A robotic test of proprioception within the hemiparetic arm post-stroke

Abstract

BackgroundProprioception plays important roles in planning and control of limb posture and movement. The impact of proprioceptive deficits on motor function post-stroke has been difficult to elucidate due to limitations in current tests of arm proprioception. Common clinical tests only provide ordinal assessment of proprioceptive integrity (eg. intact, impaired or absent). We introduce a standardized, quantitative method for evaluating proprioception within the arm on a continuous, ratio scale. We demonstrate the approach, which is based on signal detection theory of sensory psychophysics, in two tasks used to characterize motor function after stroke.MethodsHemiparetic stroke survivors and neurologically intact participants attempted to detect displacement- or force-perturbations robotically applied to their arm in a two-interval, two-alternative forced-choice test. A logistic psychometric function parameterized detection of limb perturbations. The shape of this function is determined by two parameters: one corresponds to a signal detection threshold and the other to variability of responses about that threshold. These two parameters define a space in which proprioceptive sensation post-stroke can be compared to that of neurologically-intact people. We used an auditory tone discrimination task to control for potential comprehension, attention and memory deficits.ResultsAll but one stroke survivor demonstrated competence in performing two-alternative discrimination in the auditory training test. For the remaining stroke survivors, those with clinically identified proprioceptive deficits in the hemiparetic arm or hand had higher detection thresholds and exhibited greater response variability than individuals without proprioceptive deficits. We then identified a normative parameter space determined by the threshold and response variability data collected from neurologically intact participants. By plotting displacement detection performance within this normative space, stroke survivors with and without intact proprioception could be discriminated on a continuous scale that was sensitive to small performance variations, e.g. practice effects across days.ConclusionsThe proposed method uses robotic perturbations similar to those used in ongoing studies of motor function post-stroke. The approach is sensitive to small changes in the proprioceptive detection of hand motions. We expect this new robotic assessment will empower future studies to characterize how proprioceptive deficits compromise limb posture and movement control in stroke survivors.

Use of a robotic device to measure age-related decline in finger proprioception

“…While traditional evaluations of sensory function often include proprioceptive tasks (Winward et al 1999) and have proven useful in evaluating the condition of patients with stroke (Carey and Matyas 2011) and other impairments, these assessments are frequently insensitive, unreliable, and subjective and found to lack standardization (Lincoln et al 1991;Connell and Tyson 2012). In contrast, robotic assessments are quantitative and sensitive and can detect motor and sensory deficits in patients who receive normal scores on traditional clinical assessment measures (Reinkensmeyer and Boninger 2012;Debert et al 2012;Simo et al 2014). For example, KINARM is a device that measures and perturbs shoulder and elbow joint positions and has provided reliable quantitative assessments of deficits in limb position sense for patients with stroke and traumatic brain injury (Scott 1999;Dukelow et al 2010Dukelow et al , 2012Herter et al 2014).…”

The Arm Movement Detection (AMD) test: a fast robotic test of proprioceptive acuity in the arm

“…We used linear regression to confirm the finding [55] that arm movement detection thresholds identified using the AMD test correlate strongly with the amount of limb motion observed at threshold. Finally, we used linear regression analysis to test the secondary hypothesis that within the NIC participant group, proprioceptive acuity degrades with aging [1, 24].…”

Performance Metrics for an Application-driven Selection and Optimization of Psychophysical Sampling Procedures

“…There have been few studies exploring this approach for the assessment of the upper limb (Brewer et al, 2005;Tan et al, 2007;Lambercy et al, 2011;Rinderknecht et al, 2014;Simo et al, 2014;Elangovan et al, 2014;Cappello et al, 2015). So far MOCS has been predominantly used, with experiments typically lasting about 45 min (Brewer et al, 2005;Tan et al, 2007;Lambercy et al, 2011;Simo et al, 2014). However, in order to achieve clinical utility, the number of trials and the assessment duration should be reduced to below 15 min without compromising the quality of the outcome measures.…”