Changes in the execution of a complex manual task after ipsilateral ischemic cerebral hemispheric stroke

Impairments of the ipsilesional upper-extremity in the first 6-months post-stroke

BACKGROUND

Ipsilesional motor impairments of the arm are common after stroke. Previous studies have suggested that severity of contralesional arm impairment and/or hemisphere of lesion may predict the severity of ipsilesional arm impairments. Historically, these impairments have been assessed using clinical scales, which are less sensitive than robot-based measures of sensorimotor performance. Therefore, the objective of this study was to characterize progression of ipsilesional arm motor impairments using a robot-based assessment of motor function over the first 6-months post-stroke and quantify their relationship to (1) contralesional arm impairment severity and (2) stroke-lesioned hemisphere.

METHODS

A total of 106 participants with first-time, unilateral stroke completed a unilateral assessment of arm motor impairment (visually guided reaching task) using the Kinarm Exoskeleton. Participants completed the assessment along with a battery of clinical measures with both ipsilesional and contralesional arms at 1-, 6-, 12-, and 26-weeks post-stroke.

RESULTS

Robotic assessment of arm motor function revealed a higher incidence of ipsilesional arm impairment than clinical measures immediately post-stroke. The incidence of ipsilesional arm impairments decreased from 47 to 14% across the study period. Kolmogorov-Smirnov tests revealed that ipsilesional arm impairment severity, as measured by our task, was not related to which hemisphere was lesioned. The severity of ipsilesional arm impairments was variable but displayed moderate significant relationships to contralesional arm impairment severity with some robot-based parameters.

CONCLUSIONS

Ipsilesional arm impairments were variable. They displayed relationships of varying strength with contralesional impairments and were not well predicted by lesioned hemisphere. With standard clinical care, 86% of ipsilesional impairments recovered by 6-months post-stroke.

Ipsilateral weakness caused by ipsilateral stroke: A case series

INTRODUCTION

There are few reported cases of ipsilateral weakness following ischemic or hemorrhagic stroke. In these rare cases, ipsilateral weakness is typically the result of damage to uncrossed components of the corticospinal tract (CST) which were recruited in response to previous CST injury.

PATIENTS AND METHODS

We report a series of six cases of acute ipsilateral weakness or numbness following a hemorrhagic or ischemic stroke from three medical institutions in Saudi Arabia.

RESULTS

Three of these patients presented with right-sided weakness caused by an ipsilateral right hemispheric stroke, while two exhibited left-sided symptoms and one had only left-sided numbness. In all six cases, the ipsilateral corona radiata, internal capsule, basal ganglia, insula, and thalamus were involved. No concomitant opposite hemisphere or brainstem lesion in none of the patients was evident. Two patients had previous strokes affecting the brainstem and left corona radiata, respectively. Complete stroke workup to reveal the cause of stroke was carried out, however no functional MRI was performed.

CONCLUSION

Ischemic or hemorrhagic stroke may indeed result in ipsilateral weakness or numbness, though in very rare cases. We assume that the most likely mechanism of their ipsilateral weakness subsequent to the ipsilateral stroke was a functional reorganization favoring CST pathways within the ipsilateral hemisphere.

Chronic Poststroke Deficits in Gross and Fine Motor Control of the Ipsilesional Upper Limb

OBJECTIVES

Individuals with stroke often experience contralesional and ipsilesional arm motor deficits. The aim of this study was to compare fine and gross motor hand dexterity of the ipsilesional hand post-stroke with controls, normative values, and the contralesional hand.

DESIGN

Data were collected from right-handed individuals with chronic stroke (n = 20), age-/sex-matched controls (n = 10), and normative values (n = 20) performing the Nine-Hole Peg Test and the Box and Blocks Test.

RESULTS

Individuals with stroke demonstrated poorer performance with the ipsilesional arm relative to both the control group (mean difference [95% confidence interval]: Nine-Hole Peg Test [seconds], 3.4 [-0.5 to 7.3]; Box and Blocks Test [number of blocks], -12.3 [-20.3 to -4.2]) and normative values (mean difference [95% confidence interval]: Nine-Hole Peg Test [seconds], 6.5 [4.0-9.1]; Box and Blocks Test (number of blocks), -15.3 [-20.1 to -10.5]). Ipsilesional arm performance was significantly better than performance with the contralesional arm (mean difference [95% confidence interval]: Nine-Hole Peg Test [seconds], -9.4 [-20.2 to 1.4]; Box and Blocks Test (number of blocks), 33.2 [20.9-45.5]).

CONCLUSION

These findings identify residual deficits in fine and gross dexterity of the ipsilesional hand in commonly used outcome measures of hand manipulation among individuals with chronic stroke. Possible underlying mechanisms and clinical relevance are discussed.

Accuracy and cut-off points of different models of knee extension strength analysis to identify walking performance in individuals with chronic stroke

BACKGROUND

Adequate muscle strength is essential for walking performance in individuals with stroke.

OBJECTIVE

To investigate the accuracy of different forms of muscle knee extension strength analysis to identify high or low walking performance in individuals with chronic stroke.

METHODS

Twenty-eight participants with a chronic stroke for more than six months participated. Independence for walking was judged by measurement of walking performance assessed for comfortable walking speed (CWS), maximum walking speed (MWS), and the Six Minute Walk Test (6MWT). Peak knee extension torque of the paretic side, non-paretic side, sum of the sides (SS), and difference in the sides (DS) was assessed during concentric movements using an isokinetic dynamometer.

