Dose and timing in neurorehabilitation: prescribing motor therapy after stroke

Enhancing Nervous System Recovery through Neurobiologics, Neural Interface Training, and Neurorehabilitation

After an initial period of recovery, human neurological injury has long been thought to be static. In order to improve quality of life for those suffering from stroke, spinal cord injury, or traumatic brain injury, researchers have been working to restore the nervous system and reduce neurological deficits through a number of mechanisms. For example, neurobiologists have been identifying and manipulating components of the intra- and extracellular milieu to alter the regenerative potential of neurons, neuro-engineers have been producing brain-machine and neural interfaces that circumvent lesions to restore functionality, and neurorehabilitation experts have been developing new ways to revitalize the nervous system even in chronic disease. While each of these areas holds promise, their individual paths to clinical relevance remain difficult. Nonetheless, these methods are now able to synergistically enhance recovery of native motor function to levels which were previously believed to be impossible. Furthermore, such recovery can even persist after training, and for the first time there is evidence of functional axonal regrowth and rewiring in the central nervous system of animal models. To attain this type of regeneration, rehabilitation paradigms that pair cortically-based intent with activation of affected circuits and positive neurofeedback appear to be required-a phenomenon which raises new and far reaching questions about the underlying relationship between conscious action and neural repair. For this reason, we argue that multi-modal therapy will be necessary to facilitate a truly robust recovery, and that the success of investigational microscopic techniques may depend on their integration into macroscopic frameworks that include task-based neurorehabilitation. We further identify critical components of future neural repair strategies and explore the most updated knowledge, progress, and challenges in the fields of cellular neuronal repair, neural interfacing, and neurorehabilitation, all with the goal of better understanding neurological injury and how to improve recovery.

[New aspects of neurorehabilitation: motor and language]

Advancements in medical care over the last decades have contributed to a continuous decline in immediate post-stroke mortality. The flipside of this development is that patients surviving the initial stroke are forced to live with sometimes extreme functional motor and/or language limitations for the remaining life span. The following overview presents evidence-based neurorehabilitative interventions to promote motor and language recovery in the acute and chronic post-stroke stages. Therapeutic approaches comprise intensive training, neuropharmacological drugs and non-invasive brain stimulation techniques, such as transcranial magnetic stimulation (TMS) or direct current stimulation (tDCS). Additionally, an outlook on promising future interventions for stroke neurorehabilitation is provided.

Access, timing and frequency of very early stroke rehabilitation - insights from the Baden-Wuerttemberg stroke registry

BACKGROUND

While the precise timing and intensity of very early rehabilitation (VER) after stroke onset is still under discussion, its beneficial effect on functional disability is generally accepted. The recently published randomized controlled AVERT trial indicated that patients with severe stroke might be more susceptible to harmful side effects of VER, which we hypothesized is contrary to current clinical practice. We analyzed the Baden-Wuerttemberg stroke registry to gain insight into the application of VER in acute ischemic stroke (IS) and intracerebral hemorrhage (ICH) in clinical practice.

METHODS

99,753 IS patients and 8824 patients with ICH hospitalized from January 2008 to December 2012 were analyzed. Data on the access to physical therapy (PT), occupational therapy (OT), and speech therapy (ST), the time from admission to first contact with a therapist and the average number of therapy sessions during the first 7 days of admission are reported. Multiple logistic regression models adjusted for patient and treatment characteristics were carried out to investigate the influence of VER on clinical outcome.

RESULTS

PT was applied in 90/87% (IS/ICH), OT in 63/57%, and ST in 70/65% of the study population. Therapy was mostly initiated within 24 h (PT 87/82%) or 48 h after admission (OT 91/89% and ST 93/90%). Percentages of patients under therapy and also the average number of therapy sessions were highest in those with a discharge modified Rankin Scale score of 2 to 5 and lowest in patients with complete recovery or death during hospitalization. The outcome analyses were fundamentally hindered due to biases by individual decision making regarding the application and frequency of VER.

