An fMRI-compatible force measurement system for the evaluation of the neural correlates of step initiation

Lima‐Pardini, Andrea Cristina de; Neto, Raymundo Mac Hado De Azevedo; Coelho, Daniel Boari; Boffino, Catarina Costa; Shergill, Sukhwinder S.; Souza, Carolina de; Brant, Rachael; Barbosa, Egberto Reis; Cardoso, Ellison Fernando; Teixeira, Luís Augusto; Cohen, Rajal G.; Horak, Fay B.; Amaro, Edson

doi:10.1038/srep43088

Cited by 34 publications

(55 citation statements)

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“…29 On the third day, individuals performed the leglifting task in an event-related fMRI to assess APA, as previously published. 12 Amplitude and duration of APAs and brain activation (BOLD signal) were recorded during the leg-lifting task. See Supplementary Material for a detailed description of the assessments.…”

Section: Study Proceduresmentioning

confidence: 99%

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A Randomized, Controlled Trial of Exercise for Parkinsonian Individuals With Freezing of Gait

et al. 2020

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Background Exercises with motor complexity induce neuroplasticity in individuals with Parkinson's disease (PD), but its effects on freezing of gait are unknown. The objective of this study was to verify if adapted resistance training with instability — exercises with motor complexity will be more effective than traditional motor rehabilitation — exercises without motor complexity in improving freezing‐of‐gait severity, outcomes linked to freezing of gait, and brain function. Methods Freezers were randomized either to the adapted resistance training with instability group (n = 17) or to the active control group (traditional motor rehabilitation, n = 15). Both training groups performed exercises 3 times a week for 12 weeks. The primary outcome was the New Freezing of Gait Questionnaire. Secondary outcomes were freezing of gait ratio (turning task), cognitive inhibition (Stroop‐III test), motor signs (Unified Parkinson's Disease Rating Scale part‐III [UPDRS‐III]), quality of life (PD Questionnaire 39), anticipatory postural adjustment (leg‐lifting task) and brain activation during a functional magnetic resonance imaging protocol of simulated anticipatory postural adjustment task. Outcomes were evaluated before and after interventions. Results Only adapted resistance training with instability improved all the outcomes (P < 0.05). Adapted resistance training with instability was more effective than traditional motor rehabilitation (in improving freezing‐of‐gait ratio, motor signs, quality of life, anticipatory postural adjustment amplitude, and brain activation; P < 0.05). Our results are clinically relevant because improvement in the New Freezing of Gait Questionnaire (−4.4 points) and UPDRS‐III (−7.4 points) scores exceeded the minimally detectable change (traditional motor rehabilitation group data) and the moderate clinically important difference suggested for PD, respectively. The changes in mesencephalic locomotor region activation and in anticipatory postural adjustment amplitude explained the changes in New Freezing of Gait Questionnaire scores and in freezing‐of‐gait ratio following adapted resistance training with instability, respectively. Conclusions Adapted resistance training with instability is able to cause significant clinical improvement and brain plasticity in freezers. © 2020 International Parkinson and Movement Disorder Society

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Section: Study Proceduresmentioning

confidence: 99%

“…11 Taken together, these results suggest that increasing MLR activation during APAs could decrease FOG severity. To verify MLR activation during APAs, we used a leg-lifting task in an event-related fMRI protocol that was recently validated by our group 12 as having characteristics similar to step initiation.…”

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A Randomized, Controlled Trial of Exercise for Parkinsonian Individuals With Freezing of Gait

et al. 2020

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“…Other studies have demonstrated that during static standing and in the step initiation, the mediolateral center of pressure displacement is greater than the anteroposterior direction. 9,32 Thus, the greater MDC on MLSI observed in the present study may be explained by changes in compensatory mechanisms (eg, anticipatory postural adjustment) that patients with PD perform in an automated manner 32,33 to counterbalance the effects of reductions in APSI. 9,31 In contrast, during unstable conditions also performed in the force platform (eg, AMTI), previous studies showed opposite results.…”

Section: Discussionmentioning

confidence: 63%

Minimal Detectable Change for Balance Using the Biodex Balance System in Patients with Parkinson Disease

