Publications

Several procedures have been developed to enhance the rehabilitation of stroke patients. However, most techniques struggle to promote sustained recovery in the months following the treatment. Therefore, it is essential to understand the mechanisms that can be harnessed during treatment to potentiate retention of benefits and sustained recovery. While stroke patients often suffer from thalamocortical dysrhythmia (TCD), a perturbation in alpha (8-13 Hz) rhythms caused by decreased excitation in the cortico-thalamic projections, the functional relevance of TCD in stroke patients is not yet clear. We propose that TCD can be counteracted by combining focal stimulation of the motor cortex with virtual-reality (VR) based rehabilitation, which engages distributed networks associated with goal-oriented behavior. Critically, we investigate whether this can be the key to promoting sustained recovery in stroke patients. We compare thalamocortical rhythms and behavioral recovery in patients receiving Sham and bilateral tDCS stimulation of the motor cortex during therapy with the Rehabilitation Gaming System (RGS). Our results reveal that patients in the tDCS group show a sustained recovery in all clinical scales up to three months post-treatment, as opposed to the Sham group. Furthermore, we demonstrate that the slowing down of alpha rhythms can be counteracted by transcranial direct-current stimulation (tDCS), with a particular role for enhancing the excitability of parietal areas. That said, we found no correlation between changes in alpha rhythms and motor recovery. On one hand, our findings suggest that sustained recovery can be potentiated by tDCS-enhanced VR-based rehabilitation. On the other hand, enhancing the excitability of parietal areas while recruiting brain networks associated with goal-oriented behavior can successfully counteract TCD, even though this is likely not the main driver of sustained motor recovery.

JTD Keywords: Activation, Alpha rhythms, Deep brain-stimulation, Direct-current stimulation, Excitatory-inhibitory balance, Guidelines, Human thalamus, Involvement, Motor recovery, Quality-of-life, Rehabilitation, Sensitivity, Stroke, Transcranial direct-current stimulation

Background: There is a pressing need for scalable healthcare solutions and a shift in the rehabilitation paradigm from hospitals to homes to tackle the increase in stroke incidence while reducing the practical and economic burden for patients, hospitals, and society. Digital health technologies can contribute to addressing this challenge; however, little is known about their effectiveness in at-home settings. In response, we have designed the RGS@home study to investigate the effectiveness, acceptance, and cost of a deep tech solution called the Rehabilitation Gaming System (RGS). RGS is a cloud-based system for delivering Al-enhanced rehabilitation using virtual reality, motion capture, and wearables that can be used in the hospital and at home. The core principles of the brain theory-based RGS intervention are to deliver rehabilitation exercises in the form of embodied, goal-oriented, and task-specific action.; Methods: The RGS@home study is a randomized longitudinal clinical trial designed to assess whether the combination of the RGS intervention with standard care is superior to standard care alone for the functional recovery of stroke patients at the hospital and at home. The study is conducted in collaboration with hospitals in Spain, Sweden, and France and includes inpatients and outpatients at subacute and chronic stages post-stroke. The intervention duration is 3 months with assessment at baseline and after 3, 6, and 12 months. The impact of RGS is evaluated in terms of quality of life measurements, usability, and acceptance using standardized clinical scales, together with health economic analysis. So far, one-third of the patients expected to participate in the study have been recruited (N = 90, mean age 60, days after stroke >= 30 days). The trial will end in July 2023.; Discussion: We predict an improvement in the patients' recovery, high acceptance, and reduced costs due to a soft landing from the clinic to home rehabilitation. In addition, the data provided will allow us to assess whether the prescription of therapy at home can counteract deterioration and improve quality of life while also identifying new standards for online and remote assessment, diagnostics, and intervention across European hospitals.

JTD Keywords: deep tech, e-health, home treatment, motor recovery, randomized clinical trial, stroke, upper extremities, virtual reality, Deep tech, E-health, Functional recovery, Home treatment, Humans, Middle aged, Motor recovery, Quality of life, Randomized clinical trial, Randomized controlled trials as topic, Recovery of function, Stroke, Stroke rehabilitation, Telemedicine, Upper extremities, Virtual reality, Wearables

The impact of rehabilitation on post-stroke motor recovery and its dependency on the patient's chronicity remain unclear. The field has widely accepted the notion of a proportional recovery rule with a "critical window for recovery" within the first 3-6 mo poststroke. This hypothesis justifies the general cessation of physical therapy at chronic stages. However, the limits of this critical window have, so far, been poorly defined. In this analysis, we address this question, and we further explore the temporal structure of motor recovery using individual patient data from a homogeneous sample of 219 individuals with mild to moderate upper-limb hemiparesis. We observed that improvement in body function and structure was possible even at late chronic stages. A bootstrapping analysis revealed a gradient of enhanced sensitivity to treatment that extended beyond 12 mo poststroke. Clinical guidelines for rehabilitation should be revised in the context of this temporal structure. NEW & NOTEWORTHY Previous studies in humans suggest that there is a 3- to 6-mo "critical window" of heightened neuroplasticity poststroke. We analyze the temporal structure of recovery in patients with hemiparesis and uncover a precise gradient of enhanced sensitivity to treatment that expands far beyond the limits of the so-called critical window. These findings highlight the need for providing therapy to patients at the chronic and late chronic stages.

JTD Keywords: Motor recovery, Neuroplasticity, Neurorehabilitation, Stroke recovery, Virtual reality