RESULTS

The equation with greatest predictive capacity for CWS and MWS included the DS as the main predictor (R² of 0.65 and 0.71, respectively, p < 0.05). The variable with the greatest predictive capacity for 6MWT was time since injury (R² of 0.68, p < 0.05). The highest percentile for CWS in the receiver operating characteristic curve of DS was 25 Nm/kg (cut-off: -12.75 for CWS of 0.498 m/s). The 75th percentile of the 6MWT (324.3 m) was used as the cut-off for the SS (2.1 Nm/kg). The area under the curve for CWS was 0.76 (p < 0.05) on the DS and 0.75 (p < 0.05) for 6MWT on the SS.

CONCLUSION

The models of muscle knee extension strength analysis using the SS and DS presented moderate accuracy to identify walking performance in individuals with chronic stroke.

Survivors of Chronic Stroke Experience Continued Impairment of Dexterity But Not Strength in the Nonparetic Upper Limb

OBJECTIVE

To investigate the performance of the less affected upper limb in people with stroke compared with normative values. To examine less affected upper limb function in those whose prestroke dominant limb became paretic and those whose prestroke nondominant limb became paretic.

DESIGN

Cohort study of survivors of chronic stroke (7.2±6.7y post incident).

SETTING

The study was performed at a freestanding academic rehabilitation hospital.

PARTICIPANTS

Survivors of chronic stroke (N=40) with severe hand impairment (Chedoke-McMaster Stroke Assessment rating of 2-3 on Stage of Hand) participated in the study. In 20 participants the prestroke dominant hand (DH) was tested (nondominant hand [NH] affected by stroke), and in 20 participants the prestroke NH was tested (DH affected by stroke).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

Jebsen-Taylor Hand Function Test. Data from survivors of stroke were compared with normative age- and sex-matched data from neurologically intact individuals.

RESULTS

When combined, DH and NH groups performed significantly worse on fine motor tasks with their nonparetic hand relative to normative data (P<.007 for all measures). Even the participants who continued to use their prestroke DH as their primary hand after the stroke demonstrated reduced fine motor skills compared with normative data. In contrast, grip strength was not significantly affected in either group of survivors of stroke (P>.140).

CONCLUSIONS

Survivors of stroke with severe impairment of the paretic limb continue to present significant upper extremity impairment in their nominally nonparetic limb even years after stroke. This phenomenon was observed regardless of whether the DH or NH hand was primarily affected. Because this group of survivors of stroke is especially dependent on the nonparetic limb for performing functional tasks, our results suggest that the nonparetic upper limb should be targeted for rehabilitation.

Changes in ipsilesional hand motor function differ after unilateral injury to frontal versus frontoparietal cortices in Macaca mulatta

We tested the hypothesis that injury to frontoparietal sensorimotor areas causes greater initial impairments in performance and poorer recovery of ipsilesional dexterous hand/finger movements than lesions limited to frontal motor areas in rhesus monkeys. Reaching and grasping/manipulation of small targets with the ipsilesional hand were assessed for 6-12 months post-injury using two motor tests. Initial post-lesion motor skill and long-term recovery of motor skill were compared in two groups of monkeys: (1) F2 group-five cases with lesions of arm areas of primary motor cortex (M1) and lateral premotor cortex (LPMC) and (2) F2P2 group-five cases with F2 lesions + lesions of arm areas of primary somatosensory cortex and the anterior portion of area 5. Initial post-lesion reach and manipulation skills were similar to or better than pre-lesion skills in most F2 lesion cases in a difficult fine motor task but worse than pre-lesion skill in most F2P2 lesion cases in all tasks. Subsequently, reaching and manipulation skills improved over the post-lesion period to higher than pre-lesion skills in both groups, but improvements were greater in the F2 lesion group, perhaps due to additional task practice and greater ipsilesional limb use for daily activities. Poorer and slower post-lesion improvement of ipsilesional upper limb motor skill in the F2P2 cases may be due to impaired somatosensory processing. The persistent ipsilesional upper limb motor deficits frequently observed in humans after stroke are probably caused by greater subcortical white and gray matter damage than in the localized surgical injuries studied here.

The Cortical Physiology of Ipsilateral Limb Movements

Whereas voluntary movements have long been understood to derive primarily from the cortical hemisphere contralateral to a moving limb, substantial cortical activations also occur in the same-sided, or ipsilateral, cortical hemisphere. These ipsilateral motor activations have recently been shown to be useful to decode specific movement features. Furthermore, in contrast to the classical understanding that unilateral limb movements are solely driven by the contralateral hemisphere, it appears that the ipsilateral hemisphere plays an active and specific role in the planning and execution of voluntary movements. Here we review the movement-related activations observed in the ipsilateral cortical hemisphere, interpret this evidence in light of the potential roles of the ipsilateral hemisphere in the planning and execution of movements, and describe the implications for clinical populations.

Sensory-motor impairments of ipsilesional extremities and its impact on activity limitations following stroke

Background/Aims

Stroke can result in various motor and sensory impairments on contralesional as well as ipsilesional limbs. This study examined the impact on activity limitations as a result of sensory and motor impairments of ipsilesional limbs following stroke.

Methods

A cross-sectional study was used to assess 50 adults with stroke (acute: n=6, subacute: n=10, chronic: n=34) and 50 age- and gender-matched typically healthy adults. The Modified Ashworth Scale, the Brunnstrom Approach, Nottingham Sensory Assessment, Star Cancellation Test, Right-Left Orientation Test, Trunk Impairment Scale, Single Leg Stance Test, and the Fugl Mayer Assessment were used to measure outcomes for ipsilesional side impairments. Activity limitations were scored using the Wisconsin Gait Scale and the Motor Assessment Scale.

