Effect of auditory feedback differs according to side of hemiparesis: a comparative pilot study

Background  

Following stroke, patients frequently demonstrate loss of motor control and function and altered kinematic parameters of reaching movements. Feedback is an essential component of rehabilitation and auditory feedback of kinematic parameters may be a useful tool for rehabilitation of reaching movements at the impairment level. The aim of this study was to investigate the effect of 2 types of auditory feedback on the kinematics of reaching movements in hemiparetic stroke patients and to compare differences between patients with right (RHD) and left hemisphere damage (LHD).     

Neuro-rehabilitation robot-assisted assessments of synergy patterns of forearm,elbow and shoulder joints in chronic stroke patients

Background

Abnormal synergy is one of the major motor deficits in stroke patients. Abnormal muscle synergies, in conjunction with weakness and spasticity, interfere with voluntary movements and restrict the range of motion. This study aimed to quantify abnormal synergies in the affected upper limbs of chronic stroke patients by using a neuro-rehabilitation robot.

Methods

Twelve chronic stroke patients and eight age-matched control subjects were recruited to perform rectilinear tracking movements in four horizontal directions (back–forth, two oblique directions at 45°, and right–left). Kinematic, kinetic and electromyogram data were recorded and used to develop two biomechanical indices and one electromyogram assessment index based on principal component analysis.

Findings

Significant differences between upper limbs of control subjects and the affected side of stroke patients were observed in all three assessment indices. Higher correlation between the elbow joint angle and the forearm pronation/supination torque, higher variation of the forearm torque, and abnormal co-contraction of the elbow and shoulder muscles were observed in the affected limbs of stroke patients. The difference was more prominent in the right–left direction and the oblique direction contra-proximal to ipsi-distal.

Interpretation

The proposed assessment indices could be employed to quantify the abnormal synergies in stroke patients. Rectilinear tracking along the right–left direction and the oblique direction of contra-proximal to ipsi-distal is more suitable for assessing abnormal synergies.     

A new electromechanical trainer for sensorimotor rehabilitation of paralysed fingers: A case series in chronic and acute stroke patients

Background

The functional outcome after stroke is improved by more intensive or sustained therapy. When the affected hand has no functional movement, therapy is mainly passive movements. A novel device for repeating controlled passive movements of paralysed fingers has been developed, which will allow therapists to concentrate on more complicated tasks. A powered cam shaft moves the four fingers in a physiological range of movement.

Methods

After refining the training protocol in 2 chronic patients, 8 sub-acute stroke patients were randomised to receive additional therapy with the Finger Trainer for 20 min every work day for four weeks, or the same duration of bimanual group therapy, in addition to their usual rehabilitation.

Results

In the chronic patients, there was a sustained reduction in finger and wrist spasticity, but there was no improvement in active movements. In the subacute patients, mean distal Fugl-Meyer score (0–30) increased in the control group from 1.25 to 2.75 (ns) and 0.75 to 6.75 in the treatment group (p < .05). Median Modified Ashworth score increased 0/5 to 2/5 in the control group, but not in the treatment group, 0 to 0. Only one patient, in the treatment group, regained function of the affected hand. No side effects occurred.

Conclusion

Treatment with the Finger Trainer was well tolerated in sub-acute & chronic stroke patients, whose abnormal muscle tone improved. In sub-acute stroke patients, the Finger Trainer group showed small improvements in active movement and avoided the increase in tone seen in the control group. This series was too small to demonstrate any effect on functional outcome however.     

Quantification of functional weakness and abnormal synergy patterns in the lower limb of individuals with chronic stroke

Background  

The presence of abnormal muscle activation patterns is a well documented factor limiting the motor rehabilitation of patients following stroke. These abnormal muscle activation patterns, or synergies, have previously been quantified in the upper limbs. Presented here are the lower limb joint torque patterns measured in a standing position of sixteen chronic hemiparetic stroke subjects and sixteen age matched controls used to examine differences in strength and coordination between the two groups.     

