Effects of flexor reflex stimulation on gait aspects in stroke patients: randomized clinical trial.

BACKGROUND: Gait deficits are very common after stroke and therefore an important aspect in poststroke rehabilitation. A currently little used method in gait rehabilitation after stroke is the activation of the flexor reflex (FR) by electrical stimulation of the sole of foot while walking. The aim of this study was to investigate the effect of FR stimulation on gait performance and gait parameters in participants with stroke within a single session of flexor reflex stimulation using Incedo™. METHODS: Twenty-five participants with subacute (n = 14) and chronic (n = 11) stroke were enrolled in the study. Motor functions were tested with a 10-m walk test (10mWT), a 2-min walk test (2minWT), and a gait analysis. These tests were performed with and without Incedo™ within a single session in randomized order. RESULTS: In the 10mWT, a significant difference was found between walking with Incedo™ (15.0 ± 8.5 s) versus without Incedo™ (17.0 ± 11.4 s, p = 0.01). Similarly, the 2minWT showed a significant improvement with Incedo™ use (90.0 ± 36.4 m) compared to without Incedo™ (86.3 ± 36.8 m, p = 0.03). These results indicate that while the improvements are statistically significant, they are modest and should be considered in the context of their clinical relevance. The gait parameters remained unchanged except for the step length. A subgroup analysis indicated that participants with subacute and chronic stroke responded similarly to the stimulation. There was a correlation between the degree of response to electrostimulation while walking and degree of improvement in 2minWT (r = 0.50, p = 0.01). CONCLUSIONS: This study is the first to examine FR activation effects in chronic stroke patients and suggests that stimulation effects are independent of the time since stroke. A larger controlled clinical trial is warranted that addresses issues as the necessary number of therapeutical sessions and for how long stimulation-induced improvements outlast the treatment period. TRIAL REGISTRATION: The trial was retrospectively registered in German Clinical Trials Register. CLINICAL TRIAL REGISTRATION NUMBER: DRKS00021457. Date of registration: 29 June 2020.

The Evolution of Hand Proprioceptive and Motor Impairments in the Sub-Acute Phase After Stroke.

BACKGROUND: Hand proprioception is essential for fine movements and therefore many activities of daily living. Although frequently impaired after stroke, it is unclear how hand proprioception evolves in the sub-acute phase and whether it follows a similar pattern of changes as motor impairments. OBJECTIVE: This work investigates whether there is a corresponding pattern of changes over time in hand proprioception and motor function as comprehensively quantified by a combination of robotic, clinical, and neurophysiological assessments. METHODS: Finger proprioception (position sense) and motor function (force, velocity, range of motion) were evaluated using robotic assessments at baseline (<3 months after stroke) and up to 4 weeks later (discharge). Clinical assessments (among others, Box & Block Test [BBT]) as well as Somatosensory/Motor Evoked Potentials (SSEP/MEP) were additionally performed. RESULTS: Complete datasets from 45 participants post-stroke were obtained. For 42% of all study participants proprioception and motor function had a dissociated pattern of changes (only 1 function considerably improved). This dissociation was either due to the absence of a measurable impairment in 1 modality at baseline, or due to a severe lesion of central somatosensory or motor tracts (absent SSEP/MEP). Better baseline BBT correlated with proprioceptive gains, while proprioceptive impairment at baseline did not correlate with change in BBT. CONCLUSIONS: Proprioception and motor function frequently followed a dissociated pattern of changes in sub-acute stroke. This highlights the importance of monitoring both functions, which could help to further personalize therapies.

The locations of stroke lesions next to the posterior internal capsule may predict the recovery of the related proprioceptive deficits.

