Effects of a Stimulus Response Task Using Virtual Reality on Unilateral Spatial Neglect: A Randomized Controlled Trial.

OBJECTIVE: To investigate the effects of a stimulus response task using virtual reality (VR) for unilateral spatial neglect (USN). DESIGN: Double-blind randomized controlled trial. SETTING: Acute phase hospital where stroke patients are hospitalized. PARTICIPANTS: The participants were 42 patients (N=42) with right-hemisphere cerebral damage who had been experiencing USN in their daily lives. They were randomly assigned to 3 groups: a stimulus response task with a background shift (SR+BS group), a stimulus response task without a background shift (SR group), and an object gazing task (control group). INTERVENTIONS: The stimulus response task was to search for balloons that suddenly appeared on the VR screen. A background shift was added to highlight the search in the neglected space. The control task was to maintain a controlled gaze on a balloon that appeared on the VR screen. The intervention period was 5 days. MAIN OUTCOME MEASURES: The primary outcome was the participants' scores on a stimulus-driven attention test (SAT) using the reaction time. The stimuli of the SAT were divided into 6 blocks of 3 lines on each side (-3 to +3). The secondary outcomes were their scores on the Behavioral Intention Test conventional, Catherine Bergego Scale, and straight ahead pointing tests. RESULTS: In the SAT, there were significant interaction effects of reaction time between time and group factors in left-2, right+2, and right+3. The SR+BS and SR groups showed significant improvements in the reaction time of left-2 and right+3 compared with the control group. Moreover, the SR+BS group showed a significant improvement in the reaction time of left-2, which was the neglected space, compared with the SR group. However, there were no significant interaction effects of Behavioral Intention Test conventional, Catherine Bergego Scale, and straight ahead pointing. CONCLUSIONS: Our results suggest that the use of stimulus response tasks using VR combined with background shifts may improve left-sided USN.

Effects of Functional Electrical Stimulation on Attention and Brain Activity in Healthy Participants Using Near-Infrared Spectroscopy: An Interventional Study.

Background Involuntary limb activation using functional electrical stimulation (FES) can improve unilateral spatial neglect. However, the impact of FES on brain activity related to spatial attention remains unclear. Thus, in this study, we aimed to examine the effects of FES on spatial attention. Methodology In this interventional study, 13 healthy right-handed participants were asked to perform the Posner task for six minutes both before and after either FES or sham stimulation during each set, resulting in a total of two sets. FES was applied to the left forearm extensor muscles, with a frequency of 25 Hz, a pulse width of 100 µs, and the intensity adjusted to reach the motor threshold. Both the energization and pause times were set to five seconds. The Posner task was used to measure reaction time to a target appearing on a computer screen. Brain activity, indicated by oxygenated hemoglobin values, was measured using near-infrared spectroscopy with 24 probes according to the International 10-20 system method. Results In the left hemisphere, oxygenated hemoglobin values in the premotor and supplementary motor areas, primary somatosensory cortex, and somatosensory association areas were significantly higher after FES than after sham stimulation. In the right hemisphere, oxygenated hemoglobin values were significantly increased in the premotor, primary, and supplementary motor areas; in the supramarginal gyrus; and in the somatosensory association areas after FES. Reaction times in the Posner task did not differ significantly between the FES and sham conditions. Conclusions Collectively, these results suggest that FES of the upper limbs can activate the ventral pathway of the visual attention network and improve stimulus-driven attention. Activation of stimulus-driven attentional function could potentially contribute to symptom improvement in patients with unilateral spatial neglect.

Effects of galvanic vestibular stimulation on postural righting reactions in hemiplegia.

