An Evaluation of the Effect of Vision on Standing Stability in the Early Stage of Parkinson’s Disease

Mina, Mani; Karimi, Mohammad Taghi; Esrafilian, Amir

doi:10.1159/000497041

Cited by 7 publications

(6 citation statements)

References 25 publications

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“…This altered sensory weighting in PD could be a reflection of a 'feedforward' strategy to act on possible threats to posture, which would be of higher importance given their postural instability. This alteration in sensory weighting might not generalize to early PD 43 .…”

Section: Discussionmentioning

confidence: 89%

Strategic alterations of posture are delayed in Parkinson’s disease patients during deep brain stimulation

Patel

Nilsson

Rehncrona

et al. 2021

Sci Rep

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Parkinson’s disease (PD) is characterized by rigidity, akinesia, postural instability and tremor. Deep brain stimulation (DBS) of the subthalamic nucleus (STN) reduces tremor but the effects on postural instability are inconsistent. Another component of postural control is the postural strategy, traditionally referred to as the ankle or hip strategy, which is determined by the coupling between the joint motions of the body. We aimed to determine whether DBS STN and vision (eyes open vs. eyes closed) affect the postural strategy in PD in quiet stance or during balance perturbations. Linear motion was recorded from the knee, hip, shoulder and head in 10 patients with idiopathic PD with DBS STN (after withdrawal of other anti-PD medication), 25 younger adult controls and 17 older adult controls. Correlation analyses were performed on anterior–posterior linear motion data to determine the coupling between the four positions measured. All participants were asked to stand for a 30 s period of quiet stance and a 200 s period of calf vibration. The 200 s vibration period was subdivided into four 50 s periods to study adaptation between the first vibration period (30–80 s) and the last vibration period (180–230 s). Movement was recorded in patients with PD with DBS ON and DBS OFF, and all participants were investigated with eyes closed and eyes open. DBS settings were randomized and double-blindly programmed. Patients with PD had greater coupling of the body compared to old and young controls during balance perturbations (p ≤ 0.046). Controls adopted a strategy with greater flexibility, particularly using the knee as a point of pivot, whereas patients with PD adopted an ankle strategy, i.e., they used the ankle as the point of pivot. There was higher flexibility in patients with PD with DBS ON and eyes open compared to DBS OFF and eyes closed (p ≤ 0.011). During balance perturbations, controls quickly adopted a new strategy that they retained throughout the test, but patients with PD were slower to adapt. Patients with PD further increased the coupling between segmental movement during balance perturbations with DBS ON but retained a high level of coupling with DBS OFF throughout balance perturbations. The ankle strategy during balance perturbations in patients with PD was most evident with DBS OFF and eyes closed. The increased coupling with balance perturbations implies a mechanism to reduce complexity at a cost of exerting more energy. Strategic alterations of posture were altered by DBS in patients with PD and were delayed. Our findings therefore show that DBS does not fully compensate for disease-related effects on posture.

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Section: Discussionmentioning

confidence: 89%

Strategic alterations of posture are delayed in Parkinson’s disease patients during deep brain stimulation

Patel

Nilsson

Rehncrona

et al. 2021

Sci Rep

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“…Another problem with these basic posturographic measures is that they can inadvertently capture the amplitude of the COP displacement without enlightening COP control. A better understanding of postural control will require more advanced analytical methods, which will quantify the structure of the COP [8,9]. Spectral analysis of the COP has revealed that the frequency of HC and patients with neurodegenerative diseases is different.…”

Section: Introductionmentioning

confidence: 99%

Detection of postural control in early Parkinson’s disease: Clinical testing vs. modulation of center of pressure