Results

A comparison of all impairments: tonal, voluntary control, sensation, perception, sitting and standing balance, and coordination of the ipsilesional extremity of persons with hemiparesis with corresponding extremity of typically healthy adults using unpaired t-test, showed significant impairment (P<0.05). Every participant with stroke had at least one impairment on their ipsilesional side, with 8% of participants having only one impairment, 36% had two impairments, 28% had three impairments, 18% had four impairments, 8% had five impairments and 2% had all six impairments on their ipsilesional side. The percentage of participants with stroke presenting with trunk impairment was highest (100%) and that of voluntary control impairment was lowest (24%) on their ipsilesional side. The relationship between identified impairments and activity limitations was calculated using Pearson’s correlation at 0.05 level, which showed a moderate negative correlation with the Wisconsin Gait Scale and a moderate positive correlation with the Motor Assessment Scale.

Conclusions

Ipsilesional impairments present in people with hemiparesis have a significant impact on the activity limitation; hence it is necessary to address ipsilesional impairments along with contralesional impairments.

Inhibition of the primary motor cortex and the upgoing thumb sign

Background

The upgoing thumb sign has been frequently observed in patients with minor strokes and transient ischemic attacks as an indicator of brain involvement. We assessed the effect of primary motor cortex (M1) inhibition in the development of the upgoing thumb sign.

Methods

Used repetitive Transcranial Magnetic Stimulation (rTMS, 1 Hz frequency for 15 min, 1s ISI, 900 pulses) at 60% of resting motor threshold to inhibit the right or left primary motor cortex of 10 healthy individuals. Participants were examined before and after rTMS by a neurologist who was blind to the site of motor cortex inhibition.

Results

10 neurological intact participants (5 women/5 men) were recruited for this study. 2 cases were excluded due to pre-existing possible thumb signs. After the inhibition of the primary motor cortex, in 6 subjects out of 8, we observed a thumb sign contralateral to the site of primary motor cortex inhibition. In one subject an ipsilateral thumbs sign was noted. In another case, we did not find an upgoing thumb sign.

Conclusion

The upgoing thumb sign is a subtle neurological finding that may be related to the primary motor cortex or corticospinal pathways involvements.

•

After the inhibition of the primary motor cortex, using repetitive Transcranial Magnetic Stimulation 9 (rTMS), in 7 subjects out of 8, the upgoing thumb sign was observed.

•

The upgoing thumb sign is a subtle neurological finding related to the upper motor neuron involvements.

•

The upgoing thumb sign may be seen in the primary motor cortex or corticospinal pathways lesions.

Impacts of Sensation, Perception, and Motor Abilities of the Ipsilesional Upper Limb on Hand Functions in Unilateral Stroke: Quantifications From Biomechanical and Functional Perspectives

BACKGROUND

The presence of subtle losses in hand dexterity after stroke affects the regaining of independence with regard to activities of daily living. Therefore, awareness of ipsilesional upper extremity (UE) function may be of importance when developing a comprehensive rehabilitation program. However, current hand function tests seem to be unable to identify asymptomatic UE impairments.

OBJECTIVES

To assess the motor coordination as well as the sensory perception of an ipsilesional UE using biomechanical analysis of performance-oriented tasks and conducting a Manual Tactile Test (MTT).

DESIGN

Case-controlled study.

SETTING

A university hospital.

PARTICIPANTS

A total of 21 patients with unilateral stroke, along with 21 matched healthy control subjects, were recruited.

METHODS

Each participant was requested to perform a pinch-holding-up activity (PHUA) test, object-transport task, and reach-to-grasp task via motion capture, as well as the MTT.

MAIN OUTCOME MEASUREMENTS

The kinetic data of the PHUA test, kinematics analysis of functional movements, and time requirement of MTT were analyzed.

RESULTS

Patients with ipsilesional UE had an inferior ability to scale and produce pinch force precisely when conducting the PHUA test compared to the healthy controls (P < .05). The movement time was statistically longer and peak velocity was significantly lower (P < .05) in the performance-oriented tasks for the ipsilesional UE patients. The longer time requirement in 3 MTT subtests showed that the ipsilesional UE patients experienced degradation in sensory perception (P < .001).

CONCLUSION

Comprehensive sensorimotor assessments based on functional perspectives are valid tools to determine deficits in the sensation-perception-motor system in the ipsilesional UE. Integration of sensorimotor training programs for ipsilesional UE in future neuro-rehabilitation strategies may provide more beneficial effects to regain patients' motor recovery and to promote daily living activity independence than focusing on paretic arm motor training alone.

LEVEL OF EVIDENCE

III.

The ipsilesional upper limb can be affected following stroke

OBJECTIVE

Neurological dysfunction commonly occurs in the upper limb contralateral to the hemisphere of the brain in which stroke occurs; however, the impact of stroke on function of the ipsilesional upper limb is not well understood. This study aims to systematically review the literature relating to the function of the ipsilesional upper limb following stroke and answer the following research question: Is the ipsilesional upper limb affected by stroke?

DATA SOURCE

A systematic review was carried out in Medline, Embase, and PubMed.

REVIEW METHODS

All studies investigating the ipsilesional upper limb following stroke were included and analysed for important characteristics. Outcomes were extracted and summarised. Results. This review captured 27 articles that met the inclusion criteria. All studies provided evidence that the ipsilesional upper limb can be affected following stroke.

CONCLUSION

These findings demonstrate that clinicians should consider ipsilesional upper limb deficits in rehabilitation and address this reduced functional capacity. Furthermore, the ipsilesional upper limb should not be used as a "control" measure of recovery for the contralateral upper limb.

Motor recovery of the ipsilesional upper limb in subacute stroke

OBJECTIVE

To investigate the time-related changes in motor performance of the ipsilesional upper limb in subacute poststroke patients by using clinical and kinematic assessments.

DESIGN

Observational, longitudinal, prospective, monocentric study.

SETTING

Physical medicine and rehabilitation department.

