Safety and Feasibility Study of the Medical Care Pit Walking Support System for Rehabilitation of Acute Stroke Patients.

Stroke rehabilitation with mechanical assistance improves outcomes by facilitating repetition and relieving the care burden of therapy staff. Here, we tested the Medical Care Pit (MCP) walking assistance training device in the rehabilitation of eight acute stroke patients (median age 60.7 ± 16.3 years) who had recently suffered ischemic (three) or hemorrhagic (five) stroke (14.1 ± 6.5 days). Patients received standard rehabilitation approximately 5 days per week (weekdays only), plus MCP therapy twice a week, totaling four MCP sessions over 2 weeks. Fugl-Meyer Assessment-Lower Extremities (FMA-LE), Functional Ambulation Category (FAC), and other gait-associated parameters were measured. Over the 10.5 ± 1.6 days of therapy, MCP qualitatively assisted in gait analysis and real-time patient feedback while independent walking scores significantly improved (FAC 2.2 ± 0.8 to 3.1 ± 1.3, p = 0.020). FMA-LE scores also slightly improved but not to significance (p = 0.106). Objective burden on patients, as measured by modified Borg scale, was significantly improved (2.7 ± 1.6 to 2.0 ± 1.6, p = 0.014). In terms of questionnaires, anxiety scores for the physical therapist regarding gait training and falling with MCP significantly decreased (3.8 ± 2.3 to 1.0 ± 1.6; p = 0.027 and 3.1 ± 2.2 to 0.8 ± 1.3; p = 0.045) from the first to fourth sessions. Taken together, MCP, in addition to the usual rehabilitation program, was effective in gait rehabilitation for independent walking and relieved burdens on the patients. Such walking support systems may be an important part of acute stroke rehabilitation.

Staged treatment protocol for gait with hybrid assistive limb in the acute phase of patients with stroke.

Hybrid Assistive Limb (HAL) is a wearable human assistant cyborg-type robot that helps lower-leg movement based on bioelectrical signals detected from the voluntary movement of the person wearing it. In this study, we developed a novel staged HAL treatment protocol for patients with acute stroke. The Regain Program for Gait with HAL (RPG-HAL) was formulated in four steps, based on the severity of limb paralysis. Twenty-one patients with acute stroke received a combination treatment of RPG-HAL and conventional rehabilitation. The feasibility and safety of RPG-HAL were evaluated based on changes in physical function and activities of daily living (ADL). RPG-HAL yielded improvement in gait speed, cadence, step length, and functional ambulation category (FAC). The effect size was >0.8 in all measurements. FAC (1.90) and Barthel Index (BI) (1.92) exhibited the highest scores. Twelve out of 14 patients with FAC 0 before RPG-HAL reached the upper FAC. Thus, earlier intervention using RPG-HAL as improving physical function, ADL, and gait ability in patients with stroke.

GPRC5B promotes collagen production in myofibroblasts.

Fibrosis is a condition characterized by the overproduction of extracellular matrix (ECM) components (e.g., collagen) in the myofibroblasts, causing tissue hardening and eventual organ dysfunction. Currently, the molecular mechanisms that regulate ECM production in the myofibroblasts are still obscure. In this study, we investigated the function of GPRC5B in the cardiac and lung myofibroblasts using real-time RT-PCR and siRNA-mediated knockdown. We discovered a significantly high expression of Gprc5b in the tissues of the fibrosis mice models and confirmed that Gprc5b was consistently expressed in the myofibroblasts of fibrotic hearts and lungs. We also found that Gprc5b expression was associated and may be dependent on the actin-MRTF-SRF signaling pathway. Notably, we observed that Gprc5b knockdown reduced the expression of collagen genes in the cardiac and lung myofibroblasts. Therefore, our findings reveal that GPRC5B enhances collagen production in the myofibroblasts, which directly promotes fibrosis in the tissues.

'Care literacy' in super aging Japan.

Accentuated by the ongoing coronavirus disease (COVID-19) pandemic, the change in Japan to community-based health and care services for older adults indicates an urgent need to enhance and spread citizens' understanding of care. This is a broader notion of care that incorporates conditions within the community to support the inclusion of older adults, involving not only those older adults receiving care and their direct providers of care, but also others in the community who are involved in the daily lives of these older adults. To underpin such a broader notion of care across citizens, this paper proposes 'care literacy' as a novel analytical concept, defined as the knowledge and capabilities that enable people in need of care to live their daily lives in the community and facilitate potential health and care solutions. Reflecting the interconnection of health and care and rooted in the local context, care literacy underpins aging by enabling this involvement of the broader community, and is disseminated through media and grassroot activities.

