Publications by authors named "Deepak Ravi"

Background: Unstable gait leading to falls negatively impacts the quality of life in many people with Parkinson's disease (PD). Systematic review evidence provides moderate to strong evidence of efficacy for a wide range of physiotherapy-based interventions to reduce gait impairment. However, outcomes have often focused on gait assessments conducted in controlled laboratory or clinical environments.

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Article Synopsis
  • The article explores how a patent foramen ovale (PFO) might contribute to conditions like migraines, vasospastic angina, and Takotsubo cardiomyopathy.
  • It reviews the potential role of PFO in these health issues and suggests possible treatments.
  • The authors propose a new clinical syndrome where PFO acts as a common link between migraines, coronary vasospasm, and Takotsubo cardiomyopathy in susceptible patients.
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Deep brain stimulation of the subthalamic nucleus (STN-DBS) is an established treatment for motor impairment due to Parkinson's disease (PD) progression. While treated subjects mostly experience significant amelioration of symptoms, some still report adverse effects. In particular, changes in gait patterns due to the electrical stimulation have shown mixed results across studies, with overall gait velocity improvement described as the core positive outcome.

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Patent foramen ovale (PFO) is the most common congenital cardiac abnormality and is usually considered a benign finding. This case series suggests a potential link between PFO and vasospastic angina. It also demonstrates PFO closure as a potential therapeutic intervention for individuals with PFO who suffer from refractory vasospastic angina.

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Background: Freezing of Gait (FOG) is a motor symptom frequently observed in advanced Parkinson's disease. However, due to its paroxysmal nature and diverse presentation, assessing FOG in a clinical setting can be challenging. Before FOG can be fully investigated, it is critical that a reliable experimental setting is established in which FOG can be evoked in a standardized manner, but the efficacy of various gait tasks and triggers for eliciting FOG remains unclear.

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. Subthalamic deep brain stimulation (STN-DBS) is an effective treatment for selected Parkinson's disease (PD) patients. Gait characteristics are often altered after surgery, but quantitative therapeutic effects are poorly described.

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For humans, the ability to effectively adapt footfall rhythm to perturbations is critical for stable locomotion. However, only limited information exists regarding how dynamic stability changes when individuals modify their footfall rhythm. In this study, we recorded 3D kinematic activity from 20 participants (13 males, 18-30 years old) during walking on a treadmill while synchronizing with an auditory metronome sequence individualized to their baseline walking characteristics.

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The capacity to recover after a perturbation is a well-known intrinsic property of physiological systems, including the locomotor system, and can be termed 'resilience' Despite an abundance of metrics proposed to measure the complex dynamics of bipedal locomotion, analytical tools for quantifying resilience are lacking. Here, we introduce a novel method to directly quantify resilience to perturbations during locomotion. We examined the extent to which synchronizing stepping with two different temporal structured auditory stimuli (periodic and 1/ structure) during walking modulates resilience to a large unexpected perturbation.

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Human physiological signals are inherently rhythmic and have a hallmark feature in that even distant intrasignal measurements are related to each other. This relationship is termed long-range correlation and has been recognized as an indicator of the optimal state of the observed physiological systems, among which the locomotor system. Loss of long-range correlations has been found as a result of aging as well as disease, which can be evaluated with detrended fluctuation analysis (DFA).

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Takayasu arteritis is a rare large vessel vasculitis with an incidence of 1 to 3 per million. This disease typically involves the aorta and its primary branches but has been found to involve the coronary arteries in 7% to 9% of cases. We highlight the need for prompt diagnosis and treatment.

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In order to address whether increased levels of movement output variability indicate pathological performance, we systematically reviewed and synthesized meta-analysis data on healthy and pathological motor behavior. After screening up to 24'000 reports from four databases, 85 studies were included containing 2409 patients and 2523 healthy asymptomatic controls. The optimal thresholds of variability with uncertainty boundaries (in % Coefficient of Variation ± Standard Error) were estimated in 7 parameters: stride time (2.

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Gait variability is a sensitive metric for assessing functional deficits in individuals with mobility impairments. To correctly represent the temporal evolution of gait kinematics, nonlinear measures require extended and uninterrupted time series. In this study, we present and validate a novel algorithm for concatenating multiple time-series in order to allow the nonlinear analysis of gait data from standard and unrestricted overground walking protocols.

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A stable walking pattern is presumably essential to avoid falls. Stability of walking is most accurately determined by the short-term local dynamic stability (maximum Lyapunov exponent) of the body centre of mass. In many studies related to fall risk, however, variability of step width is considered to be indicative of the stability of the centre of mass during walking.

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Our understanding of mechanisms that regulate the differentiation of specific classes of synapses is limited. Here, we investigate the formation of synapses between hippocampal dentate gyrus (DG) neurons and their target CA3 neurons and find that DG neurons preferentially form synapses with CA3 rather than DG or CA1 neurons in culture, suggesting that specific interactions between DG and CA3 neurons drive synapse formation. Cadherin-9 is expressed selectively in DG and CA3 neurons, and downregulation of cadherin-9 in CA3 neurons leads to a selective decrease in the number and size of DG synapses onto CA3 neurons.

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