunoreactivity in the BCT group was greater compared with the other groups.

Conclusion: BCT can positively affect spinal cord plasticity after a (PNI), and these modifications are important in the rehabilitation process.
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http://dx.doi.org/10.1002/mus.24889DOI Listing
April 2016

Balance and coordination training and endurance training after nerve injury.

Muscle Nerve 2015 Jan 19;51(1):83-91. Epub 2014 Nov 19.

Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rio Grande do Sul, Brazil; Laboratório de Histofisiologia Comparada, Departamento de Ciências Morfológicas, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Sarmento Leite 500, CEP: 90050-170, Porto Alegre, Rio Grande do Sul, Brazil.

Introduction: Different rehabilitation treatments have proven useful in accelerating regeneration.

Methods: After sciatic nerve crush in rats, we tested balance and coordination training (BCT) and endurance training (ET) through sensorimotor tests and analyzed nerve and muscle morphology.

Results: After BCT and ET, rats performed better in sensorimotor tests than did non-trained animals. However, only BCT maintained sensorimotor function during training. Furthermore, BCT and ET produced significantly larger muscle area than in non-trained animals.

Conclusions: These findings indicate that BCT and ET, when initiated in the early phase after sciatic nerve injury, improve morphological properties of the soleus muscle and sciatic nerve, but only the task-oriented BCT maintained sensorimotor function. The success of rehabilitative strategies appears to be highly task-specific, and strategies that stimulate sensory pathways are the most effective in improving balance and/or coordination parameters.
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http://dx.doi.org/10.1002/mus.24268DOI Listing
January 2015

Balance and coordination training after sciatic nerve injury.

Muscle Nerve 2011 Jul 12;44(1):55-62. Epub 2011 Apr 12.

Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.

Introduction: Numerous therapeutic interventions have been tested to enhance functional recovery after peripheral nerve injuries.

Methods: After sciatic nerve crush in rats we tested balance and coordination and motor control training in sensorimotor tests and analyzed nerve and muscle histology.

Results: The balance and coordination training group and the sham group had better results than the sedentary and motor control groups in sensorimotor tests. The sham and balance and coordination groups had a significantly larger muscle area than the other groups, and the balance and coordination group showed significantly better values than the sedentary and motor control groups for average myelin sheath thickness and g-ratio of the distal portion of the nerve.

Conclusions: The findings indicate that balance and coordination training improves sciatic nerve regeneration, suggesting that it is possible to revert and/or prevent soleus muscle atrophy and improve performance on sensorimotor tests.
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http://dx.doi.org/10.1002/mus.21996DOI Listing
July 2011

Effect of treadmill exercise on serotonin immunoreactivity in medullary raphe nuclei and spinal cord following sciatic nerve transection in rats.

Neurochem Res 2010 Mar 23;35(3):380-9. Epub 2009 Sep 23.

Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.

The serotoninergic system modulates nociceptive and locomotor spinal cord circuits. Exercise improves motor function and changes dopaminergic, noradrenergic, and serotonergic central systems. However, the direct relationship between serotonin, peripheral nerve lesion and aerobic treadmill exercise has not been studied. Using immunohistochemistry and optic densitometry, this study showed that the sciatic nerve transection increased the serotoninergic immunoreactivity in neuronal cytoplasm of the magnus raphe nuclei of trained and sedentary rats. In the dorsal raphe nucleus the increase only occurred in sedentary-sham-operated rats. In the spinal cord of trained, transected rats, the ventral horn showed significant changes, while the change in dorsal horn was insignificant. Von Frey's test indicated analgesia in all exercise-trained rats. The sciatic nerve functional index indicated recovery in the trained group. Thus, both the aerobic treadmill exercise training and the nervous lesion appear to contribute to changes in serotonin immunoreactivity.
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http://dx.doi.org/10.1007/s11064-009-0066-xDOI Listing
March 2010