Leeanne M. Carey

Task-specific training : evidence for and translation to clinical practice.

There is mounting evidence of the value of task-specific training as a neuromotor intervention in neurological rehabilitation. The evidence is founded in the psychology of motor skill learning and in the neuroscience of experience-dependent and learning-dependent neural plastic changes in the brain in animals and humans. Further, there is growing empirical evidence for the effectiveness of task-specific training in rehabilitation and for neural plastic changes following task-oriented training. In this paper, we position the evidence for task-specific training in the context of rehabilitation; review its relevance for occupation-based neurological rehabilitation, particularly in relation to upper limb function and everyday activities; and recommend evidence-driven strategies for its application. We recommend that task-specific training be routinely applied by occupational therapists as a component of their neuromotor interventions, particularly in management related to post-stroke upper limb recovery. Specifically, we propose five implementation strategies based on review of the evidence. These are: task-specific training should be relevant to the patient/client and to the context; be randomly assigned; be repetitive and involve massed practice; aim towards reconstruction of the whole task; and be reinforced with positive and timely feedback.

Sensory loss in stroke patients: Effective training of tactile and proprioceptive discrimination

Although somatosensory loss following stroke is common, with negative consequences for functional outcome, studies of existing somatosensory retraining programs are limited by theoretical weaknesses, poor methodology, and negative findings. We, therefore, developed a new program for stroke patients and investigated its effect on tactile discrimination in four AB, single-case quasi-experiments and its effect on tactile and proprioceptive discrimination in four multiple-baseline experiments. Training involved specific, graded discrimination tasks, attentive exploration of stimuli with vision occluded, deliberate anticipation, and quantitative feedback. Graphic and statistical interrupted time-series analyses indicated that treatment produced improvements in seven of eight tactile time series and all four proprioceptive time series. Baseline improvement in one tactile time series prevented unequivocal evaluation of treatment effect. Improvements were clinically significant, discrimination in the affected hand becoming comparable to the other hand and normal performance. Therapeutic effects were maintained at 3-month to 5-month follow-up tests.

Impaired limb position sense after stroke: A quantitative test for clinical use☆☆☆★

OBJECTIVE A quantitative measure of wrist position sense was developed to advance clinical measurement of proprioceptive limb sensibility after stroke. Test-retest reliability, normative standards, and ability to discriminate impaired and unimpaired performance were investigated. DESIGN Retest reliability was assessed over three sessions, and a matched-pairs study compared stroke and unimpaired subjects. Both wrists were tested, in counterbalanced order. SETTING Patients were tested in hospital-based rehabilitation units. PATIENTS AND OTHER PARTICIPANTS Reliability was investigated on a consecutive sample of 35 adult stroke patients with a range of proprioceptive discrimination abilities and no evidence of neglect. A consecutive sample of 50 stroke patients and convenience sample of 50 healthy volunteers, matched for age, sex, and hand dominance, were tested in the normative-discriminative study. Age and sex were representative of the adult stroke population. MAIN OUTCOME MEASURES The test required matching of imposed wrist positions using a pointer aligned with the axis of movement and a protractor scale. RESULTS The test was reliable (r = .88 and .92) and observed changes of 8 degrees can be interpreted, with 95% confidence, as genuine. Scores of healthy volunteers ranged from 3.1 degrees to 10.9 degrees average error. The criterion of impairment was conservatively defined as 11 degrees (+/-4.8 degrees) average error. Impaired and unimpaired performance were well differentiated. CONCLUSIONS Clinicians can confidently and quantitatively sample one aspect of proprioceptive sensibility in stroke patients using the wrist position sense test. Development of tests on other joints using the present approach is supported by our findings.

Fish Oil Diet Associated with Acute Reperfusion Related Hemorrhage, and with Reduced Stroke-Related Sickness Behaviors and Motor Impairment

Ischemic stroke is associated with motor impairment and increased incidence of affective disorders such as anxiety/clinical depression. In non-stroke populations, successful management of such disorders and symptoms has been reported following diet supplementation with long chain omega-3-polyunsaturated-fatty-acids (PUFAs). However, the potential protective effects of PUFA supplementation on affective behaviors after experimentally induced stroke and sham surgery have not been examined previously. This study investigated the behavioral effects of PUFA supplementation over a 6-week period following either middle cerebral artery occlusion or sham surgery in the hooded-Wistar rat. The PUFA diet supplied during the acclimation period prior to surgery was found to be associated with an increased risk of acute hemorrhage following the reperfusion component of the surgery. In surviving animals, PUFA supplementation did not influence infarct size as determined 6 weeks after surgery, but did decrease omega-6-fatty-acid levels, moderate sickness behaviors, acute motor impairment, and longer-term locomotor hyperactivity and depression/anxiety-like behavior.