PARTICIPANTS

Stroke patients (n=19; mean age, 62.9y) were included less than 30 days after a first unilateral ischemic/hemorrhagic stroke. The control group was composed of age-matched, healthy volunteers (n=9; mean age, 63.1y).

INTERVENTIONS

Clinical and kinematic assessments were conducted once a week during 6 weeks and 3 months after inclusion. Clinical measures consisted of Fugl-Meyer Assessment, Box and Block Test (BBT), Nine-Hole Peg Test (9HPT), and Barthel Index. We used a 3-dimensional motion recording system during a reach-to-grasp task to analyze movement smoothness, movement time, and peak velocity of the hand. Healthy controls performed both clinical (BBT and 9HPT) and kinematic evaluation within a single session.

MAIN OUTCOME MEASURES

BBT and 9HPT.

RESULTS

Recovery of ipsilesional upper arm capacities increased over time and leveled off after a 6-week period of rehabilitation, corresponding to 9 weeks poststroke. At study discharge, patients demonstrated similar ipsilesional clinical scores to controls but exhibited less smooth reaching movements. We found no effect of the hemispheric side of the lesion on ipsilesional motor deficits.

CONCLUSIONS

Our findings provide evidence that ipsilesional motor capacities remain impaired at least 3 months after stroke, even if clinical tests fail to detect the impairment. Focusing on this lasting ipsilesional impairment through a more detailed kinematic analysis could be of interest to understand the specific neural network underlying ipsilesional upper-limb impairment.

Valid and reliable instruments for arm-hand assessment at ICF activity level in persons with hemiplegia: a systematic review

BACKGROUND

Loss of arm-hand performance due to a hemiparesis as a result of stroke or cerebral palsy (CP), leads to large problems in daily life of these patients. Assessment of arm-hand performance is important in both clinical practice and research. To gain more insight in e.g. effectiveness of common therapies for different patient populations with similar clinical characteristics, consensus regarding the choice and use of outcome measures is paramount. To guide this choice, an overview of available instruments is necessary. The aim of this systematic review is to identify, evaluate and categorize instruments, reported to be valid and reliable, assessing arm-hand performance at the ICF activity level in patients with stroke or cerebral palsy.

METHODS

A systematic literature search was performed to identify articles containing instruments assessing arm-hand skilled performance in patients with stroke or cerebral palsy. Instruments were identified and divided into the categories capacity, perceived performance and actual performance. A second search was performed to obtain information on their content and psychometrics.

RESULTS

Regarding capacity, perceived performance and actual performance, 18, 9 and 3 instruments were included respectively. Only 3 of all included instruments were used and tested in both patient populations. The content of the instruments differed widely regarding the ICF levels measured, assessment of the amount of use versus the quality of use, the inclusion of unimanual and/or bimanual tasks and the inclusion of basic and/or extended tasks.

CONCLUSIONS

Although many instruments assess capacity and perceived performance, a dearth exists of instruments assessing actual performance. In addition, instruments appropriate for more than one patient population are sparse. For actual performance, new instruments have to be developed, with specific focus on the usability in different patient populations and the assessment of quality of use as well as amount of use. Also, consensus about the choice and use of instruments within and across populations is needed.

Short-latency crossed spinal responses are impaired differently in sub-acute and chronic stroke patients

OBJECTIVE

Investigate if patients with supraspinal lesions have impaired interlimb spinal reflex pathways. The short-latency crossed spinal response will be investigated during sitting from the non-paretic to paretic and paretic to non-paretic extremities at different stimulation intensities in chronic and sub-acute stroke patients.

METHODS

The ipsilateral tibial nerve of the paretic and non-paretic extremities were stimulated at motor threshold, 35% M-max and 85% M-max of the ipsilateral soleus while the contralateral soleus was contracted from 5% to 15% of the maximum voluntary contraction of the paretic soleus.

RESULTS

Chronic patients (from both extremities) had significantly less prominent inhibitory responses than healthy controls (post hoc tests: P<.01-P<.05). The responses were significantly modulated by stimulus intensity in healthy controls and chronic patients (P<.001-P<.05) but not sub-acute patients (P>.05). Some sub-acute patients had significantly more variable responses than chronic patients and healthy controls (P<.001-P⩽.05).

CONCLUSIONS

Short-latency interlimb reflexes are impaired differently in sub-acute vs. chronic patients, are impaired from the non-paretic and paretic extremity, and abnormal when compared to healthy controls.

SIGNIFICANCE

The inappropriate coordination could result in an inability to quickly avoid obstacles following a mechanical disturbance to the ipsilateral extremity. It also indicates that bilateral descending projections affect the response.

Volumetric effects of motor cortex injury on recovery of ipsilesional dexterous movements

Damage to the motor cortex of one hemisphere has classically been associated with contralateral upper limb paresis, but recent patient studies have identified deficits in both upper limbs. In non-human primates, we tested the hypothesis that the severity of ipsilesional upper limb motor impairment in the early post-injury phase depends on the volume of gray and white matter damage of the motor areas of the frontal lobe. We also postulated that substantial recovery would accompany minimal task practice and that ipsilesional limb recovery would be correlated with recovery of the contralesional limb. Gross (reaching) and fine hand motor functions were assessed for 3-12 months post-injury using two motor tests. Volumes of white and gray matter lesions were assessed using quantitative histology. Early changes in post-lesion motor performance were inversely correlated with white matter lesion volume indicating that larger lesions produced greater decreases in ipsilesional hand movement control. All monkeys showed improvements in ipsilesional hand motor skill during the post-lesion period, with reaching skill improvements being positively correlated with total lesion volume indicating that larger lesions were associated with greater ipsilesional motor skill recovery. We suggest that reduced trans-callosal inhibition from the lesioned hemisphere may play a role in the observed skill improvements. Our findings show that significant ipsilesional hand motor recovery is likely to accompany injury limited to frontal motor areas. In humans, more pronounced ipsilesional motor deficits that invariably develop after stroke may, in part, be a consequence of more extensive subcortical white and gray matter damage.

