A Randomized and Controlled Crossover Study Investigating the Improvement of Walking and Posture Functions in Chronic Stroke Patients Using HAL Exoskeleton – The HALESTRO Study (HAL-Exoskeleton STROke Study)

I see NO PROTOCOL coming out of this so useless.  Do researchers think stroke survivors are stupid and will accept this crapola? 

A Randomized and Controlled Crossover Study Investigating the Improvement of Walking and Posture Functions in Chronic Stroke Patients Using HAL Exoskeleton – The HALESTRO Study (HAL-Exoskeleton STROke Study)

Matthias Sczesny-Kaiser^1*, Rebecca Trost¹, Mirko Aach², Thomas A. Schildhauer³, Peter Schwenkreis¹ and Martin Tegenthoff¹

• ¹Department of Neurology, BG University Hospital Bergmannsheil Bochum, Bochum, Germany
• ²Department of Spinal Cord Injury, BG University Hospital Bergmannsheil Bochum, Bochum, Germany
• ³Department of General and Trauma Surgery, BG University Hospital Bergmannsheil Bochum, Bochum, Germany

Background: The exoskeleton HAL (hybrid assistive limb) has proven to improve walking functions in spinal cord injury and chronic stroke patients when using it for body-weight supported treadmill training (BWSTT). Compared with other robotic devices, it offers the possibility to initiate movements actively. Previous studies on stroke patients did not compare HAL-BWSTT with conventional physiotherapy (CPT). Therefore, we performed a crossover clinical trial comparing CPT and HAL-BWSTT in chronic stroke patients with hemiparesis, the HALESTRO study. Our hypothesis was that HAL-training would have greater effects on walking and posture functions compared to a mixed-approach CPT.

Methods: A total of 18 chronic stroke patients participated in this study. Treatment consisted of 30 CPT sessions and of 30 sessions of BWSTT with a double leg type HAL exoskeleton successively in a randomized, crossover study design. Primary outcome parameters were walking time and speed in 10-meter walk test (10MWT), time in timed-up-and-go test (TUG) and distance in 6-min walk test (6MWT). Secondary outcome parameters were the functional ambulatory categories (FAC) and the Berg-Balance Scale (BBS). Data were assessed at baseline, at crossover and at the end of the study, all without using and wearing HAL.

Results: Our study demonstrate neither a significant difference in walking parameters nor in functional and balance parameters. When HAL-BWSTT was applied to naïve patients, it led to an improvement in walking parameters and in balance abilities. Pooling all data, we could show a significant effect in 10MWT, 6MWT, FAC and BBS, both therapies sequentially applied over 12 weeks. Thereby, FAC improve from dependent to independent category (3 to 4). One patient dropped out of the study due to intensive fatigue after each training session.

Conclusion: HAL-BWSTT and mixed-approach CPT were effective therapies in chronic stroke patients. However, compared with CPT, HAL training with 30 sessions over 6 weeks was not more effective. The combination of both therapies led to an improvement of walking and balance functions. Robotic rehabilitation of walking disorders alone still lacks the proof of superiority in chronic stroke. Robotic treatment therapies and classical CPT rehabilitation concepts should be applied in an individualized therapy program.

Introduction

Stroke is a growing medical and socioeconomical problem these days (Feigin et al., 2015). Epidemiologic studies estimated an yearly incidence of 800,000 in the United States to 1.0 million in the European Union (EU) (Truelsen et al., 2006; Mozaffarian et al., 2016). Incidence and prevalence increased over the last 20 years, while mortality decreased remarkably due to improving emergency medicine (Reeves et al., 2008; Koton et al., 2014). Stroke incidence is supposed to raise to 1.5 million per year in 2025 in the EU (Truelsen et al., 2006). Total costs of stroke care were expected to increase up to $184.1 billion in the United States for the year 2030 (Ovbiagele et al., 2013). In the next years, stroke therapy will become an even greater burden for national socioeconomic systems. While acute stroke therapies mainly focus on reducing infarcted brain tissue, reducing expected acute functional deficits and stroke survival, rehabilitation therapies in chronic stroke patients usually focus on restoration and reducing existing and persisting functional deficits. Both treatment approaches are necessary to lower resulting costs for the public healthcare system. Therefore, studies in both stroke settings (acute/chronic) are needed to limit persisting disabilities and analyze the best possible rehabilitation options.

Today, it is generally accepted that outpatient physiotherapy and other therapies would not lead to a significant functional recovery in chronic stroke.