Lira

Ugrinowitsch

Fecchio

et al. 2019

PM&R

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Background Minimal detectable change (MDC) when assessing balance using the Biodex Balance System (BBS) in patients with Parkinson disease (PD) is currently unknown, limiting the interpretability of the scores. Objective To determine the MDC on the Anterior/Posterior Stability Index (APSI), Medial/Lateral Stability Index (MLSI), and Overall Stability Index (OSI) from postural stability and fall risk protocols of the BBS in patients with PD. Design This was a repeated‐measures design (at a 1‐week interval). Setting Strength training laboratory of a public university. Patients 46 patients with PD (men and women) at stages 2 and 3 (67.9 ± 7.4 years old) were assessed in the “on” state (fully medicated). Methods Patients performed three trials of 20 s for each protocol. Main Outcome Measurements Absolute and relative MDC (MDC%) calculated for APSI, MLSI, and OSI from the postural stability (stable condition) and fall risk protocols (unstable condition). Results For the postural stability, the MDC and MDC% were 0.26° and 17% for APSI, 0.41° and 21% for MLSI, and 0.22° and 12% for OSI, respectively. For the fall risk, the MDC and MDC% were 0.51° and 18% for APSI, 0.21° and 15% for MLSI, and 0.41° and 20% for OSI, respectively. These results were considered acceptable, despite indices with high MDC for MLSI (postural stability) and APSI (fall risk). Conclusions Patients with PD have more mediolateral and anteroposterior changes in the stable and unstable conditions, respectively. These abnormal balance strategies can occur principally due to postural instability of PD. However, our results demonstrated acceptable MDCs in both conditions in all of the assessed axes. Thus, BBS should be incorporated into the clinical evaluation to help therapists to determine if intervention‐induced changes in balance are clinically significant or due to measurement error. Level of Evidence II

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“…2009 a ; de Lima‐Pardini et al . 2017) have been related to disorders of frontocortical areas, which may be more affected in freezers than in non‐freezers because freezers have lower activity of the supplementary motor area than non‐freezers (Butler et al . 2017).…”

Section: Introductionmentioning

confidence: 99%

Loss of presynaptic inhibition for step initiation in parkinsonian individuals with freezing of gait

Lira

Ugrinowitsch

Coelho

et al. 2020

The Journal of Physiology

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Key pointsr Individuals with freezing of gait (FoG) due to Parkinson's disease (PD) have small and long anticipatory postural adjustments (APAs) associated with delayed step initiation.r Individuals with FoG ('freezers') may require functional reorganization of spinal mechanisms to perform APAs due to supraspinal dysfunction. As presynaptic inhibition (PSI) is centrally modulated to allow execution of supraspinal motor commands, it may be deficient in freezers during APAs.r We show that freezers presented PSI in quiet stance (control task), but they presented loss of PSI (i.e. higher ratio of the conditioned H-reflex relative to the test H-reflex) during APAs before step initiation (functional task), whereas non-freezers and healthy control individuals presented PSI in both the tasks.r The loss of PSI in freezers was associated with both small APA amplitudes and FoG severity. r We hypothesize that loss of PSI during APAs for step initiation in freezers may be due to FoG.Abstract Freezing of gait (FoG) in Parkinson's disease involves deficient anticipatory postural adjustments (APAs), resulting in a cessation of step initiation due to supraspinal dysfunction. Individuals with FoG ('freezers') may require functional reorganization of spinal mechanisms to perform APAs. As presynaptic inhibition (PSI) is centrally modulated to allow execution of supraspinal motor commands, here we hypothesized a loss of PSI in freezers during APA for Jumes Lira is a Master's researcher of the Exercise Neuroscience Research Group, School of Arts, Sciences and Humanities, University of São Paulo, Brazil. His work has focused on understanding the spinal inhibitory mechanisms in Parkinson's disease using neurophysiological approaches. More specifically, he is interested in identifying alterations in spinal pathways related to freezing of gait of Parkinson's disease during functional tasks, leading to the development of mechanistic-based interventions for physical therapy. others J Physiol 598.8step initiation, which would be associated with FoG severity. Seventy individuals [27 freezers, 22 non-freezers, and 21 age-matched healthy controls (HC)] performed a 'GO'-commanded step initiation task on a force platform under three conditions: (1) without electrical stimulation, (2) test Hoffman reflex (H-reflex) and (3) conditioned H-reflex. They also performed a control task (quiet stance). In the step initiation task, the H-reflexes were evoked on the soleus muscle when the amplitude of the APA exceeded 10-20% of the mean baseline mediolateral force. PSI was quantified by the ratio of the conditioned H-reflex relative to the test H-reflex in both the tasks. Objective assessment of FoG severity (FoG-ratio) was performed. Freezers presented lower PSI levels during quiet stance than non-freezers and HC (P < 0.05). During step initiation, freezers presented loss of PSI and lower APA amplitudes than non-freezers and HC (P < 0.05). Significant correlations were only found for freezers between loss of PSI and FoG-ratio (r = 0.59, P = 0.0005) and los...

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An fMRI-compatible force measurement system for the evaluation of the neural correlates of step initiation

Cited by 34 publications

References 56 publications

A Randomized, Controlled Trial of Exercise for Parkinsonian Individuals With Freezing of Gait

A Randomized, Controlled Trial of Exercise for Parkinsonian Individuals With Freezing of Gait

Minimal Detectable Change for Balance Using the Biodex Balance System in Patients with Parkinson Disease

Loss of presynaptic inhibition for step initiation in parkinsonian individuals with freezing of gait

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