Patients with post-stroke hemiplegia often exhibit reduced ability to maintain sitting balance, a crucial factor for predicting prognosis. Galvanic vestibular stimulation (GVS) influences postural control by stimulating vestibular organ. Although several studies have focused on GVS in static postures, no studies have demonstrated the influence of GVS on righting reactions. Therefore, we aimed to investigate the effects of GVS on postural righting reactions in seated patients with stroke-induced hemiplegia. Using a vertical board (VB), righting reactions were induced by tilting the VB at 10° after patients sat for 1 min. Patients adjusted their bodies until feeling vertical upon prompt. Twenty-two left hemiplegic patients with cerebrovascular disease participated, divided into two groups undergoing right cathode GVS (RC-GVS) followed by left cathode GVS or vice versa, preceded by sham stimulation. Centre of pressure and the joint angle were measured. During the postural righting reactions towards the paralysed side, RC-GVS enhanced the righting reactions and moved the mean position on the x-axis (COPx) to the right and the mean position on the y-axis (COPy) to the front. During the postural righting reaction towards the right side, RC-GVS induced resistance against the righting reaction, COPx was deflected to the right, COPy was deflected backward, and the angle of the neck tilt increased. The findings revealed that GVS with anodal stimulation on the paralysed side could promote righting reactions in patients with post-stroke hemiplegia. SIGNIFICANCE STATEMENT: The study findings suggest that using the contralesional placement of the anode promotes righting reactions, and galvanic vestibular stimulation can induce joint movements in the neck and trunk by polarising it to act as resistance against righting reactions.

Immediate effects of standing unstable board intervention on the non-paralyzed leg on sitting balance in severe hemiplegia: a randomized controlled trial.

BACKGROUND: Unstable board intervention for patients with stroke improves sitting balance and trunk function. However, because patients with severe stroke are at high risk of falling, it is mostly adapted in mild cases. OBJECTIVE: We aimed to examine the effect of standing unstable board intervention for the non-paralyzed lower limbs on sitting balance in patients with hemiplegia. METHODS: The participants were 42 patients with stroke who were randomly assigned to a control or intervention group. In the intervention group, the non-paralyzed leg was placed on an unstable board, and the patient wore a knee-ankle-foot orthosis on the paralyzed side and practiced standing and weight-bearing exercises on the unstable board for 3 days. The outcomes were the angle of righting reaction of the neck, trunk, and both lower legs and the movement distance of the center of pressure of the righting reaction from lateral tilted sitting. RESULTS: In the intervention group, the righting reaction angle of the trunk to the paralyzed and non-paralyzed sides and the movement distance of the center of pressure were increased significantly after the unstable board intervention. CONCLUSION: The standing unstable board intervention for the non-paralyzed lower limb increased sensory input to the non-paralyzed side of the trunk weight-bearing on the lower limb of the paralyzed side. The increase in the righting reaction angle and the movement distance of the center of pressure contributed to improved sitting balance.

Differences in the early stages of motor learning between visual-motor illusion and action observation.

The visual-motor illusion (VMI) induces a kinesthetic illusion by watching one's physically-moving video while the body is at rest. It remains unclear whether the early stages (immediately to one hour later) of motor learning are promoted by VMI. This study investigated whether VMI changes the early stages of motor learning in healthy individuals. Thirty-six participants were randomly assigned to two groups: the VMI or action observation condition. Each condition was performed with the left hand for 20 min. The VMI condition induced a kinesthetic illusion by watching one's ball-rotation task video. The action observation condition involved watching the same video as the VMI condition but did not induce a kinesthetic illusion. The ball-rotation task and brain activity during the task were measured pre, post1 (immediately), and post2 (after 1 h) in both conditions, and brain activity was measured using functional near-infrared spectroscopy. The rate of the ball-rotation task improved significantly at post1 and post2 in the VMI condition than in the action observation condition. VMI condition lowers left dorsolateral prefrontal cortex and right premotor area activity from post1 to pre compared to the action observation condition. In conclusion, VMI effectively aids early stages of motor learning in healthy individuals.

Effects of Visual-Motor Illusion via Image Videos Showing Increased Exercise Intensity on the Tibial Anterior during Sit-to-Stand Movement: A Study of Healthy Participants.

Visual-motor illusion (VMI) elicits kinesthetic sensation from visual stimulation. We have previously performed ankle motion VMI with resistance applied to the ankle joint on the paralyzed side (power-VMI (P-VMI)) and ankle motion VMI without resistance (standard-VMI (S-VMI)) to activate the tibialis anterior (TA) muscle in stroke-paralyzed patients and compared sit-to-stand (STS) durations, but these studies did not measure TA activity during the STS movement. The purpose of this study was to evaluate the effects of different intensities of visual stimuli presented during VMI on TA and STS movement. Healthy right-footed adults (n = 18) observed two different VMI videos of ankle dorsiflexion, including S-VMI and P-VMI, with an observation time of 2 min each. STS movement was evaluated before and after watching each video. Each participant performed both S-VMI and P-VMI interventions on the same day. Only P-VMI enhanced the integrated electromyogram of the TA, increased the angular velocities of the trunk forward inclination and the ankle dorsiflexion, and shortened the STS duration. Our results indicate that P-VMI facilitates the activation of TA during STS, and we believe that we have clarified the intervention mechanism of VMI.

