Sean P. Dukelow

Quantitative Assessment of Limb Position Sense Following Stroke

Background. Impairment of position sense of the upper extremity (UE) may impede activities of daily living and limit motor gains after stroke. Most clinical assessments of position sense rely on categorical or ordinal ratings by clinicians that lack sensitivity to change or the ability to discriminate subtle deficits. Objective. Use robotic technology to develop a reliable, quantitative technique with a continuous scale to assess UE position sense following stroke. Methods. Forty-five patients recruited from an inpatient stroke rehabilitation service and 65 age-matched healthy controls performed an arm position matching task. Each UE was fitted in the exoskeleton of a KINARM device. One UE was passively placed in one of 9 positions, and the subject was told to match his or her position with the other UE. Patients were compared with statistical distributions of control data to identify those with deficits in UE position sense. Test—retest sessions using 2 raters established interrater reliability. Results. Two thirds of left hemiparetic and one third of right hemiparetic patients had deficits in limb position sense. Left-affected stroke subjects demonstrated significantly more trial-to-trial variability than right-affected or control subjects. The robotic assessment technique demonstrated good interrater reliability but limited agreement with the clinical thumb localizing test. Conclusions. Robotic technology can provide a reliable quantitative means to assess deficits in limb position sense following stroke.

Potential of robots as next-generation technology for clinical assessment of neurological disorders and upper-limb therapy

Robotic technologies have profoundly affected the identification of fundamental properties of brain function. This success is attributable to robots being able to control the position of or forces applied to limbs, and their inherent ability to easily, objectively, and reliably quantify sensorimotor behavior. Our general hypothesis is that these same attributes make robotic technologies ideal for clinically assessing sensory, motor, and cognitive impairments in stroke and other neurological disorders. Further, they provide opportunities for novel therapeutic strategies. The present opinionated review describes how robotic technologies combined with virtual/augmented reality systems can support a broad range of behavioral tasks to objectively quantify brain function. This information could potentially be used to provide more accurate diagnostic and prognostic information than is available from current clinical assessment techniques. The review also highlights the potential benefits of robots to provide upper-limb therapy. Although the capital cost of these technologies is substantial, it pales in comparison with the potential cost reductions to the overall healthcare system that improved assessment and therapeutic interventions offer.

Assessment of Upper-Limb Sensorimotor Function of Subacute Stroke Patients Using Visually Guided Reaching

Objective. Using robotic technology, we examined the ability of a visually guided reaching task to assess the sensorimotor function of patients with stroke. Methods. Ninety-one healthy participants and 52 with subacute stroke of mild to moderate severity (26 with left- and 26 with right-affected body sides) performed an unassisted reaching task using the KINARM robot. Each participant was assessed using 12 movement parameters that were grouped into 5 attributes of sensorimotor control. Results. A number of movement parameters individually identified a large number of stroke participants as being different from 95% of the controls—most notably initial direction error, which identified 81% of left-affected patients. We also found interlimb differences in performance between the arms of those with stroke compared with controls. For example, whereas only 31% of left-affected participants showed differences in reaction time with their affected arm, 54% showed abnormal interlimb differences in reaction time. Good interrater reliability (r > 0.7) was observed for 9 of the 12 movement parameters. Finally, many stroke patients deemed impaired on the reaching task had been scored 6 or less on the arm portion of the Chedoke-McMaster Stroke Assessment Scale, but some who scored a normal 7 were also deemed impaired in reaching. Conclusions. Robotic technology using a visually guided reaching task can provide reliable information with greater sensitivity about a patient’s sensorimotor impairments following stroke than a standard clinical assessment scale.