Dissociation of initial trajectory and final position errors during visuomotor adaptation following unilateral stroke

Previous studies have demonstrated that following stroke, motor impairment can occur ipsilateral to the lesion. Such impairments have provided insight into the contributions of each hemisphere to movement control, showing that left and right hemisphere damage produce different effects on movement: Left hemisphere damage produces deficits in specifying features of movement trajectory, while right hemisphere damage produces deficits in achieving an accurate and stable final position. We now propose that left and right hemisphere damage should also produce different deficits in the adaptation of trajectory and position. To test this idea, we examined adaptation to visuomotor rotations in the ipsilesional arms of hemiparetic stroke patients with left (LHD) and right hemisphere damage (RHD). We found that LHD interfered with adaptation of initial direction, but not with the ability to adapt the final position of the limb. In contrast, RHD interfered with online corrections to the final position during the course of adaptation. These findings support our hypothesis that the control of trajectory and steady-state position may be lateralized to the left and right hemispheres, respectively.

Hemispheric specialization and functional impact of ipsilesional deficits in movement coordination and accuracy

Previous studies have demonstrated that following unilateral stroke, motor impairment occurs both contralateral, as well as ipsilateral, to the lesion. Although ipsilesional impairments can be functionally limiting, they can also provide important insight into the role of the ipsilateral hemisphere in controlling movement and the lateralization of specific motor control mechanisms, given that unilateral arm movements are thought to recruit processes in each hemisphere. The purpose of this study was to examine whether left and right hemisphere damage following stroke produces different ipsilesional deficits, and whether our dynamic dominance model of motor lateralization can predict such deficits. Specifically, the dynamic dominance model attributes control of multijoint dynamics to the left hemisphere, and control of steady-state position to the right hemisphere. Chronic stroke patients with either left or right hemisphere damage (LHD or RHD) used their ipsilesional arm, and the control subjects used either their left or right arm (LHC or RHC), to perform targeted reaching movements in different directions within the workspace ipsilateral to their reaching arm. We found that the LHD group showed deficits in controlling the arm's trajectory due to impaired multijoint coordination, but no deficits in achieving accurate final positions. In contrast, the RHD group showed deficits in final position accuracy but not in the ability to coordinate multiple joints during movement, thereby providing additional evidence for the hemisphere-specific nature of motor deficits. Furthermore, while both the LHD and RHD groups were functionally impaired to the same degree on the Jebsen Hand Function Test (JHFT), our results suggest that the underlying mechanisms for such impairment may be hemisphere-dependent.

Motor dysfunction of the "non-affected" lower limb: a kinematic comparative study between hemiparetic stroke and total knee prosthesized patients

In patients with hemispheric stroke, abnormal motor performances are described also in the ipsilateral limbs. They may be due to a cortical reorganization in the unaffected hemisphere; moreover, also peripheral mechanisms may play a role. To explore this hypothesis, we studied motor performances in 15 patients with hemispheric stroke and in 14 patients with total knee arthroplasty, which have a reduced motility in the prosthesized leg. Using the unaffected leg, they performed five superimposed circular trajectories in a prefixed pathway on a computerized footboard, while looking at a marker on the computer screen. The average trace error was significantly different between the groups of patients and healthy subjects [F ((2,25)) = 7.9; p = 0.003]; on the contrary, the test time execution did not vary significantly. In conclusion, both groups of patients showed abnormal motor performances of the unaffected leg; this result suggests a likely contribution of peripheral mechanisms.

Dexterity is impaired at both hands following unilateral subcortical middle cerebral artery stroke

Dexterity was investigated in right-handed subjects in the subacute phase of a first unilateral subcortical middle cerebral artery stroke affecting the left or right hemisphere and right-handed healthy subjects. Dexterity was quantified at both hands by kinematic recordings of finger and hand tapping, a reach-to-grasp movement, quantitative analysis of grip forces in a grasp-lift task and clinical rating scales. Stroke subjects exhibited significant deficits in timing and coordination of tapping movements at both the contralesional and ipsilesional hands, irrespective of the hemisphere affected. Likely for the reach-to-grasp and grasp-lift movements a bilateral impairment was found in stroke subjects. In particular, slowing of hand transport towards the object, deficient timing and scaling of grasp formation, discoordination between grip and lift forces and inefficient scaling of grip forces were observed. The severity of impairment was independent of the hemisphere affected and evident for both the reach (involving more proximal muscles of the arm) and grasp (involving more distal muscles of the arm and hand) components of the task. Strong correlations were found between clinical scores of hand function and loss of sensibility with the deficits in timing, coordination and efficiency of movement of the contralesional and ipsilesional hand. These data provide evidence that dexterity is impaired at both hands after subcortical middle cerebral artery stroke.

Ipsilesional motor deficits following stroke reflect hemispheric specializations for movement control

Recent reports of functional impairment in the 'unaffected' limb of stroke patients have suggested that these deficits vary with the side of lesion. This not only supports the idea that the ipsilateral hemisphere contributes to arm movements, but also implies that such contributions are lateralized. We have previously suggested that the left and right hemispheres are specialized for controlling different features of movement. In reaching movements, the non-dominant arm appears better adapted for achieving accurate final positions and the dominant arm for specifying initial trajectory features, such as movement direction and peak acceleration. The purpose of this study was to determine whether different features of control could characterize ipsilesional motor deficits following stroke. Healthy control subjects and patients with either left- or right-hemisphere damage performed targeted single-joint elbow movements of different amplitudes in their ipsilateral hemispace. We predicted that left-hemisphere damage would produce deficits in specification of initial trajectory features, while right-hemisphere damage would produce deficits in final position accuracy. Consistent with our predictions, patients with left, but not right, hemisphere damage showed reduced modulation of acceleration amplitude. However, patients with right, but not left, hemisphere damage showed significantly larger errors in final position, which corresponded to reduced modulation of acceleration duration. Neither patient group differed from controls in terms of movement speed. Instead, the mechanisms by which speed was specified, through modulation of acceleration amplitude and modulation of acceleration duration, appeared to be differentially affected by left- and right-hemisphere damage. These findings support the idea that each hemisphere contributes differentially to the control of initial trajectory and final position, and that ipsilesional deficits following stroke reflect this lateralization in control.