Evolution of Brain Activation with Good and Poor Motor Recovery after Stroke

Objective. To characterize the evolution of brain activation in stroke patients with variable motor recovery and quantify changes relative to healthy controls. Methods. Serial PET activation studies, using a simple finger-tapping task, and quantitative measures of motor performance were obtained in 9 patients (2-7 weeks poststroke and 6 months later) and compared with serial healthy volunteer data. Results. Patients with moderate impairment and good recovery (n = 5) activated the primary sensorimotor cortex (SM1) contralateral to the paretic hand moved, bilateral supplementary motor area (SMA), contralateral cingulate gyrus, and ipsilateral lateral premotor cortex. Activation in the bilateral SMA was greater at the initial study but reduced over time compared to healthy controls and poor recoverers. Patients with severe impairment and poor recovery (n =4) showed limited activation of contralateral SM1 and SMA at both studies and no significant change over time. A posterior shift in SM1 activation was evident in good and poor recoverers. Conclusions. Activation of typical motor regions and recruitment of additional sites occur subacutely poststroke, with evolution to normal patterns in moderately impaired patients who recover well. In comparison, severely impaired, poor-recovery patients show persistent, reduced activation. Dynamic changes in SMA, differentially observed in good recoverers over 6 months, highlight its importance in recovery.

Motor Impairment and Recovery in the Upper Limb After Stroke. Behavioral and Neuroanatomical Correlates

Background and Purpose— Motor recovery after stroke is associated with cerebral reorganization. However, few studies have investigated the relationship directly, and findings are equivocal. We therefore aimed to characterize the relationship between motor impairment, motor recovery, and task-related changes in regional cerebral blood flow (&Dgr;rCBF) longitudinally. Methods— We obtained a profile of motor impairment and recovery in the upper limb and conducted positron emission tomography motor activation studies using a simple finger-tapping task in 9 stroke patients 2 to 7 weeks after stroke and 6 months later. For correlation analysis, mean images of task-related &Dgr;rCBF for each individual were linearly regressed with motor impairment scores. Motor recovery was correlated with longitudinal &Dgr;rCBF images. Results— Patients (7 males; 72.0±9.8 years) demonstrated a wide range of impairment severity and variable recovery. Upper-limb motor function was linearly correlated with task-related &Dgr;rCBF. Importantly, sites of correlated &Dgr;rCBF differed over time. Subacutely correlated &Dgr;rCBF was observed in supplementary motor area (SMA), bilateral cingulate, and contralesional insula with a small area in ipsilesional primary sensorimotor cortex (SM1). Conversely, at the 6-month study, correlated &Dgr;rCBF was primarily in ipsilesional SM1, extending to the cingulate gyrus. Better motor recovery was correlated with reduction in contralesional activity and increase in ipsilesional SM1. Conclusions— Upper-limb motor function and recovery are correlated with &Dgr;rCBF in SMA, cingulate, insula, and SM1, highlighting the role of these areas in the recovery process. The dynamic nature of the relationship suggests ongoing adaptation within motor networks.

SENSe : Study of the Effectiveness of Neurorehabilitation on Sensation : A randomized controlled trial

Background. Sensory loss is common after stroke, with negative impact on exploration of the immediate environment, hand function, and return to daily activities. Objective. To compare the effectiveness of a perceptual-learning based sensory discrimination program versus non-specific exposure to sensory stimuli via passive movements and grasping of common objects. Methods. The authors conducted a randomized parallel-group controlled trial, with blinding of subjects, clinical assessors, and data analysts. Fifty subjects with impaired texture discrimination, limb position sense, and/or tactile object recognition (>6 weeks, median 48 weeks poststroke) were randomized to receive somatosensory discrimination training (n = 25) or repeated exposure to sensory stimuli (n = 25) in 60-minute sessions for a total of 10 hours. The primary outcome was change in a composite standardized somatosensory deficit (SSD) index following intervention. Follow-up was at 6 weeks and 6 months posttraining. Results. Between-group comparisons revealed a significantly greater improvement in sensory capacity following sensory discrimination training, t(47) = 2.75, P = .004, 1-tailed; mean between-group change = 11.1 SSD; confidence interval 3.0 to 19.2. Improvements were maintained at 6 weeks and 6 months. Conclusion. Sensory discrimination training can achieve significant improvements in functional sensory discrimination capacity after stroke. The clinically oriented training achieved transfer of training effects to novel stimuli. Our findings provide support for introducing SENSe discrimination training in rehabilitation of sensory deficits after stroke.

