Study on the occurrence and neural bases of hemispatial neglect with different reference frames

Yue Y, Song W, Huo S, Wang M. Study on the occurrence and neural bases of hemispatial neglect with different reference frames.ObjectivesTo study the distributions and the neural correlates of left hemispatial neglect with different reference frames.DesignData were collected from patients with right brain injury who participated in a case series.SettingHospital departments of rehabilitation and neurology.ParticipantsRight brain-damaged patients (N=110).InterventionsNot applicable.Main Outcome MeasuresThe frequency of left hemispatial neglect with different reference frames was investigated, and the respective brain lesions were displayed and analyzed.ResultsNot all subjects finished predesigned neglect tests because of their condition: 8 of the 55 neglect patients were unable to complete the test for classification. Thirty (63.83%) of 47 subjects with neglect displayed both allocentric and egocentric neglect, while 17 subjects showed pure egocentric neglect. The lesions in the inferior frontal gyrus, precentral gyrus, postcentral gyrus, superior temporal gyrus (STG), middle temporal gyrus (MTG), insula, and surrounding white matters were more frequent in the neglect group than in the control group. Compared with the egocentric neglect group, the lesions in the right STG, MTG, lenticular nucleus, and the surrounding white matter were damaged more frequently in the group displaying both allocentric and egocentric neglect.ConclusionsMore than half of the subjects with left neglect after right brain injury have both egocentric and allocentric neglect. The right inferior frontal gyrus, precentral gyrus, postcentral gyrus, STG, MTG, insula, and the surrounding white matter are associated with left hemispatial neglect. Left allocentric neglect is associated with the right STG, MTG, and lenticular nucleus.     

轮椅碰撞试验：一种评估行为偏侧忽略的新方法

目的采用一种新的方法——轮椅碰撞试验(WCT)评估脑卒中患者是否存在行为偏侧忽略并探讨其有效性。方法对19例首发脑卒中患者进行WCT检查,患者自行驱动轮椅通过2排错位排列的圆凳,圆凳间距离为120或140cm,由检查者记录患者驱动轮椅时轮椅碰撞圆凳的次数。同时采用凯瑟林波哥量表(CBS)进行行为偏侧忽略的评定,采用独立功能评定(FIM)评估患者的日常生活能力,并与WCT结果进行相关性分析。结果不同情况下,WCT的重测信度为0.68～0.97。经Kappa检验分析,圆凳间距120cm时WCT(以有碰撞和无碰撞来表示)与CBS(以有忽略和无忽略来表示)的一致率为68.4%,高于圆凳间距140cm时WCT与CBS的一致率(57.9%)。圆凳间距离为120cm和140cm时,WCT与CBS的Spearman相关系数分别为0.72(P<0.001)和0.75(P<0.001);WCT和CBS与FIM评分也有明显的相关性。结论WCT是检测患者是否存在行为偏侧忽略的一种简单、客观的方法,其结果与CBS和FIM均有明显的相关性,可以在临床推广应用。     

Dynamic Spatial Coding within the Dorsal Frontoparietal Network during a Visual Search Task

To what extent are the left and right visual hemifields spatially coded in the dorsal frontoparietal attention network? In many experiments with neglect patients, the left hemisphere shows a contralateral hemifield preference, whereas the right hemisphere represents both hemifields. This pattern of spatial coding is often used to explain the right-hemispheric dominance of lesions causing hemispatial neglect. However, pathophysiological mechanisms of hemispatial neglect are controversial because recent experiments on healthy subjects produced conflicting results regarding the spatial coding of visual hemifields. We used an fMRI paradigm that allowed us to distinguish two attentional subprocesses during a visual search task. Either within the left or right hemifield subjects first attended to stationary locations (spatial orienting) and then shifted their attentional focus to search for a target line. Dynamic changes in spatial coding of the left and right hemifields were observed within subregions of the dorsal front-parietal network: During stationary spatial orienting, we found the well-known spatial pattern described above, with a bilateral hemifield representation in the right hemisphere and a contralateral preference in the left hemisphere. However, during search, the right hemisphere had a contralateral preference and the left hemisphere equally represented both hemifields. This finding leads to novel perspectives regarding models of visuospatial attention and hemispatial neglect.     