Effects of Task-related Trunk Training with Sensory Electrical Stimulation on Sitting Balance in Stroke Survivors: A Randomized Controlled Trial.

Objectives: The aim of this study was to investigate the immediate effect of sensory electrical stimulation (SES) and task-related trunk training (TRTT) interventions on sitting postural control in stroke survivors. Methods: Acute to subacute stroke survivors were screened and recruited for this study. Patients were randomly assigned to the SES group, receiving TRTT combined with simultaneous SES of the neck and lumbar muscles, or to the sham group, receiving TRTT combined with sham stimulation. The primary outcome of the sitting task assessment was the joint angles of the neck and trunk. The outcome was measured at three time points (baseline; online effect: 10 min after the intervention started while the intervention continued; and after-effect: immediately after the intervention). Results: In total, 26 patients were divided into the SES (n=13) and sham (n=13) groups. The SES group showed a significant increase in the trunk joint angle for the online effect (P=0.03) and the after-effect (P=0.01) when compared with those measured at baseline. Conclusions: TRTT combined with simultaneous SES of the neck and lumbar muscles can immediately change the trunk angle during a sitting balancing task.

Effect of stimulation-driven attention in virtual reality balloon search training of patients with left unilateral spatial neglect after stroke: A randomized crossover study.

Patients with unilateral spatial neglect (USN) commonly experiences stimulus-driven attention deficit characterized by unexpected stimuli detection. We investigated whether virtual reality (VR) balloon search training with the screen background shifted to left space could improve stimulus-driven attention in patients with USN. The participants were divided into two groups: immediate VR group (n = 14) and delayed VR group (n = 14). The immediate VR group first received VR balloon search training, followed by control training, for two weeks each. Delayed VR group received the same training in reverse order. Outcomes were changes in scores on Catherine Bergego Scale (CBS) and reaction time on the modified Posner task (MPT). There was significant improvement in CBS score change after VR balloon retrieval training (all F > 2.71; P < 0.002). In the invalid condition of MPT, significant improvements were shown after VR balloon search training in left-sided reaction time (improvement of stimulation-driven attention). This study shows that VR balloon search training can improve neglect symptoms by using an intensive intervention lasting 2 weeks.

Intra- and inter-rater reliability of angle assessment for righting reaction from a tilted sitting position in healthy participants.

[Purpose] Lateral balance and the righting reaction are related to trunk function and many activities of daily living. However, there are no studies evaluating the assessment of the righting reaction while ensuring safety. This study aimed to clarify the reliability of assessments for the righting reaction from a tilted sitting position in healthy participants. [Participants and Methods] The participants of this study included 28 healthy young adults. Before the start of the study, markers were attached to the participants for data collection. Participants were asked to sit on a vertical board, tilted 10 degrees, and were asked to perform the righting reaction. This test was repeated four times on each side. The actions were recorded with a video camera, and two analysts used the Image J software to calculate the angles of the righting reaction of the neck, trunk, and left and right lower legs. [Results] High reliability was obtained regardless of the tilt direction and site of righting reaction. In addition, no adverse events occurred. [Conclusion] It was possible to evaluate the righting reaction while ensuring safety, and reproducibility was confirmed.

Recovery process of vertical perception and activities of daily living in stroke patients: A retrospective cohort study.