Drebrin is induced during myofibroblast differentiation and enhances the production of fibrosis-related genes.

Fibrosis is attributed to excess deposition of extracellular matrix (ECM) proteins including collagen and is associated with various organ dysfunction. This excessive ECM is produced by myofibroblasts, which are differentiated from various cells by a variety of stimuli, represented by TGF-ß. However, molecular mechanisms for the regulation of ECM production in myofibroblasts remain obscure. In this study, we demonstrate that the expression of drebrin, which binds to and increases the stability of actin filament in neurons, is increased in mouse hearts and lungs upon fibrosis. Drebrin is mainly expressed in myofibroblasts in the fibrotic hearts and lungs and promotes the expression of fibrosis-related genes, such as Acta2 and Col1a1. Taken together, our study identifies drebrin as a molecule that promotes the production of fibrosis-related genes in myofibroblasts.

Effectiveness of a Walking Program Involving the Hybrid Assistive Limb Robotic Exoskeleton Suit for Improving Walking Ability in Stroke Patients: Protocol for a Randomized Controlled Trial.

BACKGROUND: Gait disturbance often occurs in stroke survivors. Recovery of walking function is challenging, as some gait disturbance due to hemiparesis often remains even after rehabilitation therapy, presenting a major obstacle towards regaining activities-of-daily-living performance and achieving social reintegration. OBJECTIVE: This study aims to clarify the effectiveness of a walking program involving the wearable Hybrid Assistive Limb (HAL-TS01) robotic exoskeleton for improving walking ability in stroke patients with hemiparesis and stagnant recovery despite ongoing rehabilitation. METHODS: This is a multicenter, randomized, parallel-group, controlled study (HAL group, n=27; control group, n=27). The study period includes preintervention observation (until stagnant recovery), intervention (HAL-based walking therapy or conventional rehabilitation; 5 weeks), and postintervention observation (2 weeks). Following provision of informed consent and primary registration, the patients undergo conventional rehabilitation for preintervention observation, during which the recovery of walking ability is monitored to identify patients with stagnant recovery (based on weekly assessments using the 10-meter maximum walking speed [MWS] test). Patients with an MWS of 30-60 m/minute and insufficient weekly improvement in MWS undergo secondary registration and are randomly assigned to undergo HAL-based walking therapy (HAL group) or conventional rehabilitation (control group). The primary outcome is the change in MWS from baseline to the end of the 5-week intervention. RESULTS: This study began in November 2016 and is being conducted at 15 participating facilities in Japan. CONCLUSIONS: Assessments of walking ability vary greatly and it is difficult to define the threshold for significant differences. To reduce such variability, our study involves conducting conventional rehabilitation to the point of saturation before starting the intervention. Stagnation in the recovery of walking ability despite conventional rehabilitation highlights the limits of current medical care. The present study may bring evidence that HAL-based therapy can overcome such limitations and induce added recovery of walking ability, which would promote the use of HAL technology in the clinical setting. TRIAL REGISTRATION: UMIN Clinical Trials Registry UMIN000024805; https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000028545.

Feasibility and safety of Robot Suit HAL treatment for adolescents and adults with cerebral palsy.

To investigate whether Robot Suit HAL treatment (HAL-T) is safe and feasible for gait disorders in adolescents and adults with cerebral palsy (CP). We tested HAL-T in adolescents and adults with bilateral spastic CP (four men, four women; mean age: 18.2 years). Three participants were classified as level III under the Gross Motor Function Classification System (GMFCS), and five were classified as level IV. The participants underwent HAL-T twice per week for 4 weeks. The outcome measures, which were assessed before and after HAL-T, included comfortable gait speed (CGS), step length (SL), cadence, and GMFCS level. Adverse events were noted. All participants completed the HAL-T sessions despite some mild adverse events occurring. The mean increases in CGS, SL, and cadence were 0.19 ±â€¯0.14 m/s (p = 0.006), 0.09 ±â€¯0.08 m (p = 0.020), and 18.0 ±â€¯15.9 steps/min (p = 0.015), respectively. HAL-T is safe and feasible for gait disorders in patients with CP. HAL-T can significantly improve CGS, SL, and cadence and may be effective for improving walking ability in adolescents and adults with CP.