Targeted Aiming Movements Are Compromised in Nonaffected Limb of Persons With Stroke

Background. Research has shown that movement impairments following stroke are typically associated with the limb contralateral to the side of the stroke. Prior studies identified ipsilateral motor declines across a variety of tasks. Objective. Two experiments were conducted to better understand the ipsilateral contributions to organization and execution of proximal upper extremity multisegment aiming movements in persons with right-hemispheric stroke. Methods. Participants performed reciprocal aiming (Experiment 1) and 2-segment aiming movements (Experiment 2) on a digitizing tablet. In both experiments, target size and/or target orientation were manipulated to examine the influence of accuracy constraints on the planning and organization of movements. Results. Kinematic measures, submovement analysis, and harmonicity measures were included in this study. Declines in organization and execution of multisegment movements were found to contribute to performance decrements and slowing in stroke patients. Furthermore, stroke patients were unable to efficiently plan multisegment movements as one functional unit, resulting in discrete movements. Conclusions . Results suggest the importance of considering ipsilateral contributions to the control and organization of targeted aiming movements as well as implications for rehabilitation and recovery.

Executive Function Deficits in Acute Stroke

OBJECTIVES

To establish the frequency of executive dysfunction during acute hospitalization for stroke and to examine the relationship of that dysfunction to stroke severity and premorbid characteristics.

DESIGN

Inception cohort study.

SETTING

Inpatient wards at a Veterans Affairs hospital.

PARTICIPANTS

Consecutive sample of inpatients with radiologically or neurologically confirmed stroke. Final sample included 47 patients screened for aphasia and capable of neuropsychologic testing. Two nonstroke inpatient control samples (n=10 each) with either transient ischemic attack (TIA) or multiple stroke risk factors were administered the same research procedure and tests.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Composite cognitive impairment ratio (CIR), calculated from 8 scores indicative of executive function on 6 neuropsychologic tests by dividing number of tests completed into the number of scores falling below cutoff point, defined as 1.5 standard deviations below normative population mean.

RESULTS

Stroke patients had a mean CIR of .61, compared with .48 for TIAs and .44 for stroke-risk-only. Analysis of variance revealed that CIRs of stroke-risk-only patients but not TIAs were lower than those of the stroke patients (P=.02). Impairment frequencies were at least 50% for stroke patients on most test scores. The Symbol Digit Modalities Test (75% impairment) and a design fluency measure distinguished stroke from nonstroke patients. CIR was not related to stroke severity in the stroke patient sample, but was related to estimated premorbid intelligence.

CONCLUSIONS

Executive function deficits are common in stroke patients. The data suggest that limitations in information processing due to these deficits may require environmental and procedural accommodations to increase rehabilitation benefit.

How can corticospinal tract neurons contribute to ipsilateral movements? A question with implications for recovery of motor functions

In this review, the authors discuss some recent findings that bear on the issue of recovery of function after corticospinal tract lesions. Conventionally the corticospinal tract is considered to be a crossed pathway, in keeping with the clinical findings that damage to one hemisphere, for example, in stroke, leads to a contralateral paresis and, if the lesion is large, a paralysis. However, there has been great interest in the possibility of compensatory recovery of function using the undamaged hemisphere. There are several substrates for this including ipsilaterally descending corticospinal fibers and bilaterally operating neuronal networks. Recent studies provide important evidence bearing on both of these issues. In particular, they reveal networks of neurons interconnecting two sides of the gray matter at both brainstem and spinal levels, as well as intrahemispheric transcallosal connections. These may form "detour circuits" for recovery of function, and here the authors will consider some possibilities for exploiting these networks for motor control, even though their analysis is still at an early stage.

Évaluation des incapacités fonctionnelles chez le patient hémiplégique : mise au point

OBJECTIVES

To identify and describe the most useful functional disability scales for assessing post-stroke hemiplegic patients and those used largely in clinical trials.

METHODS

A literature review of Medline about the functional parameters for balance, gait and mobility, upper extremity functional abilities, and activities of daily living. The metrologic properties of the scales were specified as were their clinical use.

RESULTS

Thirty-three scales were evaluated and classified into five categories: balance (6 scales), gait and mobility (4), upper limb function (11), global motricity scales (5) and independence in activities of daily living (7).

DISCUSSION AND CONCLUSION

Many functional scales are useful for assessing post-stroke hemiplegic patients. To assess balance, the Postural Assessment Stroke Scale and Berg Balance Scale are the most interesting. The Functional Ambulation Classification and the Timed Up and Go Test are the most relevant to assess gait and mobility. The Action Research Arm Test is largely used to assess upper limb functional abilities. The Functional Independence Measure and the Barthel Index are largely used to assess independence in activities of daily living.

Functional implications of ipsilesional motor deficits after unilateral stroke

OBJECTIVE

To investigate the functional impact of ipsilesional motor deficits after unilateral stroke and the best predictors of those deficits.

DESIGN

Observational cohort.

SETTING

Primary care Veterans Affairs and private medical center.