The functional recovery curve reaches saturation after 6 months with only few fluctuations (Duncan et al., 1994; Jørgensen et al., 1995; Kwakkel et al., 2004; Langhorne et al., 2011). However, only few studies have addressed whether modern rehabilitation tools could induce significant functional recovery even in chronic stages. First positive evidence was given by innovative robotic devices for arm and walking training (Kwakkel et al., 2004; Huang and Krakauer, 2009; Reinkensmeyer et al., 2009; Lo et al., 2010). The results indicated that functional recovery might be possible even in chronic stages of stroke. The implementation of recent scientific knowledge on neurorehabilitation and neuronal plasticity like task-specificity, context-specificity and/or high-intensity and repetitive practice is a great advantage of new rehabilitation approaches. Several different robotic devices for locomotor support have been developed over the last 10 years. Most of them serve primarily as a medical and nursing device for walking support, but can be used as a training tool as well. For example, the ReWalk exoskeleton (ReWalk Robotics Ltd., Yokneam, Isreal) and the Indego bionic exoskeleton (Parker Hannifin Corporation, Cleveland, OH, United States) allow people with paraparesis due to spinal cord injury (SCI) to stand up, walk with a defined pattern and climb stairs. Induced locomotion is passive, not neurological self-induced and not based on any biological signal. Both robots use pre-programmed walking patterns that were executed irrespective of patient’s remaining walking abilities. ReWalk and Indego have the intention to be applied predominantly as a walking aid for outdoor use. For walking rehabilitation, different robotic devices and gait trainers have been developed (e.g., Locomat, Gait Trainer GT a. s. o.). Even though, scientists showed therapeutic effects on walking parameters and disability, so far, in larger studies, they failed to show superiority when compared with conventional physiotherapies (Mehrholz and Pohl, 2012; Chang and Kim, 2013; Swinnen et al., 2014). Neither Locomat nor Gait Trainer GT uses neurobiological signal for locomotion control.

In contrast, the exoskeleton hybrid assistive limb (HAL) is controlled voluntarily by the patient’s own muscle signals detected by surface electrodes. This self-initiated movement is capable to induce a somatosensory feedback-loop that enhances neural plasticity and locomotor learning (Sczesny-Kaiser et al., 2015). Pilot studies on patients with SCI, and chronic stroke showed safety and beneficial effects on walking functions (Kawamoto et al., 2013; Aach et al., 2014; Cruciger et al., 2014; Nilsson et al., 2014; Yoshimoto et al., 2015; Grasmücke et al., 2017; Jansen et al., 2017). In SCI, our study group demonstrated that HAL-assisted and body-weight supported treadmill training with supervision of a specialized physiotherapist led to a significant improvement of walking parameters and ambulatory capacity as indicated by the Walking Index for SCI II. These effects were observed in acute and chronic SCI patients, even up to 19 years after ictus (Aach et al., 2014; Grasmücke et al., 2017). Treadmill- and HAL-associated parameters like walking distance, speed and time as well as independent parameters like 10-meter walk test and 6-min walk test increased significantly up to 50% (Grasmücke et al., 2017). Moreover, these improvements could be detected in chronic tetraplegic and paraplegic patients. Older age (>50 years) and spastic motor behavior were non-significant negative predictors for walking endurance improvements. In stroke patients, similar results for HAL-assisted and body-weight supported treadmill training were demonstrated by several study groups in Japan and Sweden (Wada et al., 2010; Kawamoto et al., 2013, 2014; Nilsson et al., 2014; Yoshimoto et al., 2015) The therapeutic target was hemiparesis in all studies, and predominantly, patients with hemispheric insult were enrolled. In addition to technical requirements, safety and feasibility (Kawamoto et al., 2014; Nilsson et al., 2014), effects on treadmill-bound and treadmill-independent parameters were investigated (Kawamoto et al., 2013; Yoshimoto et al., 2015, 2016; Mizukami et al., 2017). Again, study results showed significant improvements, and even promising results indicating significant improvements in the functional ambulatory category (FAC) (Kawamoto et al., 2013). In spite of these encouraging positive results of HAL-training, most of these studies were performed in an uncontrolled design, e.g., using a conventional and mixed physiotherapy setup as control group. Thus, these results encourage to perform controlled studies using HAL-assisted treadmill training in chronic stroke patients. To become an established part of neurorehabilitation programs, HAL has to be compared with conventional physiotherapy (CPT) which is the cornerstone, today. Here, Bobath’s concept and proprioceptive neuromuscular facilitation (PNF) were used regularly (Dickstein et al., 1986; Lincoln et al., 1999; Luke et al., 2004; Wang et al., 2005).

We hypothesized that, in chronic stroke patients, HAL-assisted body-weight supported treadmill training would be more effective in recovery of walking parameters than CPT (provided according to current standards of practice). We further hypothesized that exoskeletal HAL training would improve outcome parameters reflecting functional independence more than conventional therapy.

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