CONCLUSIONS

While most patients had access to PT we noticed an undersupply of OT and ST. Only little differences were observed between patients with IS and ICH. The staff decisions for treatment seem to reflect attempts to optimize resources. Patients with either excellent or very unfavorable prognosis were less frequently assigned to VER and, if treated, received a lower average number of therapy sessions. On the contrary, severely disabled patients received VER at high frequency, although potentially harmful according to recent indications from the randomized controlled AVERT trial.

Is upper limb virtual reality training more intensive than conventional training for patients in the subacute phase after stroke? An analysis of treatment intensity and content

BACKGROUND

Virtual reality (VR) training is thought to improve upper limb (UL) motor function after stroke when utilizing intensive training with many repetitions. The purpose of this study was to compare intensity and content of a VR training intervention to a conventional task-oriented intervention (CT).

METHODS

A random sample of 50 video recordings was analyzed of patients with a broad range of UL motor impairments (mean age 61y, 22 women). Patients took part in the VIRTUES trial and were randomized to either VR or CT and stratified according to severity of paresis. A standardized scoring form was used to analyze intensity, i.e. active use of the affected UL expressed in % of total time, total active time and total duration of a training session in minutes, content of training and feedback. Two raters collected data independently. Linear regression models as well as descriptive and graphical methods were used.

RESULTS

Patients in the VR group spent significantly more time actively practicing with an activity rate of 77.6 (8.9) % than patients in the CT 67.3 (13.9) %, (p = .003). This difference was attributed to the subgroup of patients with initially severe paresis (n = 22). While in VR severely impaired patients spent 80.7 % (4.4 %) of the session time actively; they reached 60.6 (12.1) % in CT. VR and CT also differed in terms of tasks and feedback provided.

CONCLUSION

Our results indicate that patients with severely impaired UL motor function spent more time actively in VR training, which may influence recovery. The upcoming results of the VIRTUES trial will show whether this is correlated with an increased effect of VR compared to CT.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02079103 , February 27, 2014.

Asking New Questions with Old Data: The Centralized Open-Access Rehabilitation Database for Stroke

BACKGROUND

This paper introduces a tool for streamlining data integration in rehabilitation science, the Centralized Open-Access Rehabilitation database for Stroke (SCOAR), which allows researchers to quickly visualize relationships among variables, efficiently share data, generate hypotheses, and enhance clinical trial design.

METHODS

Bibliographic databases were searched according to inclusion criteria leaving 2,892 titles that were further screened to 514 manuscripts to be screened by full text, leaving 215 randomized controlled trials (RCTs) in the database (489 independent groups representing 12,847 patients). Demographic, methodological, and statistical data were extracted by independent coders and entered into SCOAR.

RESULTS

Trial data came from 114 locations in 27 different countries and represented patients with a wide range of ages, 62 year [41; 85] [shown as median (range)] and at various stages of recovery following their stroke, 141 days [1; 3372]. There was considerable variation in the dose of therapy that patients received, 20 h [0; 221], over interventions of different durations, 28 days [10; 365]. There was also a lack of common data elements (CDEs) across trials, but this lack of CDEs was most pronounced for baseline assessments of patient impairment and severity of stroke.

CONCLUSION

Data integration across hundreds of RCTs allows clinicians and researchers to quickly visualize data from the history of the field and lays the foundation for making SCOAR a living database to which researchers can upload new data as trial results are published. SCOAR is a useful tool for clinicians and researchers that will facilitate data visualization, data sharing, the finding of relevant past studies, and the design of clinical trials by enabling more accurate and comprehensive power analyses. Furthermore, these data speak to the need for CDEs specific to stroke rehabilitation in randomized controlled trials.

PROSPERO 2014

CRD42014009010.

Dose response of task-specific upper limb training in people at least 6 months poststroke: A phase II, single-blind, randomized, controlled trial

OBJECTIVE

The objectives of this work were to (1) determine whether higher doses of motor therapy in chronic poststroke hemiparesis result in better outcomes, compared to lower doses, and (2) evaluate potential modifiers of the dose-response relationship.