The independence of deficits in position sense and visually guided reaching following stroke

BackgroundSeveral studies have found correlations between proprioception and visuomotor function during stroke recovery, however two more recent studies have found no correlation. Unfortunately, most of the studies to date have been conducted with clinical assessments of sensation that are observer-based and have poor reliability. We have recently developed new tests to assess position sense and motor function using robotic technology. The present study was conducted to reassess the relationship between position sense and upper limb movement following stroke.MethodsWe assessed position sense and motor performance of 100 inpatient stroke rehabilitation subjects and 231 non-disabled controls. All subjects completed quantitative assessments of position sense (arm-position matching task) and motor performance (visually-guided reaching task) using the KINARM robotic device. Subjects also completed clinical assessments including handedness, vision, Purdue Pegboard, Chedoke-McMaster Stroke Assessment-Impairment Inventory and Functional Independence Measure (FIM). Neuroimaging documented lesion localization. Fisher’s exact probability tests were used to determine the relationship between performances on the arm-position matching and visually-guided reaching task. Pearson’s correlations were conducted to determine the relationship between robotically measured parameters and clinical assessments.ResultsPerformance by individual subjects on the matching and reaching tasks was statistically independent (Fisher’s test, P<0.01). However, performance on the matching and reaching tasks both exhibited relationships with abilities in daily activities as measured by the FIM. Performance on the reaching task also displayed strong relationships with other clinical measures of motor impairment.ConclusionsOur data support the concept that position sense deficits are functionally relevant and point to the importance of assessing proprioceptive and motor impairments independently when planning treatment strategies.

Canadian stroke best practice recommendations: Stroke rehabilitation practice guidelines, update 2015:

Stroke rehabilitation is a progressive, dynamic, goal-orientated process aimed at enabling a person with impairment to reach their optimal physical, cognitive, emotional, communicative, social and/or functional activity level. After a stroke, patients often continue to require rehabilitation for persistent deficits related to spasticity, upper and lower extremity dysfunction, shoulder and central pain, mobility/gait, dysphagia, vision, and communication. Each year in Canada 62,000 people experience a stroke. Among stroke survivors, over 6500 individuals access in-patient stroke rehabilitation and stay a median of 30 days (inter-quartile range 19 to 45 days). The 2015 update of the Canadian Stroke Best Practice Recommendations: Stroke Rehabilitation Practice Guidelines is a comprehensive summary of current evidence-based recommendations for all members of multidisciplinary teams working in a range of settings, who provide care to patients following stroke. These recommendations have been developed to address both the organization of stroke rehabilitation within a system of care (i.e., Initial Rehabilitation Assessment; Stroke Rehabilitation Units; Stroke Rehabilitation Teams; Delivery; Outpatient and Community-Based Rehabilitation), and specific interventions and management in stroke recovery and direct clinical care (i.e., Upper Extremity Dysfunction; Lower Extremity Dysfunction; Dysphagia and Malnutrition; Visual-Perceptual Deficits; Central Pain; Communication; Life Roles). In addition, stroke happens at any age, and therefore a new section has been added to the 2015 update to highlight components of stroke rehabilitation for children who have experienced a stroke, either prenatally, as a newborn, or during childhood. All recommendations have been assigned a level of evidence which reflects the strength and quality of current research evidence available to support the recommendation. The updated Rehabilitation Clinical Practice Guidelines feature several additions that reflect new research areas and stronger evidence for already existing recommendations. It is anticipated that these guidelines will provide direction and standardization for patients, families/caregiver(s), and clinicians within Canada and internationally.