Background: Somatosensory deficits after stroke correlate with functional disabilities and impact everyday-life. In particular, the interaction of proprioception and motor dysfunctions affects the recovery. While corticospinal tract (CST) damage is linked to poor motor outcome, much less is known on proprioceptive recovery. Identifying a predictor for such a recovery could help to gain insights in the complex functional recovery processes thereby reshaping rehabilitation strategies. Methods: 50 patients with subacute stroke were tested before and after neurological rehabilitation. Proprioceptive and motor impairments were quantified with three clinical assessments and four hand movement and proprioception measures using a robotic device. Somatosensory evoked potentials (SSEP) to median nerve stimulation and structural imaging data (MRI) were also collected. Voxel-based lesion-symptom mapping (VLSM) along with a region of interest (ROI) analysis were performed for the corticospinal tract (CST) and for cortical areas. Results: Before rehabilitation, the VLSM revealed lesion correlates for all clinical and three robotic measures. The identified voxels were located in the white matter within or near the CST. These regions associated with proprioception were located posterior compared to those associated with motor performance. After rehabilitation the patients showed an improvement of all clinical and three robotic assessments. Improvement in the box and block test was associated with an area in anterior CST. Poor recovery of proprioception was correlated with a high lesion load in fibers towards primary sensorymotor cortex (S1 and M1 tract). Patients with loss of SSEP showed higher lesion loads in these tracts and somewhat poorer recovery of proprioception. The VSLM analysis for SSEP loss revealed a region within and dorsal of internal capsule next to the posterior part of CST, the posterior part of insula and the rolandic operculum. Conclusion: Lesions dorsal to internal capsule next to the posterior CST were associated with proprioceptive deficits and may have predictive value. Higher lesion load was correlated with poorer restoration of proprioceptive function. Furthermore, patients with SSEP loss trended towards poor recovery of proprioception, the corresponding lesions were also located in the same location. These findings suggest that structural imaging of the internal capsule and CST could serve as a recovery predictor of proprioceptive function.

Design and Preliminary Evaluation of a Robot-assisted Assessment-driven Finger Proprioception Therapy.

Neurological injuries such as stroke often lead to motor and somatosensory impairments of the hand. Deficits in somatosensation, especially proprioception, result in difficulties performing activities of daily living involving fine motor tasks. However, it is challenging to accurately detect those impairments due to the limitations of clinical assessments. Hence therapies rarely focus on proprioception specifically, while such training could promote functional benefits. In this work we propose and preliminarily evaluate a robot-assisted, assessment-driven therapy of finger proprioception. We designed and implemented two therapeutic exercises, one targeting passive and the other active position sense. The difficulty level of the therapy exercises was adapted to each patient's proprioceptive impairment. We evaluated the exercises and their usability with 7 stroke participants and 8 clinicians in a 45-minutes protocol. We found that the exercises were feasible for stroke participants, as 5 individuals progressed in difficulty levels over multiple exercise repetitions, indicating adequacy of the adaptation algorithm. Moreover, usability was rated mostly as satisfactory by the patients (System Usability Scale = 73), and they also found the exercises interesting. Clinicians rated the exercises as difficult but clinically meaningful. Overall, these promising preliminary results pave the way for further development and validation of the proposed therapy approach.

Using the Flexor Reflex in a Chronic Stroke Patient for Gait Improvement: A Case Report.

The flexor reflex or withdrawal reflex can be elicited by electrical stimulation of the sole of the foot, which serves as a reflex to protect the stimulated limb against tissue damage and consists of flexion movements in the hip, knee, and ankle joint. Triggering this reflex might improve walking abilities in hemiparetic patients. We report the first case of a chronic stroke patient with the most severe impairment of walking. She was examined with and without flexor reflex activation by the Incedo® system. Tests included a 10-m walk and a 2-min walk at baseline, after 3 weeks of training with the Incedo® system and after a follow-up 3 weeks later. Moreover, a kinematic gait analysis was done before and after the training period. At baseline, activation of the flexor reflex induced an improved gait velocity. After the training period, the patient walked twice as fast compared with baseline. Her gait velocity without Incedo® was faster than the gait velocity with Incedo® at baseline. Examination at follow-up indicated that the improvements remained almost unchanged. The kinematic analysis showed an improved stride length and gait velocity during flexor reflex activation. Initially, the foot was elevated higher above the ground during flexor reflex activation. In conclusion, this first case report of a chronic stroke patient demonstrates that flexor reflex activation is feasible and improves gait parameters despite severe impairment of walking abilities.

Reliable and valid robot-assisted assessments of hand proprioceptive, motor and sensorimotor impairments after stroke.