Voluntary Elbow Extension-Flexion Using Single Joint Hybrid Assistive Limb (HAL) for Patients of Spastic Cerebral Palsy: Two Cases Report.

Cerebral palsy (CP) patients with spastic diplegia struggle to perform activities of daily life (ADL) using their upper arms. The single-joint-type Hybrid Assistive limb (HAL) for upper limbs is a new portable robot that can provide elbow motion support in accordance with bioelectric activation of patient's biceps and triceps brachii muscles. The purpose of this study is to assess the feasibility and efficacy of the use of HAL for CP patients. Two patients were enrolled in this study. (Case 1: a 19-years-old male, at the Gross Motor Function Classification System (GMFCS) level IV, Case 2: a 17-years-old male at GMFCS level III). Both these patients experienced difficulty in voluntary elbow extension in ADLs. The HAL intervention (eight sessions; voluntary extension-flexion training of the elbow with HAL and clinical evaluation) was conducted for both sides in Case 1 and for the right side in Case 2. Clinical assessments were conducted as follows: Surface electromyography was used to evaluate the muscle activities of the biceps, triceps brachii, trapezius, and pectoralis major during elbow extension-flexion. The voluntary extension-flexion angles of the elbow, the coactivation index of the biceps and triceps brachii muscles, synergy analysis, and the Action Research Arm Test (ARAT) scores were assessed before and after the HAL sessions; the FIM score was evaluated before and after the entire intervention. In Case 1, the voluntary extension angle tended to increase after the HAL sessions. In both cases, the ARAT scores improved after the sessions. The FIM scores improved after HAL intervention. The voluntary extension-flexion of the elbow using the HAL may be a feasible option for rehabilitation of CP patients.

Voluntary ambulation using voluntary upper limb muscle activity and Hybrid Assistive Limb® (HAL®) in a patient with complete paraplegia due to chronic spinal cord injury: A case report.

Context: We sought to describe our experience with the Hybrid Assistive Limb® (HAL®) for active knee extension and voluntary ambulation with remaining muscle activity in a patient with complete paraplegia after spinal cord injury. Findings: A 30-year-old man with complete paraplegia used the HAL® for 1 month (10 sessions) using his remaining muscle activity, including hip flexor and upper limb activity. Electromyography was used to evaluate muscle activity of the gluteus maximus, tensor fascia lata, quadriceps femoris, and hamstring muscles in synchronization with the Vicon motion capture system. A HAL® session included a knee extension session with the hip flexor and voluntary gait with upper limb activity. After using the HAL® for one month, the patient's manual muscle hip flexor scores improved from 1/5 to 2/5 for the right and from 2/5 to 3/5 for the left knee, and from 0/5 to 1/5 for the extension of both knees. Conclusion/clinical relevance: Knee extension sessions with HAL®, and hip flexor and upper-limb-triggered HAL® ambulation seem a safe and feasible option in a patient with complete paraplegia due to spinal cord injury.

Intensive Gait Treatment Using a Robot Suit Hybrid Assistive Limb in Acute Spinal Cord Infarction: Report of Two Cases.

CONTEXT: Spinal cord infarction (SCI) causes gait disturbance because of paresis, spasticity, and sensory disturbance of the lower limbs. There is no effective medical treatment for SCI, and conventional rehabilitation alone is the main approach to helping individuals work toward independent walking. The aim of this study was to evaluate the effect of gait treatment using the Hybrid Assistive Limb (HAL) on acute SCI. FINDINGS: A 61-year-old female and a 62-year-old male with incomplete paraplegia participated in this study. Our study participants received gait treatment with HAL 3-4 times per week, with a total of 7-8 sessions (20 min), in addition to conventional physical therapy. The American Spinal Injury Association Impairment Scale, Lower Extremity Motor Score (LEMS), Modified Ashworth Scale (MAS), the Walking Index for Spinal Cord Injury (WISCI II), comfortable gait speed (CGS), stride, cadence, Barthel Index (BI), Functional Independence Measure (FIM), modified Rankin Scale (mRS), joint angles, and adverse effects were assessed prior to HAL treatment and post-HAL treatment. HAL facilitated intensive gait treatment in people during the acute phase after SCI. Improvements in LEMS, WISCI II, CGS, stride, cadence, BI, FIM, mRS, and joint angles were observed in both study participants. Furthermore, decreased spasticity in the gastrocnemius muscle was found in one participant as assessed by MAS. CONCLUSION: Gait treatment using HAL may be beneficial for paraplegic, non-ambulatory individuals with acute SCI. HAL may be useful for intensive gait treatment without increasing spasticity.