Reliability and validity of a wheelchair collision test for screening behavioral assessment of unilateral neglect after stroke

OBJECTIVE: To examine the reliability and validity of a new wheelchair collision test (WCT) for screening behavioral unilateral neglect in people with stroke. DESIGN: A total of 19 patients with left hemiplegia resulting from first-ever stroke (mean +/- SD, 61.9 +/- 25.8 days after onset) were examined with the WCT, whereby the patient was asked to propel a wheelchair to pass four round chairs arranged in two rows. Separate tests were done using two different distances between the chairs: 120 and 140 cm. The number of collisions with the chairs was recorded. The Catherine Bergego Scale was used to evaluate behavioral unilateral neglect. Because unilateral neglect has an unfavorable impact on rehabilitation, the FIMtrade mark instrument was used to determine the function of daily activities. RESULTS: Test-retest reliability ranged from 0.68 to 0.97 in different situations in the WCT. The rate of agreement tested by Kappa statistics between the WCT and Catherine Bergego Scale was higher when the distance between chairs was 120 cm than when the distance was 140 cm (0.68 vs. 0.58). Spearman's rank-correlation coefficient between the WCT and Catherine Bergego Scale was 0.72 (P < 0.001) if the distance between the chairs was 120 cm and 0.75 (P < 0.001) if the distance was 140 cm. The WCT and Catherine Bergego Scale correlated well with the FIM instrument. Spearman's rank-correlation coefficient between the Catherine Bergego Scale and FIM total score was -0.70 (P < 0.001). CONCLUSION: The WCT is a simple screening test with high test-retest reliability and validity to evaluate behavioral unilateral neglect.     

Ability of People With Stroke to Learn Powered Wheelchair Skills: A Pilot Study

Mountain AD, Kirby RL, Eskes GA, Smith C, Duncan H, MacLeod DA, Thompson K. Ability of people with stroke to learn powered wheelchair skills: a pilot study.

Objectives

Our primary objective was to test the hypothesis that people with stroke can learn to use powered wheelchairs safely and effectively. Our secondary objective was to explore the influence of visuospatial neglect on the ability to learn powered wheelchair skills.

Design

Prospective, uncontrolled pilot study using within-participant comparisons.

Setting

Rehabilitation center.

Participants

Inpatients (N=10; 6 with visuospatial neglect), all with a primary diagnosis of stroke.

Interventions

Participants received 5 wheelchair skills training sessions of up to 30 minutes each using the Wheelchair Skills Training Program (version 3.2).

Main Outcome Measures

Powered wheelchair skills were tested before and after training using the Wheelchair Skills Test, Power Mobility version 3.2 (WST-P).

Results

The group's total mean WST-P scores improved from 25.5% of skills passed at baseline to 71.5% posttraining (P=.002). The participants with neglect improved their WST-P scores to the same extent as the participants without neglect, although their pretraining and posttraining scores were lower. The training and testing sessions were well tolerated by the participants, and there were no serious adverse events.

Conclusions

Many people with stroke, with or without visuospatial neglect, can learn to use powered wheelchairs safely and effectively with appropriate training.     

Understanding and measuring powered wheelchair mobility and manoeuvrability. Part I. Reach in confined spaces

Purpose. To determine: (1) what wheelchair manoeuvrability factors are important and (2) the effects of powered wheelchair design on the ability to reach in a confined space.

Method. The relative importance of five aspects of wheelchair manoeuvrability was determined through a survey of users of wheelchairs (N = 52) and health care professionals and others (N = 89). A single young, non-disabled subject undertook repeated trials of reach distance on to a counter at the end of a corridor whose width could be adjusted by moving Styrofoam walls.

Results. Reaching, moving in confined spaces and avoiding collisions were more important than speed and avoiding the need to drive backwards. The rear wheel drive powered wheelchair was found to allow the greatest reach when driving backwards into the space and the wheelchair which moved in a sideways direction allowed greatest reach in the narrowest corridor.

Conclusions. The survey concluded that manoeuvring in small spaces and reaching without collisions were important. The powered wheelchair with sideways capability afforded the greatest reach in confined spaces except when the rear wheel drive chair was driven in backwards. The survey respondents did not place a high priority on avoiding backwards driving but some people find this difficult to do safely.     

Understanding and measuring powered wheelchair mobility and manoeuvrability. Part I. Reach in confined spaces

Purpose.?To determine: (1) what wheelchair manoeuvrability factors are important and (2) the effects of powered wheelchair design on the ability to reach in a confined space.

Method.?The relative importance of five aspects of wheelchair manoeuvrability was determined through a survey of users of wheelchairs (N?=?52) and health care professionals and others (N?=?89). A single young, non-disabled subject undertook repeated trials of reach distance on to a counter at the end of a corridor whose width could be adjusted by moving Styrofoam walls.