Robotic Identification of Kinesthetic Deficits After Stroke

Background and Purpose— Kinesthesia, the sense of body motion, is essential to proper control and execution of movement. Despite its importance for activities of daily living, no current clinical measures can objectively measure kinesthetic deficits. The goal of this study was to use robotic technology to quantify prevalence and severity of kinesthetic deficits of the upper limb poststroke. Methods— Seventy-four neurologically intact subjects and 113 subjects with stroke (62 left-affected, 51 right-affected) performed a robot-based kinesthetic matching task with vision occluded. The robot moved the most affected arm at a preset speed, direction, and magnitude. Subjects were instructed to mirror-match the movement with their opposite arm (active arm). Results— A large number of subjects with stroke were significantly impaired on measures of kinesthesia. We observed impairments in ability to match movement direction (69% and 49% impaired for left- and right-affected subjects, respectively) and movement magnitude (42% and 31%). We observed impairments to match movement speed (32% and 27%) and increased response latencies (48% and 20%). Movement direction errors and response latencies were related to clinical measures of function, motor recovery, and dexterity. Conclusions— Using a robotic approach, we found that 61% of acute stroke survivors (n=69) had kinesthetic deficits. Additionally, these deficits were highly related to existing clinical measures, suggesting the importance of kinesthesia in day-to-day function. Our methods allow for more sensitive, accurate, and objective identification of kinesthetic deficits after stroke. With this information, we can better inform clinical treatment strategies to improve poststroke rehabilitative care and outcomes.

Functional Electrical Stimulation and Spinal Cord Injury

Spinal cord injuries (SCI) can disrupt communications between the brain and the body, resulting in loss of control over otherwise intact neuromuscular systems. Functional electrical stimulation (FES) of the central and peripheral nervous system can use these intact neuromuscular systems to provide therapeutic exercise options to allow functional restoration and to manage medical complications following SCI. The use of FES for the restoration of muscular and organ functions may significantly decrease the morbidity and mortality following SCI. Many FES devices are commercially available and should be considered as part of the lifelong rehabilitation care plan for all eligible persons with SCI.

Efficacy and safety of non-immersive virtual reality exercising in stroke rehabilitation (EVREST): a randomised, multicentre, single-blind, controlled trial

BACKGROUND Non-immersive virtual reality is an emerging strategy to enhance motor performance for stroke rehabilitation. There has been rapid adoption of non-immersive virtual reality as a rehabilitation strategy despite the limited evidence about its safety and effectiveness. Our aim was to compare the safety and efficacy of virtual reality with recreational therapy on motor recovery in patients after an acute ischaemic stroke. METHODS In this randomised, controlled, single-blind, parallel-group trial we enrolled adults (aged 18-85 years) who had a first-ever ischaemic stroke and a motor deficit of the upper extremity score of 3 or more (measured with the Chedoke-McMaster scale) within 3 months of randomisation from 14 in-patient stroke rehabilitation units from four countries (Canada [11], Argentina [1], Peru [1], and Thailand [1]). Participants were randomly allocated (1:1) by a computer-generated assignment at enrolment to receive a programme of structured, task-oriented, upper extremity sessions (ten sessions, 60 min each) of either non-immersive virtual reality using the Nintendo Wii gaming system (VRWii) or simple recreational activities (playing cards, bingo, Jenga, or ball game) as add-on therapies to conventional rehabilitation over a 2 week period. All investigators assessing outcomes were masked to treatment assignment. The primary outcome was upper extremity motor performance measured by total time to complete the Wolf Motor Function Test (WMFT) at the end of the 2 week intervention period, analysed in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NTC01406912. FINDINGS The study was done between May 12, 2012, and Oct 1, 2015. We randomly assigned 141 patients: 71 received VRWii therapy and 70 received recreational activity. 121 (86%) patients (59 in the VRWii group and 62 in the recreational activity group) completed the final assessment and were included in the primary analysis. Each group improved WMFT performance time relative to baseline (decrease in median time from 43·7 s [IQR 26·1-68·0] to 29·7 s [21·4-45·2], 32·0% reduction for VRWii vs 38·0 s [IQR 28·0-64·1] to 27·1 s [21·2-45·5], 28·7% reduction for recreational activity). Mean time of conventional rehabilitation during the trial was similar between groups (VRWii, 373 min [SD 322] vs recreational activity, 397 min [345]; p=0·70) as was the total duration of study intervention (VRWii, 528 min [SD 155] vs recreational activity, 541 min [142]; p=0·60). Multivariable analysis adjusted for baseline WMFT score, age, sex, baseline Chedoke-McMaster, and stroke severity revealed no significant difference between groups in the primary outcome (adjusted mean estimate of difference in WMFT: 4·1 s, 95% CI -14·4 to 22·6). There were three serious adverse events during the trial, all deemed to be unrelated to the interventions (seizure after discharge and intracerebral haemorrhage in the recreational activity group and heart attack in the VRWii group). Overall incidences of adverse events and serious adverse events were similar between treatment groups. INTERPRETATION In patients who had a stroke within the 3 months before enrolment and had mild-to-moderate upper extremity motor impairment, non-immersive virtual reality as an add-on therapy to conventional rehabilitation was not superior to a recreational activity intervention in improving motor function, as measured by WMFT. Our study suggests that the type of task used in motor rehabilitation post-stroke might be less relevant, as long as it is intensive enough and task-specific. Simple, low-cost, and widely available recreational activities might be as effective as innovative non-immersive virtual reality technologies. FUNDING Heart and Stroke Foundation of Canada and Ontario Ministry of Health.