Walking ability following hybrid assistive limb treatment for a patient with chronic myelopathy after surgery for cervical ossification of the posterior longitudinal ligament.

CONTEXT: The hybrid assistive limb (HAL) (the wearable robot) can assist kinesis during voluntary control of hip and knee joint motion by detecting the wearer's bioelectric signals on the surface of their skin. The purpose of this study was to report on walking ability following the wearable robot treatment in a patient with chronic myelopathy after surgery for cervical ossification of the posterior longitudinal ligament (OPLL). FINDINGS: The patient was a 66-year-old woman with cervical OPLL who was able to ambulate independently with the aid of bilateral crutches. The wearable robot treatment was received once every 2 weeks for ten sessions beginning approximately 14 years after surgery. Improvements were observed in gait speed (BL 22.5; post 46.7 m/min), step length (BL 0.36; post 0.57 m), and cadence (BL 61.9; post 81.6 m/min) based on a 10-m walk test and a 2-minute walk test (BL 63.4; post 103.7 m) assessing total walking distance. The improvements in walking ability were maintained after the wearable robot treatment for 6 months. CONCLUSION: We report the functional recovery in the walking ability of a patient with chronic cervical myelopathy following the wearable robot treatment, suggesting that as a rehabilitation tool, the wearable robot has the potential to effectively improve functional ambulation in chronic cervical myelopathy patients whose walking ability has plateaued, even many years after surgery.

Effects of Gait Treatment With a Single-Leg Hybrid Assistive Limb System After Acute Stroke: A Non-randomized Clinical Trial.

We hypothesized that a single-leg version of the Hybrid Assistive Limb (HAL) system could improve the gait and physical function of patients with hemiparesis following a stroke. In this pilot study, we therefore compared the efficacy of HAL-based gait training with that of conventional gait training (CGT) in patients with acute stroke. Patients admitted to the participating university hospital were assigned to the HAL group, whereas those admitted to outside teaching hospitals under the same rehabilitation program who did not use the HAL were assigned to the control group. Over 3 weeks, all participants completed nine 20 min sessions of gait training, using either HAL (i.e., the single-leg version of HAL on the paretic side) or conventional methods (i.e., walking aids and gait orthoses). Outcome measures were evaluated before and after the nine training sessions. The Functional Ambulation Category (FAC) was the primary outcome measure, but the following secondary outcome measures were also assessed: National Institutes of Health Stroke Scale, Fugl-Meyer Assessment (Lower Extremity), comfortable walking speed, step length, cadence, 6-min walk distance, Barthel Index, and Functional Independence Measure. In total, 22 post-stroke participants completed the clinical trial: 12 in the HAL group and 10 in the CGT group. No serious adverse events occurred in either group. The HAL group showed significant improvement in FAC after nine sessions when compared with the CGT group (P = 0.014). However, secondary outcomes did not differ significantly between the groups. Our results demonstrate that HAL-based gait therapy may improve independent walking in patients with acute stroke hemiplegia who are dependent on ambulatory assistance. A larger-scale randomized controlled trial is needed to clarify the effectiveness of single-leg HAL therapy. Clinical Trial Registration: UMIN Clinical Trials Registry, identifier UMIN000022410.

Optimized Design of a Variable Viscosity Link for Robotic AFO.

Herein we present the development of a novel Ankle Foot Orthosis for gait support of people with foot-drop symptoms. The developed AFO uses an elastic link mechanism to brake the ankle joint during initial contact, thus mitigating foot-slap, and an integrated energy store-and-release mechanism to support toe lift in the swing phase, thus mitigating toe-drag. This paper presents improvements in the braking-holding power of the elastic link mechanism over its previous version, the torque-angle characteristics of the developed AFO with the renewed elastic link, and a pilot test with one person with foot-drop symptoms to verify the proposed functions of the developed AFO.

Reshaping of Bilateral Gait Coordination in Hemiparetic Stroke Patients After Early Robotic Intervention.