Self-adaptive robot training of stroke survivors for continuous tracking movements

Background  

Although robot therapy is progressively becoming an accepted method of treatment for stroke survivors, few studies have investigated how to adapt the robot/subject interaction forces in an automatic way. The paper is a feasibility study of a novel self-adaptive robot controller to be applied with continuous tracking movements.     

Performance adaptive training control strategy for recovering wrist movements in stroke patients: a preliminary, feasibility study

Background  

In the last two decades robot training in neuromotor rehabilitation was mainly focused on shoulder-elbow movements. Few devices were designed and clinically tested for training coordinated movements of the wrist, which are crucial for achieving even the basic level of motor competence that is necessary for carrying out ADLs (activities of daily life). Moreover, most systems of robot therapy use point-to-point reaching movements which tend to emphasize the pathological tendency of stroke patients to break down goal-directed movements into a number of jerky sub-movements. For this reason we designed a wrist robot with a range of motion comparable to that of normal subjects and implemented a self-adapting training protocol for tracking smoothly moving targets in order to facilitate the emergence of smoothness in the motor control patterns and maximize the recovery of the normal RoM (range of motion) of the different DoFs (degrees of Freedom).     

Upper limb impairments associated with spasticity in neurological disorders

Background  

While upper-extremity movement in individuals with neurological disorders such as stroke and spinal cord injury (SCI) has been studied for many years, the effects of spasticity on arm movement have been poorly quantified. The present study is designed to characterize the nature of impaired arm movements associated with spasticity in these two clinical populations. By comparing impaired voluntary movements between these two groups, we will gain a greater understanding of the effects of the type of spasticity on these movements and, potentially a better understanding of the underlying impairment mechanisms.     

Robot-assisted reaching exercise promotes arm movement recovery in chronic hemiparetic stroke: a randomized controlled pilot study

Background and purpose  

Providing active assistance to complete desired arm movements is a common technique in upper extremity rehabilitation after stroke. Such active assistance may improve recovery by affecting somatosensory input, motor planning, spasticity or soft tissue properties, but it is labor intensive and has not been validated in controlled trials. The purpose of this study was to investigate the effects of robotically administered active-assistive exercise and compare those with free reaching voluntary exercise in improving arm movement ability after chronic stroke.     

Modulation of walking speed by changing optic flow in persons with stroke

Background  

Walking speed, which is often reduced after stroke, can be influenced by the perception of optic flow (OF) speed. The present study aims to: 1) compare the modulation of walking speed in response to OF speed changes between persons with stroke and healthy controls and 2) investigate whether virtual environments (VE) manipulating OF speed can be used to promote volitional changes in walking speed post stroke.     

Early versus late‐applied constraint‐induced movement therapy: A multisite,randomized controlled trial with a 12‐month follow‐up

Background and Purpose

A direct comparison between the effects of constraint‐induced movement therapy (CIMT) applied early after stroke and that of CIMT applied in the chronic phase has not been conducted. This study aimed to compare the long‐term effects of CIMT applied 6 months after stroke with the results of CIMT applied within 28 days post‐stroke.

Methods

This study was a single‐blinded, multicentre, randomized controlled trial with a crossover design. Forty‐seven patients received CIMT either early (within 28 days) or 6 months after stroke. Both groups received standard rehabilitation and were tested at 5 time points. The primary outcome measure was Wolf Motor Function Test (WMFT); the secondary measures were Nine‐Hole Peg Test (NHPT), the Fugl‐Meyer Assessment (FMA) of the upper extremity, Stroke Impact Scale, and Modified Rankin Scale (MRS).