Results.?Reaching, moving in confined spaces and avoiding collisions were more important than speed and avoiding the need to drive backwards. The rear wheel drive powered wheelchair was found to allow the greatest reach when driving backwards into the space and the wheelchair which moved in a sideways direction allowed greatest reach in the narrowest corridor.

Conclusions.?The survey concluded that manoeuvring in small spaces and reaching without collisions were important. The powered wheelchair with sideways capability afforded the greatest reach in confined spaces except when the rear wheel drive chair was driven in backwards. The survey respondents did not place a high priority on avoiding backwards driving but some people find this difficult to do safely.     

左侧空间忽略患者关联性注意捕捉效应的研究

目的:探讨脑损伤后致左侧空间忽略患者的注意捕捉效应。方法:本研究对右侧大脑半球损伤伴左侧忽略的患者及健康被试各20例,分别进行神经心理学背景测试及关联性注意捕捉效应测试,观察左侧空间忽略患者与健康被试之间注意捕捉效应的差异,分析影响关联性注意捕捉效应强度的因素。结果:①与健康对照组相比,左侧空间忽略组的数字捕捉正确率明显降低(P<0.01)。②健康对照组:无论干扰刺激颜色与目标刺激颜色是否一致,左侧视野出现干扰刺激时的数字捕捉正确率均明显低于右侧视野出现干扰刺激时(P<0.01);无论干扰刺激在目标刺激的左侧或右侧,当干扰刺激颜色与目标刺激颜色一致时,数字捕捉正确率低于干扰刺激颜色与目标刺激颜色不一致时(P<0.01,0.05)。③左侧空间忽略组:无论干扰刺激颜色与目标刺激颜色是否一致,右侧视野出现干扰刺激时的数字捕捉正确率均低于左侧视野出现干扰刺激时(P<0.05);左侧视野出现的干扰刺激颜色与目标刺激颜色一致或不一致时,对数字捕捉正确率的影响差异无统计学意义,而右侧视野出现的干扰刺激颜色与目标刺激颜色一致时,数字捕捉正确率低于颜色不一致时(P<0.05)。结论:左侧空间忽略患者的注意功能下降,但无论对于健康受试者或者左侧空间忽略患者,符合目标刺激颜色特征的干扰刺激均能够增强非随意性地注意捕捉效应。     

Limb activation effects in hemispatial neglect

OBJECTIVE: To assess the efficacy of passive and active limb movement to improve visual scanning in patients with hemispatial neglect. DESIGN: Before-after trial: behavioral analyses of a case series. SETTING: Stroke rehabilitation unit in a tertiary care hospital. PARTICIPANTS: Nine individuals with right-hemisphere stroke (mean time poststroke, 19.5 mo) and left-sided neglect, as assessed by the Sunnybrook Bedside Neglect Battery. INTERVENTION: Active left limb movement (button push; n=3) or passive left limb movement (n=8) with functional electric stimulation (FES) administered during visual scanning testing. MAIN OUTCOME MEASURES: Performance on visual scanning tests involving naming of letters and numbers. RESULTS: Both active and passive movement significantly improved target detection on the left side, but not on the right side, on the visual scanning task. Positive results were seen in 2 of 3 active movement patients and 6 of 8 passive movement patients. CONCLUSIONS: Both active and FES-stimulated passive movements are potential techniques for the treatment of hemispatial neglect.     

Evaluation of semiautonomous navigation assistance system for power wheelchairs with blindfolded nondisabled individuals

Some individuals with disabilities are denied powered mobility because they lack the visual, motor, and/or cognitive skills required to safely operate a power wheelchair. The Drive-Safe System (DSS) is an add-on, distributed, shared-control navigation assistance system for power wheelchairs intended to provide safe and independent mobility to such individuals. The DSS is a human-machine system in which the user is responsible for high-level control of the wheelchair, such as choosing the destination, path planning, and basic navigation actions, while the DSS overrides unsafe maneuvers through autonomous collision avoidance, wall following, and door crossing. In this project, the DSS was clinically evaluated in a controlled laboratory with blindfolded, nondisabled individuals. Further, these individuals' performance with the DSS was compared with standard cane use for navigation assistance by people with visual impairments. Results indicate that compared with a cane, the DSS significantly reduced the number of collisions. Users rated the DSS favorably even though they took longer to navigate the same obstacle course than they would have using a standard long cane. Participants experienced less physical demand, effort, and frustration when using the DSS as compared with a cane. These findings suggest that the DSS can be a viable powered mobility solution for wheelchair users with visual impairments.     