Hemiparetic gait is a common condition after stroke which alters importantly the quality of life of stroke survivors. In recent years, several robotic interventions have been developed to support and enhance rehabilitation strategies for such population. The Hybrid Assistive Limb® (HAL) robot suit is a unique device able to collect in real time bioelectric signals from the patient to support and enhance voluntary gait. HAL has been used before in early stages of stroke showing gait improvement after the intervention. However, evaluation of the coordination of gait has not been done yet. Coordination is a key factor for an adequate gait performance; consequently, its changes may be closely related to gait recovery. In this study, we used planar covariation to evaluate coordination changes in hemiparetic stroke patients after early HAL intervention. Before starting, impaired intersegmental coordination for the paretic and non-paretic side was evident. HAL intervention was able to induce recovery of the covariation loop shape and deviation from the covariation plane improving intersegmental coordination. Also, there was a tendency of recovery for movement range evidenced by comparison of peak elevation angles of each limb segment of the patients before and after HAL intervention, and also when compared to healthy volunteers. Our results suggest that early HAL intervention contributed to the improvement of gait coordination in hemiparetic stroke patients by reinforcing central pattern generators and therefore reshaping their gait pattern. Trial registration: UMIN000022410 2016/05/23.

Feasibility of Synergy-Based Exoskeleton Robot Control in Hemiplegia.

Here, we present a study on exoskeleton robot control based on inter-limb locomotor synergies using a robot control method developed to target hemiparesis. The robot control is based on inter-limb locomotor synergies and kinesiological information from the non-paretic leg and a walking aid cane to generate motion patterns for the assisted leg. The developed synergy-based system was tested against an autonomous robot control system in five patients with hemiparesis and varying locomotor abilities. Three of the participants were able to walk using the robot. Results from these participants showed an improved spatial symmetry ratio and more consistent step length with the synergy-based method compared with that for the autonomous method, while the increase in the range of motion for the assisted joints was larger with the autonomous system. The kinematic synergy distribution of the participants walking without the robot suggests a relationship between each participant's synergy distribution and his/her ability to control the robot: participants with two independent synergies accounting for approximately 80% of the data variability were able to walk with the robot. This observation was not consistently apparent with conventional clinical measures such as the Brunnstrom stages. This paper contributes to the field of robot-assisted locomotion therapy by introducing the concept of inter-limb synergies, demonstrating performance differences between synergy-based and autonomous robot control, and investigating the range of disability in which the system is usable.

Effect of inpatient rehabilitation on activities of daily living in pediatric cancer patients in Japan.

Most pediatric cancer patients decline physical performance therapy, resulting in limitations in the activities of daily living. The objective of this study was to investigate the effects of rehabilitation in pediatric patients with cancer using the functional independence measure (FIM) score. This retrospective study included 25 inpatient children diagnosed with cancer at a single university hospital from January 2016 to December 2016. All patients underwent rehabilitative intervention during their hospital stay. We investigated the contents of the rehabilitation program and the FIM scores before and after the rehabilitative intervention. The average FIM scores improved in all patients; however, only the total-FIM scores (+4.96 points, P=0.009) and motor-FIM scores (+4.04 points, P=0.005) improved significantly. Conversely, cognitive-FIM score did not significantly improve (+0.92 points, P=0.159). In addition, motor-FIM subgroup scores for locomotion (walk/wheelchair and stairs) were significantly higher (+0.36 points, P=0.039 and +0.64 points, P=0.046, respectively) after rehabilitative intervention, regardless of the length of hospital stay. This study showed that FIM score, particularly motor-FIM score and locomotion subgroup scores, significantly improved owing to participation in inpatient rehabilitation. In conclusion, we found that rehabilitative intervention improved physical activity, especially locomotion.

Hybrid Assistive Limb Intervention in a Patient with Late Neurological Deterioration after Thoracic Myelopathy Surgery due to Ossification of the Ligamentum Flavum.

PURPOSE: We evaluated improvements in gait after using the Hybrid Assistive Limb (HAL®) exoskeleton robot in a patient with late-onset neurological deterioration of lower extremity function after undergoing thoracic spine surgery for a myelopathy due to ossification of the ligamentum flavum. CASE PRESENTATION: A 70-year-old man participated in ten 20 min sessions of HAL intervention, twice weekly for five weeks. The effects of each HAL session were evaluated based on changes in performance on the 10 m walk test (10 MWT), lower limb kinematics quantified from motion capture, and the activation ratio of the gastrocnemius, measured before and after the intervention. Muscle activity was recorded using surface electromyography and synchronized to measured kinematics. The HAL intervention improved gait speed and step length, with an increase in the hip flexion angle during the swing phase and a decrease in the activation ratio of the gastrocnemius. The modified Ashworth scale improved from 1+ to 1 and International Standards for Neurological and Functional Classification of Spinal Cord Injury motor scores from 34 to 49. CONCLUSION: Intervention using the HAL exoskeleton robot may be an effective method to improve functional ambulation in patients with chronic spinal disorders.