Impaired Discrimination of Surface Friction Contributes to Pinch Grip Deficit After Stroke

Background. Impaired sensation and force production could both contribute to handgrip limitation after stroke. Clinically, training is usually directed to motor impairment rather than sensory impairment despite the prevalence of sensory deficit and the importance of sensory input for grip control. Objective. The aim of this study was to investigate if sensory deficits contribute to pinch grip dysfunction beyond that attributable to motor deficits poststroke. Methods. The study enlisted 45 stroke participants and 45 healthy controls matched for age, gender, and hand dominance. Ability to differentiate surface friction (Friction Discrimination Test [FDT]), match object weight (Weight Matching Test [WMT]), produce grip force to track a visual target (Visually Guided Pinch Test [VGPT]), and perform a Pinch-Grip Lift-and-Hold Test (PGLHT) was quantified relative to normative performance, as defined by matched controls. The relationship between sensory ability (FDT, WMT) and altered PGLHT performance adjusted for motor ability (VGPT) after stroke was then examined using multivariate regression. Results. Deficits in FDT, WMT, and VGPT ability were present in at least half of the stroke sample and were largely independent across the variables. Poorer friction discrimination was significantly associated with longer latencies of grip-lift (r = .34; P = .03) and grip force dysregulation (r= .34; P= .03) after the impact of VGPT was statistically removed from PGLHT ability. However, performance on WMT did not relate to either PGLHT deficit. Conclusion. The findings indicate that impaired friction discrimination ability contributes to altered timing and force adjustment during PGLHT poststroke.

Functional neuroimaging in stroke recovery and neurorehabilitation : Conceptual issues and perspectives.

Background In stroke, functional neuroimaging has become a potent diagnostic tool; opened new insights into the pathophysiology of ischaemic damage in the human brain; and made possible the assessment of functional–structural relationships in postlesion recovery. Summary of review Here, we give a critical account on the potential and limitation of functional neuroimaging and discuss concepts related to the use of neuroimaging for exploring the neurobiological and neuroanatomical mechanisms of poststroke recovery and neurorehabilitation. We identify and provide evidence for five hypotheses that functional neuroimaging can provide new insights into: adaptation occurs at the level of functional brain systems; the brain–behaviour relationship varies with recovery and over time; functional neuroimaging can improve our ability to predict recovery and select individuals for rehabilitation; mechanisms of recovery reflect different pathophysiological phases; and brain adaptation may be modulated by experience and specific rehabilitation. The significance and application of this new evidence is discussed, and recommendations made for investigations in the field. Conclusion Functional neuroimaging is an important tool to explore the mechanisms underlying brain plasticity and, thereby, to guide clinical research in neurorehabilitation.

Measuring participation after stroke: a review of frequently used tools

OBJECTIVE To identify and critique the measures currently used to assess participation in clinical stroke studies. DATA SOURCES Relevant articles published between January 2001 and April 2012 identified through Medline, CINAHL, and ProQuest Central databases. STUDY SELECTION Published articles involving poststroke assessment of participation. Case studies, cohort studies, and randomized controlled trials were included. DATA EXTRACTION The most frequently used measures were identified and the psychometric properties evaluated. Three raters independently evaluated each measure relative to the first and second coding levels of the International Classification of Functioning, Disability and Health (ICF) Activities and Participation domain categories. DATA SYNTHESIS Thirty-six measures were identified. The Stroke Impact Scale (SIS), London Handicap Scale, Assessment of Life Habits (LIFE-H), Frenchay Activities Index, and Activity Card Sort (ACS) were used most frequently. No single measure met criteria across all psychometric indices, and not one covered all 9 of the ICF Activities and Participation domains. The SIS, LIFE-H, and ACS covered the widest range. The domains covered most frequently were Community, Social and Civic Life, Domestic Life, and Mobility. Learning and Applying Knowledge, General Tasks and Demands, and Communication were the domains less frequently covered. CONCLUSIONS This review identified and evaluated the most frequently used participation measures in clinical stroke studies. The SIS, LIFE-H, and ACS covered the ICF Activities and Participation domain categories most comprehensively. However, none of the measures covered all the ICF Activities and Participation domain categories. The information provided in this systematic review can be used to guide the selection of participation measures to meet specific clinical and research purposes.