Robotic assessment of sensorimotor deficits after traumatic brain injury.

Background and Purpose: Robotic technology is commonly used to quantify aspects of typical sensorimotor function. We evaluated the feasibility of using robotic technology to assess visuomotor and position sense impairments following traumatic brain injury (TBI). We present results of robotic sensorimotor function testing in 12 subjects with TBI, who had a range of initial severities (9 severe, 2 moderate, 1 mild), and contrast these results with those of clinical tests. We also compared these with robotic test outcomes in persons without disability. Methods: For each subject with TBI, a review of the initial injury and neuroradiologic findings was conducted. Following this, each subject completed a number of standardized clinical measures (Fugl-Meyer Assessment, Purdue Peg Board, Montreal Cognitive Assessment, Rancho Los Amigos Scale), followed by two robotic tasks. A visually guided reaching task was performed to assess visuomotor control of the upper limb. An arm position-matching task was used to assess position sense. Robotic task performance in the subjects with TBI was compared with findings in a cohort of 170 person without disabilities. Results: Subjects with TBI demonstrated a broad range of sensory and motor deficits on robotic testing. Notably, several subjects with TBI displayed significant deficits in one or both of the robotic tasks, despite normal scores on traditional clinical motor and cognitive assessment measures. Discussion and Conclusions: The findings demonstrate the potential of robotic assessments for identifying deficits in visuomotor control and position sense following TBI. Improved identification of neurologic impairments following TBI may ultimately enhance rehabilitation.

A robotic object hitting task to quantify sensorimotor impairments in participants with stroke

BackgroundExisting clinical scores of upper limb function often use observer-based ordinal scales that are subjective and commonly have floor and ceiling effects. The purpose of the present study was to develop an upper limb motor task to assess objectively the ability of participants to select and engage motor actions with both hands.MethodsA bilateral robotic system was used to quantify upper limb sensorimotor function of participants with stroke. Participants performed an object hit task that required them to hit virtual balls moving towards them in the workspace with virtual paddles attached to each hand. Task difficulty was initially low, but increased with time by increasing the speed and number of balls in the workspace. Data were collected from 262 control participants and 154 participants with recent stroke.ResultsControl participants hit ~60 to 90% of the 300 balls with relatively symmetric performance for the two arms. Participants with recent stroke performed the task with most participants hitting fewer balls than 95% of healthy controls (67% of right-affected and 87% of left-affected strokes). Additionally, nearly all participants (97%) identified with visuospatial neglect hit fewer balls than healthy controls. More detailed analyses demonstrated that most participants with stroke displayed asymmetric performance between their affected and non-affected limbs with regards to number of balls hit, workspace area covered by the limb and hand speed. Inter-rater reliability of task parameters was high with half of the correlations above 0.90. Significant correlations were observed between many of the task parameters and the Functional Independence Measure and/or the Behavioural Inattention Test.ConclusionsAs this object hit task requires just over two minutes to complete, it provides an objective and easy approach to quantify upper limb motor function and visuospatial skills following stroke.