METHODS

Eighty-five adults with upper extremity paresis ≥6 months poststroke were randomized to one of four dose groups in this single-blind, parallel, randomized, control trial. The dosing parameter manipulated was amount of task-specific training, as indexed by the number of task repetitions. Groups received 3,200, 6,400, 9,600, or individualized maximum (IM) repetitions, during 1-hour sessions, 4 days/week for 8 weeks. The intervention was an individualized, progressive, task-specific upper-limb training program designed to improve upper-limb functional motor capacity. The primary outcome was the slope of the Action Research Arm Test (ARAT) during the intervention. Effects of dose and potential modifiers of the dose-response relationship were evaluated with hierarchical linear models.

RESULTS

ARAT scores for the 3,200, 9,600, and IM groups improved over time as indicated by slopes (ΔARAT/week, mean ± standard errors) of 0.40 ± 0.15, 0.31 ± 0.16, and 0.66 ± 0.14, respectively (p < 0.05). The slope of the 6,400 group was smaller (-0.05 ± 0.15) and significantly different from the 3,200 and IM groups (p < 0.001). Initial motor capacity, neglect, and other tested characteristics did not modify the dose-response relationship.

INTERPRETATION

Overall, treatment effects were small. There was no evidence of a dose-response effect of task-specific training on functional capacity in people with long-standing upper-limb paresis poststroke. Ann Neurol 2016;80:342-354.

Coaching or gaming? Implications of strategy choice for home based stroke rehabilitation

Background

The enduring aging of the world population and prospective increase of age-related chronic diseases urge the implementation of new models for healthcare delivery. One strategy relies on ICT (Information and Communications Technology) home-based solutions allowing clients to pursue their treatments without institutionalization. Stroke survivors are a particular population that could strongly benefit from such solutions, but is not yet clear what the best approach is for bringing forth an adequate and sustainable usage of home-based rehabilitation systems. Here we explore two possible approaches: coaching and gaming.

Methods

We performed trials with 20 healthy participants and 5 chronic stroke survivors to study and compare execution of an elbow flexion and extension task when performed within a coaching mode that provides encouragement or within a gaming mode. For each mode we analyzed compliance, arm movement kinematics and task scores. In addition, we assessed the usability and acceptance of the proposed modes through a customized self-report questionnaire.

Results

In the healthy participants sample, 13/20 preferred the gaming mode and rated it as being significantly more fun (p < .05), but the feedback delivered by the coaching mode was subjectively perceived as being more useful (p < .01). In addition, the activity level (number of repetitions and total movement of the end effector) was significantly higher (p < .001) during coaching. However, the quality of movements was superior in gaming with a trend towards shorter movement duration (p = .074), significantly shorter travel distance (p < .001), higher movement efficiency (p < .001) and higher performance scores (p < .001). Stroke survivors also showed a trend towards higher activity levels in coaching, but with more movement quality during gaming. Finally, both training modes showed overall high acceptance.

Conclusions

Gaming led to higher enjoyment and increased quality in movement execution in healthy participants. However, we observed that game mechanics strongly determined user behavior and limited activity levels. In contrast, coaching generated higher activity levels. Hence, the purpose of treatment and profile of end-users has to be considered when deciding on the most adequate approach for home based stroke rehabilitation.

Brain stimulation: Neuromodulation as a potential treatment for motor recovery following traumatic brain injury

There is growing evidence that electrical and magnetic brain stimulation can improve motor function and motor learning following brain damage. Rodent and primate studies have strongly demonstrated that combining cortical stimulation (CS) with skilled motor rehabilitative training enhances functional motor recovery following stroke. Brain stimulation following traumatic brain injury (TBI) is less well studied, but early pre-clinical and human pilot studies suggest that it is a promising treatment for TBI-induced motor impairments as well. This review will first discuss the evidence supporting brain stimulation efficacy derived from the stroke research field as proof of principle and then will review the few studies exploring neuromodulation in experimental TBI studies. This article is part of a Special Issue entitled SI:Brain injury and recovery.