INTRODUCTION: Clarifications regarding the recovery process of the subjective postural vertical (SPV) and activities of daily living in stroke patients are required to help clinicians determine treatment plans. Therefore, we aimed to investigate the characteristics of the longitudinal recovery process of SPV and activities of daily living after stroke. METHODS: Overall, 109 patients with stroke were enrolled. Clinical assessments included the SPV and total functional independence measure (FIM), initially and after 1 month. The mean and standard deviation of SPV indicated the directional and variability errors, respectively. Participants were categorized as follows: nondeviation group comprised directional and variability errors within the standard values, deviation of variability errors group comprised directional errors within the standard value and variability errors greater than the standard value, and deviation of both directional and variability errors group comprised directional and variability errors greater than the standard values. In addition, a two-way analysis of variance was performed for initial pre- and post-SPV, and pre- and posttotal FIM scores (p < .05). RESULTS: The deviation of variability errors group, and deviation of both directional and variability errors group, had larger SPV variability errors than did the nondeviation group. Furthermore, the deviation of variability errors group showed a significant improvement in variability errors after 1 month. There was a correlation between the initial SPV with eyes opened variability error and total FIM after 1 month in Pusher patients with unilateral spatial neglect in the deviation of both directional and variability errors group. CONCLUSIONS: SPV with eyes opened variability errors and initial FIM score may influence the independence of activities of daily living after 1 month in the recovery of patients with stroke with Pusher and unilateral spatial neglect.

Predictive factors for walking in acute stroke patients: a multicenter study using classification and regression tree analysis.

[Purpose] Walking ability should be predicted as early as possible in acute stroke patients. The purpose is to construct a prediction model for independent walking from bedside assessments using classification and regression tree analysis. [Participants and Methods] We conducted a multicenter case-control study with 240 stroke patients. Survey items included age, gender, injured hemisphere, the National Institute of Health Stroke Scale, the Brunnstrom Recovery Stage for lower extremities, and "turn over from a supine position" from the Ability for Basic Movement Scale. The National Institute of Health Stroke Scale items, such as language, extinction, and inattention, were grouped under higher brain dysfunction. We used the Functional Ambulation Categories to classify patients into independent (four or more the Functional Ambulation Categories; n=120) and dependent (three or fewer the Functional Ambulation Categories; n=120) walking groups. A classification and regression tree analysis was used to create a model to predict independent walking. [Results] The Brunnstrom Recovery Stage for lower extremities, "turn over from a supine position" from the Ability for Basic Movement Scale, and higher brain dysfunction were the splitting criteria for classifying patients into four categories: Category 1 (0%), severe motor paresis; Category 2 (10.0%), mild motor paresis and could not turn over; Category 3 (52.5%), with mild motor paresis, could turn over, and had higher brain dysfunction; and Category 4 (82.5%), with mild motor paresis, could turn over, and no higher brain dysfunction. [Conclusion] We constructed a useful prediction model for independent walking based on the three criteria.

Immediate Effect of an Intervention Using a Head-mounted Display with a Modified Pitch Angle on Spatial Awareness and Standing Balance in Stroke Hemiparesis.

Objectives: This study aimed to clarify the effect of an intervention using a head-mounted display with a web camera set at a modified pitch angle on spatial awareness, sit-to-stand movement, and standing balance in patients with left and right hemisphere damage. Methods: The participants were 12 patients with right hemisphere damage and 12 patients with left hemisphere damage. The line bisection test, a sit-to-stand movement, and balance assessment were performed before and after the intervention. The intervention task involved pointing at targets 48 times in an upward bias condition. Results: Significant upward deviation on the line bisection test was noted in patients with right hemisphere damage. The load on the forefoot during the sit-to-stand movement was significantly increased. The range of anterior-posterior sway during forward movement in the balance assessment was reduced. Conclusions: An adaptation task performed in an upward bias condition may produce an immediate effect on upward localization, sit-to-stand movement, and balance performance in patients with right hemisphere stroke.

Analyses of weight-bearing asymmetry pattern for standing in the early phase after stroke: a cross-sectional study.