Kamieniarz¹,

Michalska²,

Marszałek³

et al. 2021

PLoS ONE

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Introduction Little is known about the early stage balance changes in PD. Many clinicians assume that there are no postural issues in early PD because of failure to identify them on bedside and clinical testing. Here, we quantify balance changes in early and moderate stage PD and compared these values to healthy controls (HC) using clinical assessments of balance and posturography. Methods We compared 15 HC with 15 early PD (PD-II; Hoehn and Yahr stage II) and 15 moderate PD (PD-III; H&Y stage III). Participants performed various clinical tests of balance and a standing postural task on a force platform. We quantified the spatiotemporal parameters of the center of pressure (COP), the sample entropy and power spectral density (PSD) of the COP. Results The PSD of the COP differentiated PD-II from HC from 0–0.5 Hz and PD-II from PD-III from 0.5–1 Hz. Specifically, PD-II and PD-III manifested greater power than HC from 0–0.5 Hz, whereas PD-III exhibited greater power than PD-II and HC from 0.5–1.0 Hz (p<0.05). However, there were no significant differences between PD-II and HC in all clinical tests and in spatiotemporal parameters of the COP (p>0.05). Although the sample entropy was significantly lower in the PD groups (p<0.05), entropy failed to differentiate PD-II from PD-III. Conclusion The low-frequency modulation of the COP in this small cohort differentiated early PD from HC and from moderate PD. Clinicians should be aware that there are early balance deficits in PD. A larger sample size is needed to confirm these findings.

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“…Current evidence suggests PD patients exhibit larger angular and linear displacement and velocity of the trunk during static balance compared to elderly controls (5, 6). While vision affects sway amplitude and frequency (7, 8), the effects of PD on static balance performance are independent of visual condition (9–11). Additionally, in response to dynamic perturbations delivered to the trunk, PD patients show increased trunk displacement compared to elderly controls (12).…”

Section: Introductionmentioning

confidence: 99%

A Novel MRI Compatible Balance Simulator to Detect Postural Instability in Parkinson's Disease

et al. 2019

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Background: Postural instability is a debilitating and largely treatment-resistant symptom of Parkinson's disease (PD). A better understanding of the neural substrates contributing to postural instability could lead to new targets for improved pharmacological and neurosurgical interventions. However, investigating these neural substrates necessitates the use of functional MRI scanners, which are almost exclusively horizontally-based. Objective: We aimed to develop, and validate the use of, an MRI compatible balance simulator to study static and dynamic balance control in PD patients and elderly controls. Methods: Our MRI compatible balance simulator allowed participants to actively balance an inverted pendulum by activating postural muscles around the ankle joint while supine. Two studies were performed to compare static and dynamic balance performance between upright stance and simulated stance in PD patients and controls. Study 1 (14 PD; 20 controls) required participants to maintain static balance during upright and simulated stance for 120 s with eyes open and closed. In study 2 (20 PD; 22 controls) participants repeated the static balance task (80 s, eyes closed only), and also completed a dynamic balance task which required maintaining balance while experiencing random anterior-posterior perturbations applied to the trunk/pendulum. Postural sway of the body/pendulum was measured using an angular velocity sensor (SwayStar TM , study 1) and Optotrak motion capture (study 2). Outcome measures were amplitude and frequency of center of mass sway for static balance, and peak and time-to-peak of center of mass displacement and velocity for dynamic balance. Results: PD patients had larger sway amplitude during both upright and simulated static balance compared to controls. PD patients had larger peak and time-to-peak sway, and larger time-to-peak sway velocity, during simulated, but not upright, dynamic balance compared to controls. Conclusions: Deficits in static and dynamic balance control can be detected in PD patients using a novel MRI compatible balance simulator. This technique allows for functional neuroimaging to be combined with balance-relevant tasks, and provides a new means to create insights into the neural substrates contributing to postural instability in PD.

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An Evaluation of the Effect of Vision on Standing Stability in the Early Stage of Parkinson’s Disease

Cited by 7 publications

References 25 publications

Strategic alterations of posture are delayed in Parkinson’s disease patients during deep brain stimulation

Strategic alterations of posture are delayed in Parkinson’s disease patients during deep brain stimulation

Detection of postural control in early Parkinson’s disease: Clinical testing vs. modulation of center of pressure

A Novel MRI Compatible Balance Simulator to Detect Postural Instability in Parkinson's Disease

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