Robot-assisted voluntary initiation reduces control-related difficulties of initiating joint movement: A phenomenal questionnaire study on shaping and compensation of forward gait.

Humans employ various control strategies to initiate and maintain bodily movement. In case that the normal gait function is impaired, exoskeleton robots provide motor assistance during therapy. While the robotic control system builds on kinematic gait functions, the patient's voluntary efforts to initiate motion also contribute to the effectiveness of the therapy process. However, it is currently not well understood how voluntary initiation as a subjective capacity affects the physiological level of motor control. In order to understand the functional nexus between voluntary initiation and motor control, we interviewed patients undergoing robotic gait rehabilitation with the HAL exoskeleton robot about their experience and command of voluntarily initiating forward gait while using the HAL system. Their reports provide phenomenal evidence for voluntary initiation as a distinct cognitive act that comes as phenomenal performance. Furthermore, phenomenal evidence about the functional relation of intention and initiation correlates with FIM-M gait scores. Based on the assumption that HAL reduces control-related difficulties of voluntarily initiating joint movement, we identified two cognitive control strategies, shaping and compensation of gait, that imply a heterarchic organization of the human system of action control.

The Hybrid Assistive Limb® intervention for a postoperative patient with spinal dural arteriovenous fistula and chronic spinal cord injury: A case study.

CONTEXT: The purpose of this report was to describe the improvement in walking ability using the Hybrid Assistive Limb® (HAL®) intervention in the case of a patient with paraplegia after spinal cord injury whose condition deteriorated because of a spinal dural arteriovenous fistula (SDAVF). FINDINGS: A 48-year-old man started the HAL® intervention twice per week (total 10 sessions), after his neurologic improvement had plateaued from 3 to 6 months postoperatively for an SDAVF. During the HAL® intervention, the 10-m walk test (10MWT) without HAL® was performed before and after each session. An electromyography system was used to evaluate muscle activity of both the gluteus maximus (Gmax) and quadriceps femoris (Quad) muscles in synchronization with the Vicon motion capture system. The International Standards for Neurological and Functional Classification of Spinal Cord Injury (ISNCSCI) motor scores of the lower extremities and the Walking Index for Spinal Cord Injury II (WISCI II) score were also assessed to evaluate motor function. The HAL® intervention improved gait speed and cadence during the 10MWT. Before the intervention, both the Gmax and left Quad muscles were not activated. After the intervention, the right Gmax and both Quad muscles were activated in stance phase rhythmically according to the gait cycle. The ISNCSCI motor score also improved from 14 to 16, and the WISCI II scored improved from 7 to 12. CONCLUSION/CLINICAL RELEVANCE: Our experience with this patient suggests that the HAL® can be an effective tool for improving functional ambulation in patients with chronic spinal cord injury.

Relationship between somatosensory event-related potential N140 aberrations and hemispatial agnosia in patients with stroke: a preliminary study.

PURPOSE: The somatosensory event-related potential N140 is thought to be related to selective attention. This study aimed to compare the somatosensory event-related potential N140 in healthy subjects to that in patients with stroke to determine whether N140 and attentiveness are associated in patients with stroke with or without hemispatial agnosia. MATERIALS AND METHODS: Normal somatosensory event-related potential N140 values were determined using data from ten healthy subjects. Fifteen patients with stroke were divided into two groups based on the presence of hemispatial neglect. Somatosensory event-related potential N140 components were compared between the two groups. RESULTS: Stimulation of the affected limb in the hemispatial agnosia group resulted in significantly longer N140 latency at the contralateral vs. the ipsilateral electrode. This was the inverse of the relationship observed in normal subjects, with stimulation of the intact side in patients with hemispatial agnosia, and with stimulation of both the intact and affected sides in patients without agnosia. In the hemispatial agnosia group, the peak latency of N140 following stimulation of the affected side was significantly longer than it was following stimulation of the intact side and when compared to that in patients without agnosia. In addition, abnormal N140 peak latencies were observed at the Cz and ipsilateral electrodes in patients with hemispatial agnosia following stimulation of the intact side. CONCLUSIONS: These findings suggest that somatosensory event-related potential N140 is independently generated in each hemisphere and may reflect cognitive attention.