PARTICIPANTS

Volunteer right-handed sample; stroke patients with left (LHD) or right hemisphere damage (RHD) a mean of 3.9 to 5.2 years poststroke and able-bodied participants who were tested using their left (LAB) or right hand.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

The Jebsen-Taylor Hand Function Test (JHFT).

RESULTS

Ipsilesional JHFT performance was impaired to the same extent in the LHD and RHD groups. LHD patients with apraxia had poorer scores on the JHFT than LHD patients without apraxia and the LAB group. Regression analyses showed that severity of apraxia was the best predictor of JHFT performance for the LHD group and that right (ipsilesional) motor performance (grip strength, finger tapping) was the best predictor of JHFT performance for the RHD group.

CONCLUSIONS

Ipsilesional deficits are present on simulated activities of daily living after LHD or RHD, suggesting that rehabilitation after stroke should include the ipsilesional arm and that ipsilesional limb apraxia is a better predictor of ipsilesional functional motor skills after LHD than aphasia or simple motor skills (grip strength, finger tapping). These findings suggest that limb apraxia should be assessed more routinely after stroke of the left hemisphere.

Evidence for bilateral control of skilled movements: ipsilateral skilled forelimb reaching deficits and functional recovery in rats follow motor cortex and lateral frontal cortex lesions

Unilateral damage to cortical areas in the frontal cortex produces sensorimotor deficits on the side contralateral to the lesion. Although there are anecdotal reports of bilateral deficits after stroke in humans and in experimental animals, little is known of the effects of unilateral lesions on the same side of the body. The objective of the present study was to make a systematic examination of the motor skills of the ipsilateral forelimb after frontal cortex lesions to either the motor cortex by devascularization of the surface blood vessels (pial stroke), or to the lateral cortex by electrocoagulation of the distal branches of the middle cerebral artery (MCA stroke). Plastic processes in the intact hemisphere were documented using Golgi-Cox dendritic analysis and by intracortical microstimulation analysis. Although tests of reflexive responses in forelimb placing identified a contralateral motor impairment following both cortical lesions, quantitative and qualitative measures of skilled reaching identified a severe ipsilateral impairment from which recovery was substantial but incomplete. Golgi-impregnated pyramidal cells in the forelimb area showed an increase in dendritic length and branching. Electrophysiological mapping showed normal size forelimb representations in the lesioned rats relative to control animals. The finding of an enduring ipsilateral impairment in skilled movement is consistent with a large but more anecdotal literature in rats, nonhuman primates and humans, and suggests that plastic changes in the intact hemisphere are related to that hemisphere's contribution to skilled movement.

Ipsilesional deficits during fast diadochokinetic hand movements following unilateral brain damage

Impaired sensorimotor function of the hand ipsilateral to a unilateral brain lesion has been reported in a variety of motor tasks; however, elementary diadochokinetic movements, such as tapping with the index finger, seem to be preserved in chronic-lesion patients. Three different diadochokinetic movements (forearm diadochokinesis, hand tapping (HT) and finger tapping (FT)) were tested in patients with left brain damage (LBD) and right brain damage (RBD) and control subjects. Movements were measured three-dimensionally and the kinematics of joint angles were analyzed. While the patients' measures of movement speed and symmetry appeared normal, detailed kinematic analysis revealed clear deficits in several measures of movement variability, which reflected decreased regularity of the alternating movement cycles. This impairment was greater in LBD patients and tended to be greater during forearm diadochokinesis. The necessity of ipsilateral control in addition to dominant, contralateral control, especially during left hand and more complex or more proximal manual tasks may account for these findings. In addition, the role of apraxia (defined by impairments during the imitation of gestures) in the performance deficits of LBD patients was also assessed. Although, some performance decrements were associated with the presence of apraxia, these were different from the group findings and restricted to the two tapping tasks. Thus, although apraxia may have caused deficits in establishing dynamic representations of the elementary postures in conditions of high speed and low complexity, the disturbances during diadochokinetic movements must for the most part be attributed to more motor-related deficits of ipsilateral sensorimotor control, which are particularly apparent when the motor dominant left hemisphere is affected. The absence of clear correlations between performance deficits and lesion characteristics suggests that a distributed network is involved in this ipsilateral control.

The ABILHAND questionnaire as a measure of manual ability in chronic stroke patients: Rasch-based validation and relationship to upper limb impairment

BACKGROUND AND PURPOSE

Chronic hemiparetic patients often retain the ability to manage activities requiring both hands, either through the use of the affected arm or compensation with the unaffected limb. A measure of this overall ability was developed by adapting and validating the ABILHAND questionnaire through the Rasch measurement model. ABILHAND measures the patient's perceived difficulty in performing everyday manual activities.

METHODS

One hundred three chronic (>6 months) stroke outpatients (62% men; mean age, 63 years) were assessed (74 in Belgium, 29 in Italy). They lived at home and walked independently and were screened for the absence of major cognitive deficits (dementia, aphasia, hemineglect). The patients were administered the ABILHAND questionnaire, the Brunnström upper limb motricity test, the box-and-block manual dexterity test, the Semmes-Weinstein tactile sensation test, and the Geriatric Depression Scale. The brain lesion type and site were recorded. ABILHAND results were analyzed with the use of Winsteps Rasch software.

RESULTS

The Rasch refinement of ABILHAND led to a change from the original unimanual and bimanual 56-item, 4-level scale to a bimanual 23-item, 3-level scale. The resulting ability scale had sufficient sensitivity to be clinically useful. Rasch reliability was 0.90, and the item-difficulty hierarchy was stable across demographic and clinical subgroups. Grip strength, motricity, dexterity, and depression were significantly correlated with the ABILHAND measures.