BACKGROUND: How the weight-bearing asymmetry pattern and related maximum lateral weight-bearing capacity, physical functions, balance, and mobility involved in weight-bearing asymmetry and lesions are related to weight-bearing asymmetry in patients with early-onset stroke remains unclear. OBJECTIVE: To investigate the difference between weight-bearing in the early phase after stroke categorized as symmetrical or nonsymmetrical regarding impairments, balance, walking, and independence, and any lesion location difference. METHODS: This cross-sectional study included 46 persons with hemiparetic stroke within 3 weeks from onset undergoing inpatient rehabilitation and classified into symmetrical, paretic, and non-paretic groups. We performed posturographic, functional, mobility, and lesion location assessments on participants once the evaluation was possible. RESULTS: The symmetrical, paretic, and non-paretic groups included 14, 11, and 21 patients, respectively. The non-paretic group had lesser mean % body weight in maximum lateral weight-bearing to the paretic direction (79% versus 55%, p < .001), motor function of the hip lower limb (64 versus 58, p = .003) per the Stroke Impairment Assessment Set, Trunk Impairment Scale (18 versus 15, p = .020), and Berg Balance Scale (42 versus 32, p = .047) than the paretic group with more lesions in the insula (55% versus 0%, p < .001) and parietal cortex (36% versus 0%, p = .009) than the non-paretic group. CONCLUSION: The non-paretic group had low dynamic balance, severe motor paresis, and trunk dysfunction. The paretic group had lesions in the insula or parietal cortex.

Effects of unilateral neck muscle vibration on standing postural orientation and spatial perception in healthy subjects based on stimulus duration and simultaneous stimulation of trunk muscles.

Neck muscle vibration (NMV) influences proprioceptive sensations and modulates standing postural orientation and spatial perception. However, the effects of NMV in healthy participants would vary based on the influence of stimulus duration and combination with trunk muscle vibration. Therefore, this study with a cross-over design clarified these effects. Twenty-four healthy participants (mean age, 25.7±3.7 years) were enrolled. To assess standing postural orientation, standing center-of-pressure (COP) measurements were recorded on a COP platform, starting with closed eyes and then with open eyes. The mean mediolateral (ML) and anteroposterior (AP) position [mm] of COP and other parameters were calculated. To assess spatial perception, subjective straight ahead (SSA) measurements were recorded, wherein participants were instructed to point and project the position of the manubrium of sternum on the touch panel using their right index finger with their eyes closed. Measurements were taken before and after four conditions: no vibration (control), left NMV for 30 s, left NMV for 10 min, and left NMV and left lumbar back vibration for 10 min. Vibratory stimulation was performed with the eyes closed at 80 Hz. The measurements under the four conditions were conducted with random cross-over and 5-min resting period between the conditions. COP and SSA values were subtracted before and after each condition for standardized variation and compared. NMV combined with trunk muscle vibration for 10 min resulted in significant deviations of the ML-COP toward the stimulation side and AP-COP toward the anterior side compared to the control condition with closed eyes. SSA showed no significant differences. These findings suggest that NMV-induced nervous system modulation would be amplified by proprioceptive sensory input to trunk muscles. Therefore, this method could provide a new option for clinical trials on postural orientation using NMV. SSA based on proprioceptive sensation may not be biased without visual illusions.

Immediate effect of standing and sit-to-stand training on postural vertical for backward disequilibrium following stroke: a case report.

BACKGROUND: Effects of therapeutic interventions backward disequilibrium following stroke are scarcely reported. OBJECTIVE: To clarify the effects of standing and sit-to-stand/stand-to-sit training aimed at postural deviation in the anterior direction for backward disequilibrium and posterior deviation of subjective postural vertical. CASE DESCRIPTION: The participant presented with backward disequilibrium and pontine hemorrhage-associated sensory impairment of the extremities. Physical therapy included standing and sit-to-stand/stand-to-sit training, expected to bias the center of gravity in the anterior direction. We measured subjective postural vertical on the sagittal plane to assess vertical perception. Backward disequilibrium was evaluated using the Backward Disequilibrium Scale. Walking ability was assessed using the functional ambulation category. These outcomes were assessed before and at 3 days post-intervention. OUTCOMES: Neurological findings were unchanged between pre- and post-intervention. Post-intervention, in subjective postural vertical, tilt direction modulated from -6.1° to 1.3°, variability changed from 5.9° to 3.3°, and Backward Disequilibrium Scale score improved from 7 to 1 point. Functional ambulation category changed from 2 to 3. CONCLUSION: Standing and sit-to-stand/stand-to-sit training aimed at shifting center of gravity and subjective postural vertical in the anterior direction appeared to improve backward disequilibrium and correct tilt to the anterior direction for this participant. Long-term effects of the training for this participant were not determined.

Effects of visual-motor illusion in stroke hemiplegic patients with left-side personal neglect: A report of two cases.