Evaluation of an ambient noise insensitive hum-based powered wheelchair controller

Purpose: A recently-developed assistive technology nicknamed “the Hummer” was investigated as a potential powered wheelchair controller for individuals with severe and multiple disabilities. System performance in a noisy environment was compared to that obtained with a commercial automatic speech recognition (ASR) system. Method: A bi-hum driving protocol was developed to allow the Hummer to serve as a powered wheelchair controller. Participants performed several virtual wheelchair driving tasks of increasing difficulty using the two systems. Custom-written software recorded task execution time, number of commands issued and wall collisions, speed, and trajectory. Results: The bi-hum protocol was shown to be non-intuitive and required user training. Overall, the Hummer achieved lower performance relative to ASR. Once users became accustomed to the protocol, the difference in performance between the two systems became insignificant, particularly for the higher-difficulty task. Conclusions: The Hummer provides a promising new alternative for powered wheelchair control in everyday environments for individuals with severe and multiple disabilities who are able to hum, particularly for those with severe dysarthria which precludes ASR usage. A more intuitive driving protocol is still needed to reduce user frustration and mitigate user-generated errors; recommendations on how this can be achieved are given herein.

Implications for Rehabilitation

• The “Hummer” allows for noise-insensitive powered wheelchair control in everyday environments

• The “Hummer” accommodates individuals without functional speech or those with severe dysarthria to gain mobility independence, thus improving their quality of life.

     

Evaluating the potential for powered mobility

It has been 5 years since Chris was evaluated for a powered wheelchair, and she has had two occupational therapists and three physical therapists since the evaluation and training process began. It has been a long and arduous process, full of triumphs and setbacks. Chris's level of functional mobility, self-confidence, and ability to socialize, however, have increased dramatically as a result of her perseverance. The powered wheelchair, which she can control herself, has increased her ability to explore her environment and to master the increased activities made available through an expanded environment.     

Older people's use of powered wheelchairs for activity and participation.

OBJECTIVE: The aims of this study were to investigate outcomes of older people's use of powered wheelchairs and risk factors for negative outcomes. DESIGN: The study was a cross-sectional interview-study including 111 powered wheelchair users over 65 years of age. RESULTS: All participants used their powered wheelchair in the summer; nearly all users regarded it as important and found that it gave them independence. The wheelchair made activity and participation possible for the users. The most frequent activity in the summer was going for a ride, and in the winter it was shopping. However, some could not use the wheelchair for visits, and supplementary travel modes are called for. Users who could not walk at all or who could not transfer without assistance were more likely not to be able to carry out prioritized activities. Furthermore, other risk factors for negative outcomes and need for further research were identified. CONCLUSION: The use of powered wheelchairs is a relevant societal intervention in relation to older people with limited walking ability in order to make activity and participation possible. It is likely that a larger proportion of older people could benefit from this intervention, in particular if current practices are improved taking activity and participation outcomes into consideration.     

Muscular effort in multiple sclerosis patients during powered wheelchair manoeuvres

BACKGROUND: This study applied EMG analysis methods to identify muscle group activity profiles and potential overload risks in powered wheelchair use. METHODS: We quantified muscle effort and fatigue using EMG analysis methods during powered wheelchair manoeuvres by 10 multiple sclerosis patients. Video recordings of the different sub-tasks were related to information on surface EMG amplitude (rectified EMG) and spectral information (Median frequency) from M. trapezius, M. deltoideus (pars medius), M. deltoideus (pars anterior), M. pectoralis, M. biceps, M. triceps, wrist extensors and flexors, using Joint Analysis of EMG Spectrum and Amplitude (JASA analysis). FINDINGS: Task durations and subjective data indicated that tasks requiring finer motor control took longer and were perceived as more difficult. Kinesiological functions of all muscle groups identified forward steering to be associated with activation of M. deltoideus (pars anterior), M. pectoralis, M. trapezius and M. deltoideus (pars medius); backwards steering with predominant activation of M. deltoideus (pars medius), M. biceps brachii and wrist flexors; left steering with maximal activation of M. biceps and wrist flexors, and right steering with maximal activation of M. triceps and wrist extensors. These profiles were confirmed in analysis of the functional tasks. JASA analysis documented muscle fatigue in the wrist extensors, whereas increased activation was found in M. trapezius, M. deltoideus (pars anterior) and wrist flexors. INTERPRETATION: EMG based kinesiological analysis gives insight in muscle activity and fatigue during powered wheelchair manoeuvres.     