Results

Compared with baseline data, both groups showed significant improvements in the primary and secondary outcome measures after 12 months. No significant differences between the 2 treatment groups were found before and after the delayed intervention group received CIMT at 6 months and during the 12‐month follow‐up. Both groups recovered considerably and showed only minor impairment (median FMA score of 64) after 6 months. The early intervention group showed an initially faster recovery curve of WMFT, NHPT, and MRS scores.

Discussion

In contrast to most CIMT studies, our study could not find an effect of CIMT applied 6 months after stroke. Our results indicate that commencing CIMT early is as good as delayed intervention in the long term, specifically in this group of patients who might have reached a ceiling effect during the first 6 months after stroke. Nevertheless, the early CIMT intervention group showed a faster recovery curve than the delayed intervention group, which can be a clinically important finding for patients in the acute phase.     

Adjusting kinematics and kinetics in a feedback-controlled toe walking model

Background

The majority of stroke patients have to cope with impaired arm function. Gravity compensation of the arm instantaneously affects abnormal synergistic movement patterns. The goal of the present study is to examine whether gravity compensated training improves unsupported arm function.

Methods

Seven chronic stroke patients received 18 half-hour sessions of gravity compensated reach training, in a period of six weeks. During training a motivating computer game was played. Before and after training arm function was assessed with the Fugl-Meyer assessment and a standardized, unsupported circle drawing task. Synergistic movement patterns were identified based on concurrent changes in shoulder elevation and elbow flexion/extension angles.

Results

Median increase of Fugl-Meyer scores was 3 points after training. The training led to significantly increased work area of the hemiparetic arm, as indicated by the normalized circle area. Roundness of the drawn circles and the occurrence of synergistic movement patterns remained similar after the training.

Conclusions

A decreased strength of involuntary coupling might contribute to the increased arm function after training. More research is needed to study working mechanisms involved in post stroke rehabilitation training. The used training setup is simple and affordable and is therefore suitable to use in clinical settings.     

Reliability and validity of pendulum test measures of spasticity obtained with the Polhemus tracking system from patients with chronic stroke

Background  

Spasticity is a common impairment accompanying stroke. Spasticity of the quadriceps femoris muscle can be quantified using the pendulum test. The measurement properties of pendular kinematics captured using a magnetic tracking system has not been studied among patients who have experienced a stroke. Therefore, this study describes the test-retest reliability and known groups and convergent validity of the pendulum test measures obtained with the Polhemus tracking system.     

Quantifying kinematics of purposeful movements to real, imagined, or absent functional objects: Implications for modelling trajectories for robot-assisted ADL tasks**

Background  

Robotic therapy is at the forefront of stroke rehabilitation. The Activities of Daily Living Exercise Robot (ADLER) was developed to improve carryover of gains after training by combining the benefits of Activities of Daily Living (ADL) training (motivation and functional task practice with real objects), with the benefits of robot mediated therapy (repeatability and reliability). In combining these two therapy techniques, we seek to develop a new model for trajectory generation that will support functional movements to real objects during robot training. We studied natural movements to real objects and report on how initial reaching movements are affected by real objects and how these movements deviate from the straight line paths predicted by the minimum jerk model, typically used to generate trajectories in robot training environments. We highlight key issues that to be considered in modelling natural trajectories.     

Rehabilitation robotics: pilot trial of a spatial extension for MIT-Manus

Background  

Previous results with the planar robot MIT-MANUS demonstrated positive benefits in trials with over 250 stroke patients. Consistent with motor learning, the positive effects did not generalize to other muscle groups or limb segments. Therefore we are designing a new class of robots to exercise other muscle groups or limb segments. This paper presents basic engineering aspects of a novel robotic module that extends our approach to anti-gravity movements out of the horizontal plane and a pilot study with 10 outpatients. Patients were trained during the initial six-weeks with the planar module (i.e., performance-based training limited to horizontal movements with gravity compensation). This training was followed by six-weeks of robotic therapy that focused on performing vertical arm movements against gravity. The 12-week protocol includes three one-hour robot therapy sessions per week (total 36 robot treatment sessions).     