Personal neglect is the neglect of self-body space, which often occurs in patients with unilateral spatial neglect (USN), but lacks a dedicated rehabilitation. The purpose of this study was to investigate the effects of visual-motor illusion (VMI) on two-stroke hemiplegic patients with left-side personal neglect. Case 1 was a 53-year-old man diagnosed with a right lenticulostriate artery infarction. Case 2 was a 76-year-old woman diagnosed with a right middle cerebral artery infarction. USN symptoms were not observed in either patient in the desk USN assessment, but personal neglect and USN symptoms in daily life were observed in both patients. Intervention effects were verified using an ABA design, comprising a 5-day three-phase (A1, B, A2). In phase B, VMI was performed on the paralyzed upper limb for 10 min in addition to conventional physical therapy. Outcomes measures were the Fluff test, Catherine Bergego Scale (CBS), Fugl-Meyer Assessment (FMA), and Functional Independence Measure (FIM). In both patients, no improvements were noted in FMA, but improvements were observed in the Fluff test, CBS, and FIM in phase B; these effects were retained in phase A2. Therefore, VMI may have contributed to improvements in Personal neglect and USN symptoms in daily life.

Effects of visual-motor illusions with different visual stimuli on the sit-to-stand of people with hemiplegia following stroke: A randomized crossover controlled trial.

BACKGROUND: The objective of this study was to determine the effects of different visual stimuli during visual-motor illusion on sit-to-stand in people with hemiplegia following stroke. METHODS: This was a randomized crossover controlled trial. Twenty people with hemiplegia following stroke were randomly divided into groups. The video images used for visual-motor illusion were ankle dorsiflexion without resistance (standard visual-motor illusion [standard illusion]) and maximum effort dorsiflexion with resistance (power visual-motor illusion [power illusion]). People with hemiplegia following stroke underwent both illusion interventions with a 1-week washout period in between; group A started with the standard illusion intervention and group B started with the power illusion intervention. Outcomes included the sit-to-stand duration, maximum weight-bearing value, trunk movement during sit-to-stand, ankle joint movement during sit-to-stand, and active ankle dorsiflexion movement on the paralyzed side. RESULTS: The angular velocity of the trunk and ankle joints increased significantly during sit-to-stand, and sit-to-stand duration decreased significantly in response only to power illusion. In addition, the change in angular velocity of active ankle dorsiflexion was significantly greater in response to power illusion than was the change in response to standard illusion. CONCLUSION: Power illusion induces a greater improvement in paralyzed ankle dorsiflexion function than standard illusion, resulting in shorter sit-to-stand duration.

Effects of a visual search task in a virtual reality space with a moving background on spatial cognition and standing balance in patients with left hemiparetic stroke.

We examined effects of a visual search task (VST) in virtual reality (VR) with a moving background on spatial cognition and standing balance in left hemiparetic strokes. The VST with background deviation was allocated to Case A. In Case B, the VST without the deviation was performed. As a results, in Case A, the reaction time of VST was shortened in the paretic space and ability of weight-shift to the paretic side was improved. In conclusion, the VST in the VR with a spatial manipulation may improve spatial cognition and standing balance in left hemiparetic strokes.

The Effect of Trunk Position on Attentional Disengagement in Unilateral Spatial Neglect.

Unilateral spatial neglect (USN) causes difficulties in disengaging attention from the right side to unexpected targets on the left. However, the relationship between egocentric spatial position and attentional disengagement remains unclear. Therefore, this study aimed to clarify the relationship between trunk position and attentional disengagement. Thirty-eight patients with early stroke onset were classified as follows: USN (n = 18), right brain damage without USN (n = 10), and left brain damage (n = 10). The primary outcome was reaction time (RT) in the modified Posner task (MPT). The MPT comprised a condition in which the preceding cue and target direction were the same (valid condition) and a condition in which the directions were opposite (invalid condition). RT to the target was calculated. The MPT was performed in three different trunk positions (trunk midline, left, and right). In each group, the RT was compared on the basis of the stimulus conditions and trunk position. The RT was delayed in the valid and invalid left conditions, especially in the invalid left condition. The RT of the trunk right condition was significantly reduced compared with that of trunk midline and left conditions in the invalid left condition. Thus, trunk position influences attentional disengagement. This study contributes to the rehabilitation of patients with neglect symptoms.