The Value of an Outdoor Powered Wheelchair With Regard to the Quality of Life of Persons With Stroke: A Follow-Up Study

Evaluating the use of a powered wheelchair is of importance because of the increasing number of people with disabilities who are provided with one. The aim of this study is to describe characteristics of persons with stroke using an outdoor powered wheelchair and to evaluate the impact of the wheelchair on quality of life. A further aim is to compare the impact on quality of life in respect to age, gender, different disability characteristics, and living conditions. The 32 participants with stroke were recruited consecutively from three county council areas in Sweden. A follow-up design was applied including the EuroQol-5D questionnaires at baseline before the persons were prescribed an outdoor powered wheelchair, and after the participants had used the wheelchair for 3 to 5 months, data were collected by means of the EuroQol-5D and the Psychosocial Impact of Assistive Devices Scale (PIADS). The results indicated an improved quality of life with respect to the items competence, independence, capability, quality of life, well-being, happiness, and self-esteem on the PIADS. The usual activity dimension on the EuroQol-5D showed a significant improvement after wheelchair use. The group who drove the powered wheelchair at least once a day in the summer showed a more positive score on the total PIADS and its Competence subscale than persons who drove less. Furthermore, the group with higher rankings of the importance of the powered wheelchair scored higher on psychosocial impact than did the group with lower rankings. The conclusion is that the powered wheelchair mostly has a positive impact on the quality of life of users with stroke. Service providers should be alert, however, to the possible negative impact of a powered wheelchair on quality of life and support the user.     

脑卒中患者偏侧忽略线分法试验中线段位置对结果的影响

目的研究线分法试验中线段位置对不同程度偏侧忽略脑卒中患者线分结果的影响，探讨线段位置对线分结果影响的机制。方法根据凯瑟林一波哥量表（CatherineBergegoScale，CBS）检出26例首发脑卒中致左侧偏侧忽略的患者，分为轻度忽略组（15例）和重度忽略组（11例），20例年龄匹配的健康成人作为对照组。进行线分法检查时，让患者中分在Ag纸的左侧、中央和右侧的长度为10cm的水平线段。然后在另外一张同样的Ag纸上，先让患者标出他所看到的线段两端，然后再在标出的线段中央划一条垂直分隔线。计算分隔线右侧长度占所分隔线段长度的百分比。结果轻度忽略组与对照组在上述线分试验中所有结果的差异均无统计学意义。在标出线段两端前，重度忽略组患者分隔左侧及中央线段时分隔线较实际中点出现明显右移。重度忽略患者标记后的3条线段长度均明显短于对照组和轻度忽略组，缩短的原因是标记左侧端点时标记点明显右移。结论线段位置主要对重度偏侧忽略患者的线分结果有影响，其主要机制是重度偏侧忽略患者所看到的线段均较实际线段短，忽略了所有位置线段的左侧端，这种忽略程度白左向右逐渐减轻。     

The value of an outdoor powered wheelchair with regard to the quality of life of persons with stroke: a follow-up study

Evaluating the use of a powered wheelchair is of importance because of the increasing number of people with disabilities who are provided with one. The aim of this study is to describe characteristics of persons with stroke using an outdoor powered wheelchair and to evaluate the impact of the wheelchair on quality of life. A further aim is to compare the impact on quality of life in respect to age, gender, different disability characteristics, and living conditions. The 32 participants with stroke were recruited consecutively from three county council areas in Sweden. A follow-up design was applied including the EuroQol-5D questionnaires at baseline before the persons were prescribed an outdoor powered wheelchair, and after the participants had used the wheelchair for 3 to 5 months, data were collected by means of the EuroQol-5D and the Psychosocial Impact of Assistive Devices Scale (PIADS). The results indicated an improved quality of life with respect to the items competence, independence, capability, quality of life, well-being, happiness, and self-esteem on the PIADS. The usual activity dimension on the EuroQol-5D showed a significant improvement after wheelchair use. The group who drove the powered wheelchair at least once a day in the summer showed a more positive score on the total PIADS and its Competence subscale than persons who drove less. Furthermore, the group with higher rankings of the importance of the powered wheelchair scored higher on psychosocial impact than did the group with lower rankings. The conclusion is that the powered wheelchair mostly has a positive impact on the quality of life of users with stroke. Service providers should be alert, however, to the possible negative impact of a powered wheelchair on quality of life and support the user.     