BACKGROUND: Neurological injuries such as stroke often differentially impair hand motor and somatosensory function, as well as the interplay between the two, which leads to limitations in performing activities of daily living. However, it is challenging to identify which specific aspects of sensorimotor function are impaired based on conventional clinical assessments that are often insensitive and subjective. In this work we propose and validate a set of robot-assisted assessments aiming at disentangling hand proprioceptive from motor impairments, and capturing their interrelation (sensorimotor impairments). METHODS: A battery of five complementary assessment tasks was implemented on a one degree-of-freedom end-effector robotic platform acting on the index finger metacarpophalangeal joint. Specifically, proprioceptive impairments were assessed using a position matching paradigm. Fast target reaching, range of motion and maximum fingertip force tasks characterized motor function deficits. Finally, sensorimotor impairments were assessed using a dexterous trajectory following task. Clinical feasibility (duration), reliability (intra-class correlation coefficient ICC, smallest real difference SRD) and validity (Kruskal-Wallis test, Spearman correlations [Formula: see text] with Fugl-Meyer Upper Limb Motor Assessment, kinesthetic Up-Down Test, Box & Block Test) of robotic tasks were evaluated with 36 sub-acute stroke subjects and 31 age-matched neurologically intact controls. RESULTS: Eighty-three percent of stroke survivors with varied impairment severity (mild to severe) could complete all robotic tasks (duration: <15 min per tested hand). Further, the study demonstrated good to excellent reliability of the robotic tasks in the stroke population (ICC>0.7, SRD<30%), as well as discriminant validity, as indicated by significant differences (p-value<0.001) between stroke and control subjects. Concurrent validity was shown through moderate to strong correlations ([Formula: see text]=0.4-0.8) between robotic outcome measures and clinical scales. Finally, robotic tasks targeting different deficits (motor, sensory) were not strongly correlated with each other ([Formula: see text]0.32, p-value>0.1), thereby presenting complementary information about a patient's impairment profile. CONCLUSIONS: The proposed robot-assisted assessments provide a clinically feasible, reliable, and valid approach to distinctly characterize impairments in hand proprioceptive and motor function, along with the interaction between the two. This opens new avenues to help unravel the contributions of unique aspects of sensorimotor function in post-stroke recovery, as well as to contribute to future developments towards personalized, assessment-driven therapies.

[Lung Ultrasound on Admission to a Covid Decision Unit - Helpful in Differential Diagnosis or a Waste of Time?] / Thoraxsonografie bei Aufnahme auf einer COVID-Verdachtsstation ­ differenzialdiagnostisch hilfreich oder Zeitverschwendung?

BACKGROUND: In patients with Covid-19, typical and often severe lung lesions have been reported. In addition to the use of chest CT, the diagnostic benefit of lung ultrasound has been advocated.This trial investigates if in patients presenting with symptoms compatible with Covid-19, lung ultrasound is of use in the early differential diagnosis. METHODS: This study includes 46 patients of the first wave of the Covid-19 pandemic (23 with confirmed infection, 23 controls with later on excluded infection), who were initially admitted to the Covid Decision Unit of an academic teaching hospital under the clinical suspicion of SARS-CoV-2 infection. All patients were examined by pulmonary ultrasound shortly after admission. The final diagnosis of infection was made or ruled out by means of - sometimes repeated - PCR of nasal/pharyngeal swabs.Findings of SARS-CoV-2 patients and controls were compared and analyzed for significant differences in chest sonographic parameters. RESULTS: There were significant differences in the lung ultrasound findings of both groups. In the Covid group there were significantly fewer A-lines, more pathological B-lines (increased or confluent) and more consolidations. Pleural effusions were significantly more frequent in the control group. The calculated lung ultrasound score (LUS) was higher in the Covid group than in the control group. However, a reliable differentiation between the two groups was not possible due to the wide range and overlap.  CONCLUSION: In a clinical setting, lung ultrasound reveals more frequent and different lesions in SARS-CoV-2 infected patients than in patients in whom the initial clinical suspicion was not confirmed. However, due to the overlap of findings between the two groups, lung ultrasound was not suitable to differentiate with sufficient certainty between SARS-CoV-2 infected and non-infected patients.

The social embedding of biomedicine: an analysis of German media debates 1995-2004.

Biomedical research and technologies such as cloning, stem cell research, and the deciphering of the human genome have met with opposition--albeit of different intensity--motivated by ethical values. The debates over the continuation of research and the implementation of the respective technologies are being staged in the mass media. The media have assumed the function of edding" controversial knowledge and technologies into society by using public discourse. The hypothesis is that these discourses follow a common pattern revealing the process of "embedding," and ultimately leading to a change of existing values. In this study, three debates over cloning, stem cell research and the Human Genome Project are analyzed in ten German daily and weekly newspapers over the period 1995-2004. It is shown that the patterns of reporting are more complex than anticipated. Rather than being identical for all technologies, they reveal different courses depending on the kind of knowledge/technology and value sensitivity.