Controlling patient participation during robot-assisted gait training

Background  

The overall goal of this paper was to investigate approaches to controlling active participation in stroke patients during robot-assisted gait therapy. Although active physical participation during gait rehabilitation after stroke was shown to improve therapy outcome, some patients can behave passively during rehabilitation, not maximally benefiting from the gait training. Up to now, there has not been an effective method for forcing patient activity to the desired level that would most benefit stroke patients with a broad variety of cognitive and biomechanical impairments.     

A pilot study evaluating use of a computer-assisted neurorehabilitation platform for upper-extremity stroke assessment

Background  

There is a need to develop cost-effective, sensitive stroke assessment instruments. One approach is examining kinematic measures derived from goal-directed tasks, which can potentially be sensitive to the subtle changes in the stroke rehabilitation process. This paper presents the findings from a pilot study that uses a computer-assisted neurorehabilitation platform, interfaced with a conventional force-reflecting joystick, to examine the assessment capability of the system by various types of goal-directed tasks.     

Spontaneous cervicocephalic arterial dissection with headache and neck pain as the only symptom

Background and objective  

Cervicocephalic arterial dissection can cause both ischemic stroke and hemorrhagic stroke. However, spontaneous cervicocephalic arterial dissection presenting only with headache and neck pain has rarely been reported. The clinical features of patients with spontaneous cervicocephalic arterial dissection presenting only with headache and neck pain were investigated.     

Internally and Externally Paced Finger Movements Differ in Reorganization After Acute Ischemic Stroke

Askim T, Indredavik B, Håberg A. Internally and externally paced finger movements differ in reorganization after acute ischemic stroke.

Objective

To identify adaptive changes within the motor network for internally and externally paced finger movements in the acute and chronic phase after ischemic stroke.

Design

A functional magnetic resonance imaging study of internally and externally paced thumb-index-finger opposition 4 to 7 days and 3 months after stroke and in healthy controls. Images were compared within and between groups, with the actual number of movements as regressors.

Setting

Stroke Unit, University Hospital.

Participants

Twelve patients with mild to moderate acute ischemic stroke and 15 controls (N=27).

Intervention

Stroke unit treatment focused on very early rehabilitation, followed by early supported discharge service.

Main Outcome Measure

Differences in brain activation between patients and controls and between the tasks.

Results

Patients showed significant improvement in hand function at follow-up. Brain activity related to internally paced finger movements normalized with time. For the externally paced, accurate timing task, brain activity in the chronic phase differed from that seen in the controls despite successful recovery of hand function. In comparing the externally and internally paced tasks, a trend toward recruiting a premotor-parietal-striatal network was found in patients in the chronic phase, whereas controls had increased activation of a sensorimotor network consisting of primary motor cortex, supplementary motor cortex, superior parietal lobe, thalamus, and cerebellum.

Conclusions

After ischemic stroke, brain activity subserving an internally paced motor task normalized with time, whereas motor activity in response to an externally paced task became dependent on a premotor network. These findings underscore the importance of task-specific training in the rehabilitation of stroke patients. In the future, physiotherapists should evaluate the possibility of enhancing the recovery of a more efficient network for externally paced tasks.     

Ambulatory monitoring of activity levels of individuals in the sub-acute stage following stroke: a case series

Background  

There is an important need to better understand the activities of individual patients with stroke outside of structured therapy since this activity is likely to have a profound influence on recovery. A case-study approach was used to examine the activity levels and associated physiological load of patients with stroke throughout a day.     

Effects of intensive arm training with the rehabilitation robot ARMin II in chronic stroke patients: four single-cases

Background  

Robot-assisted therapy offers a promising approach to neurorehabilitation, particularly for severely to moderately impaired stroke patients. The objective of this study was to investigate the effects of intensive arm training on motor performance in four chronic stroke patients using the robot ARMin II.