CONCLUSIONS

The ABILHAND questionnaire results in a valid person-centered measure of manual ability in everyday activities. The stability of the item-difficulty hierarchy across different patient classes further supports the clinical application of the scale.

Upper and lower face apraxia: role of the right hemisphere

The aim of this study was to evaluate face apraxia in left- and right-hemisphere-damaged patients both in the acute and chronic stage of their disease. Two newly devised tests that assess movements of the upper and lower face districts were employed. On the whole, the proportion of left-hemisphere-damaged patients showing face apraxia were 46 and 68% for upper and lower face, respectively. A substantial proportion of right-hemisphere-damaged patients also showed face apraxia, i.e. 44% upper face and 38% lower face. Concomitant variables such as general severity, locus of lesion, language or visuo-spatial impairments, presence of neglect, interval from stroke, peculiarity of clusters of items or scoring procedures did not account for these results. These findings suggest that face apraxia in some patients may affect movements of the upper face district and that the right hemisphere plays a significant part in both upper and lower face praxis.

Normative and validation studies of the Nine-hole Peg Test with children

This study evaluated norms for fine motor dexterity skills on elementary school children of ages 5 through 10 and conducted reliability and validity stud ies utilizing the Nine-hole Peg Test. The sample included 826 students in 10 elementary schools. Moderately high test-retest reliability (rs = .81 and .79) and high interrater agreement (rs > .99) were obtained. Older students had shorter completion time that measured fine motor dexterity than younger students. Significant sex differences were found in completion time, but only for the dominant hand. Correlations of -.80 and -.74 between the scores on the Nine hole Peg Test and Purdue Pegboard Test at all tested ages indicated adequate concurrent validity of the measures and a significant difference in test scores between regular and special education groups provided further evidence of construct validity. The findings supported the Nine-hole Peg Test as an effective screening tool for fine motor dexterity of school-age children.

Recovery of ipsilateral dexterity after stroke

BACKGROUND AND PURPOSE; Previous work indicated that patients within 1 month of parietal or posterior frontal damage are often abnormally slow or clumsy when using the ipsilateral hand for dexterity tasks. This article reports a 6-month follow-up study to assess recovery and the impact on functional outcome.

METHODS

Twenty-four patients (80%) were available for follow-up. They used the ipsilateral hand on a dexterity test that simulated everyday hand function. Weakness and ideomotor apraxia were also assessed. Performance was compared with that of healthy age-matched control subjects using the same hand. Rating scales for self-care and dexterity in everyday life were completed by patients and carers.

RESULTS

Significant recovery had occurred on all measures, but patients with left hemisphere damage remained impaired on the dexterity test, with 7 patients (58%) scoring below the normal range. Five of these were apraxic. Reports of everyday functioning did not reflect this impairment, but there were inconsistencies in these reports, which raised doubts as to their accuracy.

CONCLUSIONS

Ipsilateral dexterity shows recovery during the first 6 months, but there may be persistent impairment related to apraxia after left hemisphere stroke. It appears that the impact of this on functional outcome is typically small compared with the large effect of severity of contralateral paresis. It may be a significant factor in some cases, however, and direct observation of everyday functioning would be needed to clarify more subtle effects on outcome.

Quantification of force abnormalities during passive and active-assisted upper-limb reaching movements in post-stroke hemiparesis

We evaluated a method for measuring abnormal upper-limb motor performance in post-stroke hemiparetic subjects. A servomechanism (MIME) moved the forearm in simple planar trajectories, directly controlling hand position and forearm orientation. Design specifications are presented, along with system performance data during an initial test of 13 stroke subjects with a wide range of impairment levels. Performance of subjects was quantified by measuring the forces and torques between the paretic limb and the servomechanism as the subjects relaxed (passive), or attempted to generate force in the direction of movement (active). During passive movements, the more severely impaired subjects resisted movement, producing higher levels of negative work than less-impaired subjects and neurologically normal controls. During active movements, the more severely impaired subjects produced forces with larger directional errors, and were less efficient in producing work. These metrics had significant test-retest repeatability. These motor performance metrics can potentially detect smaller within-subject changes than motor function scales. This method could complement currently used measurement tools for the evaluation of subjects during recovery from stroke, or during therapeutic interventions.

Impaired dexterity of the ipsilateral hand after stroke and the relationship to cognitive deficit

BACKGROUND AND PURPOSE

Previous research has reported impaired hand function on the "unaffected" side after stroke, but its incidence, origins, and impact on rehabilitation remain unclear. This study investigated whether impairment of ipsilateral dexterity is common early after middle cerebral artery stroke and explored the relationship to cognitive deficit.

METHODS

Thirty patients within 1 month of an infarct involving the parietal or posterior frontal lobe (15 left and 15 right hemisphere) used the ipsilateral hand in tests that simulated everyday hand functions. Performance was compared with that of healthy age-matched controls using the same hand. Standardized tests were used to assess apraxia, visuospatial ability, and aphasia.

RESULTS

All patients were able to complete the dexterity tests, but video analysis showed that performance was slow and clumsy compared with that of controls (P<0.001). Impairment was most severe after left hemisphere damage, and apraxia was a strong correlate of increased dexterity errors (P<0.01), whereas reduced ipsilateral grip strength correlated with slowing (P<0.05). The pattern of performance was different for patients with right hemisphere damage. Here there was no correlation between grip strength and slowing, while dexterity errors appeared to be due to visuospatial problems.

CONCLUSIONS

Subtle impairments in dexterity of the ipsilateral hand are common within 1 month of stroke. Ipsilateral sensorimotor losses may contribute to these impairments, but the major factor appears to be the presence of cognitive deficits affecting perception and control of action. The nature of these deficits varies with side of brain damage. The effect of impaired dexterity on functional outcome is not yet known.