Combined optokinetic stimulation and cueing-assisted reading therapy to treat hemispatial neglect: A randomized controlled crossover trial

BackgroundHemispatial neglect is a disabling cognitive disorder following stroke and effective therapies are required.ObjectivesTo evaluate the effects of combined optokinetic stimulation (OKS) and cueing-assisted reading therapy (READ) on the remission of hemispatial neglect following stroke.MethodsRandomized, controlled, two-period, crossover trial conducted at a German neurorehabilitation center. Twenty participants with left neglect following right hemispheric stroke (mean age 66 years (SD 11), mean time since stroke 50 days (SD 33)) finished the trial (12 received OKSREAD first, 8 CONTROL first). The intervention consisted of 15 daily sessions of OKS (20 min) and text reading assisted by a therapist providing cues (20 min). The control treatment was a same-number, same-length neuropsychological treatment not targeting visuospatial attention. Primary outcomes were the change in performance of a customized neuropsychological test battery for neglect (0% worst - 100% best) and a test of neglect-related functional disability (Catherine Bergego Scale, 0 no impairment - 30 severest impairment), assessed before and after each treatment period. Secondary outcomes were performance in the 6 single tests composing the battery (e.g., omissions in text reading, center of cancellation in the Bells test, spatial bias of fixations when freely viewing photographs) and a clinical test of anosognosia.ResultsOverall performance in the neglect test battery improved slightly more after OKSREAD than after CONTROL (d=6%; p=0.002). The remission of neglect-related functional disability did not differ between treatments (d=-2; p=0.291). Ipsilesional fixation bias during free viewing was the only secondary outcome that was improved by OKSREAD as compared to CONTROL (d= -2.8°; p=0.005).ConclusionAt the applied intensity, the combined OKSREAD intervention slightly attenuated the ipsilesional attention bias in persons with neglect, but it did not improve neglect-related functional disability, anosognosia, or other neglect symptoms to a clinically meaningful degree.Clinical trial registrationURL: http://www.clinicaltrials.gov. Unique identifier: NCT04273620.     

Patients with hemispatial neglect are more prone to limb spasticity, but this does not prolong their hospital stay

Wilkinson D, Sakel M, Camp S-J, Hammond L. Patients with hemispatial neglect are more prone to limb spasticity, but this does not prolong their hospital stay.ObjectiveTo determine whether stroke patients who suffer from hemispatial neglect tend to stay in hospitals longer because they are prone to limb spasticity.DesignRetrospective analysis of inpatient medical notes.SettingInpatient neurorehabilitation unit of a regional UK teaching hospital.ParticipantsAll patients (N=106) admitted to the neurorehabilitation unit between 2008 and 2010 who had suffered a stroke, as confirmed by computed tomography or magnetic resonance imaging.InterventionsNot applicable.Main Outcome MeasuresStatistical coincidence of hemispatial neglect and spasticity; length of hospital stay.ResultsChi-square analyses indicated that individuals with left neglect were nearly one third more likely to develop spasticity than those without neglect (87% vs 57%), while nearly one half of those with left-sided spasticity showed neglect (44% vs 13%). Individuals with neglect stayed in the hospital 45 days longer than those without neglect, but the presence or absence of spasticity did not affect length of stay.ConclusionsThe results provide the first statistical evidence, to the best of our knowledge, that neglect and limb spasticity tend to co-occur poststroke, though it is only the former that significantly prolongs stay. Diagnostic value aside, these results are important because they tell us that the treatment of neglect should not be overshadowed by efforts to reduce comorbid spasticity. Despite its poor prognosis, hemispatial neglect continues to receive little targeted therapy in some units.     

Intelligent single switch wheelchair navigation

We have developed an intelligent single switch scanning interface and wheelchair navigation assistance system, called intelligent single switch wheelchair navigation (ISSWN), to improve driving safety, comfort and efficiency for individuals who rely on single switch scanning as a control method. ISSWN combines a standard powered wheelchair with a laser rangefinder, a single switch scanning interface and a computer. It provides the user with context sensitive and task specific scanning options that reduce driving effort based on an interpretation of sensor data together with user input. Trials performed by 9 able-bodied participants showed that the system significantly improved driving safety and efficiency in a navigation task by significantly reducing the number of switch presses to 43.5% of traditional single switch wheelchair navigation (p < 0.001). All participants made a significant improvement (39.1%; p < 0.001) in completion time after only two trials. [Box: see text].